Helical IMRT-Based Stereotactic Body Radiation Therapy Using an Abdominal Compression Technique and Modified Fractionation Regimen for Small Hepatocellular Carcinoma

Purpose: To assess the efficacy and safety of stereotactic body radiation therapy using an abdominal compression technique and modified fractionation regimen (5-10 fractions) in patients with small-sized hepatocellular carcinoma. Methods: A total of 101 patients with small-sized hepatocellular carcinoma treated with stereotactic body radiation therapy using an abdominal compression technique and modified fractionation regimen were registered between June 2011 and June 2019 in our hospital. A total dose of 48 to 60 Gy was applied over 5 to 14 consecutive days. Liver motion was controlled by abdominal compression, and a helical intensity-modified radiation therapy-based stereotactic body radiation therapy administrated in tomotherapy platform. Results: The median follow-up period was 23.2 months (range: 4.1-99.2 months). Complete response and partial response were observed in 63 (62.4%) patients and in 24 (23.8%) patients, respectively. At the time of our analysis, the 1-, 3-, and 5-year local control rates after stereotactic body radiation therapy were 96.1%, 89.0%, and 89.0%, respectively. However, logistic regression analysis revealed no correlation between the biologically effective dose and 3-year local control rates. The 1-, 3-, and 5-year overall survival rates were 96.9%, 69.0%, and 64.3%, respectively. For patients who were treatment-naive, the 1-, 3-, and 5-year overall survival were 96.3%, 82.0%, and 82.0%, respectively. No patients experienced classic radiation-induced liver disease or nonclassic radiation-induced liver disease after stereotactic body radiation therapy completion. Conclusions: When using an abdominal compression technique and modified fractionation regimen (5-10 fractions) based on helical intensity-modified radiation therapy, stereotactic body radiation therapy led to a lower toxicity and comparative rate of local control and overall survival for patients who with small-sized hepatocellular carcinoma.

Early results of localised, high-risk prostate cancer treated by moderate hypo-fractionation (70 Gy at 2·5 Gy per fraction): 5-year experiences of a moderate hypo-fractionation regimen

Background:Radiotherapy is one of the treatments used to treat prostate cancer, and dose escalation to 74–78 Gy in conventional fractionation is the standard regimen. Currently, according to the hypothesis of low alpha/beta ratio in prostate cancer cells, using hypo-fractionation has been reported in many publications with promising results. This retrospective study was designed to evaluate the implementation of a moderate hypo-fractionation regimen in high-risk prostate cancer in our division.Materials and Methods:Between 2012 and 2017, 40 patients with high-risk, localised prostate cancer were treated by a moderate hypo-fractionation regimen (70 Gy at 2·5 Gy per fraction) with intensity-modulated radiation therapy. The data related to treatment outcomes and toxicities were evaluated.Results:The mean PSA at diagnosis was 86·2 ng/mL (95% CI 49·9–122·4). Thirty-eight patients received long-term hormonal therapy. Fifty-two percent had a Gleason score of 8–10, and 65% had an initial PSA >20 ng/mL. The mean doses (in EQD2) to the D50% of PTV, D2% of organs at risk (bladder, rectum and bowels) were 80, 78·3, 76·4, and 50·2 Gy, respectively. Two patients had biochemical recurrence during the follow-up period.Conclusion:A moderate hypo-fractionation regimen (70 Gy at 2·5 Gy per fraction) is feasible. Our experience found that this regimen yields tolerable, acceptable toxicity profiles in high-risk, localised prostate cancer patients.

Radiobiological Evaluation of Dosimetric Plans for Stereotactic Radiotherapy for Prostate Cancer According to Fractionation Regimen

Objective. To determine the most effective irradiation regimen (total dose and dose per fraction) for hypofractionated treatment for prostate carcinomas according the TCP/NTCP radiobiological criteria.Material and methods. Using the tomographic information of five patients with low-risk prostate adenocarcinoma as an example, the authors devised dosimetric radiation therapy plans using the volumetric modulated arc therapy (VMAT) procedure. They considered the range of total doses of 33.5 to 38 Gy administered in 4 and 5 fractions. Based on the equivalent uniform dose concept proposed by A. Niemierko and on the computed differential dose volume histograms, the investigators modeled local tumor control probability (TCP) values, by taking into account the uncertainties of main radiobiological parameters, and estimated normal tissue complication probabilities (NTCP) for the anterior rectal wall as the organ most at risk of irradiation. An effective dosimetric plan was selected according to the UTCP criterion and the probability of complication-free tumor control, i.e. TCP (1 – NTCP).Results. The results of modeling the UTCP criterion show that with a higher total dose, the TCP value increases and so does the NTCP value, therefore the optimal radiation therapy plans are to irradiate with a total dose of 34 Gy over 4 fractions or with a dose of 36–37 Gy over 5 fractions. The difference between the fractionation regimens is that the UTCP value is achieved with a higher TCP value over 4 fractions and with a lower load on the rectal wall over 5 fractions.Conclusion. The choice of a specific fractionation regimen should be determined from the calculated values of differential dose volume histograms for each patient, as well as from radiobiological criteria, such as TCP, NTCP and UTCP.

Application of Stereotactic Radiation Therapy for Removing Pain Syndrome to Patients with Non-researchable Cancer of Pancreas

Purpose. Control of pain syndrome in patients with locally advanced and recurrent pancreatic cancer using stereotactic radiation therapy (SBRT). Materials and methods. Our clinical observations relate to 103 patients with locally advanced (LAPC)and recurrent pancreatic cancer who received radiation therapy in the radiological unit of the NIITs NMI. NN Blokhin "in the periods: 2000-2010. and 2010-2015. The first group consisted of 77 patients with locally advanced non-resectable pancreatic cancer, of which (1a subgroup), 30 patients received radiotherapy in a classical fractionation regimen of 54-60 Gy/5 fraction, 40 patients (1b subgroup) in a mode of hypofractionation. per week 37.5 Gy/5 fraction. Group 2: 26 patients with recurrent pancreatic cancer, including 15 patients (2a subgroup), radiation therapy was performed in the classical fractionation regimen of 54-60 Gy/5 fraction, 11 patients (2b subgroup) underwent a course of radiation therapy in the mode of hypofractionation. Gr 5 times a week 37.5 Gy/5 fraction. Results. In SBRT, in 70% of cases, there was a reduction of all types of pain syndrome compared to 37.8% in the control group. The conclusion. Stereotactic beam therapy in the mode of hypofractionation is a highly effective, safe method of radiotherapy that effectively reduces pain syndrome in unresectable pancreatic cancer in a short time of treatment in comparison with the traditional method of radiotherapy, which significantly improves the quality of life of this severe category of patients.

Economic evaluation of postoperative hypofractionated radiation therapy in patients with breast cancer

Breast cancer remains the most common malignant neoplasm in women. According to the current standards, radiation therapy is one of the most important components of the multi-disciplinary treatment. The efficacy of the postoperative radiotherapy in both the traditional fractionation regimen and in the hypofractionation mode is not questioned. Contrary to the conventional fractionation, hypofractionation implies an increase in the daily dose and a reduction in the total treatment time. This approach helps reduce the treatment costs in patients with breast cancer while maintaining a high treatment efficacy and quality of life.The aim of the study was to analyze the economic efficiency of the dose hypofractionation as compared to the traditional mode of dose fractionation during postoperative radiation therapy in patients with breast cancer.Materials and methods. The study included 220 patients with breast cancer who received a combined treatment. Of these, 120 patients (study group) received hypofractionated radiotherapy (40.5 Gy in 15 fractions) whereas 100 patients of the control group were treated by the conventional therapy of 50 Gy in 25 fractions. Patients of the both groups were comparable by stages of the disease, systemic treatment, age and molecular type of tumor. The cost of treatment was calculated from the price list of this research center.Results. The present economic analysis showed that the method of hypofractionation was more (30% on average) cost-efficient than the conventional regimen while both modalities produced similar rates of total and relapse-free survival. We were then able to identify the main items in the list of medical services that contributed to the estimated difference in the treatment costs. Reducing the number of examinations and the treatment duration help reduce the expenditure of this medical organization.Сonclusion. Hypofractionation of postoperative radiotherapy in patients with breast cancer allows one to reduce the treatment costs as compared to the conventional fractionation regimen. The funds saved by optimizing the costs of postoperative radiation can be directed to the development of additional means of cancer treatment.