Biopsy findings and magnetic resonance imaging (MRI) can be used to select index lesions amenable to salvage partial gland ablation (sPGA) in men with recurrent prostate cancer after radiation therapy, according to a new study.
The results can guide patient evaluation for inclusion in clinical trials, Gregory T. Chesnut, MD, of Memorial Sloan Kettering Cancer Center in New York, New York, and colleagues concluded in a paper published online in Urologic Oncology.
Of 77 men who underwent salvage radical prostatectomy (sRP) following whole-gland radiation therapy who had biopsy data, tumor maps, and MRI scans available, 15 (19%) were considered eligible for sPGA based on biopsy-proven unilateral disease in contiguous biopsy sextant segments, a dominant lesion on MRI that was concordant with biopsy location or no focal region of interest, and no imaging evidence of extraprostatic disease. The median tumor volume of the index lesion was 0.4 cc. Analysis of detailed tumor maps created from whole-mount slides of sRP specimens from the 15 patients demonstrated a single-focus cancer in 12 patients (80%).
Recurrent tumor involved the apex, mid-gland, and base in 80%, 100%, and 20% of patients, respectively, the investigators noted.
A review of tumor maps identified 6 additional men who would have met criteria for sPGA, bringing to 21 (27%) the number of patients who would be eligible for sPGA and resulting in a sensitivity of 71% and specificity of 100%, Dr Chesnut’s team reported.
None of the 15 men who met the criteria for sPGA based on clinical data were incorrectly identified on tumor maps as requiring full gland surgery, according to the investigators.
“Our analysis of our whole-mount sRP specimens shows that 27% of men [with radiorecurrent prostate cancer] may be eligible for sPGA, and that clinical and radiographic criteria can identify men who may benefit from the improved outcomes in terms of morbidity and function afforded by sPGA,” the authors wrote.
Chesnut GT, Tin AL, Sivaraman A, et al. Defining the index lesion for potential salvage partial or hemi-gland ablation after radiation therapy for localized prostate cancer. Published online February 11, 2021. Urol Oncol. doi:10.1016/j.urolonc.2021.01.011