ESTRO 2024 - Abstract Book

S1489

Clinical - Lower GI

ESTRO 2024

modulated arc therapy (VMAT). Sixty patients received six cycles of capecitabine and oxaliplatin (CAPOX) regimen and 40% received FOLFOX. Radical operation (total mesorectal excision) was performed by either low anterior resection, ultralow anterior resection, or abdominal perineal resection. The pathological complete response (pCR) ypT0N0 was achieved in12 patients (48 %). Twenty patients (80 %) had complete response of the nodal disease and twenty one patients (84%) had R0 resection. Three patients had moderate diarrhea managed conservatively.

Conclusion:

Pathological complete response was almost 50% in those who received SIB with limited toxicity. This may need further investigation with Randomized controlled trial to enhance the efficacy of short course preoperative radiotherapy in total Neoadjuvant protocol.

Keywords: Simlatnous boost, RAPIDO

References:

Melton, M. K., N. T. Pfister, C. S. Schneider, M. Akce, J. Gunnells, R. Hollis, and R. Jacob. "Short Course Radiotherapy (SCRT) with Simultaneous Integrated Boost (SIB) in the Treatment of Rectal Cancer: Feasibility and Early Toxicities." International Journal of Radiation Oncology, Biology, Physics 117, no. 2 (2023): e324-e325. Zhang, Meng-xia, Xiao-bo Li, Bing-jie Guan, Guo-xian Guan, Xiao-yan Lin, Xiao-dong Wu, Pan Chi, and Ben-hua Xu. "Dose escalation of preoperative short-course radiotherapy followed by neoadjuvant chemotherapy in locally advanced rectal cancer: protocol for an open-label, single-centre, phase I clinical trial." BMJ open 9, no. 3 (2019): e025944. Lee, Dong Soo, Seong-Taek Oh, Chang-Hyeok Ahn, Jaeim Lee, Kil-Yong Lee, Hiun Suk Chae, Sung Soo Kim, Sang Woo Kim, and Kyung Jin Seo. "Simultaneous Integrated Boost Volumetric Modulated Arc Therapy for Rectal Cancer: Long-Term Results after Protocol-Based Treatment." Journal of Oncology 2022 (2022). Meldolesi, Elisa, Giuditta Chiloiro, Roberta Giannini, Roberta Menghi, Roberto Persiani, Barbara Corvari, Claudio Coco et al. "The role of simultaneous integrated boost in locally advanced rectal cancer patients with positive lateral pelvic lymph nodes." Cancers 14, no. 7 (2022): 1643 Geng, Jian-Hao, Yang-Zi Zhang, Yong-Heng Li, Shuai Li, Lin Wang, Zhi-Long Wang, Xiang-Gao Zhu et al. "Preliminary results of simultaneous integrated boost intensity-modulated radiation therapy based neoadjuvant chemoradiotherapy on locally advanced rectal cancer with clinically suspected positive lateral pelvic lymph nodes." Annals of Translational Medicine 9, no. 3 (2021). Cummings, Michael A., Kenneth Y. Usuki, Fergal J. Fleming, Mohamedtaki A. Tejani, and Alan W. Katz. "Short course radiation therapy for rectal cancer in the elderly: can radical surgery be avoided?." Journal of Gastrointestinal Oncology 10, no. 2 (2019): 357.

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Digital Poster

Immunoscore-based wait-and-watch after short course radiation and chemotherapy in rectal cancer