An intraoperative real-time sleeved seed technique for 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.

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.

Is it necessary to perform week three dosimetric analysis in low-dose-rate brachytherapy for prostate cancer when day 0 dosimetry is done? A quality assurance assessment

PURPOSE

To determine whether computed tomography/magnetic resonance imaging-based day 0 (d0) dosimetry is a meaningful predictor of day 21 (d21) dosimetry in low-dose-rate brachytherapy for localized prostate cancer.

METHODS AND MATERIALS

The study population consisted of 277 men with localized (T1-2 N0 M0), low-/intermediate-risk prostate cancer treated with low-dose-rate brachytherapy. Computed tomography/magnetic resonance imaging fusion was used for postimplant dosimetry at d0 and d21. Logistic regression was used to construct receiver operating characteristic curves for achieving each constraint at d21, based on d0 D90 and V100, and Youden's index was used to evaluate cutpoints. Freedom from biochemical failure (FBCF) was estimated with the Kaplan-Meier method.

RESULTS

The median d0 D90 increased from 133 to 150 Gy at d21, and median d0 V100 increased from 87% to 91%. For achieving the D90 constraint at d21, the optimal cut-point for d0 D90 was 135 Gy, with 84% of these patients maintaining a d21 D90 > 145 Gy. For achieving the D90 constraint at d21, the optimal cut-point for d0 V100 was 87%, with 83% of these patients maintained a d21 V100 > 90%. There was no improvement in FBCF in patients with a d0 D90 > 135 Gy or D90 > 145 Gy. Similarly, there was no improvement in FBCF in patients with a d0 V100 > 87% or V100 > 90%.

CONCLUSIONS

Meeting dosimetric constraints on d0 does not obviate d21 dosimetric analysis. Constraints used for dose prescriptions on d0 are not the ideal predictors of d21 dosimetry.

Salvage low-dose-rate (125)I partial prostate brachytherapy after dose-escalated external beam radiotherapy

Purpose

To report outcomes on 5 patients treated with salvage partial low-dose-rate (LDR) 125-iodine (¹²⁵I) permanent prostate seed brachytherapy (BT) for biopsy-proven locally persistent prostate cancer, following failure of dose-escalated external beam radiotherapy (EBRT).

Material and methods

A retrospective review of the Fox Chase Cancer Center prostate cancer database identified five patients treated with salvage partial LDR ¹²⁵I seed implant for locally persistent disease following dose-escalated EBRT to 76-84 Gy in 2 Gy per fraction equivalent. All patients had post-EBRT biopsies confirming unilateral locally persistent prostate cancer. Pre-treatment, EBRT and BT details, as well as post-treatment characteristics were documented and assessed.

Results

The median follow-up post-implant was 41 months. All five patients exhibited low acute genitourinary and gastrointestinal toxicities. Increased erectile dysfunction was noted in three patients. There were no biochemical failures following salvage LDR ¹²⁵I seed BT to date, with a median post-salvage PSA of 0.4 ng/mL.

Conclusions

In carefully selected patients with local persistence of disease, partial LDR ¹²⁵I permanent prostate seed implant appears to be a feasible option for salvage local therapy with an acceptable toxicity profile. Further study is needed to determine long-term results of this approach.