ESTRO 2024 - Abstract Book

S1110

Clinical - Gynaecology

ESTRO 2024

7. Ikushima H et al. Prediction of out-of-field recurrence after chemoradiotherapy for cervical cancer using a combination model of clinical parameters and magnetic resonance imaging radiomics: a multi-institutional study of the Japanese Radiation Oncology Study Group. J Radiat Res. 2022 Jan 20;63(1):98-106. doi: 10.1093/jrr/rrab104. PMID: 34865079

8. Gui B et al. Pretreatment MRI Radiomics Based Response Prediction Model in Locally Advanced Cervical Cancer. Diagnostics (Basel). 2021 Mar 31;11(4):631. doi: 10.3390/diagnostics11040631. PMID: 33807494

9. Meng J et al. Apparent diffusion coefficient histogram shape analysis for monitoring early response in patients with advanced cervical cancers undergoing concurrent chemo-radiotherapy. Radiat Oncol. 2016 Oct 22;11(1):141. doi: 10.1186/s13014-016-0715-6. PMID: 27770816

2976

Mini-Oral

CT- VS MRI-based Bone Marrow Dose in CCRT for Cervix cancer: A Pooled Data from 2 Prospective Trials

Putthipong Chanwichu, Tissana Prasartseree, Pittaya Dankulchai, Wiwatchai Sittiwong

Faculty of Medicine Siriraj Hospital, Mahidol University, Division of Radiation Oncology, Department of Radiology, Bangkok, Thailand

Purpose/Objective:

Bone marrow (BM) sparing in definitive concurrent chemoradiotherapy (CCRT) for cervical cancer is an appealing approach as high grade hematotoxicity (HemTox) interrupt radiation treatment leading to protracted overall treatment time and worsening oncologic outcome. Pooled analysis of two prospective trials in single institute [HYPOCx-iRex and EMBRACE-II, HYPO(44Gy/20F) and CVRT(45Gy/25F) CCRT with weekly cisplatin 40mg/m2 and all with IMRT/VMAT technique] was performed to investigate BM dose-HemTox correlation.

Material/Methods:

40 patients from HYPOCx-iRex with prospective BM-dose limited planning with criteria of V10Gy<90% and V20Gy<75% were pooled with 28 patients receiving concurrent chemotherapy from EMBRACE-II study without prospective BM constraint. BM volume was defined as lumbosacral spine and pelvic bones within PTV44/45 level and classified into “MRI guided BM (BM_MRI)” and “CT-guided BM (BM_Full)”. In scarcity of PET/CT, active red marrow was assumed as the iso-to-hypo signal intensity in T1 and T2 planning MRI and was delineated as “BM_MRI” which was also used for prospective BM optimization in HYPOCx-iRex. Whereas “BM_CT” was delineated from planning CT and included bone marrow and cortex. Post-hoc delineation of bone marrow was performed: BM_MRI for EMBRACE-II patients and BM_CT for all patients from both trials. Demographic, dosimetric data, and CTCAEv5.0-graded HemTox including anemia, leukopenia, neutropenia, lymphopenia, and thrombocytopenia were analysed with descriptive statistics. Overall HemTox data excluded lymphopenia as it was experienced by most patients. HemTox, BM dose including V10,20,25,30,40Gy in both %