Imaging of prostate cancer local recurrences: why and how?

Abstract

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 CommentThe 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 stud-

A CT-based radiomics model to detect prostate cancer lymph node metastases in PSMA radioguided surgery patients

“…Besides the prostatic bed, pelvic lymph nodes (LNs) present a common site of recurrent disease that might alter clinical management. Using conventional imaging, it remains challenging to detect the exact site of recurrence to optimally guide personalized therapy [3]. Computed tomography (CT) is widely used for LN recurrence detection.…”

Accuracy of 68Ga-PSMA PET-CT and PET-MRI in lymph node staging for localized prostate cancer

“…Using conventional imaging tests, it is still a challenge to detect the exact site of recurrence and optimally guide personalized treatment. (2,3) In men treated with radical prostatectomy for localized prostate cancer, the presence of lymph node metastases is a strong adverse prognostic factor associated with higher recurrence rates and shorter long-term survival. (4) Accurate nodal staging (N staging) is therefore key for planning treatment einstein (São Paulo).…”