RT Journal Article SR Electronic T1 Implementation of 99mTc-GSA SPECT Image-guided Inverse Planning into Palliative Radiotherapy for Diffuse Liver Metastases: A Novel Approach JF In Vivo JO In Vivo FD International Institute of Anticancer Research SP 1523 OP 1526 DO 10.21873/invivo.12862 VO 36 IS 3 A1 RYO TOYA A1 TAKAHIRO WATAKABE A1 YUDAI KAI A1 TOMOHIKO MATSUYAMA A1 YOSHIYUKI FUKUGAWA A1 TADASHI MATSUMOTO A1 SHINYA SHIRAISHI A1 YOSHINOBU SHIMOHIGASHI A1 SHO SAEKI A1 TAKURO SAKAGAMI A1 TOSHINORI HIRAI A1 NATSUO OYA YR 2022 UL http://iv.iiarjournals.org/content/36/3/1523.abstract AB Background/Aim: This is a report of the first clinical implementation of 99mTc-labeled diethylene triamine pentaacetate-galactosyl human serum albumin (99mTc-GSA) single-photon emission computed tomography (SPECT) image-guided inverse planning into palliative radiotherapy (RT) for diffuse liver metastases. Case Report: A 48-year-old man developed chemo-refractory diffuse liver metastases from thymic carcinoma characterized by abdominal pain and distension. Palliative RT was performed with a total dose of 20 Gy in five fractions using double arc volumetric modulated arc therapy to reduce the dose to functional liver defined by 99mTc-GSA SPECT images. His symptoms were immediately relieved after RT and did not experience radiation-induced liver disease. Both Functional Assessment of Cancer Therapy (FACT)-G and FACT-Hep total scores improved after 2 weeks of RT initiation and did not become worse than baseline scores. Conclusion: The 99mTc-GSA SPECT image-guided palliative RT is an effective and safe treatment for patients with diffuse liver metastases.