Knowledge-based automatic plan optimization for left-sided whole breast tomotherapy. (July 2022)

• Record Type: Journal Article
• Authors: Esposito, Pier Giorgio; Castriconi, Roberta; Mangili, Paola; Broggi, Sara; Fodor, Andrei; Pasetti, Marcella; Tudda, Alessia; Di Muzio, Nadia Gisella; del Vecchio, Antonella; Fiorino, Claudio
• Is Part Of: Physics and imaging in radiation oncology. Volume 23(2022)
• Page Start: 54
• Page End: 59
• Publication Date: 2022-07
• Subjects: Radiotherapy planning optimization -- Tomotherapy -- Breast cancer -- Knowledge-based models -- AI in Radiation Oncology; Radiotherapy -- Periodicals; Radiation dosimetry -- Periodicals; Cancer -- Imaging -- Periodicals; Oncology -- Periodicals; 615.842
• DOI: 10.1016/j.phro.2022.06.009
• Languages: English
• ISSNs: 2405-6316

Abstract

Abstract: Background/Purpose: Tomotherapy may deliver high-quality whole breast irradiation at static angles. The aim of this study was to implement Knowledge-Based (KB) automatic planning for left-sided whole breast using this modality. Materials/Methods: Virtual volumetric plans were associated to the dose distributions of 69 Tomotherapy (TT) clinical plans of previously treated patients, aiming to train a KB-model using a commercial tool completely implemented in our treatment planning system. An individually optimized template based on the resulting KB-model was generated for automatic plan optimization. Thirty patients of the training set and ten new patients were considered for internal/external validation. Fully-automatic plans (KB-TT) were generated and compared using the same geometry/number of fields of the corresponding clinical plans. Results: KB-TT plans were successfully generated in 26/30 and 10/10 patients of the internal/external validation sets; for 4 patients whose original plans used only two fields, the manual insertion of one/two fields before running the automatic template was sufficient to obtain acceptable plans. Concerning internal validation, planning target volume V95% /D1% /dose distribution standard deviation improved by 0.9%/0.4Gy/0.2Gy (p < 0.05) against clinical plans; Organs at risk mean doses were also slightly improved (p < 0.05) by 0.07/0.4/0.2/0.01 Gy for left lung/heart/right breast/right lung respectively. Similarly satisfactory results were replicated in the external validation set. The resulting treatment duration was 8 ± 1 min, consistent with our clinical experience. The active planner time per patient was 5–10 minutes. Conclusion: Automatic TT left-sided breast KB-plans are comparable to or slightly better than clinical plans and can be obtained with limited planner time. The approach is currently under clinical implementation.