Initial Postoperative Prostate Specific Antigen and PSA Velocity Are Important Indicators of Underlying Malignancy After Simple Prostatectomy.

Background: There is a paucity of guidelines for prostate-specific antigen (PSA) monitoring after simple prostatectomy (SP) despite these patients remaining at risk for prostate cancer (PCa). Our objective was to determine if PSA kinetics can be a potential indicator of PCa after SP. Methods: A retrospective review was performed of all simple prostatectomies at our institution from 2014 to 2022. All patients who met criteria were included in the study. Relevant clinical variables were collected preoperatively, including PSA value, prostate size, and voiding symptoms. Surgical and urinary function outcomes were analyzed. Results: A total of 92 patients were divided into two groups based on malignancy status. Sixty-eight patients did not have PCa, while 24 patients had known PCa before surgery (14) or were diagnosed as having incidental PCa from the pathological specimen (10). Patients with benign prostates had an initial postoperative PSA value of 0.76 ng/mL compared with 1.68 ng/mL for those with cancer (p < 0.01). PSA velocity for the first 24 months after surgery was 0.042 ± 1.61 ng/(mL·year) for the benign cohort compared with 1.29 ± 1.02 ng/(mL·year) for the malignant cohort (p = 0.01). Voiding improvements were noted by objective (postvoid residual and flow rate) and subjective (American Urological Association symptom score and quality of life score) measures in both groups. Conclusions: PSA interpretation and monitoring after SP have not been well established. Our study indicates that initial postoperative PSA value and PSA velocity are important indicators of underlying malignancy in patients after SP. Further efforts are needed to establish threshold values and formal guidelines.

Urethral Stricture Formation After Artificial Urinary Sphincter Cuff Erosion Is Uncommon in the Absence of Pelvic Radiation.

PURPOSE: Reported rates of urethral stricture development after artificial urinary sphincter erosion are highly variable. We hypothesized that the risk of stricture is commensurate with the degree of erosion. MATERIALS AND METHODS: We reviewed our prospectively maintained quality improvement database for all patients with artificial urinary sphincter erosion from 2011 to 2022. The incidence of postoperative stricture development was compared to the severity of erosion using a graded scale: 1, <25% circumference; 2, 25%-50% circumference; 3, >50% and <100% circumference; and 4, 100% circumference. From 862 artificial urinary sphincter surgeries, 102 erosion cases were identified, and 63 with documented erosion severity were included for analysis. Additional analysis was performed on 28 cases without documented erosion severity for validation. RESULTS: Within the main cohort, urethral stricture developed in 22 (34.9%) patients. The incidence of stricture did not vary by grade of erosion (P = .73) and was not significantly higher in men with grade 4 erosion vs lower-grade erosions (32.7% vs 50.0%, P = .34). Radiation exposure was associated with a 41.1% higher incidence of stricture (P < .01) and nearly every stricture occurred in the setting of prior radiation (21 of 22; 95.5%). In the validation group, 10 (35.7%) developed stricture, mostly in the setting of radiation (8 of 10; 80%). Overall, 29 of 32 (90.6%) cases of stricture involved a history of radiation. CONCLUSIONS: Artificial urinary sphincter erosion does not lead to urethral stricture formation in most cases and is not associated with degree of erosion. Those who develop strictures nearly always have a history of pelvic radiation.

Toward adaptive proton therapy guided with a mobile helical CT scanner.

PURPOSE: To evaluate the feasibility of image-guided adaptive proton therapy (IGAPT) with a mobile helical-CT without rails. METHOD: CT images were acquired with a 32-slice mobile CT (mCT) scanning through a 6 degree-of-freedom robotic couch rotated isocentrically 90 degrees from an initial setup position. The relationship between the treatment isocenter and the mCT imaging isocenter was established by a stereotactic reference frame attached to the treatment couch. Imaging quality, geometric integrity and localization accuracy were evaluated according to AAPM TG-66. Accuracy of relative stopping power ratio (RSPR) was evaluated by comparing water equivalent distance (WED) and dose calculations on anthropomorphic phantoms to that of planning CT (pCT). Feasibility of image-guided adaptive proton therapy was demonstrated on fractional images acquired with the mCT scanner. RESULTS: mCT images showed slightly lower spatial resolution and a higher contrast-to-noise ratio compared to pCT images from the standard helical CT scanner. The geometric accuracy of the mCT was <1 mm. Localization accuracy was <0.4 mm and <0.3° with respect to 2DkV/kV matching. WED differences between mCT and pCT images were negligible, with discrepancies of 0.8 ±â€¯0.6 mm and 1.3 ±â€¯0.9 mm for brain and lung phantoms respectively. 3D gamma analysis (3% and 3 mm) passing rate was >95% on dose computed on mCT, with respect to dose calculation on pCT. CONCLUSION: Our study has demonstrated that the geometric integrity, image quality and RSPR accuracy of the mCT are sufficient for IGAPT.