RESUMO
BACKGROUND: Craniospinal irradiation (CSI) of medulloblastoma poses technological challenges due to the involvement of large treatment volume. Commonly, the whole treatment length is covered with two different isocentric plans in which the junction is shifted after every five fractions to overcome the possibility of hot and cold spot. OBJECTIVE: This study aims to evaluate dosimetrically and clinically the innovative planning technique for the CSI which doesn't need re-planning and re-setup of patients after every five fractions. MATERIAL AND METHODS: Computed tomography was done for fifteen (ten children and five adults) patients diagnosed with medulloblastoma. Treatment planning for 36 Gray (Gy) in 20 fractions (#) at the rate of 1.8Gy/# was done on the treatment planning system. A single plan for children was created with two bilateral fields of 6 Mega Voltage (MV) energy for cranium and one posterior field of 6 MV for spinal cord (C1-S2). Two plans for adult patients were created, first plan was with two bilateral fields of 6 MV for cranium and two posterior oblique fields of 6 MV for cervical and the part of thoracic spinal cord (up to T8-T9). The second plan was with a single posterior field of 15 MV covering remaining thoracic (T8-T9 to T12), lumbar and sacrum (up to lower border of S2) spine. After careful evaluation of all the plans, treatment was delivered; acute toxicities were recorded. RESULTS: 95% of prescribed dose was received by more than 95% of planning target volume in all the plans with the acceptable hot spot and good homogeneity index. All the patients reported common radiation induced acute toxicities (headache, vomiting, weakness) during radiotherapy. CONCLUSION: The new planning technique for CSI has acceptable dosimetric and acute clinical possibilities; therefore it can be used for CSI for improved homogeneous dose delivery.
RESUMO
PURPOSE: The main objective of our study is to evaluate response and toxicity profile in patients receiving external beam radiotherapy with concurrent chemotherapy followed by intraluminal brachytherapy boost for a carcinoma of the oesophagus. MATERIAL AND METHODS: Twenty patients with biopsy-proven carcinoma of the oesophagus received external beam radiotherapy (50Gy in 25 fractions) with concurrent chemotherapy (cisplatin: 40mg/m2). After a gap of two to three weeks, intraluminal brachytherapy (10Gy in two fractions each 1 week apart by a high dose rate 60Co source) was given. Response was evaluated at 1 month and at 1 year of completion of treatment. In addition, acute and chronic toxicity was evaluated at 1 month and 6 months of treatment. RESULTS: Complete response were seen in 80% of patients and partial response in 20% at 1 month. Moreover, there were 65% complete response, 10% local recurrences, 15% patients showed local control with distant metastasis and 10% patients died at 1 year. Grade 1, grade 2 and grade 3 oesophagitis were seen in 10%, 70% and 20% of patients respectively. Stricture was seen in 40% of patients and fistula in 10% of patients. There was no spinal cord, cardiac and nephrotoxicity found. CONCLUSIONS: With the concept that high tumoricidal dose for adequate tumor control achieved by intraluminal brachytherapy as a mean of dose escalation, while sparing surrounding normal tissue and potentially improving therapeutic ratio, external beam radiotherapy followed by intraluminal brachytherapy could be a better choice for oesophagus carcinoma.
