Long Term Clinical Outcome and Late Toxicity of Intensity Modulated Versus Conventional Pelvic Radiation Therapy for Locally Advanced Cervix Carcinoma

Abstract

Introduction: Role of intensity modulated radiotherapy in definitive management of Locally Advanced Cervical Carcinoma (LACC) is not yet well defined with limited available literature. Aim: We had earlier reported early clinical outcome and acute toxicities in patients with locally advanced carcinoma cervix treated with Whole Pelvic Conventional Radiotherapy (WPCRT) versus Intensity Modulated Radiotherapy (WP-IMRT). This study aims to evaluate the long term clinical outcome and late toxicities. Materials and Methods: A total of 44 patients of stage IIB-IIIB {International Federation of Gynaecology and Obstetrics (FIGO 2009)} squamous cell carcinoma of the cervix was randomised between WP-CRT or WP-IMRT to receive 50.4 Gy in 28 fractions with weekly cisplatin 40 mg/m2 followed by high dose rate intracavitary brachytherapy (7 Gy in 3 fractions each one week apart). Survival was calculated from the date of initiation of treatment. Late toxicity was graded as per the Radiation Therapy Oncology Group (RTOG) system. Results: A total of 22 patients each were assigned to the two treatment arms. Out of 44 patients, 13 and 12 patients belonged to stage IIB; 9 and 10 patients had stage IIIB disease respectively in WP-CRT and WP-IMRT arms. Median follow-up time was 46.7 months (22.8-59.8 months) for the WP-IMRT and 51.23 months (21.7-59.8 months) for the WP-CRT arm. Fiveyear loco-regional failure free survival and distant metastasis free survival rates were 85.7% versus 90.9% (p=0.58) and 76.4% versus 69.4% (p=0.79) in WP-IMRT versus WP-CRT respectively. Five-year disease free survival and overall survival rate in the WP-IMRT arm versus the WP-CRT were 72.7% versus 66.2% (p=0.80) and 72.4% versus 74.4% (p=0.61). For combined Grade-1-3, patients in the WP-IMRT arm experienced significantly fewer chronic gastrointestinal toxicity (18.2% versus 50%, p=0.027). Grade-2 late bladder toxicity was seen more in WP-CRT arm versus WP-IMRT arm (13.6% versus 0%, p=0.116). Conclusion: WP-IMRT continues to show comparable long term survival outcome and is associated with significantly less chronic gastrointestinal toxicity compared to WP-CRT. We suggest the use of WP-IMRT for LACC till further results from ongoing multicentric trial are available.

Keywords

• cancer of the uterine cervix
• concurrent chemoradiotherapy
• intensity-modulated radiotherapy