Clinical outcome and dosimetric parameters of chemo-radiation including MRI guided adaptive brachytherapy with tandem-ovoid applicators for cervical cancer patients: A single institution experience

Abstract

PurposeTo evaluate dosimetric parameters and clinical outcome for cervical cancer patients treated with chemo-radiation and MR-image guided adaptive brachytherapy (MR-IGABT) using tandem-ovoid applicators for intracavitary or combined intracavitary/interstitial approaches. MethodThis retrospective analysis includes 46 patients treated between 2006 and 2008. Dose–volume parameters D90 HR-CTV (high-risk clinical target volume) and D2cc OARs (organs at risk) were determined and converted into biologically equivalent doses in 2Gy fractions (EQD2). Clinical outcome parameters (local control (LC), progression free survival (PFS) and overall survival (OS)) were analysed actuarially and late morbidity crude rates were scored using CTCAEv3.0. ResultsMean D90 HR-CTV was 84 (SD9) Gy EQD2 for HR-CTV volumes of mean 57 (SD37) cm3 at time of first brachytherapy (BT). Median follow-up was 41 (range, 4–67)months. Three year LC, PFS, and OS rates were 93, 71, and 65%, respectively. Node negative patients had significantly higher 3-year survival rates compared to node positive ones (PFS 85 versus 53% (p=0.013), OS 77 versus 50% (p=0.032), respectively) with an even larger difference for patients with FIGO stages IB-IIB (PFS 87 versus 42% (p=0.002), OS 83 versus 46% (p=0.007), respectively). Late grade 3–4 mainly gastrointestinal or vaginal morbidity was observed in 4 patients (9.5%). No correlations were seen between morbidity and D2cc OAR values. Conclusion(Chemo-) radiation and MR-IGABT with tandem-ovoid applicators result in high LC and promising survival rates with reasonable morbidity.