clinical outcomes of brachytherapy combined with applicator-guided IMRT in bulky cervical tumor
PO-2130
Abstract
clinical outcomes of brachytherapy combined with applicator-guided IMRT in bulky cervical tumor
Authors: Shunbin Wang1, Jinyi Lang2, Lu Shun3
1University of Electronic Science and Technology of China, School of Medicine, Chengdu, China; 2Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, Department of radiation oncology, Chengdu, China; 3Department of radiation oncology, ichuan Cancer Hospital & Institute, Sichuan Cancer Center, Chengdu, China
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Purpose or Objective
To investigate the clinical outcomes and toxicity in patients with locally advanced cervical cancer treated with supplementary applicator guided-intensity modulated radiation therapy (IMRT) based on conventional intracavitary brachytherapy.
Material and Methods
Large high risk clinical target volume (HR-CTV) volume (>40cc) at the time of brachytherapy cervical cancer patients were recruited in Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, China.. This study is a retrospective analysis of 76 patients with locally advanced cervical cancer (FIGO IIB-IVA) treated with concurrent chemo-radiotherapy followed by IC/IMRT between June 2010 and October 2016. External radiotherapy (45 Gy in 25 fractions) with cisplatin chemotherapy treated before IC/IMRT. The prescription dose for HR-CTV and IR-CTV were 6 Gy and 5 Gy per fraction for 5 fractions respectively.
Results
Mean HR-CTV was 65.8±23.6 cc at the time of brachytherapy. D90 for HR-CTV and IR-CTV were 88.7±3.6 Gy and 78.1±2.5 Gy. D2cc for bladder, rectum, sigmoid and small intestine were 71.8±3.8 Gy, 64.6±4.9 Gy, 63.9±5.3 Gy and 56.7±8.7 Gy respectively. Median follow-up was 85 months (47.9-124.2 months). Five-year local recurrence free survival rate, metastasis recurrence free survival rate, disease free survival rate and cancer special survival rate were 87.6%, 82.4%, 70.9% and 76.3%, respectively. The grade 1+2 gastrointestinal and urinary late toxicities were 15.8% and 21.1%, while grade 3 late toxicities were 3.9% and 5.2%, respectively. Neither acute nor late grade 4 gastrointestinal or urinary toxicities were seen.
Conclusion
The combination of ICBT with an applicator-guided supplementary IMRT boost achieved an excellent local control and overall survival with low toxicity for bulky residual cervical tumor.