RADIOTHERAPY FRACTIONATIONS IN SKIN LESIONS TREATMENTS AT HOSPITAL ERASTO GAERTNER FROM 2015 TO 2019

Objective: This study aims to analyze radiotherapy fractionation at Hospital Erasto Gaertner regarding skin lesions, toxicity, and compliance. Material and Methods: The study was the retrospective analysis of data from patients submitted to radiotherapy for malignant neoplasm of skin and benign lesions. From 2015 to 2019, there were 687 radiotherapy treatments for skin lesions, and the techniques applied were orthovoltage, betatherapy, electronbeam radiotherapy, and external beam radiotherapy. Results: 226 patients were submitted to radiotherapy for basal cell carcinoma (33%); among them, 84% received electron-beam radiotherapy and 14% received orthovoltage. The applied fractionation varied from 5Gy in five fractions to 2Gy in 35 fractions. The patients who received radiotherapy up to 55Gy in 20 fractions have completed the treatment during the estimated time (99%). The group of patients that received radiotherapy superior to 30 fractions has completed the treatment in two weeks beyond the estimated (35%). The group that received more than 30 fractions showed higher skin toxicity (RTOG 2 or superior) than the one that received up to 20 fractions (65% vs 24%). Similar results were seen in patients submitted to treatment due to squamous cell carcinoma, total of 177 patients (25%), the same fractionation dose was applied, however, 67% of the patients in this group received radiotherapy more than 30 fractions, with toxicity RTOG 2 or superior in 44% of them. Only 2% of the group have been treated with external beam radiotherapy (60Gy in 30 fractions). 20 patients were in the Merkel cell carcinoma group (3% of them) with no difference in the fractionation of the results compared to the previous groups. Concerning benign lesions, 37 % (254 patients) were treated: 218 patients received orthovoltage and fractionation of 20Gy in 10 fractions, in 65% of cases (141 patients); 27% with 18Gy in 6 fractions or 20Gy in 5 fractions, and 1% up to 10Gy in one fraction. Patients treated with electron-beam radiotherapy got the same fractionation variation (36% of the patients). Discussion: Besides healing, aesthetic results are also expected in skin lesions treatment, whether benign or malign. There was more compliance and less aesthetic complication rates in the group of patients who received up to 20 fractions. Conclusion: the radiotherapy treatment to those lesions showed itself to be safe in less fractions than the conventional ones, with more treatment compliance rates.