Radium-223 dichloride is an alpha-emitting radiopharmaceutical shown to prolong survival in patients with castrate-resistant prostate cancer (CRPC) and symptomatic skeletal metastases. This report describes in two patients the acute changes in bone metastatic activity detected by F-18 choline PET/CT imaging midway during treatment with radium-223 dichloride.
In addition to visual and standardized uptake value analysis, changes in the whole-body tumor burden were quantified by measuring the difference in net metabolically active tumor volume (MATV) and total lesion activity (TLA) between pre- and mid-treatment PET scans. After the third dose of radium-223 dichloride, near-total disappearance of abnormal skeletal activity was observed in one case (net MATV change from 260. 7 to 0. 8 cc; net TLA change from 510. 7 to 2. 1), while a heterogeneous tumor response was observed in the other (net MATV change from 272. 2 to 241. 3 cc; net TLA change from 987. 1 to 779. 4). Corresponding normalization and persistent elevation in serum alkaline phosphatase levels were observed in these cases, respectively. Further research is needed to determine the predictive value of serial F-18 choline PET/CT imaging in patients receiving radium-223 dichloride for CRPC.
Nuclear medicine and molecular imaging. 2015 Jan 09 [Epub]
Kyle S Miyazaki, Yu Kuang, Sandi A Kwee
Oncology Research Department and Hamamatsu/Queen's PET Imaging Center, The Queen's Medical Center, 1301 Punchbowl St. , Honolulu, HI 96813 USA. , Department of Medical Physics, School of Allied Health Sciences, University of Nevada Las Vegas, Las Vegas, NV USA. , Oncology Research Department and Hamamatsu/Queen's PET Imaging Center, The Queen's Medical Center, 1301 Punchbowl St. , Honolulu, HI 96813 USA ; University of Hawaii John A. Burns School of Medicine, Honolulu, HI USA.