Assessing the uncertainty in a normal tissue complication probability difference (∆NTCP): radiation-induced liver disease (RILD) in liver tumour patients treated with proton vs X-ray therapy. (12th March 2018)

• Record Type: Journal Article
• Authors: Kobashi, Keiji; Prayongrat, Anussara; Kimoto, Takuya; Toramatsu, Chie; Dekura, Yasuhiro; Katoh, Norio; Shimizu, Shinichi; Ito, Yoichi M; Shirato, Hiroki
• Is Part Of: Journal of radiation research. Volume 59(2018)Supplement 1
• Page Start: i50
• Page End: i57
• Publication Date: 2018-03-12
• Subjects: normal tissue complication probability -- uncertainty -- proton therapy -- radiation-induced liver disease -- liver tumour; Radiology, Medical -- Periodicals; Radiobiology -- Periodicals; Radiation -- Periodicals; 616.0757
• DOI: 10.1093/jrr/rry018
• Languages: English
• ISSNs: 0449-3060

Abstract

Abstract: Modern radiotherapy technologies such as proton beam therapy (PBT) permit dose escalation to the tumour and minimize unnecessary doses to normal tissues. To achieve appropriate patient selection for PBT, a normal tissue complication probability (NTCP) model can be applied to estimate the risk of treatment-related toxicity relative to X-ray therapy (XRT). A methodology for estimating the difference in NTCP (∆NTCP), including its uncertainty as a function of dose to normal tissue, is described in this study using the Delta method, a statistical method for evaluating the variance of functions, considering the variance–covariance matrix. We used a virtual individual patient dataset of radiation-induced liver disease (RILD) in liver tumour patients who were treated with XRT as a study model. As an alternative option for individual patient data, dose-bin data, which consists of the number of patients who developed toxicity in each dose level/bin and the total number of patients in that dose level/bin, are useful for multi-institutional data sharing. It provides comparable accuracy with individual patient data when using the Delta method. With reliable NTCP models, the ∆NTCP with uncertainty might potentially guide the use of PBT; however, clinical validation and a cost-effectiveness study are needed to determine the appropriate ∆NTCP threshold.