BERKELEY, CA (UroToday.com) - External beam radiotherapy (EBRT) for prostate cancer (PCa) is a treatment of choice for patients with early-stage cancer and a long life expectancy. Serum prostate-specific antigen (PSA) levels, patient history, and digital rectal examinations (DREs) are commonly used to determine the effectiveness of treatment during the follow-up in PCa patients treated with EBRT. However, because the prostate tissue remains in place during and after EBRT, a rising PSA > 2.0 ng/mL above the nadir value (biochemical relapse) is the most reliable sign of recurrent/persistent disease after radiotherapy; nevertheless, no pattern of PSA kinetics has been demonstrated to be able to differentiate between local and distant failure of EBRT.
Currently, 3D magnetic resonance imaging (MRI) and 3D magnetic resonance spectroscopic imaging (MRSI) are able to demonstrate the presence of PCa and to depict its recurrence; in particular, MRSI has been claimed to be superior to position emission tomography CT (PET-CT) with 18F-choline in the evaluation of both PCa and recurrence. The present study is set in this scenario.
3D-MRSI with a 3T scan were correlated with PSA levels in patients treated with EBRT for localized low- to intermediate-risk PCa, in order to assess the real advantages of MRSI in the follow-up of patients with PCa. Two radiologists independently evaluated 3D-MRSI data set with a quantitative approach (CC/C ratio in the tumour voxels) and totally aware of the clinical data (PSA level).
The results were quite interesting. In particular, MRSI was able to depict recurrence as early as biochemical relapse. MRSI shows a greater potential than PSA in monitoring patients after radiotherapy because it anticipates PSA nadir, and especially BR. These data represent an important critical clinical point because it could be a possible way to identify, as early as possible, those patients eligible for hormone deprivation therapy as salvage therapy. Flip the coin, the MRSI pattern could be used as a biomarker in the evaluation of PCa patients.
Written by:
Chiara Zini,* Nicola Raffetto,* and Alessandro Sciarra** as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
* Dept of Radiological Sciences, Oncology and Pathology, Sapienza, University of Rome
** Dept of Urological Sciences, Sapienza, University of Rome
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