Patterns of locoregional failure following post-operative intensity-modulated radiotherapy to oral cavity cancer: quantitative spatial and dosimetric analysis using a deformable image registration workflow.
BACKGROUND: We sought to identify spatial/dosimetric patterns of failure for oral cavity cancer patients receiving post-operative IMRT (PO-IMRT).
METHODS: Two hundred eighty-nine OCC patients receiving PO-IMRT were retrospectively reviewed from 2000 to 2012. Diagnostic CT documenting recurrence (rCT) was co-registered with planning CT (pCT) using a validated deformable image registration software. Manually segmented recurrent gross disease (rGTV) was deformed to co-registered pCTs. Mapped rGTVs were compared dosimetrically to planned dose and spatially to planning target volumes using centroid-based approaches. Failures types were classified using combined spatial/dosimetric criteria: A (central high-dose), B (peripheral high-dose), C (central intermediate/low-dose), D (peripheral intermediate/low-dose), and E (extraneous-dose).
RESULTS: Fifty-four patients with recurrence were analyzed; 26 local recurrence, 19 regional recurrence, and 9 both local and regional recurrence. Median time to recurrence was 4 months (range 0-71). Median rGTVs volume was 3.7 cm
CONCLUSIONS: Approximately half of patients with local/regional failure had non-central high dose recurrence. Peripheral high dose misses were uncommon reflecting adequate delineation and dose delivery. Future strategies are needed to reduce types C and E failures.
Published In/Presented At
Mohamed ASR, Wong AJ, Fuller CD, Kamal M, Gunn GB, Phan J, Morrison WH, Beadle BM, Skinner H, Lai SY, Quinlan-Davidson SR, Belal AM, El-Gowily AG, Frank SJ, Rosenthal DI, Garden AS. Patterns of locoregional failure following post-operative intensity-modulated radiotherapy to oral cavity cancer: quantitative spatial and dosimetric analysis using a deformable image registration workflow. Radiat Oncol. 2017 Aug 15;12(1):129. doi: 10.1186/s13014-017-0868-y. PMID: 28806994; PMCID: PMC5557312.
Medicine and Health Sciences | Oncology
Department of Radiation Oncology