RESUMEN
Background: Accurate identification of men who harbor nodal metastases is necessary to select patients who most likely benefit from whole pelvis radiotherapy (WPRT). Limited sensitivity of diagnostic imaging approaches for the detection of nodal micrometastases has led to the exploration of the sentinel lymph node biopsy (SLNB). Objective: To evaluate whether SLNB can be used as a tool to select pathologically node-positive patients who likely benefit from WPRT. Design setting and participants: We included 528 clinically node-negative primary prostate cancer (PCa) patients with an estimated nodal risk of >5% treated between 2007 and 2018. Intervention: A total of 267 patients were directly treated with prostate-only radiotherapy (PORT; non-SLNB group), while 261 patients underwent SLNB to remove lymph nodes directly draining from the primary tumor prior to radiotherapy (SLNB group); pN0 patients were treated with PORT, while pN1 patients were offered WPRT. Outcome measurements and statistical analysis: Biochemical recurrence-free survival (BCRFS) and radiological recurrence-free survival (RRFS) were compared using propensity score weighted (PSW) Cox proportional hazard models. Results and limitations: The median follow-up was 71 mo. Occult nodal metastases were found in 97 (37%) SLNB patients (median metastasis size: 2 mm). Adjusted 7-yr BCRFS rates were 81% (95% confidence interval [CI] 77-86%) in the SLNB group and 49% (95% CI 43-56%) in the non-SLNB group. The corresponding adjusted 7-yr RRFS rates were 83% (95% CI 78-87%) and 52% (95% CI 46-59%), respectively. In the PSW multivariable Cox regression analysis, SLNB was associated with improved BCRFS (hazard ratio [HR] 0.38, 95% CI 0.25-0.59, p < 0.001) and RRFS (HR 0.44, 95% CI 0.28-0.69, p < 0.001). Limitations include the bias inherent to the study's retrospective nature. Conclusions: SLNB-based selection of pN1 PCa patients for WPRT was associated with significantly improved BCRFS and RRFS compared with (conventional) imaging-based PORT. Patient summary: Sentinel node biopsy can be used to select patients who will benefit from the addition of pelvis radiotherapy. This strategy results in a longer duration of prostate-specific antigen control and a lower risk of radiological recurrence.
RESUMEN
Background: Considering that most men benefit diagnostically from increased sampling of index lesions, limiting systematic biopsy (SBx) to the region around the index lesion could potentially minimize overdetection while maintaining the detection of clinically significant prostate cancer (csPCa). Objective: To evaluate the diagnostic performance of a hypothetical magnetic resonance imaging (MRI)-directed targeted-plus-perilesional biopsy approach. Design setting and participants: This single-center, retrospective analysis of prospectively generated data included all biopsy-naïve men with unilateral MRI-positive lesions (Prostate Imaging Reporting and Data System category ≥3), undergoing both MRI-directed targeted biopsies and SBx. Grade group 2-5 cancers were considered csPCa. Outcome measurements and statistical analysis: The diagnostic performance of a targeted-plus-perilesional biopsy approach was compared with that of a targeted-plus-systematic biopsy approach. The primary outcome was the detection of csPCa. Secondary outcomes included the detection of clinically insignificant prostate cancer (ciPCa) and the number of total biopsy cores. Results and limitations: A total of 235 men were included in the analysis; csPCa and ciPCa were detected, respectively, in 95 (40.4%) and 86 (36.6%) of these 235 men. A targeted-plus-perilesional biopsy approach would have detected 92/95 (96.8%; 95% confidence interval [CI] 91.0-99.3%) csPCa cases. At the same time, detection of systematically found ciPCa would be reduced by 11/86 (12.8%; 95% CI 6.6-21.7%). If a targeted-plus-perilesional biopsy approach would have been performed, the number of biopsy cores per patient would have been reduced significantly (a mean difference of 5.2; 95% CI 4.9-5.6, p < 0.001). Conclusions: An MRI-directed targeted-plus-perilesional biopsy approach detected almost all csPCa cases, while limiting overdiagnosis and reducing the number of biopsy cores. Prospective clinical trials are needed to substantiate the withholding of nonperilesional SBx in men with unilateral lesion(s) on MRI. Patient summary: Limiting systematic biopsies to the proximity of the suspicious area on magnetic resonance imaging helps detect an equivalent number of aggressive cancers and fewer indolent cancers. These findings may help patients and physicians choose the best biopsy approach.