Impact of setup and range uncertainties on TCP and NTCP following VMAT or IMPT of oropharyngeal cancer patients
| Autor: | Hanne M. Kooy, Marcel Verheij, Annie W. Chan, Olga Hamming-Vrieze, David Craft, Nicolas Depauw, Coen R. N. Rasch, Jan-Jakob Sonke |
|---|---|
| Přispěvatelé: | Radiotherapy, CCA - Cancer Treatment and Quality of Life, CCA - Cancer Treatment and quality of life |
| Rok vydání: | 2019 |
| Předmět: |
Systematic error
Organs at Risk Population Planning target volume Normal Distribution 030218 nuclear medicine & medical imaging Normal distribution 03 medical and health sciences All institutes and research themes of the Radboud University Medical Center 0302 clinical medicine Evaluation methods Range (statistics) Proton Therapy Humans Radiology Nuclear Medicine and imaging Population effect education Proton therapy TCP/NTCP Mathematics Probability Retrospective Studies education.field_of_study Models Statistical Radiological and Ultrasound Technology business.industry Radiotherapy Planning Computer-Assisted Uncertainty Radiotherapy Dosage robust evaluation Oropharyngeal Neoplasms 030220 oncology & carcinogenesis head and neck cancer Radiotherapy Intensity-Modulated Nuclear medicine business Algorithms Rare cancers Radboud Institute for Health Sciences [Radboudumc 9] |
| Zdroj: | Physics in Medicine and Biology, 64(9). IOP PUBLISHING LTD Physics in Medicine and Biology, 64 Physics in medicine and biology, 64(9). IOP Publishing Ltd. Physics in Medicine and Biology, 64(9):095001. IOP Publishing Ltd. Physics in Medicine and Biology, 64, 9 |
| ISSN: | 1361-6560 0031-9155 |
| Popis: | Setup and range uncertainties compromise radiotherapy plan robustness. We introduce a method to evaluate the clinical effect of these uncertainties on the population using tumor control probability (TCP) and normal tissue complication probability (NTCP) models. Eighteen oropharyngeal cancer patients treated with curative intent were retrospectively included. Both photon (VMAT) and proton (IMPT) plans were created using a planning target volume as planning objective. Plans were recalculated for uncertainty scenarios: two for range over/undershoot (IMPT) or CT-density scaling (VMAT), six for shifts. An average shift scenario ([Formula: see text]) was calculated to assess random errors. Dose differences between nominal and scenarios were translated to TCP (2 models) and NTCP (15 models). A weighted average (W_Avg) of the TCP\NTCP based on Gaussian distribution over the variance scenarios was calculated to assess the clinical effect of systematic errors on the population. TCP/NTCP uncertainties were larger in IMPT compared to VMAT. Although individual perturbations showed risks of plan deterioration, the [Formula: see text] scenario did not show a substantial decrease in any of the TCP endpoints suggesting evaluated plans in this cohort were robust for random errors. Evaluation of the W_Avg scenario to assess systematic errors showed in VMAT no substantial decrease in TCP endpoints and in IMPT a limited decrease. In IMPT, the W_Avg scenario had a mean TCP loss of 0%-2% depending on plan type and primary or nodal control. The W_Avg for NTCP endpoints was around 0%, except for mandible necrosis in IMPT (W_Avg: 3%). The estimated population impact of setup and range uncertainties on TCP/NTCP following VMAT or IMPT of oropharyngeal cancer patients was small for both treatment modalities. The use of TCP/NTCP models allows for clinical interpretation of the population effect and could be considered for incorporation in robust evaluation methods. Highlights: - TCP/NTCP models allow for a clinical evaluation of uncertainty scenarios. - For this cohort, in silico-PTV based IMPT plans and VMAT plans were robust for random setup errors. - Effect of systematic errors on the population was limited: mean TCP loss was 0%-2%. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|