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

Hanschristian Rischke,Wolfgang Schultze-Seemann,Ursula Nestle,Arnd O Schäfer,Anca L Grosu,Matthias R Benz,Mathias Langer,Natalja Volegova-Neher,Karl Henne

doi:10.1186/1748-717x-7-185

Abstract

PurposeTo 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 methodsThirty-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.ResultsIn 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.ConclusionsThis 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.

Highlights

In 22/33 patients (67%) early contrast enhancing nodules were detected in the post-prostatectomy fossa on pre-RT dynamic contrast enhanced Magnetic Resonance Imaging (DCE-Magnetic Resonance Imaging (MRI)) images
A pre-RT prostate specific antigen (PSA) cut-off value of ≥0.54 ng/ml readily predicted a positive dynamic contrast enhanced (DCE)-MRI finding. This is the first study that shows that DCE-MRI without endorectal coil (EC) can detect local recurrent prostate cancer (PC) with an estimated accuracy of 83% at low PSA levels
Salvage radiotherapy (RT) of the prostate fossa is considered the standard therapeutic intervention that offers a potential of cure for patients with post-radical prostatectomy (RP) local recurrence [1]

Summary

Introduction

Salvage radiotherapy (RT) of the prostate fossa is considered the standard therapeutic intervention that offers a potential of cure for patients with post-radical prostatectomy (RP) local recurrence [1]. Serum prostate specific antigen (PSA) kinetic is the most accurate and early index for detecting prostate cancer (PC) recurrence after RP [2,3]. Dependent on initial tumor stage, PSA level, Gleason-score and resection status, 10 to 53% of patients develop a biochemical relapse following RP [4]. Local PC recurrence can most accurately be detected on Magnetic Resonance Imaging (MRI) [5,6]. The sensitivity and specificity of this imaging test was further improved by the introduction of dynamic contrast enhanced (DCE)-MRI with endorectal coil (EC) [7,8]. DCE-MRI visualizes tumor neo-vascularisation, which is typically found in PC, showing rapid enhancement in the first 90 seconds after intravenous administration of gadolinium contrast agent [9,10,11]

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Discussion

Conclusion