S2012
Physics - Dose prediction/calculation, optimisation and applications for photon and electron planning
ESTRO 2026
without SIB in five patients and five with SIB. Plan objectives were PTV40 V38Gy ≥ 98% prescription dose and organs of interest (OOI) limits within EMBRACE II and adjusted protocol as shown in Figure 1. The script was fully automated for plan creation, beam setup, virtual organ generation, optimizing objective function, and dose calculation with built-in timing analysis on RayStation Scripting API.The analysis was divided into two parts. First, ASB plans for all 10 cases were evaluated based on institutional and clinical trial criteria. The second part aimed to estimate plan variation among different planners. ASB plans from the three cervical cancer cases with lymph node SIB were compared with two manual plans generated independently by different planners (3- and 10-year experiences), following the same clinical protocol. Planning time and dosimetric parameters, including target coverage and organs of interest (OOI) sparing, were compared between ASB and manual approaches. Results: All cervical cancer cases were successfully planned with ASB workflow. PTV40 volume was 1392.84(IQR1250.83-1593.56) cc and all achieved clinical criteria with a mean V40Gy of 96.08(95.7- 96.47), while PTV53 achieved a mean D95% of 52.26(52.42-52.51) Gy. Doses to organs of interest were maintained within tolerance with mean values of bladder D0.03cc 46.15(42.31-50.95) Gy, rectum D0.03cc 44.35(42.42-43.64) Gy, and bowel D0.03cc = 45.24 (42.36-46.67) Gy (Figure 1).In the second analysis, comparing ASB and inter-planner variation, all approaches produced clinically acceptable plans. Across three cases, target coverage differences were below 2% relative to clinical manual plans and strong agreement in dose-volume histograms (Figure 2 – DVH compare graph). The ASB workflow achieved comparable dosimetric quality while significantly reducing planning time to 24 ± 4 minutes, compared with 2.5–3.5 hours for manual planning (Figure 2 – Bar graph).
higher: 250-300 cc. This could be due to the small population analysed. V20 (cc) appears to be a powerful predictor of toxicity and could be implemented in the radiotherapy planning phase. References: Cicchetti A, Mangili P, Fodor A, Gabellini MGU, Chiara A, Deantoni C, Mori M, Pasetti M, Palazzo G, Rancati T, Del Vecchio A, Gisella Di Muzio N, Fiorino C. Skin dose- volume predictors of moderate-severe late side effects after whole breast radiotherapy. Radiother Oncol. 2024 May;194:110183. doi: 10.1016/j.radonc.2024.110183. Epub 2024 Feb 27. PMID: 38423138.Vincenzi MM, Cicchetti A, Castriconi R, Mangili P, Ubeira-Gabellini MG, Chiara A, Deantoni C, Mori M, Pasetti M, Palazzo G, Tummineri R, Rancati T, Di Muzio NG, Vecchio AD, Fodor A, Fiorino C. Training and temporally validating an NTCP model of acute toxicity after whole breast radiotherapy, including the impact of advanced delivery techniques. Radiother Oncol. 2025 Mar;204:110700. Keywords: breast radiotherapy NTCP model skin toxicity Digital Poster 4808 Automation of Script-Based Planning for 40Gy/20F VMAT-based Cervical Cancer Radiotherapy to Enhance Efficiency and Consistency: UPFRONTCx Study Napatsorn Thumyongkit 1,2 , Tissana Prasartseree 1,3 , Paritt Wongtrakool 1 , Satawatchara Suwanprateep 1 , Sawanya Suwandee 1 , Sajjaporn Pojai 1 , Natcha Nuchsirikulaphong 1 , Tanwiwat Jaikuna 1,2 , Pitchayut Nakkrasae 1,2 , Wiwatchai Sittiwong 1,2 , Pittaya Dankulchai 1,2 1 Division of Radiation Oncology, Department of Radiology, Faculty of Medicine Siriraj Hospital,Mahidol University, Bangkok, Bangkok, Thailand. 2 Siriraj Brachytherapy Center (SiBTC), Siriraj Center of Excellence (SiCOE), Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. 3 Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston,TX, USA Purpose/Objective: To develop and evaluate an automated script-based (ASB) planning performance against manual plans from individual planners, with the goal of minimizing planning time and inter-planner variability in future trial for cervical cancer patients. Material/Methods: The ASB workflow was first developed and validated on a separate dummy patient before being adopted for 10-patient evaluation set. The prescribed dose was 40 Gy in 20 fractions with a simultaneous integrated boost (SIB) to 53 Gy. VMAT field covered whole pelvis
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