Biochemical and clinical experience with real-time intraoperatively planned permanent prostate brachytherapy

Comparison of perioperative and subacute postoperative complications between LDR and HDR monotherapy brachytherapy for prostate cancer

PURPOSE

We aim to investigate perioperative and subacute postoperative complications in patients undergoing LDR or HDR monotherapy for prostate cancer. We hypothesize a low rate of complications, and a favorable toxicity profile in patients treated with HDR compared to LDR.

MATERIALS AND METHODS

A prospectively collected institutional database was queried for patients treated with HDR or LDR prostate monotherapy between 1998 and 2021. Toxicities were determined per CTCAE. Claims based billing codes were obtained to identify additional events. Events occurring within 4 months of treatment were defined as perioperative or subacute postoperative complications.

RESULTS

759 patients were identified, 446 received LDR with 125I, and 313 received HDR with 192Ir. HDR patients had higher risk features: 75.7% with Gleason score 7+ versus 2.4% of LDR, and 16% with initial PSA 10+ ng/mL versus 2.7% of LDR. Toxicities were mild with the most common being grade 1 GU frequency and nocturia at ∼50%. HDR patients had significantly less grade 2 dysuria (2.6% vs. 9.0%), frequency (4.8% vs. 9.4%), hematuria (1.0% vs. 5.2%), nocturia (3.8% vs. 9.4%), and urinary obstructive symptoms (7.3% vs. 11.2%), all statistically significant. 11 (1.4%) patients had infection requiring antibiotics: 8 (1.8%) from the LDR group and 3 (1%) from the HDR group. Cardiopulmonary events were low at <2% overall, without difference between HDR and LDR.

CONCLUSIONS

Overall toxicity rates support the safety of prostate brachytherapy. HDR monotherapy is associated with significantly less perioperative and subacute postoperative GU events when compared to LDR monotherapy. Cardiopulmonary events were equally rare in both groups.

Biochemical outcomes and predictive factors by risk group after permanent iodine-125 seed implantation: Prospective cohort study in 2,316 patients

PURPOSE

To evaluate the biochemical freedom from failure (bFFF) by risk group and treatment modality and the predictive factors of bFFF by risk group in patients with prostate cancer undergoing permanent seed implantation (PI) with or without external beam radiation therapy (EBRT) in a nationwide prospective cohort study (Japanese Prostate Cancer Outcome Study of Permanent Iodine-125 [I-125] Seed Implantation) in Japan during the first 2 years.

METHODS AND MATERIALS

The analyses included 2,316 participants in 42 institutions; bFFF was evaluated using the Phoenix definition and calculated using the Kaplan-Meier method, and the Cox proportional hazards model was used to identify the factors associated with bFFF.

RESULTS

Median followup period was 60.0 months. The 5-year bFFF rates in all patients, 1,028 low-risk patients, 1,114 intermediate-risk patients, and 133 high-risk patients were 93.6%, 94.9%, 92.7%, and 91.1%, respectively. The 5-year bFFF rates in the PI group and EBRT combination therapy group were 93.7% and 93.3%, respectively. In a multivariate analysis, younger age, higher Gleason score (GS), higher percent positive biopsies (%PB), and lower prostate V₁₀₀ (p = 0.0012, 0.0030, 0.0026, and 0.0368) in all patients; younger age, higher pretreatment prostate-specific antigen, and lower prostate V₁₀₀ (p = 0.0002, 0.0048, and 0.0012) in low-risk patients; higher GS, higher %PB, and no hormonal treatment (p = 0.0005, 0.0120, and 0.0022) in intermediate-risk patients; and higher GS and higher %PB (p = 0.0329 and 0.0120) in high-risk patients were significantly associated with bFFF.

CONCLUSIONS

PI with or without EBRT resulted in excellent short-term biochemical outcomes in all risk groups, especially in high-risk patients. Age, pretreatment prostate-specific antigen, and prostate V₁₀₀ in low-risk patients; GS, %PB, and hormonal treatment in intermediate-risk patients; and GS and %PB in high-risk patients were independently affected bFFF.

The impact of trainee involvement on outcomes in low-dose-rate brachytherapy for prostate cancer

PURPOSE

To determine the impact of fellow, resident, or medical student (MS) involvement on outcomes in patients undergoing permanent (125)I prostate seed implant.

METHODS AND MATERIALS

The study population consisted of men with clinically localized low/intermediate-risk prostate cancer treated with low-dose-rate permanent interstitial brachytherapy. Cases were stratified according to resident, fellow, MS, or attending involvement. Outcomes were compared using analysis of variance, logistic regression, and log rank tests.

RESULTS

A total of 291 patients were evaluated. Fellows, residents, and MS were involved in 47 (16.2%), 231 (79.4%), and 34 (11.7%) cases, respectively. Thirteen (4.4%) cases were completed by an attending physician alone. There was no difference in freedom from biochemical failure when comparing the resident, fellow, or attending alone groups (p = 0.10). There was no difference in V100 (volume of the prostate receiving 100% of the prescription dose) outcomes when comparing resident cases to fellow cases (p = 0.72) or attending alone cases (p = 0.78). There was no difference in D90 (minimum dose covering 90% of the postimplant volume) outcomes when comparing resident cases to fellow cases (p = 0.74) or attending alone cases (p = 0.58). When examining treatment toxicity, fellow cases had higher rates of acute Grade 2 + GU toxicity (p = 0.028). With the exception of higher urethra D90 among PGY 2-3 cases (p = 0.02), dosimetric outcomes were similar to cases with PGY 4-5 resident participation. There was no difference in outcomes for cases with and without MS participation.

CONCLUSIONS

Interstitial prostate seed implants can be safely performed by trainees with appropriate supervision. Hands-on brachytherapy training is effective and feasible for trainees.

Permanent seed brachytherapy for clinically localized prostate cancer: long-term outcomes in a 700 patient cohort

PURPOSE

Few large European studies have evaluated long-term outcomes for permanent prostate brachytherapy (PPB) as monotherapy for clinically localized prostate cancer. The objective of the present study was to evaluate long-term survival in this patient profile.

METHODS AND MATERIALS

Retrospective study of 700 patients who underwent transperineal ultrasound-guided iodine-125 PPB (145 Gy) between January 2000 and July 2012. Median age was 64.8 years (range, 35-79). Most patients (638 of 700; 91%) had low-risk disease (D'Amico criteria). Eighty-five patients (12%) received hormonal treatment. Overall survival, cause-specific survival, and biochemical relapse-free survival were calculated and estimated using actuarial and Kaplan-Meier methods. Differences between groups were assessed using the log-rank test.

RESULTS

Median followup was 63 months (range, 6-164). At 5- and 10-year followup, respectively, overall survival was 94% (95% confidence interval [CI], 92-96) and 84% (95% CI, 78-90); cause-specific survival was 100% and 97% (95% CI, 95-99); and biochemical relapse-free survival was 95% (95% CI, 93-97) and 85% (95% CI, 79-91).

CONCLUSIONS

The long-term results presented in this report confirm previous studies and provide additional support for the use of PPB in patients with favorable-risk prostate cancer. Seed brachytherapy provides excellent long-term results in this patient profile.

Evaluating toxicity from definitive radiation therapy for prostate cancer in men with inflammatory bowel disease: Patient selection and dosimetric parameters with modern treatment techniques

PURPOSE

Inflammatory bowel disease (IBD) is considered a contraindication to abdominopelvic radiation therapy (RT). We examined our experience in men with IBD who were treated with definitive RT for prostate cancer.

METHODS AND MATERIALS

We queried our institutional database for patients with a diagnosis of ulcerative colitis, Crohn disease, or IBD not otherwise specified. Endpoints were: acute and late ≥grade 2 (G2) GI toxicity and IBD flare after RT. Outcomes were compared with controls using propensity scoring matched 3 to 1. We matched controls to the IBD cohort according to: RT technique, RT dose, risk group, hormone use, treatment year, and age. We determined predictors of acute outcomes using the Fisher exact test and time to outcomes using the log-rank test.

RESULTS

Between 1990 and 2010, 84 men were included. Sixty-three men served as matched controls and 21 with IBD: 13 ulcerative colitis, 7 Crohn disease, and 1 IBD not otherwise specified. For men with IBD, median age was 69 years, and median follow-up was 49 months. Median flare-free interval before RT was 10 years. Seven were taking IBD medications during RT. There was no difference in acute or late gastrointestinal (GI) toxicity in the IBD group versus controls. Among IBD patients, IBD medication use was the only predictor of acute ≥G2 GI toxicity: 57.1% with medication versus7.7% without (49.4% absolute difference, 95% confidence interval [CI] 10.0%-88.9%, P = .03). The 5-year risk of late GI toxicity in men with IBD versus controls was not statistically significant (hazard ratio = 1.19, 95%CI 0.28-5.01, P = .83). The crude incidence of late ≥G2 GI toxicity was 10%.

CONCLUSIONS

Acute GI toxicity appears to be exacerbated in patients on concomitant medical therapy for IBD. Overall, late GI toxicity was relatively low and not significantly different between patients with IBD versus no IBD. However, the small sample size limits the interpretation of our estimates and the wide confidence intervals indicate these patients warrant careful selection.