Irradiation of lymph nodes in prostate cancer

Radiation therapy

Over the past 25 years, radiation therapy has been used as an independent method for the treatment of prostate cancer stages T1N0M0 - T3N0M0 (stages A - C according to classification A - D), with poorly differentiated tumors with a high probability of primary estrogen resistance and the frequency of metastases in the lymph nodes, after radical prostatectomy, with tumor recurrence against the background of previous hormonal therapy, in combination with chemotherapy. Radiation therapy is an alternative to radical prostatectomy if it is impossible to perform it due to extensive metastases in the regional lymph nodes of the pelvis. In these cases, the complications associated with a large-scale operation, including pelvic lymphadenectomy, are much more severe than after radiation therapy. Modern methods of radiation therapy for Prostate cancer include remote c-therapy (they affect the primary tumor site, paraprostatic tissue and seminal vesicles, pelvic lymph nodes) and interstitial (interstitial) therapy with the introduction of nuclides 198 Au, 125 I into the tumor. The effectiveness of radiation therapy is largely determined by a comprehensive examination of patients, including radiography and CT of the pelvis, echography of the prostate gland, lymphangioadenography. The results of these studies allow us to establish the localization, size of the primary focus of prostate cancer, the degree of involvement in the process of the surrounding tissue, seminal vesicles, ampullae of the vas deferens, the bladder neck, the anterior wall of the rectum, metastases in the pelvic lymph nodes, which, during radiation therapy, are included in irradiated area. It is also necessary to have information about the histological structure of prostate cancer and the degree of its differentiation, to conduct an examination of the patient, to identify concomitant diseases.

In connection with the improvement of methods for detecting metastases in the pelvic lymph nodes, determining the location and size of the prostate gland, as well as its topographic and anatomical relationships with surrounding tissues and organs, the possibilities of more accurate determination of the scale of exposure have expanded. CT plays an important role in planning remote c-therapy, which allows you to change the radiation field, reduce the prevalence of radiation exposure and, if possible, reduce the dose of radiation absorbed by the bladder or rectum. The optimal total doses of radiation when using remote c-therapy for prostate cancer stages TI - 2N0M0 range from 65 to 70 J/kg. In the treatment of stage T3Nx -1M0-1 prostate cancer, an irradiation dose of 70 J/kg does not prevent recurrence of the primary tumor and metastases in the lymph nodes and pelvic bones in 25% of patients. At the same time, increasing the dose to 75 - 80 J / kg to the bladder and rectum significantly increases the incidence of complications. At 70 J/kg complications are 3.5%, and at higher doses - 7%. The most effective and reducing the risk of complications is to reserve an optimally high dose for the prostate region (65 - 75 J / kg) and smaller doses for the regional lymph nodes of the pelvis (not higher than 50 J / kg). Measures to prevent early and late complications are the lengthening of the treatment period, if necessary, exposure to large areas of pathological tissue, the use of treatment according to the "split" method (split course of treatment). According to this method, after reaching a total dose of irradiation to the pelvis of 40 - 45 J / kg, treatment is interrupted for 2 - 3 weeks, and then an additional 20 - 25 J / kg is supplied to the prostate gland. This reduces the complication rate to 1.2%. In recent years, encouraging results have been achieved with the use of various methods of radiation therapy for a localized form of prostate cancer. This is confirmed by the 16-year life expectancy of prostate cancer patients who underwent radiation therapy, and the absence of histological signs of malignancy in prostate biopsies during repeated studies.

The results of radiation therapy for prostate cancer are determined by the clinical stage of the disease and the histological characteristics of the tumor. The life expectancy of patients with prostate cancer after radiation therapy with no obvious clinical manifestations of the disease is greatest in stages T1 and T2 and with tumors related to a high or moderate degree of differentiation. With a follow-up period of 2 to 7 years, the absence of clinical signs of the disease was observed in 91% of patients with stage A prostate cancer, 70% of stage B and 40% of stage C Reddy E. et al., 1984. Four-year survival rate of patients with prostate cancer with no clinical signs of the disease was 92, 78, 56 and 50% for stages A, B, C and D, respectively, during remote c-therapy with a total radiation dose of 70 J/kg Leonard K., Stryker A., 1986, The predetermination of the effectiveness of radiation therapy should be based in each individual case on the relationship between the clinical stage of prostate cancer and its histological characteristics. Survival of patients is significantly higher with a small size of the primary focus of prostate cancer of a well-differentiated histological type than with a tumor of low differentiation spread throughout the prostate. Analysis of the histological gradation of prostate cancer in relation to a certain clinical stage of the disease indicates the prevalence of tumors of a well-differentiated type in stages T1 and T2. In contrast, there is an increase in the number of moderately or poorly differentiated tumors in stages T3 and T4. These data are consistent with the results of radiation therapy of intraglandular localization of the tumor (stages T1 and T2) and prostate cancer spread beyond the capsule (stages T3 and T4). Five-year life expectancy after radiotherapy in patients with prostate cancer stages T1 and T2 is 78.9%, and in stages T3 and T4 -41%.

Evaluation of the pelvic lymph nodes has an important prognostic value when planning radiation therapy. The detection of metastases in them with a localized form of prostate cancer gives reason to believe the subsequent development of distant metastases within 5 years. Their frequency after radiation therapy is significantly higher in patients with recurrence of the primary tumor and metastases in the pelvic lymph nodes. This is due to the incompetence of the antitumor immune mechanism, the activity of the tumor biopotential and further dissemination of cancer cells from newly activated metastatic foci in the lymph nodes. A certain prognostic value in planning radiation therapy is the identification of the histological characteristics of the primary focus of prostate cancer according to the system of "marks" D. Gleason, which are associated with the frequency of megastases in the pelvic lymph nodes Bagshaw M. et al., 1985. There are no metastases in the lymph nodes with marks according to the D. Gleason system, less than 5 and make up 100% at marks 9 - 10. Thus, high marks according to the D. Gleason system increase the likelihood of metastases in the lymph nodes, which is reflected in the results of radiation therapy for prostate cancer. In the presence of metastases in the lymph nodes, the survival rate of patients with prostate cancer after radiation therapy for 10 years is reduced by 20%. In contrast, in the absence of pelvic lymph node metastases, 75% of radiotherapy-treated prostate cancer patients live 10 years or more. In prostate cancer patients with pelvic lymph node metastases, the prognosis may be improved by whole pelvic irradiation. However, this is a controversial issue, since large-scale exposure is accompanied by an increase in the frequency of complications associated with radiation exposure. In this regard, immediate radiotherapy is more promising when a diagnosis of T1 and T2 prostate cancer is established, which gives significantly better results than delayed radiotherapy and reduces the incidence of complications. The size of the primary tumor affects the outcome of radiation therapy. Radiation therapy with a solitary node in the prostate about 1 cm in size gives a 15-year survival rate in 80% of patients, and with a tumor widespread in the gland, it is 60%. When metastases are detected in the pelvic lymph nodes, a reduction in the risk of radiation complications can be achieved by fractionating radiation doses to the entire pelvic area.

Radiation therapy is a valuable adjunctive treatment after radical prostatectomy. This is due to the fact that 50% of prostate cancers clinically regarded as confined to the prostate have local spread to the seminal vesicles and paraprostatic tissue. This is the cause of local recurrence of prostate cancer after radical prostatectomy. Indications for radiation therapy after radical prostatectomy for prostate cancer are: detection of malignant cells in biopsy tissue taken during surgery from the edges of the prostate bed, micro- and macroscopic signs of penetration of the gland capsule, involvement of seminal vesicles in the malignant process, changes in tissue structure in the region corresponding to the apex of the gland. In such cases, the potential for radiation complications does not justify the delay in radiotherapy, which after radical prostatectomy slightly increases the risk of complications observed in connection with radiotherapy or radical prostatectomy as independent treatments Forman J. et al., 1986.Thus, the frequency of urinary incontinence in connection with radical prostatectomy was 15%, with radiation therapy - 3% and after radiation therapy in patients previously subjected to radical prostatectomy - 15% (9% of 15% of patients suffered from early urinary incontinence); narrowing of the urethra was observed in 9%, 1% and 6% of patients, respectively, with these three methods of treatment. Damage to the rectum was observed in 4% of patients undergoing radical prostatectomy, in 5% after radiation therapy and in 9% after radical prostatectomy and radiation therapy. At the same time, the frequency of thromboembolic complications did not increase in patients using radiation therapy after radical prostatectomy and was 6% after radical prostatectomy as an independent method of treatment. Radiation therapy after radical prostatectomy in cases of histological confirmation of malignant cells preserved in the prostate bed increases the life expectancy of patients up to 10-15 years.

The issue of combined radiation and hormone therapy still remains an unresolved and rather controversial problem. There is an opinion that the combined use of radiation therapy and hormonal treatment (especially estrogenic drugs) does not increase the effectiveness of radiation exposure to prostate cancer due to the risk of thromboembolic complications. At the same time, the latter can be reduced by using adequate doses of estrogenic drugs, antiandrogens, gonadotropin-releasing hormone analogues and by correcting hormonal and metabolic changes in the patient's body. Immediate conduct of combined radiation and hormonal therapy after the diagnosis of a local form of prostate cancer significantly increases the effectiveness of treatment due to the impact on various tumor cell populations. Combined remote c-therapy in combination with hormone therapy can achieve stable and long-term remission (up to 5 years) and reduce the size of the primary focus of prostate cancer. The literature provides data on the effectiveness of orchiectomy followed by delayed (after 5 - 6 months) external c-therapy on the pelvic area in patients with prostate cancer stages A, B, C MefTan P. et al., 1986. The effectiveness of delayed radiotherapy after orchiectomy proved to be significantly greater than estrogen therapy. Five-year survival was observed in 91% of patients with localized prostate cancer and 35% with disseminated prostate cancer. The mechanism of action of delayed radiation therapy against the background of a previous orchiectomy is explained by the elimination of the source of testicular androgenic secretion, which leads to a decrease in the size of the primary tumor focus, shrinkage of the prostate gland and increases the radiosensitivity of prostate cancer cells.

The literature provides positive results of treatment of prostate cancer with adriamycin in combination with bleomycin or monochemotherapy with adriamycin with radiation therapy Uyama T., Moriwaki Sh. pelvic area up to 30 - 45 J/kg. The effectiveness of combined radiation and chemotherapy is confirmed by histological studies of biopsy specimens of the primary tumor focus obtained by puncture biopsy 2 weeks and 1 year after the start of treatment. The histological picture after combined radiation and chemotherapy reflects a pronounced degree of destruction of tumor structures, the development of granulation tissue with the absence or a small number of viable tumor cells.

Remote c-therapy of the mammary glands is used as a preventive method for the development of hormone-induced gynecomastia and breast tenderness in patients receiving estrogen therapy. In this case, a total dose of 12-15 J / kg in three fractions is used.

Irradiation of lymph nodes in prostate cancer

Prostate cancer is a malignant tumor that usually develops from the tissue of the prostate glands. Like other malignant tumors, prostate cancer tends to metastasize (spread throughout the body).

The statistics are relentless: prostate cancer occurs in every seventh man over 50 years old. And, unfortunately, this disease is one of the most common causes of death for older men.

In the early stages, prostate cancer, as a rule, does not show anything. In view of the fact that prostate cancer progresses relatively slowly, the disease is asymptomatic for several years. The only sign of the disease in the absence of pronounced symptoms is an increase in the blood level of PSA (prostate specific antigen). As a rule, in this case, the size of the tumor is small.

If the tumor grows and grows into the urethra and bladder neck, symptoms of bladder irritation are possible:

Difficulty urinating; frequent urination; urinary incontinence; frequent urge to urinate.

In some cases, symptoms of upper urinary tract obstruction may occur:

Formation of kidney stones; pain in the lumbar region; expansion of the ureters and cavities of the kidneys.

In the case of damage to the bones by metastases, pain in the limbs appears, and compression of the spinal cord by metastases leads to paralysis and paresthesia. The formation of metastases in other organs leads to dysfunction of the latter.

Let's add that the symptoms of prostate cancer are non-specific and are expressed in violation of the functions of the affected organs, therefore, in order to prevent the uncontrolled development of the disease, regular examinations are necessary, especially for men over 50 years old.

Spine cancer first symptoms at the link.

The main causes of prostate cancer are:

- Genetic predisposition. The risk of developing prostate cancer is higher if close relatives: father, grandfather or brothers - have been diagnosed with this disease.

- Hormonal changes caused by age. Violation of the hormonal balance in the body often leads to the degeneration of prostate cells into malignant ones.

- Improper nutrition. Nutritional imbalances, as well as eating a lot of fat and foods containing carcinogens, can trigger the development of a cancerous tumor.

- Bad habits. Drinking alcohol and smoking greatly increase the risk of developing cancers in all organs.

Diagnosis

At the first visit of the patient, the urologist feels the prostate gland through the rectum (digital rectal examination). This simple and useful method allows you to suspect prostate cancer. Unfortunately, if the tumor can be felt, it is most often one of the later stages of the disease, in which the operation will no longer help. Further, if cancer is suspected, a series of tests are performed.

Other studies - ultrasound, x-ray methods, allow only to more accurately determine the size of the tumor and the condition of other organs. Radioisotope bone scan, radiography, excretory urography, computed tomography of the pelvic organs and retroperitoneal space can detect metastases in the most commonly affected organs.

The final diagnosis of prostate cancer is made after a biopsy of the prostate - a small piece of the gland is taken with a special needle through the perineum or through the rectum for examination.

The best and most progressive method today is the determination of PSA in the blood - the so-called prostate-specific antigen. This is a substance, the amount of which in the blood increases dramatically when cancer occurs in the prostate. The advantage of this method is that today it is practically the only way to suspect prostate cancer at an early stage, when it can still be removed. The method is very simple and looks like a regular blood test for the patient

The discovery of the prostate specific antigen (PSA), as the most specific oncomarker - an indicator of prostate cancer, makes it possible to detect this disease already in the early stages, when there is no tumor spread and there is a real possibility of curing the patient through radical surgery.

Prostate specific antigen (PSA) is a protein substance that is produced by cells of the prostate gland. The main amount of PSA is located in the ducts of the prostate gland and contributes to the dilution of the seminal fluid. A small amount of PSA enters the blood through the barrier between the prostate duct system and the bloodstream

Normal PSA values:

Total PSA levels tend to increase with age. Therefore, the upper limit of the norm for different age groups is different:

40 - 49 years - 2.5 ng / ml 50 - 59 years - 3.5 ng / ml 60 - 69 years - 4.5 ng / ml 70 - 79 years - 6.5 ng / ml

Prostate cancer in stages T3 and T4 is considered advanced cancer. For these stages, the most characteristic is the appearance of bone metastases, as well as metastases in the lymph nodes. It is at these stages that prostate cancer manifests itself more intensely than in the early stages. Note that metastases to bone tissue and lymph nodes according to the TNM classification are denoted by the letters M and N, respectively.

So, in stage III cancer, the tumor passes through the prostate capsule to neighboring organs. The seminal vesicles are the first to be affected. In stage IV prostate cancer, the tumor affects other tissues and organs, in particular, the neck of the bladder, the internal sphincter (the muscle that is responsible for opening the internal opening of the urethra) and the rectum.

Metastases are the spread of a tumor to more distant areas from the original focus. This is usually due to the spread of cancer cells by blood or lymph. Most often, such cells in prostate cancer enter the bone tissue, as well as the lymph nodes.

Metastases in lymph nodes

Metastases in the lymph nodes naturally enter through the lymph. Lymph is a clear liquid that circulates in a separate system - the lymphatic. Lymphatic vessels envelop almost all organs and tissues. The function of lymph is cleansing. It contains a large amount of protein. When bacteria or cancer cells enter the lymph flow, the latter are carried away by the lymph and are usually retained by the first lymph nodes. Such lymph nodes, which are located in close proximity to the tumor focus and are the first to delay the spread of cancer through the lymph, are called regional. However, over time, the cancerous tumor, getting into the regional lymph node, grows and, finally, goes beyond the lymph node. Thus, the tumor cells are spread further by the lymph. This time, the cancer cells travel to more distant lymph nodes. Such lymph nodes are called metastases.

The first two regional lymph nodes in prostate cancer are the lymph nodes on either side of the bladder neck. At the same time, regional lymph nodes affected by cancer are designated in the classification as N1, while the absence of a lesion in these nodes is N0. With cancer metastases in distant lymph nodes, the classification of the disease is designated as M1a.

There are surgical, drug and radiation treatments for prostate cancer.

Surgical methods of treatment are used only when the tumor has not yet metastasized. In this case, the removal of the prostate is performed in the same way as described in the article "Adenoma of the prostate gland". If the operation is performed successfully, it practically guarantees a complete cure for prostate cancer without any health consequences.

Medicated treatments are hormone treatments. It has already been said that tumor growth depends on the level of testosterone in the patient's blood. Hormonal drugs reduce or block testosterone, and this can reduce the rate of tumor growth and its metastases. Hormone treatment does not give a complete cure, but improves the patient's condition and reduces the symptoms of the disease. Unfortunately, hormonal drugs have a number of unpleasant side effects - increased blood pressure, reduced potency, gynecomastia and others. If you are prescribed hormone therapy, be sure to consult your doctor about what to do if such phenomena occur.

Radiation therapy is the irradiation of the area of the prostate gland with radioactive radiation. This allows you to reduce the rate of tumor growth, reduce the likelihood of metastases. Radiation therapy also does not provide a cure for cancer, but improves the patient's condition, facilitates and prolongs his life. Often radiation and drug therapy are used together to enhance the effect of treatment.

Surgery is an effective method of treatment when cancer cells are only inside the prostate gland. Therefore, the choice of this method requires an accurate examination and determination of the location of cancer cells.

The essence of the operation is the complete removal of the gland along with a cancerous tumor. If it is not possible to completely remove the cancer with the help of the operation, and there is a possibility that additional radiation is needed after the operation, it is better to refuse the operation.

For surgery, cases without risk factors are most often indicated: the PSA level is below 10, the PSA rise should be slower than 2 units per year, the Gleason sum should be 2-6, MRI images should not show capsule damage or suspicion of the location of the cancer at the apex of the prostate.

The operation is indicated in cases where the prostate gland is significantly enlarged, does not function well, and the patient has problems with urination. If, nevertheless, after the operation, the spread of cancer beyond the capsule is detected, radiation therapy is immediately recommended.

Radiation therapy

To date, oncologists have in their arsenal several different methods of radiation therapy used in the complex treatment of prostate cancer. These include standard methods: external irradiation, transcutaneous radiotherapy and brachytherapy (the introduction of small beam sources directly into the prostate), as well as non-standard methods: intense modulation radiotherapy (IMRT) and targeted, highly focused ultrasound that destroys cancer cells.

Absolutely painless methods of radiation therapy are not dangerous, side effects are insignificant and therefore they are widely used in complex cancer therapy, especially successfully in elderly patients.

The stage of the oncological disease plays a particularly important role in planning individual doses for upcoming radiological sessions.The most effective is the use of radiation therapy in the early stages - up to T2A, with or without taking into account the planned operation to remove the prostate.

In the presence of large prostate tumors, the use of radiation therapy sessions helps to reduce it. We are talking about the so-called. neoadjuvant therapy - radiation prior to prostatectomy. It should also adhere to the principle that the higher the irradiated dose, the less chance there is for a recurrence of the disease in the future.

In adjuvant (postoperative) therapy, designed to destroy the remaining microfoci of cancer cells, the effectiveness of radiobeam exposure is significantly increased when combined with 3-6-month hormone therapy. If the level of PSA control tests (>20 ng / ml) indicates a high probability of recurrence of the disease, then such a combination, carried out for a total duration of up to 3 years, is defined as the standard therapy of choice.

If there is a high probability of penetration of cancer cells beyond the capsule of the prostate gland, then the areas of lymphatic drainage, as well as the regional lymph nodes themselves, are subject to radiological irradiation.

Folk remedies

Pour fresh crushed hemlock inflorescences (collect in early June) with vodka (1: 1), hermetically close the dishes, insist in a dark, cool place for 18 days; take on an empty stomach 1 hour before meals. On the 1st day - 1 cup per 0.5 glass of water; on the 2nd day - 2 k., etc. up to 40 k., then also reduce the dose daily. Repeat the course 2-3 times.

Immortelle (flowers), nettle (leaf), plantain (leaf), motherwort (grass) - 75 g each; birch (bud), cowberry (leaf), oak (bark), shepherd's purse (herb), yarrow (herb), string (herb), sage (herb)

50 g each; centaury (grass), buckthorn (bark), wormwood (grass), horsetail (grass) - 25 g each; wild rose (fruits) - 100 g. Mix, divide into 10 parts, pour 0.25 of one part of 2 liters of water, boil for 20 minutes, strain, cool, store in a cool place; take 1 glass 3 times a day 30 minutes before meals (course - 3 months, break - 2 weeks, then continue).

Celandine (herb), cocklebur (leaf) - 5 g each, calendula - 3-4 flowers.

Pour 1 cup boiling water, boil for 3-5 minutes, leave for 2 hours; take 0.25 cup 4 times a day on an empty stomach and 30 minutes before meals. The course of treatment - 1 month.

Eucalyptus (leaf), yarrow (herb), bedstraw (herb), nettle (leaf), licorice (rhizome), astragalus (herb), thorn (fruit), calendula (flowers), St. John's wort (herb), celandine (grass), succession (grass), tartar (leaves), bearberry (leaf), knotweed (grass), golden rod (grass), agrimony (grass) - 5 g each. Pour 3 liters of vodka into the mixture, boil for 3-4 minutes ; take 0.5 cup before each meal. The course of treatment - 1 month.

Pour 25 g of pine (birch) buds with 1 liter of boiling water, leave for 1 day, strain; mix chaga - 150 g (befungin - 200 g), aloe (crushed leaf - 500 g), plantain (juice of fresh leaves - 20 g), wormwood (tincture) - 10 g, alcohol - 250 g, honey - 300 g, sugar - 250 g; pour the mixture with infusion of the kidneys, leave for 3-5 days; take 2 tbsp. spoons 2 times a day 30 minutes before meals.

Recipes of the famous healer M. V. Galyuk

Pour 50 g of crushed marina root with 0.5 l of vodka, insist in a dark bottle for 10 days. Take 30-40 k. 3 times a day 30 minutes before meals (daily for 3 months).

Grind bergenia root to the size of buckwheat, pour 50 g of raw material into 350 ml of hot boiled water (60 ° C), leave for 8 hours, wrapping (leave the root in the infusion); take 2-3 teaspoons 3 times a day 1 hour before meals (3 days in a row).

Pour 100 g of dried celandine herb with 0.5 l of vodka, insist in a dark bottle for 5 days; take 1 tbsp. spoon 3 times a day 40 minutes before meals (3 days in a row).

Pour 100 g of crushed Eleutherococcus root into 0.5 l of vodka, insist in a dark bottle for 10 days; take 1 teaspoon 3 times a day 30 minutes before meals (3 days in a row).

Each tincture in the indicated order is taken for 3 days, on the basis of marin root - all 3 months.

Tinctures on vodka should be diluted with water (1:3) when taken.

For liver metastases, prepare all medicines with water.

Treatment with kerosene (healer V. Tishchenko's recipes)

Take 1-2 teaspoons at night with water.

Pour the crushed milky walnut fruits with kerosene (1:1), leave for 10 days in a dark place, shaking occasionally; take 1 teaspoon 3 times a day 30 minutes before meals.

Fruits and vegetables are considered important sources of fiber and vitamins. Foods rich in vitamins and microelements are essential in the diet for prostate cancer. Insufficient amounts of these substances in the diet of men with prostate cancer can influence the uncontrolled growth of cancer cells, which stimulates the progress of the disease. Spinach, beef liver, lettuce, apricots are a source of vitamin A. Citrus fruits, sauerkraut, red pepper, black currant contain a large amount of vitamin C.Be sure the daily menu should include cereal porridge, dairy products (low-fat), carrots, pumpkin. These products contain vitamins D, E, B and minerals - zinc, calcium, selenium.

Proper nutrition in prostate cancer is impossible without the daily consumption of vegetables and fruits, especially the usefulness of tomatoes in the diet for prostate cancer should be noted. The constituent substance of the tomato is lycopene, a natural antioxidant of a large group of carotenoids. Interestingly, cooked tomato dishes that have been processed at high temperatures contain more lycopene than raw tomatoes. US scientists have experimentally proven that daily consumption of tomato sauce significantly improves the condition of patients with prostate cancer and slows down the development of a malignant tumor. Because of this, the people have given the title of "healthy prostate product" to tomatoes. The systematic use of another vegetable - cabbage, also has a beneficial effect on the well-being of men suffering from prostate cancer. Cauliflower, white cabbage, Brussels sprouts - all these types of cabbage contain sulforafin, a compound that prevents the development of cancer cells.

Garlic plays a very interesting role in the prostate cancer diet. The substances included in it stimulate the immune system and significantly increase the defenses of the human body in the treatment of prostate cancer. The use of low-calorie vegetables and fruits in the diet for prostate cancer allows you to maintain a healthy and proper body weight, which is very important for sick men.

Proper nutrition for prostate cancer is nutrition that excludes excessive consumption of sugar, which increases the level of insulin in the blood, and thereby stimulating the development of a malignant tumor. Also accelerate the growth of cancer and omega-6 fatty acids found in raw seeds and nuts. There is evidence that yeast bread can cause prostate cancer, so the diet for prostate cancer should not contain these products.

Prevention

A balanced diet and smoking cessation can markedly reduce the risk of prostate cancer. But there are other ways to protect your health.

- Prostate cancer progression is slowed down by a diet high in vegetables and low in saturated fat. This conclusion was reached by Susan Bercow from George Mason University, USA, summarizing the results of 17 nutritional studies. The most effective in this regard is cabbage: broccoli, Brussels sprouts, cauliflower and regular cabbage.

- Selenium prevents the development of cancer, it is abundant in whole grains, seafood, tomatoes and nuts. A study was conducted at Harvard University, which involved more than 33,000 men. It turned out that the likelihood of advanced prostate cancer in men with high levels of selenium in the body is 65% less than in men with low levels of selenium.

- Men who watch their weight have a lower risk of getting cancer. According to one study, men who are physically active are 45% less likely to develop prostate cancer compared to men who have a sedentary job.

- Australian researchers from the Queen Victoria Cancer Center in Melbourne found that if a man over the age of 20 ejaculates more than five times a week, the risk of prostate cancer is reduced by almost a third. Ejaculation in middle and old age also lowers the risk.

External Beam Therapy for Prostate Cancer

Photon External Beam Therapy

Radiotherapy (RT) for the treatment of prostate cancer was first used by N.N. Young in 1915

He used intracavitary (intraurethral) irradiation with radium sources.

The era of remote radiation therapy began approximately in the 50s of the XX century, when linear electron accelerators and X-ray simulators were widely used.

The next strategic step was the use of computed and magnetic resonance imaging for planning the volume of exposure, three-dimensional dosimetry, as well as the development of hadron therapy, the emergence of multileaf collimators for conducting RT with simulated intensity. Work continues on studying the combination of radiation therapy and local hyperthermia.

One of the debatable issues is the average level of total focal doses in external beam radiation therapy for prostate cancer. According to the treatment standards developed at the end of the 20th century, the total focal dose to the prostate is quite high - about 70 Gy. However, in a number of works, there are concerns that this may not be enough for a complete local cure in a significant proportion of patients.

Nevertheless, further escalation of the dose of radiation therapy is associated with an increased risk of radiation damage to adjacent organs and tissues.Zietman (2005) presents the results of a controlled randomized study of two groups of patients with localized prostate cancer with a favorable prognosis. The groups differed in the level of total focal doses, which amounted to 70.2 and 79.2 Gy-eq.

It should be noted that all patients at the first stage underwent proton therapy at a total focal dose (SOD) of 19.8 and 28.8 Gy-eq, respectively. The results indicate a significant increase in relapse-free survival and, unfortunately, the level of radiation complications from the rectum with dose escalation.

On the other hand, Seung compared two radiotherapy regimens with an average total focal dose of 69.5 and 76.4 Gy in a similar group of 187 patients and concluded that dose escalation does not lead to a significant increase in disease-free survival . Obviously, an acceptable frequency and severity of radiation complications should be the main criterion for dosing RT.

Radiation therapy in its various modifications is one of the main methods of special treatment for both localized and locally advanced prostate cancer.

As with any type of treatment, in addition to the direct - antitumor - effect, radiation therapy has side effects. Complications from nearby organs are due to their entry into the irradiation volume, although, as a rule, not in the 90% isodose circuit. For remote radiation therapy of prostate cancer, this pattern is most pronounced due to the topographic and anatomical features of neighboring organs.

So, the urethra passes directly through the prostate gland, the neck of the bladder is tightly adjacent to the middle lobe of the gland, and the rectum is located directly under the prostate. Thus, the total focal dose in these organs ranges from 50 to 70 Gy. Ionizing radiation causes early radiation complications due to acute aseptic inflammation, edema of the stroma, hyperemia, erosion of the mucosa.

Clinically, this is manifested by the rectum - pain, burning sensation, discharge of blood, mucus, frequent urge to defecate; from the side of the lower urinary tract - pain, increased urination, weakening of the pressure of the urine stream (up to acute urinary retention).

Late (after 3 months after treatment) radiation complications are associated with depletion of the vascular bed, stromal fibrosis, ulceration of the mucosa, and even perforation of the wall of a hollow organ. Clinical manifestations are similar to those in early complications, but fistulas, persistent hemorrhagic syndrome, bladder shrinkage can form, moreover, the course is less favorable, longer, due to already formed morphological changes (1.54,1.55).

1.54. Plethora of capillaries in the neck of the bladder - acute radiation cystitis on SOD 40 Gy (RNTSRR, 2009)

1.55. Late radiation rectitis: mucosal atrophy against the background of areas of single, multiple and confluent telangiectasias (RSCRR, 2009)

According to a number of authors, the following risk factors can be distinguished: a total focal dose for a critical organ of more than 57 Gy, the presence of concomitant diseases such as diabetes mellitus and, possibly, a mutation in the ataxiatelangiectasia gene. Oddly enough, we did not find any reports on the relationship between radiation complications and pathology of the rectum itself

T1-T3Nx-N0-N1M0 stage malignant tumor of the prostate gland is an indication for external beam radiation therapy. The main principle of remote radiation therapy for prostate cancer is the use of high-energy radiation on linear accelerators with an energy of 4-25 MeV with precision irradiation by a mobile method (sector or circular rotation) or using a "box" technique with 4 or 6 fields.

In some cases, gamma therapy is used (devices "Rocus-AM", "Rocus-AT" source of cobalt 60), mainly when it is impossible to irradiate on a linear electron accelerator. With six-field irradiation, 2 additional "narrow" fields are used, bypassing the rectum, but forming the necessary dose distribution in the lower pararectal parts of the paraprostatic tissue, which makes it possible to reduce the radiation load on the posterior wall of the rectum.

Preference is given to the regime of conventional fractionation with a single dose of 2 Gy with mandatory daily irradiation from all fields up to total focal doses of 70-76 Gy for the prostate region and 44-50 Gy for the lymph nodes of the small pelvis (1-2nd order - group obturator, internal and external iliac lymph nodes). The irradiation regimen can be continuous while maintaining acceptable conformity, but a split course of radiation therapy is more commonly used.

Lymph nodes are not irradiated if the absence of metastatic lesions during laparotomy / laparoscopy is proven, in patients older than 75 years, in the case of a low or moderate Gleason index (6 or less) and an initial PSA of less than 10 ng / ml.

The use of external beam radiation therapy in the treatment of localized prostate cancer with a favorable prognostic status is an alternative to prostatectomy and brachytherapy with almost the same treatment effect rates. So, according to S.H. Stokes (2000), 5-year relapse-free survival is about 70%, regardless of the chosen method (surgery / HTLT / ESWL) and does not have a statistically significant difference.

The generally accepted practice in this group of patients is irradiation of the entire volume of the prostate gland and seminal vesicles, which is carried out, as a rule, from 4 fields at angles or in the mode of uniaxial rotation up to a total focal dose of 70-74 Gy for 35-37 fractions. Significant differences are observed in the frequency, severity and nature of adverse reactions and complications depending on the chosen treatment (Table 1.35). It should be noted that the spread in the frequency of the above complications is largely related to the age of patients.

Table 1.35. Comparative characteristics of complications of various types of radical treatment of prostate cancer

In the presence of unfavorable prognosis factors and a locally advanced process, it is advisable to include prostatic tissue in the volume of steam irradiation, zones of regional lymph nodes - obturator, iliac on both sides, and bring a total focal dose of 40-46 Gy to these areas.

For example, with a Gleason score of 8-10, penetration of the capsule occurs 4 times, and a tumor along the incision edge is 3 times more likely, the volume of the tumor is 2 times larger. In the presence of unfavorable prognosis factors and a locally advanced process, it is advisable to include steam irradiation of prostatic tissue, zones of regional lymph nodes - obturator, iliac on both sides and bring to these areas a total focal dose of 40-46 Gy.

For example, with a Gleason score of 8-10, penetration of the capsule occurs 4 times, and a tumor along the edge of the incision - 3 times more often, the volume of the tumor is 2 times more, invasion into the seminal vesicles - 48 times and metastases in the lymph nodes - 24 times more likely than with a score of 5.

Currently, conformal radiotherapy techniques are widely used, which involve 3-dimensional radiation planning using helical computed tomography or magnetic resonance imaging. Volumetric planning allows you to rely on dose / volume histograms when analyzing a dosimetric plan for irradiation.

Many radiology centers are equipped with radiotherapy machines combined with computed tomography (CT). This makes it possible to verify the treatment program in real time and, most importantly, under absolutely identical patient positioning conditions. To form a conformal dose field, multileaf collimators and equipment for intensively modulated radiation therapy are used.

These improvements significantly reduce the percentage of radiation reactions and complications while increasing the effectiveness of treatment. So, for example, a comparative assessment of the dose distribution in the focus (prostate) and surrounding tissues (bladder, rectum) carried out by N. Aoyama et al. using a multileaf collimator than under 3D irradiation conditions.

Proton beam therapy

Technically, the average energy of a proton beam ranges from 200 to 250 MeV. The proton beam formation system, in addition to the synchrocyclotron, in which heavy particles are accelerated, contains a beam diffuser, a collimator, a comb filter, and a bolus. An individual collimator forms such an outgoing proton beam that coincides (in the same plane) with a given treatment volume.

With the help of a comb filter, the problem of the necessary length plateau on the Braga curve is solved, i.e. the maximum of absorbed ionization is precisely in the given irradiated volume. However, it should be remembered that the planned volume of irradiation, as a rule, does not have the correct geometric shape and varies significantly in different planes. One way to achieve greater precision is to create an irregular comb filter, i.e. formation of a plateau depending on the anatomical features of the target.

Proton therapy IMRT techniques have now begun to be used. Another option is to scan the exposure volume. This means that the proton beam irradiates only a geometrically homogeneous volume, starting from the smallest one, then (already with a different comb filter) the next identical volume is processed, and so on. Thus, a kind of scanning irradiation is carried out.Another problem that has already been solved by now was the lack of vertical, and even more so mobile, proton beams.

In the medical use of "scientific" synchrocyclotrons, the only possibility was the lateral exit of the proton beam, which limited the possibilities of laying the patient and mobile irradiation. Thus, despite the high precision of this type of treatment, the parameters of conformity and homogeneity of the dose distribution in the focus were far from ideal. The first medical proton center, equipped with a GANTRY device and intended only for medical purposes, was organized in the USA (Loma Linda) in 1990.

By 2005, the number of proton centers reached 31 worldwide and is expected to double by 2015. It should be noted that for the implementation of proton beam therapy, it is necessary to use individual fixing devices and stereotaxic frames, as well as to verify the volume of exposure in identical conditions of patient placement.

The technique of proton therapy for prostate cancer has recently received significant development. Much experience has been gained by Slater, who published the results of the treatment of 643 patients with localized prostate cancer, with a 5-year survival without clinical recurrence of 89%.

However, the author noted an inverse relationship between the initial level of prostate specific antigen (PSA) and biochemical recurrence-free survival, which decreased from 100 to 53% when the initial PSA increased from normal values to more than 20 ng / ml. With such impressive success rates, his study shows a quite acceptable level of toxicity; thus, early rectitis of the 1st degree was detected only in 21% of patients, and more pronounced changes in 1% of patients (Table 1.36).

Table 1.36. Survival without biochemical recurrence of patients after proton beam therapy for prostate cancer

Note: BFFS - biochemical relapse survival rate.

Significant experience in the combination of proton and photon irradiation in patients with poor prognosis of locally advanced and localized prostate cancer is reflected in the study by Yonemoto (1997). The results of treatment of 106 patients were analyzed. The small pelvis was irradiated with photon radiation therapy up to SOD 45 Gy and proton therapy with a beam energy of 250 MeV locally on the prostate up to SOD 75 Gy-eq.

As a result, the 2-year actuarial survival without biochemical recurrence was 63-96%, depending on the initial level of PSA; late radiation changes of the 1st-2nd degree from the rectum were observed in 8% of cases, from the urinary tract - in 4%.

Indications: Proton Photon Beam Therapy is for use in patients with stage T1-T3N0-N1-N1M0 prostate cancer.

Absolute contraindications to the use of this technique are:

- acute multiple organ failure; - concomitant diseases in the stage of decompensation.

Mention in this article certainly deserves the experience of using proton beam therapy of the pituitary gland in patients with prostate cancer. This technique provides "radiation castration" of patients. In our country, it was used, for example, by Academician N.A. Lopatkin, seeking to reduce the level of androgens and testosterone.

A similar conclusion was made in the IAEA expert opinion more than 10 years ago, since proton beam therapy increases the effectiveness of the treatment of malignant neoplasms.