325P - Preliminary review of computed tomography (CT)-based image-guided brachytherapy (IGBT) in treatment of cervical cancers: The National Cancer Instit...

Date 18 December 2016
Event ESMO Asia 2016 Congress
Session Poster lunch
Topics Cervical Cancer
Imaging, Diagnosis and Staging
Surgery and/or Radiotherapy of Cancer
Presenter Norhidayu Salimin
Citation Annals of Oncology (2016) 27 (suppl_9): ix94-ix103. 10.1093/annonc/mdw585
Authors N. Salimin, S. Mohammad, H.L. Goh, S.P. Tang, C.T. Chong, S. Mohd Salim, H.Z. Ahmad, N. Abdullah, M.Z. Muzzamer, A.N.A. Ahmad Sayuty, S.H. Abdul Rahman
  • Radiotherapy & Oncology, National Cancer Institute (Institut Kanser Negara), 62250 - Putrajaya/MY

Abstract

Background

IGBT enables accurate planning of sufficient radiation doses to treat cervical cancers. NCI is the first facility in Ministry of Health of Malaysia to initiate this advanced technique. This review evaluates dose volume parameters of tumour & organs at risk (OAR) by CT-based treatment planning and clinical treatment outcomes

Methods

Patients were treated with external beam radiotherapy (EBRT) to pelvis; 45Gy over 25 fractions with or without concurrent cisplatin chemotherapy, followed by 7Gy high dose rate (HDR) brachytherapy for 4 fractions with CT-based planning. All patients underwent pelvic Magnetic Resonance Imaging (MRI) prior to IGBT. We aimed to deliver minimum dose to 90% (D90) of high risk clinical target volume (HR-CTV) of ≥ 75 Gy10, intermediate risk clinical target volume (IR-CTV) of ≥ 60Gy10 and dose volume constraint (D2cc) of ≤ 90Gy3 for urinary bladder & ≤70-75Gy3 for rectum & sigmoid colon. We evaluated toxicities clinically and radiological response via MRI.

Results

From January 2014 to January 2016, 44 patients (median age 56-year-old) of FIGO stages IB-IVB were treated. Histology was squamous cell carcinoma in 33 patients (75%) and tumour size >5cm in 27 patients (61.4%). 30 patients (68.2%) received concurrent chemotherapy. Total prescribed mean dose for D90 was 86.9Gy for HR-CTV, 67.7Gy for IR-CTV, D2cc 82.1Gy for urinary bladder, 69.1Gy for rectum and 60.9Gy for sigmoid colon. Median follow-up time was 6 months. 2 patients (4.5%) developed grade III vaginal stricture and 1 patient (2.3%) developed grade III cystitis. No grade IV toxicities observed. Out of 44 patients, 37 were evaluated with MRI. 7 patients (18.9%) achieved complete response and 29 patients (78.3%) had partial response by Response Evaluation Criteria In Solid Tumors (RECIST) criteria.

Conclusions

We were able to achieve recommended dose to HR-CTV & IR-CTV and dose constraint for OAR. We recommend interstitial brachytherapy in larger tumours to improve dose received by tumour volume & minimize toxicity to OAR. Emphasis on follow-up to patients and standardised follow-up practice can improve reporting of clinical outcome.

Clinical trial indentification

Legal entity responsible for the study

National Cancer Institute

Funding

National Cancer Institute

Disclosure

All authors have declared no conflicts of interest.