@article {KOBAYASHI489, author = {KAZUMA KOBAYASHI and NAOYA MURAKAMI and KANA TAKAHASHI and KOJI INABA and HIROSHI IGAKI and RYUJI HAMAMOTO and JUN ITAMI}, title = {Tensor Regression-based Model to Investigate Heterogeneous Spatial Radiosensitivity After I-125 Seed Implantation for Prostate Cancer}, volume = {35}, number = {1}, pages = {489--497}, year = {2021}, doi = {10.21873/invivo.12283}, publisher = {International Institute of Anticancer Research}, abstract = {Background/Aim: We established a data-driven method for extracting spatial patterns of dose distribution associated with radiation injuries, based on patients with prostate cancer who underwent iodine-125 (I-125) seed implantation. Patients and Methods: Seventy-five patients underwent I-125 seed implantation for prostate cancer. We modeled the severity of lower urinary tract symptoms (LUTS) to be estimated using a linear model, which is formulated as an inner product between the dose distribution D and voxel-wise radiosensitivity B inside the prostate. For the estimation, tensor regression based on a low-rank decomposition with generalized fused lasso penalty was applied. Results: The spatial distribution of B was visually assessed. Positive parameters appeared dominantly in the region close to the urethra and the prostate base. Conclusion: Our tensor regression-based model can predict intra-organ radiosensitivity in a data-driven manner, providing a compelling parameter distribution associated with the development of LUTS after I-125 seed implantation for prostate cancer.}, issn = {0258-851X}, URL = {https://iv.iiarjournals.org/content/35/1/489}, eprint = {https://iv.iiarjournals.org/content/35/1/489.full.pdf}, journal = {In Vivo} }