Predictive Models to Determine Clinically Relevant Deviations in Delivered Dose for Head and Neck Cancer
| Autor: | Daniel F. Polan, Molly M. McCulloch, Jan-Jakob Sonke, Chrissy M. Lockhart, Carlos J. R. Anderson, James M. Balter, Avraham Eisbruch, Kristy K. Brock, Clifton D. Fuller, J. Heukelom, Justin D. Kamp, Jae Y. Lee, Randall K. Ten Haken, B.S. Rosen, Peter G. Hawkins, Choonik Lee |
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| Rok vydání: | 2019 |
| Předmět: |
Male
Planning target volume Image registration Dose constraints Article 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine stomatognathic system Humans Medicine Radiology Nuclear Medicine and imaging Cone beam ct business.industry Radiotherapy Planning Computer-Assisted Head and neck cancer Radiotherapy Dosage medicine.disease Oncology Head and Neck Neoplasms 030220 oncology & carcinogenesis Maximum dose Dose assessment Female business Nuclear medicine Inferior constrictor |
| Zdroj: | Pract Radiat Oncol |
| ISSN: | 1879-8500 |
| DOI: | 10.1016/j.prro.2019.02.014 |
| Popis: | Purpose This study aimed to improve the understanding of deviations between planned and accumulated doses and to establish metrics to predict clinically significant dosimetric deviations midway through treatment to evaluate the potential need to re-plan during fractionated radiation therapy (RT). Methods and materials A total of 100 patients with head and neck cancer were retrospectively evaluated. Contours were mapped from the planning computed tomography (CT) scan to each fraction cone beam CT via deformable image registration. The dose was calculated on each cone beam CT and evaluated based on the mapped contours. The mean dose at each fraction was averaged to approximate the accumulated dose for structures with mean dose constraints, and the daily maximum dose was summed to approximate the accumulated dose for structures with maximum dose constraints. A threshold deviation value was calculated to predict for patients needing midtreatment re-planning. This predictive model was applied to 52 patients treated at a separate institution. Results Dose was accumulated on 10 organs over 100 patients. To generate a threshold deviation that predicted the need to re-plan with 100% sensitivity, the submandibular glands required re-planning if the delivered dose was at least 3.5 Gy higher than planned by fraction 15. This model predicts the need to re-plan the submandibular glands with 98.7% specificity. In the independent evaluation cohort, this model predicts the need to re-plan the submandibular glands with 100% sensitivity and 98.0% specificity. The oral cavity, intermediate clinical target volume, left parotid, and inferior constrictor patient groups each had 1 patient who exceeded the threshold deviation by the end of RT. By fraction 15 of 30 to 35 total fractions, the left parotid gland, inferior constrictor, and intermediate clinical target volume had a dose deviation of 3.1 Gy, 5.9 Gy, and 4.8 Gy, respectively. When a deformable image registration failure was observed, the dose deviation exceeded the threshold for at least 1 organ, demonstrating that an automated deformable image registration–based dose assessment process could be developed with user evaluation for cases that result in dose deviations. Conclusions A midtreatment threshold deviation was determined to predict the need to replan for the submandibular glands by fraction 15 of 30 to 35 total fractions of RT. |
| Databáze: | OpenAIRE |
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