Biochemical control of prostate cancer with iodine-125 brachytherapy alone: experience from a single institution

Prostate brachytherapy with iodine-125 seeds: analysis of a single institutional cohort

Objectives:

Brachytherapy (BT) with iodine-125 seeds placement is a consolidated treatment for prostate cancer. The objective of this study was to assess the clinical outcomes in patients with prostate cancer who underwent low-dose-rate (LDR) -BT alone in a single Brazilian institution.

Materials and Methods:

Patients treated with iodine-125 BT were retrospectively assessed after at least 5 years of follow-up. Patients who received combination therapy (External beam radiation therapy-EBRT and BT) and salvage BT were not included.

Results:

406 men were included in the study (65.5% low-risk, 30% intermediate-risk, and 4.5% high-risk patients). After a median follow-up of 87.5 months, 61 (15.0%) patients developed biochemical recurrence. The actuarial biochemical failure-free survival (BFFS) at 5 and 10 years were 90.6% and 82.2%, respectively. A PSA nadir ≥ 1 ng / mL was associated with a higher risk of biochemical failure (HR = 5.81; 95% CI: 3.39 to 9.94; p ≤ 0.001). The actuarial metastasis-free survival (MFS) at 5 and 10 years were 98.3% and 94%, respectively. The actuarial overall survival (OS) at 5 and 10 years were 96.2% and 85.1%, respectively. Acute and late grade 2 and 3 gastrointestinal toxicities were observed in 5.6%, 0.5%, 4.6% and 0.5% of cases, respectively. For genitourinary the observed acute and late grade 2 and 3 toxicities rates were 57.3%, 3.6%, 28% and 3.1%, respectively. No grade 4 and 5 were observed.

Conclusions:

BT was effective as a definitive treatment modality for prostate cancer, and its endpoints and toxicities were comparable to those of the main series in the literature.

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.

Brachytherapy and radical prostatectomy in patients with early prostate cancer

OBJECTIVE

this study analyzes the survival of prostate cancer patients cared for at a hospital in Minas Gerais, Brazil according to one of the following treatments: iodine-125 seed implantation or radical prostatectomy. From January 2002 to December 2005, 129 patients underwent either brachytherapy (64 patients) or surgery (65 patients).

METHODS

all had prostate-specific antigen, Gleason scores and clinical stage recorded prior to treatment. Biochemical relapse was defined as prostate-specific antigen (PSA)>0.4 ng/mL for radical prostatectomy, and any elevation equal or higher than 2 ng/mL over the PSA nadir for implanted patients. To analyze the effect of treatment on biochemical recurrence-free survival (BRFS), Kaplan-Meier curves and Cox regression were generated. Mean follow-up time was 56.1 months for patients with the implant, and 26.6 months for those operated on. BRFS in 5 years was 69% (95% CI: 58.18-77.45) for the whole cohort.

DISCUSSION

when stratified according to treatment, survival of patients who had undergone brachytherapy (79.70%) was higher to those operated on (44.30%; p value= 0.0056). Upon multivariate analysis, independent predictors were iPSA (HR: 2.91, 95% CI: 1,32-6,42), Gleason score (HR: 2.18, 95% CI: 1,00-4,81) and treatment modality (HR: 2.61, 95% CI: 1.18-5,75). Risk of biochemical failure was higher with surgery than brachytherapy, which may be related to the failure criteria adopted, which is different for each therapy, as well as the high rate of histological progression between preoperative prostate biopsy and surgical specimen.

CONCLUSION

it was found that brachytherapy is a good therapeutic option for low risk prostate cancer.