Focal Salvage Guided by T2-Weighted and Dynamic Contrast-Enhanced Magnetic Resonance Imaging for Prostate Cancer Recurrences
Presented, in part, in abstract form as a poster presentation at the 27th meeting of the European Society for Therapeutic Radiology and Oncology, September 14–18, 2008, Göteborg, Sweden.
Received 2 October 2008; received in revised form 27 January 2009; accepted 14 February 2009. published online 05 October 2009.
Purpose
Salvage treatment of the entire prostate for local recurrent cancer after primary radiotherapy is associated with high toxicity rates. Our goal was to show that, using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for the visualization of a recurrence, focal salvage treatment can be performed, with, potentially, a reduction in toxicity.
Methods and Materials
We performed MRI, including a DCE sequence, in 7 patients with biopsy-proven locally recurrent prostate cancer. The specific regions of interest suspect for containing tumor were delineated using DCE and T2-weighted MRI scans. Subsequently, focal salvage high-dose-rate brachytherapy plans were created to illustrate the principle of focal salvage. Total salvage treatment plans were also created for comparison.
Results
The transfer constant (Ktrans) values from the DCE were 0.33–0.67 min−1 for areas suspect for tumor and 0.07–0.25 min−1 for normal tissue. In 4 cases, a focal salvage plan could be generated; 93–100% of the gross tumor volume was covered with the prescribed dose, with relative sparing of the bladder, rectum, and urethra. In the total salvage plans, 24–53% of the gross tumor volume was covered, and the organs at risk received high doses. In 3 cases, a focal salvage plan could not be created because of multifocal tumor, seminal vesicle extension, or capsular extension.
Conclusion
Focal salvage treatment plans can be created in patients with local recurrent prostate cancer after radiotherapy. DCE-MRI supports the localization of the target area. This could lead to less toxicity in patients with local recurrent prostate cancer.
∗Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, The Netherlands
†Department of Urology, University Medical Center Utrecht, Utrecht, The Netherlands
Reprint requests to: Maaike R. Moman, M.D., Department of Radiation Oncology, 000.118, University Medical Center Utrecht, Heidelberglaan 100, Utrecht 3584 CX The Netherlands. Tel: (+31) 88-755-7208; Fax: (+31) 88-755-5850
Supported by a grant from the Dutch Cancer Society.
ABSTRACT