Purpose: Verification of the IMRT prior to the introduction the new Versa HD (Elekta) Linac into operation using test examples given in the AAPM TG-119 report. Materials and methods: The verification of plans created both on the basis of the dose prescriptions given in the AAPMTG-119 report and on the basis of the constraints used in the NMRRC was made. The plans were verified using a matrix of ionization chambers (MatriXX Evolution) placed in a mini Phantom (IBA Dosimetry), using gamma criteria of 3 %/3 mm and 3 %/2 mm at a dose threshold of 10 %. In addition to checking the coincidence of the calculated and measured dose distribution in the plane, a comparison of the dose at the point calculated in the Monaco planning system (Elekta) and measured by the CC13 ionization chamber (0.13 cm3 , Iba Dosimetry) inside the PTV and in the organ at risk was carried out. Results: The difference in the dose measured by the ionization chamber and calculated in the planning system was less than 2 %, and correlates well with the results of accredited clinics. The measured dose distribution in the plane well (97-100 % of the points) coincided with the calculated one for all localizations. An exception was the test case with several targets, in which the assessment was carried out according to the 3 %/2 mm gamma criterion. Conclusions: The results obtained when testing IMRT according to the protocol described in the AAPM TG-119 report, can be used to compare their results with the results of other accredited clinics.

No abstract

Ïå÷åíüЦель. Определить эффективность применения стереотаксической радиотерапии у пациентов с метастатическим поражением печени. Материал и методы. Стереотаксическая радиотерапия метастатических новообразований в печени проводилась за три фракции в течение 5-8 дней с разовой очаговой дозой 10, 12, 15 или 20 Гр. Метод применили 66 пациентам: 40 (60,5%) женщинам и 26 (39,5%) мужчинам. Возраст больных варьировал от 37 до 82 лет (средний возраст 60 лет). У 24 (36,5%) больных первичные опухоли были представлены колоректальным раком, у 12 (18%) -раком молочных желез, у 7 (10,5%) -раком яичников, у 23 (35%) -другими злокачественными опухолями. Результаты. Медиана наблюдения составляет 14,5 мес (1,8-53,5 мес). Трое больных не представили результаты контрольного обследования. Среди остальных 63 больных у 16 (25,5%) был зафиксирован полный эффект, у 30 (47,5%) -частичная регрессия метастазов, у 11 (17,5%) -стабилизация, у 6 (9,5%) -прогрессирование. Таким образом, показатель локального контроля составил 90,5%. Лучевые повреждения III степени были зафиксированы в 2 (3%) наблюдениях, II степени -в 7 (11%). Заключение. Стереотаксическая радиотерапия пациентов с метастатическим поражением печени представляется высокоэффективным, безопасным методом и может быть рекомендована к применению у больных с ограниченным поражением печени, которым было отказано в оперативном лечении.Клю че вые сло ва: печень, метастазы, колоректальный рак, рак молочной железы, рак яичников, стереотаксическая радиотерапия, локальный контроль. Aim.To determine the effectiveness of stereotaxic radiotherapy in patients with liver metastases. Material and Methods. Stereotaxic radiotherapy of liver metastatic tumors was carried out in three fractions for 5-8 days with single focal dose of 10, 12, 15, or 20 Gy. The procedure was performed in 66 patients including 40 (60.5%) women and 26 (39.5%) men. The average age was 60 years (37-82). In 24 (36.5%) cases primary tumor was presented by colorectal cancer, in 12 (18%) -breast cancer, in 7 (10.5%) -ovarian cancer and in 23 (35%) -other malignant tumors. Results. Median follow-up was 14.5 months (range 1.8-53.5). 3 patients did not present data of control examination. Among other 63 patients full effect was established in 16 (25.5%) cases, in 30 (47.5%) patients -partial regression of metastases, in 11 (17.5%) -stabilization, in 6 (9.5%) -progression of tumoral process. Thus, local control rate was 90.5%. Degree III of radiation damage was reported in 2 cases (3%), II -in 7 cases (11%). Conclusion. Stereotaxic radiotherapy seems highly effective and safe method of the treatment of patients with liver metastases and can be recommended for use in patients with limited liver metastases who have been denied in surgery.

Treatment of patients with hepatocellular carcinoma is an urgent problem of modern oncology. Despite the possibility of using various methods of local and systemic exposure and their continuous improvement, the results of treatment of patients with hepatocellular carcinoma in general remain unsatisfactory. Modern radiation therapy can be considered as one of the significant methods of local exposure due to relative efficacy and acceptable tolerability. Implementation of radiation treatment in the mode of stereotactic radiotherapy is a promising direction in the treatment of patients with hepatocellular carcinoma because of the possibility of applying ablative doses with a significant restriction of doses to healthy organs and tissues in a short period of time and the possibilities of combining this method with other variants of specific treatment.

No abstract