Effectiveness of surface mould brachytherapy in electron era.

Abstract

e21562 Background: In India, skin cancers constitute about 1-2% of all diagnosed cancers.Surgery stays main modality of treatment with adequate surgical margin shown excellent local control rates - generally 95%.However, conditions where surgery is not feasible, brachytherapy is alternative approach.Advanced technology improved the ability to deliver safe and effective radiotherapy, resulting in renewed interest in this modality.Brachytherapy has many advantages: they can deposit a significantly higher dose within a tumor, with better sparing of adjacent normal structures over external beam radiotherapy or electron therapy, which sometimes require irradiating a large volume of tissue in order to provide adequately coverage, which in term increase toxicity. The purpose of our paper is to find out the clinical outcomes of skin tumors and superficial tumours of head and neck region treated with Surface mould brachytherapy (SMB), in terms of survival and toxicity.We report on our institution’s experience with using Co-60 based HDR SMB for the treatment of skin and head and neck superficial malignancies. Methods: A retrospective review of all patients treated with surface mould Co-60-based HDR brachytherapy at our center.A total of 23 patients, with 23 lesions, were treated during this period, and included in the analysis. A total of three of these lesions were treated with a palliative intent, and were included. The most common fractionation scheme was 35 Gy in 10 fractions given daily (52%, n = 12), though a range of doses were used, from 8/2 fractions to 36 Gy/12 fractions. Results: Median age at diagnosis was 52 (range = 28-91). The majority were Squamous cell (43%, n = 10) or Basal cell carcinomas (34%, n = 8). Most lesions were located in the head and neck region. The most commonly used RT dose was 3GyX10 fractions; all patients had individualized CT-based planning.The 5-year overall survival (OS) was 86 %( twenty patients). Three patients were died. Most deaths were from unrelated causes. Response was assessed in OPD 2-4 months post-treatment. Our complete response (CR) rate was 73.9% (seventeen patients), with partial response in three patients; two patients could not be assessed for response and one patient died due to other medical condition. We report a 2-year local control (LC) rate of 91.3%, and local recurrence was found in two patients. The procedure was well tolerated, with no grade 3 or more acute or late toxicities. There was one case of grade 3 ulcer (CTCAE). The 100% isodose line median depth was 0.5 cm, and median surface dose = 126.5%. The median V90 = 92.3%. Conclusions: Surface mould brachytherapy is a safe, effective modality for treatment of skin malignancies or tumors. Brachytherapy was overall well tolerated, with no grade 3-5 acute or late toxicities. This treatment is a good alternative option for those patients unwilling or unable to undergo surgery for their skin malignancies