Positron Emission Tomography/Computed Tomography is a valuable tool to detect lymph node (LN) metastases in patients with biochemical failure after primary treatment for prostate cancer (PCa). The aim was to assess the predictive role of imaging parameters derived by (11)C-choline PET/CT (choline-PET/CT) on survival outcomes: overall survival (OS), loco regional- (lRFS), clinical- (cRFS) and biochemical relapse free survival (bRFS) in patients treated with helical tomotherapy (HTT) for LN recurrence.
This retrospective study included 68 patients affected by PCa (mean age: 68 years; range: 51-81 years) with biochemical recurrence after primary treatment (median PSA0: 2. 42 ng/ml; range: 0. 61-27. 56 ng/ml) who underwent choline-PET/CT from January 2005 to January 2013 and then treated with HTT in correspondence of the pathological choline LN uptake. PET derived parameters, including maximum/mean standardized uptake value (SUVmax/mean) and metabolic tumor volume (MTV) with a threshold of 40-50-60% were calculated. The best cut-off values of PET derived parameters discriminating between patients with/without relapse, after treatment guided by PET, were assessed by ROC analysis. Univariate and multivariate Cox-regression analysis including the most predictive PET derived parameters and survival outcomes were performed.
The median follow-up was 20 months (mean: 26 months; range: 3-97 months). Choline-PET/CT showed pathologic LN uptake in 4 patients at pelvic level, in 5 at abdominal level, in 13 at both pelvic and abdominal level, in 46 at abdominal and/or pelvic and/or other sites. The 2-year OS, lRFS, cRFS, bRFS were 87%, 91%, 51% and 40%, respectively. Based on ROC curves, the most discriminative cut-off value for MTV values was MTV60> 0. 64cc. No significant cut-off values were found for SUVmax/mean at univariate analysis, while MTV60 confirming its independent predictive role in multivariate analysis and its significantly correlation with bRFS and cRFS. MTV60 and extra-pelvic disease well predicts the risk of cRFS.
Choline-PET/CT performed as guide for HTT treatment on LN recurrence is predictive of survival. In particular, MTV60 and extra-pelvic disease resulted to be the best predictor of tumor response for bRFS and cRFS in PCa patients with LN recurrent after primary treatment. This information may be useful in emerging treatment strategies.
Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2015 Sep 24 [Epub ahead of print]
Elena Incerti, Andrei Fodor, Paola Mapelli, Claudio Fiorino, Pierpaolo Alongi, Margarita Kirienko, Giampiero Giovacchini, Elena Busnardo, Luigi Gianolli, Nadia Di Muzio, Maria Picchio
Department of Nuclear Medicine, IRCCS San Raffaele Scientific Institute, Italy;, Department of Radiotherapy, IRCCS San Raffaele Scientific Institute, Italy;, Department of Nuclear Medicine, IRCCS San Raffaele Scientific Institute, Italy;, Department of Medical Physics, IRCCS San Raffaele Scientific Institute, Italy;, Department of Nuclear Medicine, IRCCS San Raffaele Scientific Institute, Italy;, University of Milano-Bicocca, Italy;, Department of Radiology and Nuclear Medicine, Stadtspital Triemli, Switzerland. , Department of Nuclear Medicine, IRCCS San Raffaele Scientific Institute, Italy;, Department of Nuclear Medicine, IRCCS San Raffaele Scientific Institute, Italy;, Department of Radiotherapy, IRCCS San Raffaele Scientific Institute, Italy;, Department of Nuclear Medicine, IRCCS San Raffaele Scientific Institute, Italy;