IMAGING

doi: 10.1590/S1677-553820100003000019

Imaging of prostate cancer local recurrences: why and how?
Rouvière O, Vitry T, Lyonnet D
Université de Lyon, Lyon, France
Eur Radiol. 2010; 20: 1254-66.

• Objective: Because prostate cancer local recurrences can be efficiently treated by salvage therapies, it becomes critical to detect them early.
  Methods: The first alert is the rise of the prostate specific antigen (PSA) level after the post-treatment nadir, which can correspond to a distant recurrence, a local recurrence or both. This so-called biochemical failure (BF) is defined as PSA level > 0.2 ng/ml after radical prostatectomy (RP) and PSA level > nadir + 2 ng/ml after radiotherapy. There is no consensual definition of BF after cryotherapy, high-intensity focused ultrasound (HIFU) ablation or brachytherapy.
  Results: Local recurrences after RP are treated by radiotherapy, those after radiotherapy by RP, cryotherapy, brachytherapy or HIFU ablation. Recurrences after cryotherapy or HIFU ablation can be treated by a second session or radiotherapy. Recurrences after brachytherapy are difficult to treat. In patients with BF, MRI can detect local recurrences, whatever the initial treatment was. Dynamic contrast-enhanced MRI seems particularly accurate. The role of spectroscopy remains controversial. Ultrasound-based techniques are less accurate, but this may change with the advent of ultrasonic contrast media.
  Conclusion: These recent advances in imaging may improve the outcome of salvage therapies (by improving patient selection and treatment targeting) and should open the way to focal salvage treatments in the near future.

• Editorial Comment
  The authors should be congratulated for reviewing this important issue on uro-oncology. Important aspects of local recurrence after radical prostatectomy (RP), external-beam radiotherapy (EBRT), HIFU ablation, cryotherapy and brachytherapy are presented and discussed. For each modality of local treatment of prostate cancer, the authors define biochemical failure and discuss treatment options and the role of imaging techniques for the detection of tumor recurrence.
  In our experience, dynamic-contrast enhanced MRI is the best modality for the detection of local recurrence after RP. For local recurrence after EBRT our better results are obtained with spectroscopy although dynamic-contrast enhanced MRI can also be useful in most cases. We also prefer to use spectroscopy for the detection of local tumor recurrence after brachytherapy. The quality of dynamic-contrast enhanced MRI studies in post-brachytherapy glands may be impaired due to the presence of several false-positive results. In our institution we have no experience with MRI for the detection of local tumor recurrence after HIFU ablation or cryotherapy.

Dr. Adilson Prando
Head, Department of Radiology and
Diagnostic Imaging, Vera Cruz Hospital
Campinas, São Paulo, Brazil
E-mail: adilson.prando@gmail.com