Effect and Toxicity of Radiation Therapy in Selected Palliative Indications.

BACKGROUND: Radiotherapy (RT) is a mainstay of oncology treatment in both curative and palliative situations. With respect to palliative and supportive care, RT improves local control of disease and relieves symptoms, particularly pain, compression of surrounding structures, and/or bleeding. The aim here was to evaluate the effects and toxicity of palliative RT in our department from April 2015 to April 2018. PATIENTS AND METHODS: During this period, 338 cases received palliative RT, representing approximately one third of indications for this treatment method. We evaluated selected subgroups of patients: those with advanced lung cancer, bone metastases, or soft tissue metastases. Patients were irradiated by the IMRT (intensity modulated radiation therapy) technique using the TomoTherapy HD (Accuray, USA) platform. RESULTS: Palliative RT for primary lung cancer was performed for 29 patients. Of these, symptoms were relieved in 22 patients (76%) and local control (confirmed by imaging) was achieved in 19 patients (66%). Treatment-related toxicity was acceptable. Overall, 104 patients received irradiation for bone metastases; pain relief was achieved in more than 75% of cases. Another 71 patients were irradiated to treat soft tissue metastases; symptoms were relieved in 60% of cases. Treatment-related toxicity in our patients was lower than reported previously, suggesting improved quality of life for patients irradiated using modern RT technologies. CONCLUSION: Palliative RT provided excellent symptom control in our patients, with minimal toxicity. Thus, RT is an effective and easy-to-use method for many palliative indications. Key words: palliative care - radiotherapy - lung neoplasms - neoplasm metastasis - bone metastases - pain management The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 28. 8. 2018 Accepted: 29. 10. 2018.

The influence of antioxidant THPC on the properties of polymer gel dosimeter.

In order to decrease the negative influence of oxygen to the response of PAG dosimeters THPC has been added to the gel in the role of scavenger. Apart from the decreased influence of oxygen, THPC also influences other properties of gel dosimeters. This study examines these influences and their quantification. Previous studies have shown that increasing the concentration of THPC causes a decreasing response of the dosimeter (as measured in the relaxation rate R2). Evaluation of the IR spectrum of gels irradiated by a variety of doses has shown that it is caused mostly by the changed structure of the arising polymer, not due to the decreased polymerization. THPC also changes the kinetics of the subsequent reactions in the gel after the end of irradiation. THPC has its influence also on the size of the dose response overshoot that happens in the areas of steep dose gradients. An easy model of action in the gel was suggested, which allows one to estimate the size and kinetics of the changed response of the dosimeter after the end of irradiation depending on the content of THPC, the size of the dose and the dose gradient.