Integration of 68Ga-PSMA-PET/CT in Radiotherapy Planning for Prostate Cancer Patients. (September 2019)

• Record Type: Journal Article
• Authors: Onal, Cem; Torun, Nese; Akyol, Fadil; Guler, Ozan Cem; Hurmuz, Pervin; Yildirim, Berna Akkus; Cağlar, Meltem; Reyhan, Mehmet; Ozyigit, Gokhan
• Is Part Of: Clinical nuclear medicine. Volume 44:Number 9(2019)
• Publication Date: 2019-09
• Subjects: prostate cancer -- 68Ga-PSMA-PET/CT -- radiotherapy -- staging; Nuclear medicine -- Periodicals; Radioisotope scanning -- Periodicals; Nuclear Medicine -- Periodicals; 616.07575
• DOI: 10.1097/RLU.0000000000002691
• Languages: English
• ISSNs: 0363-9762

Abstract

Purpose: To assess the role of 68 Gallium-labeled-prostate-specific membrane antigen PET/CT ( 68 Ga-PSMA-PET/CT) in risk group definition and radiotherapy planning in the initially planned definitive radiotherapy (RT) for prostate cancer patients. Methods: The clinical data of 191 prostate cancer patients treated with definitive intensity-modulated RT were retrospectively analyzed. All patients were initially staged with thoracoabdominal CT and bone scintigraphy, and the second staging was performed using 68 Ga-PSMA-PET/CT. Both stages were evaluated for the decision making of RT and any change in RT target volumes. Results: After staging with 68 Ga-PSMA-PET/CT, 26 patients (13.6%) had risk group changes, 16 patients (8.4%) had an increase in risk group, and 10 patients (5.2%) had a decrease in risk group. Down-staging occurred in 22 patients (11.5%), and upstaging was observed in 30 patients (15.7%). A total of 26 patients (13.6%) had nodal stage changes. After the 68 Ga-PSMA-PET/CT scans, the number of metastatic patient increased to 17 (8.9%), with 4 of them moving from oligo- to polymetastatic disease. An additional irradiation of pelvic lymphatics and metastatic site was performed in 13 patients (6.8%) and 6 patients (3.2%), respectively. The RT was aborted in 4 patients (2.1%) because of parenchymal or distant site metastasis observed in the 68 Ga-PSMA-PET/CT. Conclusions: We found that 68 Ga-PSMA-PET/CT causes considerable migration in stage, risk group, and RT field arrangements, especially in high-risk patients regardless of the GS and baseline prostate-specific antigen values alone. 68 Ga-PSMA-PET/CT seems to have a great influence on RT decision making in prostate cancer patients.