Purpose or Objective: To assess efficacy & toxicity of reduced CTV margins in the IMRT of head and neck cancers Material and Methods: Between 2010 and 2015, 83 consecutive patients with locally advanced Head & Neck squamous cell cancers, treated with a radical intent with chemoradiation by IMRT, with reduced CTV margins were analysed for local control, toxicity, compliance & survival. Nodal delineation was as per DAHANCA guidelines. Toxicity was assessed by CTCAE version 4.0 Results: Median age of the cohort was 58 years (32‐76) with 65 males & 18 female patients. Hypopharyngeal cancers were 47% followed by oropharyngeal (27%) and laryngeal (26%) cancers. TNM stage grouping in the cohort was IVA in 72% followed by IVB & III. CECT based delineation of the involved primary and nodal volumes were expanded uniformly by 5 mm to create the high risk CTV and this expanded by 5 mm to create the PTV1. Similarly the involved nodal level was considered as intermediate risk (PTV2) and remaining nodal levels as low risk (PTV3). Inverse planning was performed using Varian Eclipse planning system with dose constraints to OAR's as per guidelines. SIB‐IMRT was delivered to a dose 70, 63 and 56Gy in 35 fractions to high, intermediate and low risk volumes respectively. Median overall treatment time was 49(40‐70) days. 24% of the patients received 6 fractions per week. Weekly Cisplatin (40mg/sqm) was given concurrently with IMRT except in 10 patients receiving Carboplatin (2AUC), 90% received a minimum of 4 cycles. Grade 3 mucositis was seen in 40%, grade 3 dysphagia in 6%, radiation dermatitis was predominantly grade 2, Xerostomia was predominantly grade 1 in 93%, 10% required placement of nasogastric tube and treatment interruption. Myelosuppression of grade 3 was seen towards completion of treatment in 24% of the cohort, predominantly in total leukocyte count. A complete response of 90% and 86% was seen in primary and nodal disease at the end of the treatment and eventually in 100% and 94% in first three months. 3 patients needed neck dissection and showed residual disease. At a median follow up of 2 years, 62 patients are controlled with an overall survival of 74.7%. Deaths are due to distant metastasis in 4% and 8% due to other medical causes. Conclusion: Reduction of CTV margin to 5 mm seems to be appropriate, with good loco‐regional control, reduced overall treatment time, better compliance, reduced toxicity & superior outcomes. This study forms basis for a prospective controlled randomised study to generate further evidence.
Chitradurga Abdul Razack, T. P., Annasagara Srinivasa, U. K., Chandraraj, V., Shenoy, A., Jacob, L., Ramar, N., … Patil, C. N. (2016). EP-1060: Can reduced CTV margin for IMRT in Head and Neck cancers improve therapeutic outcomes? Radiotherapy and Oncology, 119, S511. https://doi.org/10.1016/s0167-8140(16)32310-6