Open Access Research

Detection of local recurrent prostate cancer after radical prostatectomy in terms of salvage radiotherapy using dynamic contrast enhanced-MRI without endorectal coil

Hans Christian Rischke1*, Arnd O Schäfer2, Ursula Nestle1, Natalja Volegova-Neher1, Karl Henne1, Matthias R Benz3, Wolfgang Schultze-Seemann4, Mathias Langer2 and Anca L Grosu1

Author Affiliations

1 Department of Radiation Oncology, University of Freiburg, Robert Koch Str. 3, Freiburg, 79106, Germany

2 Department of Diagnostic Radiology, University of Freiburg, Freiburg, Germany

3 Department of Molecular and Medical Pharmacology, University of California in Los Angeles, Los Angeles, USA

4 Department of Urology, University of Freiburg, Freiburg, Germany

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Radiation Oncology 2012, 7:185  doi:10.1186/1748-717X-7-185

Published: 31 October 2012

Abstract

Purpose

To evaluate the value of dynamic contrast enhanced Magnetic Resonance Imaging (DCE-MRI) without endorectal coil (EC) in the detection of local recurrent prostate cancer (PC) after radical prostatectomy (RP).

Material and methods

Thirty-three patients with recurrent PC underwent DCE-MRI without EC before salvage radiotherapy (RT). At median 15 (mean 16±4.9, range 12–27) months after completion of RT all patients showed complete biochemical response. Additional follow up post RT DCE-MRI scans were available. Prostate specific antigen (PSA) levels at the time of imaging were correlated to the imaging findings.

Results

In 22/33 patients (67%) early contrast enhancing nodules were detected in the post-prostatectomy fossa on pre-RT DCE-MRI images. The average pre-RT PSA level of the 22 patients with positive pre-RT DCE-MRI findings was significantly higher (mean, 0.74±0.64 ng/mL) compared to the pre-RT PSA level of the 11 patients with negative pre-RT DCE-MRI (mean, 0.24±0.13 ng/mL) (p<0.001). All post-RT DCE-MRI images showed complete resolution of initial suspicious lesions. A pre-RT PSA cut-off value of ≥0.54 ng/ml readily predicted a positive DCE-MRI finding.

Conclusions

This is the first study that shows that DCE-MRI without EC can detect local recurrent PC with an estimated accuracy of 83% at low PSA levels. All false negative DCE-MRI scans were detected using a PSA cut-off of ≥0.54 ng/mL.

Keywords:
Prostate cancer; PSA recurrence; Salvage radiotherapy; Dynamic contrast enhanced MRI; Gross tumor volume