PET/CT Plus MRI May Aid Salvage Radiotherapy for Nodal Recurrent PCa
This approach is feasible and is associated with low acute and late toxicity
Patients with nodal recurrent prostate cancer after radical prostatectomy may benefit from extended salvage radiotherapy directed by positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI), a study found.
The study included 25 prostate cancer (PCa) patients who after primary radical prostatectomy (RP) or previous prostate fossa salvage radiotherapy (RT) experienced nodal or nodal plus locally recurrent prostate cancer confirmed by choline-PET/CT and MRI. Following extended salvage radiotherapy (esRT) at the sites of recurrence, the cohort had a mean follow-up of 2.9 years.
Of the 25 patients, 21 (84%) had cancer recurrence only in pelvic lymph nodes, 3 had recurrence in retroperitoneal lymph nodes only, and 1 had recurrence in both pelvic and retroperitoneal lymph nodes. Researchers led by Hans Christian Rischke, MD, of Albert-Ludwigs University Hospital of Freiburg in Germany, and colleagues found that esRT resulted in complete biochemical remission in 7 patients (28%) at the latest follow-up, according to a report in Advances in Medical Sciences (2016;61:212-218). The median time to PSA progression for the entire cohort was 19.6 months, but it was significantly longer for patients with 1–2 PET-positive lymph nodes than for those with 3 or more PET-positive lymph nodes (median 34.9 vs. 12.7 months).
Patients experienced mild to moderate acute and late toxicity and no grade 3 adverse events, according to the investigators.
The authors concluded that PET/CT- and MRI-directed esRT of nodal recurrent PCa with or without local recurrence after RP is feasible and may have the potential to prolong PSA progression in patients with 1–2 PET-positive lymph nodes with a low acute and late toxicity.
Dr. Rischke's team noted that an “essential prerequisite for successful esRT and other local salvage approaches in local recurrent or oligometastatic PCa is accurate imaging.” With respect to biochemical recurrence, choline-PET/CT has a pooled sensitivity and specificity of greater than 85% for detecting tumor lesions on a per-patient basis, the researchers stated.