TY - JOUR T1 - Determination of Deformable Image Registration Algorithms for Accumulating Dose in Carbon-ion Radiotherapy for Pancreatic Cancer JF - Anticancer Research JO - Anticancer Res SP - 835 LP - 843 DO - 10.21873/anticanres.14836 VL - 41 IS - 2 AU - YANG LI AU - YOSHIKI KUBOTA AU - MASAHIKO OKAMOTO AU - SHINTARO SHIBA AU - SHOHEI OKAZAKI AU - TOSHIAKI MATSUI AU - SHUNICHIRO KOMATSU AU - TATSUYA OHNO Y1 - 2021/02/01 UR - http://ar.iiarjournals.org/content/41/2/835.abstract N2 - Background/Aim: This study aimed to determine appropriate deformable image registration (DIR) algorithms for pancreatic cancer patients undergoing carbon ion radiotherapy (CIRT). Patients and Methods: The performance of three types of DIR algorithms, including intensity-based DIR (iDIR), contour-based DIR (cDIR), and hybrid DIR (hDIR) were evaluated using seventy-one CT images from eight pancreatic cancer patients. Both the geometry of the CTV and subsequent dose warping discrepancies were evaluated using the dice similarity coefficient (DSC) and the difference in V95. Results: cDIR and hDIR had superior performance than iDIR in both DSC and V95 (p<0.0001). iDIR caused accumulated dose to be underestimated by 5% in the median CTV V95 compared to the other methods. Conclusion: hDIR and cDIR can be utilized to assess the accumulated dose in CIRT for pancreatic cancer. iDIR can be considered when the obtained DSC is greater than 0.89. ER -