Magnetic Resonance Image Guided Adaptive Brachytherapy in Locally Advanced Cervical Cancer: An Experience From a Tertiary Cancer Center in a Low and Middle Income Countries Setting

Purpose: To determine the clinical impact of magnetic resonance image guided adaptive brachytherapy (IGABT) for locally advanced cervical cancer (LACC) (stages II and III) in a tertiary care cancer hospital in a low and middle income countries setting. Methods and Materials: Ninety-four LACC patients enrolled in a prospective EMBRACE (An International Study onMRI-Guided Brachytherapy in Locally Advanced Cervical Cancer) protocol treated with external radiation therapy (45 Gy in 25 fractions) with or without weekly cisplatin, followed by magnetic resonance IGABT (4 fractions of 7Gy), were analyzed in detail for dosimetric and clinical outcomes including late toxicities. Results: Themean (+/- standard deviation) high-risk clinical target volume (HR-CTV) at the first session of brachytherapy and at the second session of brachytherapy for the current study cohort was 46.94 +/- 24.6 cm(-3) and 42.7 +/- 22.5 cm(-3), respectively, with mean minimum dose received by 90% volume (D90) of 88.3 +/- 4.4 equivalent 2-Gy fractionation (GyEQD2). At median follow-up (39 months), the local control rate (LCR) and overall progression-free survival ratewere 90.1% +/- 3.4% and 72.1% +/- 4.8%, respectively, with grade 3 bladder toxicity in 3% of patients and rectum toxicity in 9%. The LCR at 39 months was significantly better in patients with stage IIB and IVA disease versus stage IIIB disease (100% vs 85%, P = .013). Local failures were limited to stage IIIB only and were associated with significantly larger HR-CTVs at brachytherapy (70 +/- 25.7 cm(-3) vs 44.3 +/- 21.9 cm(-3), P = .01) but not with HRCTV D90 doses (which were similar for patients who had local failures vs thosewho did not: 86.3 +/- 3.9 a/b equal to 10 Gy (Gy10) vs 88.5 +/- 5 alpha/beta equal to 10 Gy, P = .987). Conclusions: IGABTleads to a significant improvement inLCRand overall progression-free survival inLACCand should be considered for wider implementation in developing countries to improve outcomes. (C) 2017 Elsevier Inc. All rights reserved.