Abstract

IntroductionThe purpose of this study was to describe the pattern of nodal relapse with 18F-fluoro-choline (FCH) Positron Emission Tomography/Computerized Tomography (PET/CT) in prostate cancer patients after radiotherapy. Materials and methodsEighty-three patients had a FCH PET/CT at time of biochemical failure. Of 65 patients with positive findings, 33 had positive nodes. This analysis included 31 patients who had undergone prior prostate-only radiotherapy with or without a prior radical prostatectomy. Each FCH positive node was assigned to a lymph node station with respect to the CTV defined by the RTOG guidelines (CTVRTOG). 3D mapping was performed after each node was manually placed in a reference planning CT scan after automatic co-registration of the two scans based on bone anatomy. Eighteen patients (58%) underwent focal salvage FCH PET-guided stereotactic radiotherapy with no hormones. ResultsFourteen patients (45.2%) had a relapse outside the CTVRTOG. Of the 17 patients with a positive node inside the CTVRTOG, 15 had a single node (88.2%) while seven patients out of the 13 evaluable patients (53.9%) who had a relapse outside the CTVRTOG had ⩾2 positive nodes on FCH PET/CT (OR=8.75, [95% CI: 1.38–54.80], p=0.020). Relapses that occurred outside the CTVRTOG involved the proximal common iliac (19.3%) and lower periaortic nodes (19.3%) up to L2–L3. Conclusion3D mapping of nodal relapses evaluated with FCH PET/CT suggests that with IMRT the upper field limit of pelvic radiotherapy could be extended to L2–L3 safely to cover 95% of nodal stations at risk of an occult relapse.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.