INTRODUCTION: The 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 METHODS: Eighty-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.
RESULTS: Fourteen 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.
CONCLUSION: 3D 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.
Written by:
Lépinoy A, Cochet A, Cueff A, Cormier L, Martin E, Maingon P, Bosset JF, Brunotte F, Créhange G. Are you the author?
Lab of Imaging Engineering (Le2I), IMAC Core, CNRS-UMR 6306, University of Burgundy, Dijon, France; Department of Radiation Oncology, University Hospital Jean Minjoz, Besançon, France; Department of Biostatistics, Georges François Leclerc Cancer Center, Dijon, France; Department of Urology, University Hospital Le Bocage, Dijon, France; Department of Radiation Oncology, Georges François Leclerc Cancer Center, Dijon, France; Department of Radiation Oncology, University Hospital Jean Minjoz, Besançon, France.
Reference: Radiother Oncol. 2014 Apr 26. pii: S0167-8140(14)00130-3.
doi: 10.1016/j.radonc.2014.03.008
PubMed Abstract
PMID: 24780635
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