Five-year biochemical outcome following permanent interstitial brachytherapy for clinical T1-T3 prostate cancer

Effect of Brachytherapy With External Beam Radiation Therapy Versus Brachytherapy Alone for Intermediate-Risk Prostate Cancer: NRG Oncology RTOG 0232 Randomized Clinical Trial

PURPOSE

To determine whether addition of external beam radiation therapy (EBRT) to brachytherapy (BT) (COMBO) compared with BT alone would improve 5-year freedom from progression (FFP) in intermediate-risk prostate cancer.

METHODS

Men with prostate cancer stage cT1c-T2bN0M0, Gleason Score (GS) 2-6 and prostate-specific antigen (PSA) 10-20 or GS 7, and PSA < 10 were eligible. The COMBO arm was EBRT (45 Gy in 25 fractions) to prostate and seminal vesicles followed by BT prostate boost (110 Gy if 125-Iodine, 100 Gy if 103-Pd). BT arm was delivered to prostate only (145 Gy if 125-Iodine, 125 Gy if 103-Pd). The primary end point was FFP: PSA failure (American Society for Therapeutic Radiology and Oncology [ASTRO] or Phoenix definitions), local failure, distant failure, or death.

RESULTS

Five hundred eighty-eight men were randomly assigned; 579 were eligible: 287 and 292 in COMBO and BT arms, respectively. The median age was 67 years; 89.1% had PSA < 10 ng/mL, 89.1% had GS 7, and 66.7% had T1 disease. There were no differences in FFP. The 5-year FFP-ASTRO was 85.6% (95% CI, 81.4 to 89.7) with COMBO compared with 82.7% (95% CI, 78.3 to 87.1) with BT (odds ratio [OR], 0.80; 95% CI, 0.51 to 1.26; Greenwood T P = .18). The 5-year FFP-Phoenix was 88.0% (95% CI, 84.2 to 91.9) with COMBO compared with 85.5% (95% CI, 81.3 to 89.6) with BT (OR, 0.80; 95% CI, 0.49 to 1.30; Greenwood T P = .19). There were no differences in the rates of genitourinary (GU) or GI acute toxicities. The 5-year cumulative incidence for late GU/GI grade 2+ toxicity is 42.8% (95% CI, 37.0 to 48.6) for COMBO compared with 25.8% (95% CI, 20.9 to 31.0) for BT (P < .0001). The 5-year cumulative incidence for late GU/GI grade 3+ toxicity is 8.2% (95% CI, 5.4 to 11.8) compared with 3.8% (95% CI, 2.0 to 6.5; P = .006).

CONCLUSION

Compared with BT, COMBO did not improve FFP for prostate cancer but caused greater toxicity. BT alone can be considered as a standard treatment for men with intermediate-risk prostate cancer.

Brachytherapy Combined With or Without Hormone Therapy for Localized Prostate Cancer: A Meta-Analysis and Systematic Review

Purpose: The purpose of this study was to evaluate the efficacy of brachytherapy combined with or without hormone therapy in patients with localized prostate cancer.

Methods and Materials: We systemically searched the Medline, Web of Science, Cochrane Library and Embase databases for studies published between the databases' dates of inception and February 2019. The primary endpoints were the 5-year overall survival (OS) rates, 5-year biochemical progression-free survival (bPFS) rates and 10-year bPFS rates. The results were expressed as the relative risk (RR) and 95% confidence interval (CI). Based on the heterogeneity evaluated with the I² statistic, a meta-analysis was performed using either a random- or fixed-effects model.

Results: A total of 16 cohort studies including 9,359 patients met all the criteria for inclusion in the analysis. Our data showed that brachytherapy (BT) combined with hormone therapy (HT) increased the patients' 5-year bPFS rates (RR = 1.04, 95% CI: 1.01–1.08, P = 0.005) and 10-year bPFS rates (RR = 1.12, 95% CI: 1.02–1.23, P = 0.001) compared with BT monotherapy. However, BT combined with HT did not increase the patients' 5-year OS rates (RR = 1.02, 95% CI: 0.99–1.095, P = 0.1) compared with BT monotherapy.

Conclusions: BT combined with HT can increase the bPFS rates of patients with localized prostate cancer, but it does not improve patients' OS rates.

Salvage Therapy Options for Local Prostate Cancer Recurrence After Primary Radiotherapy: a Literature Review

PURPOSE OF REVIEW

While recurrence after primary treatment of prostate cancer (PCa) is not uncommon, there is currently no consensus on the most appropriate management after radiation treatment failure. This article seeks to explore the currently utilized modalities for salvage treatment for radiorecurrent PCa. We focused our review on the oncologic outcomes and reported toxicity rates in the latest studies examining salvage radical prostatectomy (SRP), salvage cryotherapy (SCT), salvage high-intensity focused ultrasound (HIFU) and re-irradiation.

RECENT FINDINGS

There does not appear to be any significant difference in overall survival for more invasive salvage radical prostatectomy compared to the minimally invasive salvage approaches. Additionally, there seems to be a trend towards lower morbidity rates associated with minimally invasive and focal salvage treatment. We are encouraged by the results presented in this review and find that there is clearly a role for emerging minimally invasive and focal therapies as durable options for salvage treatment in patients with radiorecurrent PCa.

A retrospective analysis after low-dose-rate prostate brachytherapy with permanent 125I seed implant: clinical and dosimetric results in 70 patients

Aims and background

To evaluate the biochemical disease-free survival (bDFS) rate after 125I permanent-implant prostate brachytherapy.

Methods

Patients with a diagnosis of prostate adenocarcinoma and adequate PSA follow-up were selected for this retrospective study. Brachytherapy with permanent 125I seeds was performed as monotherapy, with a prescribed dose of 145 Gy to the prostate. Patients were stratified into recurrence risk groups according to the National Comprehensive Cancer Network (NCCN) guidelines. Biochemical failure was defined using the American Society of Therapeutic Radiology and Oncology (ASTRO) guidelines. The post-implant D90 (defined as the minimum dose covering 90% of the prostate) was obtained for each patient. Two cutoff points were used to test the correlation between D90 and bDFS results: 130 Gy and 140 Gy. bDFS was calculated from the implant date to the date of biochemical recurrence. Univariate and multivariate analysis were performed using the SPSS software and included clinical stage, pretreatment PSA, Gleason score (GS), androgen deprivation therapy, D90, and risk groups. In the univariate analysis we used a cutoff point of 5.89 ng/mL for PSA and 5 for GS.

Results

From June 2003 to April 2007, 70 patients were analyzed. The patients' distribution into recurrence risk groups was as follows: 39 patients (56%) in the low-risk group, 23 patients (33%) in the intermediate-risk group, and 8 patients (11%) in the high-risk group. At a median follow-up of 47 months (range, 19–70 months) bDFS was 88.4%, with a global actuarial 5-year bDFS of 86%. Disease-related factors including initial PSA level, GS and risk group were significant predictors of biochemical failure (P = 0.01, P = 0.01, P = 0.006, respectively). In multivariate analysis, risk group (P = 0.005) and GS (P = 0.03) were statistically significant.

Conclusion

Our data are in agreement with those in the literature and, despite the short follow-up, confirm the advantage of brachytherapy for patients at low and intermediate risk of recurrence.

Palliative treatment of pelvic bone tumors using radioiodine (125I) brachytherapy

Background

Complete resection of pelvic bone tumors, especially recurrent and metastatic ones, is often impossible to achieve using conventional surgery. This study aimed to assess the benefits and adverse effects of computed tomography (CT)-guided radioiodine (¹²⁵I) brachytherapy for inoperable recurrent and metastatic bone tumors of the pelvis.

Methods

This was a retrospective study of 22 patients with confirmed pelvic bone tumors (10 females and 12 males; 15–84 years; 21 with primary pelvic tumor and one with pelvic metastasis). CT-guided ¹²⁵I brachytherapy was performed using 9–21 ¹²⁵I seeds (radioactivity of 0.5–0.7 mCi). Seed implantation was validated by postoperative CT scanning. Complications, pain, survival, and CT-estimated tumor size were carried out to evaluate the therapeutic benefits.

Results

Postoperative CT scans revealed satisfactory ¹²⁵I seed implantation, and the radiation dose delivered to 90% of the target area (D90) was higher than the prescription dose (PD). No obvious complications were observed. Pain was reported by 19 of 22 patients, but 17 reported pain relief after implantation. Follow-up ranged 8–27 (median, 19) months. Tumor size was reduced in 11 patients within 1 month after surgery, nine patients showed no change, and tumor size increased in two patients. Finally, 1- and 2-year survival was 81.8 and 45.5%, respectively; 1- and 2-year local tumor control rates were 59.1 and 36.4%, respectively.

Conclusions

¹²⁵I seed implantation significantly reduced bone tumor size and relieved pain, with a low complication rate. These findings suggest that ¹²⁵I brachytherapy treatment could be a useful palliative approach for pelvic bone tumor treatment.

Penile Rehabilitation Strategies Among Prostate Cancer Survivors

Despite advances in technical and surgical approaches, erectile dysfunction (ED) remains the most common complication among prostate cancer survivors, adversely impacting quality of life. This article analyzes the concept and rationale of ED rehabilitation programs in prostate cancer patients. Emphasis is placed on the pathophysiology of ED after diagnosis and treatment of prostate cancer to understand the efficacy of rehabilitation programs in clinical practice. Available evidence shows that ED is a transient complication following prostate biopsy and cancer diagnosis, with no evidence to support rehabilitation programs in these patients. A small increase in ED and in the use of phosphodiesterase type 5 (PDE5) inhibitors was reported in patients under active surveillance. Patients should be advised that active surveillance is unlikely to severely affect erectile function, but clinically significant changes in sexual function are possible. Focal therapy could be an intermediate option for patients demanding treatment/refusing active surveillance and invested in maintaining sexual activity. Unlike radical prostatectomy, there is no support for PDE5 inhibitor use to prevent ED after highly conformal external radiotherapy or low-dose rate brachytherapy. Despite progress in the understanding of the pathophysiologic mechanisms responsible for ED in prostate cancer patients, the success rates of rehabilitation programs remain low in clinical practice. Alternative strategies to prevent ED appear warranted, with attention toward neuromodulation, nerve grafting, nerve preservation, stem cell therapy, investigation of neuroprotective interventions, and further refinements of radiotherapy dosing and delivery methods.

Case series analysis of post-brachytherapy prostate edema and its relevance to post-implant dosimetry. Post-implant prostate edema and dosimetry

PURPOSE

We evaluated the post-operative pattern of prostate volume (PV) changes following prostate brachytherapy (PB) and analyzed variables which affect swelling.

MATERIAL AND METHODS

Twenty-nine patients treated with brachytherapy (14) or combined brachytherapy and external beam radiotherapy modality (15) underwent pre- and post-implant computed tomography (CT). Prostate volume measurements were done on post-operative days 1, 9, 30, and 60. An observer performed 139 prostate volume (PV) measurements. We analyzed the influence of pre-implant PV, number of needles and insertion attempts, number and activity of seeds, Gleason score, use of hormonal therapy and external beam radiation therapy on the extent of edema. We computed a volume correction factor (CF) to account for dosimetric changes between day 1 and day 30. Using the calculated CF, the dose received by 90% (D(90)) of the prostate on day 30 (D(90)Day30) was obtained by dividing day 1 (D(90)Day1) by the CF.

RESULTS

The mean PV recorded on post-operative day 1 was 67.7 cm(3), 18.8 cm(3) greater than average pre-op value (SD 15.6 cm(3)). Swelling returned to pre-implant volume by day 30. Seed activity, treatment modality, and Gleason score were significant variables. The calculated CF was 0.76. After assessment using the CF, the mean difference between estimated and actual D(90)Day30 was not significant.

CONCLUSIONS

We observed maximum prostate size on post-operative day 1, returning to pre-implant volume by day 30. This suggests that post-implant dosimetry should be obtained on or after post-operative day 30. If necessary, day 30 dosimetry can be estimated by dividing D(90)Day1 by a correction factor of 0.76.

Current status of brachytherapy for prostate cancer

Brachytherapy was developed to treat prostate cancer 50 years ago. Current advanced techniques using transrectal ultrasonography were established 25 years ago. Transrectal ultrasound (TRUS) has enabled the prostate to be viewed with improved resolution with the use of modern ultrasound machines. Moreover, the development of software that can provide images captured in real time has improved treatment outcomes. Other new radiologic imaging technologies or a combination of magnetic resonance and TRUS could be applied to brachytherapy in the future. The therapeutic value of brachytherapy for early-stage prostate cancer is comparable to that of radical prostatectomy in long-term follow-up. Nevertheless, widespread application of brachytherapy cannot be achieved for several reasons. The treatment outcome of brachytherapy varies according to the skill of the operator and differences in patient selection. Currently, only three radioactive isotopes are available for use in low dose rate prostate brachytherapy: I-125, Pd-103, and Cs-131; therefore, more isotopes should be developed. High dose rate brachytherapy using Ir-192 combined with external beam radiation, which is needed to verify the long-term effects, has been widely applied in high-risk patient groups. Recently, tumor-selective therapy or focal therapy using brachytherapy, which is not possible by surgical extraction, has been developed to maintain the quality of life in selected cases. However, this new application for prostate cancer treatment should be performed cautiously because we do not know the oncological outcome, and it would be an interim treatment method. This technique might evolve into a hybrid of whole-gland treatment and focal therapy.

High dose brachytherapy as monotherapy for intermediate risk prostate cancer

PURPOSE

We evaluated our retrospective, single institution experience with high dose rate brachytherapy as monotherapy for intermediate risk prostate cancer.

MATERIALS AND METHODS

Our cohort included 284 patients with intermediate risk prostate cancer, defined as clinical stage T2b/T2c, Gleason score 7 and/or prostate specific antigen 10 to 20 ng/ml, and 1-year minimum followup. Treatment was 2 high dose rate brachytherapy sessions at 3 fractions of 6.5 Gy each for a mean of 19 days. Prostate specific antigen failure was defined as nadir +2 ng/ml.

RESULTS

Mean followup was 35.1 months (median 31.9). Actuarial 5-year cause specific survival and clinical local control were 100%, distant-metastasis-free survival 98.8% and biochemical disease-free survival 94.4%. Clinical stage predicted biochemical disease-free survival. For stage T2a or less 5-year biochemical disease-free survival was 95.1% vs 100% for stage T2b and 77.4% for T2c (p = 0.012). Percent positive biopsy cores and prostate specific antigen nadir were also predictive. International Prostate Symptom Score results remained stable and potency was maintained in 82.6% of patients at 2 years. Pads were used for the first time after brachytherapy in 22 patients (7.7%), mostly for grade 1 incontinence (occasionally or less per week). Excluding patients with prior transurethral prostatectomy, stroke or tremor 2.5% used pads for the first time after treatment. No patient had urethral stricture. Radiation Therapy Oncology Group grade 1 rectal toxicity developed in 12 patients (4.2%) but not beyond grade 1.

CONCLUSIONS

High dose rate brachytherapy as monotherapy is safe and effective for patients with intermediate risk prostate cancer. We recommend caution for percent positive biopsy cores exceeding 75% or clinical stage T2c. Excluding such patients the 5-year biochemical disease-free survival rate was 97.5%.

Low-dose rate brachytherapy for men with localized prostate cancer

BACKGROUND

Localized prostate cancer is a slow growing tumor for many years for the majority of affected men. Low-dose rate brachytherapy (LDR-BT) is short-distance radiotherapy using low-energy radioactive sources. LDR-BT has been recommended for men with low risk localized prostate cancer.

OBJECTIVES

To assess the benefit and harm of LDR-BT compared to radical prostatectomy (RP), external beam radiotherapy (EBRT), and no primary therapy (NPT) in men with localized prostatic cancer.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 1950), and EMBASE (from 1980) were searched in June 2010 as well as online trials registers and reference lists of reviews.

SELECTION CRITERIA

Randomized, controlled trials comparing LDR-BT versus RP, EBRT, and NPT in men with clinically localized prostate cancer.

DATA COLLECTION AND ANALYSIS

Data on study methods, participants, treatment regimens, observation period and outcomes were recorded by two reviewers independently.

MAIN RESULTS

We identified only one RCT (N = 200; mean follow up 68 months). This trial compared LDR-BT and RP. The risk of bias was deemed high. Primary outcomes (overall survival, cause-specific mortality, or metastatic-free survival) were not reported. Biochemical recurrence-free survival at 5 years follow up was not significantly different between LDR-BT (78/85 (91.8%)) and RP (81/89 (91.0%)); P = 0.875; relative risk 0.92 (95% CI: 0.35 to 2.42).For severe adverse events reported at 6 months follow up, results favored LDR-BT for urinary incontinence (LDR-BT 0/85 (0.0%) versus RP 16/89 (18.0%); P < 0.001; relative risk 0) and favored RP for urinary irritation (LDR-BT 68/85 (80.0%) versus RP 4/89 (4.5%); P < 0.001; relative risk 17.80, 95% CI 6.79 to 46.66). The occurrence of urinary stricture did not significantly differ between the treatment groups (LDR-BT 2/85 (2.4%) versus RP 6/89 (6.7%); P = 0.221; relative risk 0.35, 95% CI: 0.07 to 1.68). Long-term information was not available.We did not identify significant differences of mean scores between treatment groups for patient-reported outcomes function and bother as well as generic health-related quality of life.

AUTHORS' CONCLUSIONS

Low-dose rate brachytherapy did not reduce biochemical recurrence-free survival versus radical prostatectomy at 5 years. For short-term severe adverse events, low-dose rate brachytherapy was significantly more favorable for urinary incontinence, but radical prostatectomy was significantly more favorable for urinary irritation. Evidence is based on one RCT with high risk of bias.

Relative biological effectiveness and cell-killing efficacy of continuous low-dose-rate 125I seeds on prostate carcinoma cells in vitro

The aim of this study was to determine the effects of (125)I seeds on prostate carcinoma (PC3) cells. The relative biological effectiveness of (125)I seeds on PC3 cells with respect to (60)Co gamma rays was 1.4. Both 4 Gy of (60)Co gamma ray and (125)I seed irradiation increased the percentage of cells in G(2) phase, but there was no significant difference between these 2 types of radiation. Significantly, (125)I seeds induced higher apoptotic rates of PC3 cells compared with (60)Co gamma ray irradiation. Furthermore, Bcl-2 expression, but not caspase-3 activity, in PC3 cells was downregulated after irradiation with (125)I seed or (60)Co gamma rays.

Population-based study of biochemical and survival outcomes after permanent 125I brachytherapy for low- and intermediate-risk prostate cancer

OBJECTIVES

To analyze the biochemical and survival outcomes after permanent low-dose-rate prostate brachytherapy in a large, consecutive, population-based cohort of patients.

METHODS

A total of 1006 consecutive implants were performed from July 20, 1998 to October 23, 2003 for men with low-risk and "low-tier" intermediate-risk prostate cancer. The prescribed minimal peripheral dose was 144 Gy, using 0.33 mCi (125)I sources and a preplan technique with a strong posterior-peripheral dose bias. Most patients (65%) had received 6 months of androgen deprivation therapy. Supplemental external beam radiotherapy was not used. The prognostic features, dose metrics, and follow-up data were prospectively collected. Kaplan-Meier and Cox regression analyses were used to assess the factors associated with freedom from biochemical recurrence and survival.

RESULTS

The median patient age at treatment was 66 years. The median follow-up was 54 months for biochemical outcomes and 66 months for survival. The actuarial freedom from biochemical recurrence rate was 95.6% +/- 1.6% at 5 years and 94.0% +/- 2.2% at 7 years. On multivariate analysis, the pretreatment prostate-specific antigen level (P = .03) and androgen deprivation therapy use (P = .04) were predictive of the freedom from biochemical recurrence. The actuarial rates of distant metastasis and disease-specific death at 5 years were both <1%. The overall survival rate at 5 years was 95.2% +/- 1.4% and was 93.4% +/- 1.8% at 7 years. On multivariate analysis, only age was predictive of overall survival (P = .011).

CONCLUSIONS

When consistently planned and delivered, low-dose-rate brachytherapy, without supplemental external beam radiotherapy or intraoperative planning, can produce cancer-specific outcomes for men with low- and "low-tier" intermediate-risk prostate cancer at least equal to that produced by dose-escalated external beam radiotherapy or surgical prostatectomy.

Prostate-specific antigen 'bounce' after permanent 125I-implant brachytherapy in Japanese men: a multi-institutional pooled analysis

OBJECTIVE

To examine the incidence, timing, and magnitude of the prostate-specific antigen (PSA) level 'bounce' after permanent prostate brachytherapy (BT) and correlate the PSA bounce with clinical and dosimetric factors in Japanese patients with prostate cancer.

PATIENTS AND METHODS

A multi-institutional pooled analysis was carried out in 388 consecutive patients with T1-T2N0M0 prostate cancer treated with (125)I-seed implant BT with no hormonal therapy or external beam radiotherapy. All patients had >or=1 year of follow-up and at least three follow-up PSA level measurements. Three definitions of PSA bounce were used: definition A, a PSA level rise of 0.1 ng/mL; definition B, a PSA level rise of 0.4 ng/mL; and definition C, a PSA level rise of 35% over the previous value, followed by a subsequent fall.

RESULTS

The actuarial likelihood of having PSA bounce at 24 months was 50.8% for definition A, 23.5% for definition B, and 19.4% for definition C. The median time to develop PSA bounce was 12 months for definition A, 18 months for definition B, and 18 months for definition C. There was a PSA bounce magnitude of 2 ng/mL in 5.3% of patients, and 95.3% of PSA bounce occurred within 24 months after (125)I-BT. Among the before and after (125)I-BT factors, clinical stage, initial PSA level, and Gleason score did not predict for PSA bounce using any definition; only being younger predicted for PSA bounce on multivariate analysis (P < 0.001).

CONCLUSIONS

PSA bounce is a common phenomenon after (125)I-BT and occurred at a rate of 19-51% in the Japanese men who underwent (125)I-BT, depending on the definition used. It is more common in younger patients, and early PSA bounce should be considered when assessing a patient with a rising PSA level after (125)I-BT, before implementing salvage interventions. Furthermore, PSA bounce magnitude might be lower in Japanese than in Caucasian patients.

15-Year biochemical relapse free survival in clinical Stage T1-T3 prostate cancer following combined external beam radiotherapy and brachytherapy; Seattle experience

PURPOSE

Long-term biochemical relapse-free survival (BRFS) rates in patients with clinical Stages T1-T3 prostate cancer continue to be scrutinized after treatment with external beam radiation therapy and brachytherapy.

METHODS AND MATERIALS

We report 15-year BRFS rates on 223 patients with clinically localized prostate cancer that were consecutively treated with I(125) or Pd (103) brachytherapy after 45-Gy neoadjuvant EBRT. Multivariate regression analysis was used to create a pretreatment clinical prognostic risk model using a modified American Society for Therapeutic Radiology and Oncology consensus definition (two consecutive serum prostate-specific antigen rises) as the outcome. Gleason scoring was performed by the pathologists at a community hospital. Time to biochemical failure was calculated and compared by using Kaplan-Meier plots.

RESULTS

Fifteen-year BRFS for the entire treatment group was 74%. BRFS using the Memorial Sloan-Kettering risk cohort analysis (95% confidence interval): low risk, 88%, intermediate risk 80%, and high risk 53%. Grouping by the risk classification described by D'Amico, the BRFS was: low risk 85.8%, intermediate risk 80.3%, and high risk 67.8% (p = 0.002).

CONCLUSIONS

I(125) or Pd(103) brachytherapy combined with supplemental EBRT results in excellent 15-year biochemical control. Different risk group classification schemes lead to different BRFS results in the high-risk group cohorts.

Biochemical (prostate-specific antigen) relapse-free survival and toxicity after125I low-dose-rate prostate brachytherapy

OBJECTIVE

To report our clinical experience and 5-year prostate-specific antigen (PSA) relapse-free survival rate for early-stage prostate cancer after (125)I low-dose-rate prostate brachytherapy.

PATIENTS AND METHODS

In all, 300 patients were treated between March 1999 and April 2003, and followed prospectively. Patients were stratified into low-, intermediate- and high-risk groups, and those receiving neoadjuvant androgen deprivation (NAAD) or not. Kaplan-Meier estimates of PSA relapse-free survival and PSA nadirs were obtained for all patients and for the risk groups. Toxicity, as urinary and erectile dysfunction (ED), were reported from a prospective database.

RESULTS

The median (range) follow-up was 45 (33-82) months. The actuarial PSA relapse-free survival was 93% at 5 years; 21 (7%) of patients had evidence of biochemical failure as defined by the American Society of Therapeutic Radiation Oncology criteria. There was no significant difference in actuarial survival for patients in the different risk groups, or between those receiving NAAD or not (low-risk 96%, intermediate 89%, high 93%, P = 0.12; NAAD 92%, no NAAD 95%, P = 0.30). Overall the 3-year median PSA level was 0.3 ng/mL (192 men). There was no significant difference in median 3-year PSA levels for different risk groups, or for those treated with or with no NAAD. The 3- and 4-year PSA nadir of <0.5 ng/mL was achieved by 71% and 86% of men, respectively. The acute urinary retention rate was 7%; 5.6% of men developed urethral strictures requiring dilatation, while 2.7% required a transurethral resection of the prostate after implantation, for obstructive symptoms. Of patients with no ED before treatment, 62% had no ED at 2 years, and of these 60% used a phosphodiesterase inhibitor.

CONCLUSION

This prospective series confirms the excellent overall biochemical survival after (125)I brachytherapy; the treatment was tolerated well, with early and late urinary toxicity and ED similar to other published results.

Impact of interseed attenuation and tissue composition for permanent prostate implants

The purpose is to evaluate the impact of interseed attenuation and prostate composition for prostate treatment plans with 125I permanent seed implants using the Monte Carlo (MC) method. The effect of seed density (number of seeds per prostate unit volume) is specifically investigated. The study focuses on treatment plans that were generated for clinical cases. For each plan, four different dose calculation techniques are compared: TG-43 based calculation, superposition MC, full MC with water prostate, and full MC with realistic prostate tissue. The prostate tissue description is from the ICRP report 23 (W. S. Snyer, M. J. Cook, E. S. Nasset, L. R. Karkhausen, G. P. Howells, and I. H. Tipton, "Report of the task group on reference man," Technical Report 23, International Commission on Radiological Protection, 1974). According to the comparisons, the seed density has an influence on interseed attenuation. A plan with a typical low seed density (42 0.6 mCi seeds in a 26 cm3 prostate) suffers a 1.2% drop in the CTV D90 value due to interseed attenuation. A drop of 3.0% is calculated for a higher seed density (75 0.3 mCi seeds, same prostate). The influence of the prostate composition is similar for all seed densities and prostate sizes. The difference between MC simulations in water and MC simulations in prostate tissue is between 4.4% and 4.8% for the D90 parameter. Overall, the effect on D90 is ranging from 5.8% to 12.8% when comparing clinically approved TG-43 and MC simulations in prostate tissue. The impact varies from one patient to the other and depends on the prostate size and the number of seeds. This effect can reach a significant level when reporting correlations between clinical effect and deposited dose.

Dosimetry of a thyroid uptake detected in seed migration survey following a patient's iodine-125 prostate implant and in vitro measurements of intentional seed leakages

As a quality control procedure, a post-implant seed migration survey has been accomplished on 340 prostate cancer patients since November 2001. Pulmonary seed embolization and intracardiac seed embolization have been detected. A case of thyroid uptake due to leaking iodine-125 (I-125) sources was also seized. In order to determine the dose to the thyroid, a dosimetry method was developed to link in vivo measurements and the cumulated dose to the thyroid. The calculated source leakage half-life in the case was approximately 15 days based on the measurements and the estimated cumulated dose to thyroid was 204 cGy. It is concluded that one seed was leaking. In order to verify the in vivo measurements, intentional in vitro seed leakage tests were performed. A seed was cut open and placed in a sealed glass container filled with a given volume of saline. The I-125 concentration in the saline was subsequently measured over a period of six months. Consistent in vivo and in vitro results were obtained. Recent incidents of seed leaks reported from other centers have drawn practitioners' attention to this problem. In order to make the measurements more useful, the seed leakage tests were expanded to include I-125 seeds from six other vendors. The results show that the leakage half-lives of those seeds varied from nine days to a half-year. Two seed models demonstrated least leakage. Since the measurements lasted for six months, the escape of iodine resulted from oxidation of iodide in the saline was a concern for the measurement accuracy. As a reference, another set of leakage tests were performed by adding sodium thiosulfate salt (Na2S2O3 x 5 H2O) to the saline. Sodium thiosulfate is a reducing agent that prevents the conversion of iodide to iodate so as to minimize I-125 evaporation. As a result, significantly shortened leakage half-lives were observed in this group. Seed agitation was also performed and no significant deviations of the leakage rates were observed. Considering the body fluid is more complex than saline, the in vivo leakage half-life, in case a source leak is encountered, may vary significantly from what is presented in this paper due to chemical reactions. In vivo measurements thus may produce a more accurate estimation of leakage half-life and thyroid uptake dose.

Defining biochemical failure following radiotherapy with or without hormonal therapy in men with clinically localized prostate cancer: recommendations of the RTOG-ASTRO Phoenix Consensus Conference

In 1996 the American Society for Therapeutic Radiology and Oncology (ASTRO) sponsored a Consensus Conference to establish a definition of biochemical failure after external beam radiotherapy (EBRT). The ASTRO definition defined prostate specific antigen (PSA) failure as occurring after three consecutive PSA rises after a nadir with the date of failure as the point halfway between the nadir date and the first rise or any rise great enough to provoke initiation of therapy. This definition was not linked to clinical progression or survival; it performed poorly in patients undergoing hormonal therapy (HT), and backdating biased the Kaplan-Meier estimates of event-free survival. A second Consensus Conference was sponsored by ASTRO and the Radiation Therapy Oncology Group in Phoenix, Arizona, on January 21, 2005, to revise the ASTRO definition. The panel recommended: (1) a rise by 2 ng/mL or more above the nadir PSA be considered the standard definition for biochemical failure after EBRT with or without HT; (2) the date of failure be determined "at call" (not backdated). They recommended that investigators be allowed to use the ASTRO Consensus Definition after EBRT alone (no hormonal therapy) with strict adherence to guidelines as to "adequate follow-up." To avoid the artifacts resulting from short follow-up, the reported date of control should be listed as 2 years short of the median follow-up. For example, if the median follow-up is 5 years, control rates at 3 years should be cited. Retaining a strict version of the ASTRO definition would allow comparisons with a large existing body of literature.

Update on Radiation Therapy in Prostate Cancer

Higher doses of radiation result in improved clinical control of prostate cancer,and the recent advances in prostate cancer radiotherapy are designed to escalate dose while minimizing toxicity. To achieve this goal, tighter treatment margins are needed, which require more accurate delineation of the prostate target and normal tissue at the time of treatment planning and before actual daily treatments. Modem radiation therapy techniques can deposit conformal dose virtually anywhere in the body; however, this precise therapy is of no value if it is not accurately hitting the target. Whether dose escalation is achieved by external beam techniques (eg, IMRT, protons) or brachytherapy, these ba-sic planning and delivery considerations are essentially the same. Future directions in prostate radiation therapy will use even higher radiation doses,alternative fractionation patterns, intraprostatic targets (eg, prostate tumor seen on MRI), and improved patient selection regarding which patients will benefit the most from these advanced techniques.

192Ir low dose rate brachytherapy for boosting locally advanced prostate cancers after external beam radiotherapy: A phase II trial

BACKGROUND AND PURPOSE

To evaluate on 201 locally advanced prostatic cancers prospectively treated in a phase II trial, the efficacy of a combination of external beam radiotherapy (39.6 Gy) and (192)Ir low dose rate brachytherapy (Bt) (40-45 Gy).

PATIENTS AND METHODS

Sixty-four patients were included in the intermediate prognosis group with only one of the following adverse factors (PSA > 10 ng/ml, Gleason score > or = 7 or clinical stage > or =T2b) and 137 in the unfavourable group when at least two of these factors were present.

RESULTS

The actuarial 4 years biochemical no evidence of disease is 82.8% for the entire population. It is, respectively, 97 and 76% in the intermediate and unfavourable prognosis groups (P < 0.0001). Grade > or =3 late urinary complications occurred in 13 patients (6.5%). Eight patients (4%) presented late grade 2 rectal complications but no grades 3-5 was observed.

CONCLUSIONS

Even if an alpha/beta of 1.5-3 Gy theoretically favours the use of a high dose rate mode of irradiation, the early results presented here are as good as those reported for similar groups of patients with high dose rate treatments. Late toxicity is identical but our urinary toxicity is within the less favourable and rectal toxicity within the most favourable results. We can postulate that while inducing very high hyperdosage regions (V150) mainly focused on the peripheral zone, most of the Bt techniques consist of a more ablative treatment. Many of the radiobiological studies on Bt did not in fact take into account the heterogeneity of irradiation inside the CTV. This study highlights the need to explore pulsed dose rate therapies, permanent implant and new available radioisotopes such as (169)Ytterbium that will offer the safety of low and lower dose rates. The actual late toxicity of the different Bt techniques is not yet inexistent indeed.

A phase II study of external beam radiotherapy combined with permanent source brachytherapy for intermediate-risk, clinically localized adenocarcinoma of the prostate: Preliminary results of RTOG P-0019

PURPOSE

To estimate the rate of acute and late Grade 3-5 genitourinary and gastrointestinal toxicity after treatment with external beam radiotherapy and permanent source brachytherapy in a multi-institutional, cooperative group setting.

METHODS AND MATERIALS

All patients were treated with external beam radiotherapy (45 Gy in 25 fractions), followed 2-6 weeks later by an interstitial implant using 125I to deliver an additional 108 Gy. Late genitourinary toxicity was graded according to the Common Toxicity Criteria Version 2.0, and the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer late radiation morbidity scoring system was used for all other toxicity.

RESULTS

A total of 138 patients from 28 institutions were entered on this study. Acute toxicity information was available in 131 patients, and 127 patients were analyzable for late toxicity. Acute Grade 3 toxicity was documented in 10 of 131 patients (7.6%). No Grade 4 or 5 acute toxicity has been observed. The 18-month month estimate of late Grade 3 genitourinary and gastrointestinal toxicity was 3.3% (95% confidence interval, 0.1-6.5). No late Grade 4 or 5 toxicity has been observed.

CONCLUSIONS

The acute and late morbidity observed in this multi-institutional, cooperative group study is consistent with previous reports from single institutions with significant prostate brachytherapy experience.

Effect of post-implant edema on prostate brachytherapy treatment margins

PURPOSE

To determine if postimplant prostate brachytherapy treatment margins calculated on Day 0 differ substantially from those calculated on Day 30.

METHODS

Thirty patients with 1997 American Joint Commission on Cancer clinical stage T1-T2 prostatic carcinoma underwent prostate brachytherapy with I-125 prescribed to 144 Gy. Treatment planning methods included using loose seeds in a modified peripheral loading pattern and treatment margins (TMs) of 5-8 mm. Postimplant plain radiographs, computed tomography scans, and magnetic resonance scans were obtained 1-4 hours after implantation (Day 0). A second set of imaging studies was obtained at 30 days after implantation (Day 30) and similarly analyzed. Treatment margins were measured as the radial distance in millimeters from the prostate edge to the 100% isodose line. The TMs were measured and tabulated at 90 degrees intervals around the prostate periphery at 0.6-cm intervals. Each direction was averaged to obtain the mean anterior, posterior, left, and right margins.

RESULTS

The mean overall TM increased from 2.6 mm (+/-2.3) on Day 0 to 3.5 mm (+/-2.4) on Day 30. The mean anterior margin increased from 1.2 mm on Day 0 to 1.8 mm on Day 30. The posterior margin increased from 1.2 mm on Day 0 to 2.8 mm on Day 30. The lateral treatment margins increased most over time, with mean right treatment margin increasing from 3.9 mm on Day 0 to 4.7 mm on Day 30.

CONCLUSION

Treatment margins appear to be durable in the postimplant period, with a clinically insignificant increase from Day 0 to Day 30.

192Ir or 125I prostate brachytherapy as a boost to external beam radiotherapy in locally advanced prostatic cancer: a dosimetric point of view

PURPOSE

This work aims at comparing the dosimetric possibilities of 125I or 192Ir prostate brachytherapy (Bt) as a boost to external beam radiotherapy in the treatment of locally advanced adenocarcinoma.

METHODS AND MATERIALS

From 1/1997 to 12/2002, 260 patients were treated. Until 12/2001 a low dose rate (LDR) treatment with 192Ir wires was used, later replaced by a high dose rate (HDR) delivered with an 192Ir stepping source technology. For the present work, we selected 40 patients including the last 20 treated, respectively, by LDR and HDR. The planning CT Scans of all these 40 patients were transferred into the 3D Prowess system for 125I permanent implants design according to the Seattle method. The reference data for dosimetric comparisons were the V100 and the prescribed dose for 192Ir as well as the dose delivered with 125I techniques to the 192Ir V100. We compared V100-150 data as well as doses to the organs at risks (OR) and cold spots (CS).

RESULTS

The V100 is 85.3+/-8% for 192Ir LDR and 96+/-2% for HDR techniques (P < 0.0001). In comparison with 125I, the 192Ir LDR mode induces higher hyperdosage volumes inside the CTV but also more CS, while maximal doses to urethra and rectum are, respectively, 17 and 39% less with 125I (P < 0.0001). In comparison with the 192Ir HDR mode, 125I Bt induces higher hyperdosage volumes and slightly more CS deliberately planned around the bladder neck. If delivered doses to urethra are identical, those to the 20% anterior part of the rectum are 33% less with 125I (P < 0,0001). The 125I Bt technique was only possible in 24 out of the 40 patients studied due to pelvic bone arch interference.

CONCLUSIONS

At the present time, there is no evident dosimetric superiority of one Bt method when all the criteria are taken into account. However, improving Bt techniques to implant any prostatic size could found the superiority of the 125I or permanent implants. 125I indeed allows large hyperdosage volumes inside the CTV in comparison with 192Ir HDR techniques while lowering doses to OR and minimizing CS.

[Retrospective study of 130 patients with organconfined prostate cancer treated with brachytherapy]

INTRODUCTION

The prostate brachytherapy with I 125 seeds has an indication in patients with organconfined prostate cancer. Our objective is to describe the population treated in our institution with permanent I125 seeds implants, the dosimetric characteristics of the technique and the preliminary results of our group-study in terms of evolution and toxicity.

MATERIAL AND METHODS

Between May 2000 and March 2003, 130 patients with permanent implants of I125 seeds were treated. Beforehand we did prostate volumetric with transrectum prostate echography in order to assess the configuration of the implant, number of seeds and their place in the prostate with the objective to get a fine coverage of PTV (planet target volume). Stage distribution: 75.72% T1c; 24.28% T2a; Gleason<6, 94%. The PSA pretreatment average was 6.38 ng/ml. The average prostate volume was 30 cc. The 16.67% of the patients included had hormonal treatment previously to get the implants. The average age was 64 years. The characteristic techniques of the implants were: the average width of the needle as 24 (14-35) and the average of the seeds 76 (46-111). Finally the average activity was 0.39 mCi/seed, which means average total implant activity of 80 mCi.

RESULTS

We analyzed 130 patients with average follow up 6 months. A 1 to 2 year surveillance was carried out on 98.9% and the global free disease surveillance (biochemic relapse) of 98.9% at the year and of the 87.8% at the end of the 2 years. The relapse in the low risk patients was 98.8% after the first year and 88.7% at the end of 2 year. On the contrary in the middle risk was of 100% and 83% respectively, although the amount of patients in significantly less. As a relevant acute secondary effects we found slight rectitys or GI (RTOG scale) in 1.4 and that needs synthomatic medication or GII (RTOG scale) in 0.8%. We found slide hematuria or GI (RTOG scale) in the 53% and other measures or GII (RTOG scale) in the 2.64% was needed. Finally we had to set a urinary prove for acute retention in 4.3%.

CONCLUSION

The prostate brachyterapy is a complex procedure that needs a multidisciplinary team participation in order to be able to carry out. It avoids a long term hospitalization and allows for the patient to have daily activity within a short period of time. Despite the fact of the brief follow-up, the results over biochemical relapse and toxicity were similar to the ones in the literature. Tolerance to the implant was good. It would necessary a longer follow-up in order to be able to come to long term conclusions.

Does inverse planning applied to Iridium192 high dose rate prostate brachytherapy improve the optimization of the dose afforded by the Paris system?

BACKGROUND AND PURPOSE

The purpose of the work is to analyse for 192Ir prostate brachytherapy (BT) some of the different steps in optimizing the dose delivered to the CTV, urethra and rectum.

MATERIALS AND METHODS

Between 07/1998 and 12/2001, 166 patients were treated with 192Ir wires providing a low dose rate, according to the Paris system philosophy and with the 2D version of the treatment planning IsisR. 40-45 Gy were delivered after an external beam radiotherapy of 40 Gy. The maximum tolerable doses for BT were 25 Gy to the anterior third of the rectum on the whole length of the implant (R dose) and 52 Gy to the urethra on a 1cm length (Umax). A Umax/CTV dose ratio >1.3 represented a pejorative value as the planned dose of 40-45 Gy could not be achieved. On the other side a ratio <or=1.25 was considered optimal and the intermediate values satisfactory. A R/CTV dose ratio <0.55 which is easily obtained was also stated as an optimal situation. From the CT Scan images performed for these implants, a theoretical study investigated the possibilities of complementary optimization afforded by a 3D treatment planning. This work was based on an inverse planning philosophy and a stepping source technology (SST) for high dose rate 192Ir sources.

RESULTS

At the end of a learning curve reaching a plateau after the first 71 patients, 90% of the implants with 192Ir wires were stated at least satisfactory for a total rate of 82% for the whole population. When the 3D dosimetry for SST was used, the initial values >1.25 decreased significantly with optimization required on CTV contours and additional constraints on urethra while the R/CTV ratio was maintained under 0.55. For initial Umax/CTV >1.3 or >1.25 but <or=1.3 indeed, the mean respective values of 1.41+/-0.16 and 1.28+/-0.01 decreased to 1.28+/-0.24 and 1.17+/-0.09 (P<0.001), allowing to increase the total dose to the CTV by 4 Gy.

CONCLUSIONS

The Paris system which assumes a homogeneous distribution of a minimum number of catheters inside the CTV allowed to anticipate a satisfactory dosimetry in 82% of cases. However, this precision rate could be improved until 95% with an optimization approach based on an inverse planning philosophy. These new 3D optimization methods, ideally based on good quality implants at first allow to deliver the highest doses with minimal probability of creating cold spots inside the CTV or unacceptable hot spots outside.

Dosimetry and cancer control after low-dose-rate prostate brachytherapy

PURPOSE

To describe the relationship between two commonly used dosimetric quantifiers (dose received by 90% of the prostate [D(90)] and volume receiving 100% of dose [V(100)]) and biochemical disease-free survival (bDFS) in a cohort of men treated with low-dose-rate prostate brachytherapy (LDRPB).

METHODS AND MATERIALS

The information in this report concerned the first 63 men treated with LDRPB alone at our institution between September 1997 and September 1998. All men had histologically confirmed, clinically localized prostate cancer. All men were treated with(125)I. The prescription dose was 144 Gy according to the Task Group 43 formalism. LDRPB was performed jointly by a radiation oncologist and urologist. Dosimetric quantifiers (D(90), V(100)) were calculated from a CT scan performed 1 month after LDRPB. Biochemical recurrence was defined according to the American Society for Therapeutic Radiology and Oncology consensus definition. Biochemical relapse-free survival (bRFS) was estimated using the product-limit method. D(90) and V(100) were examined as putative covariates for bRFS using the proportional hazards regression method. All p values are two-sided.

RESULTS

The median follow-up for the entire cohort was 62 months. The median D(90) was 122 Gy (range, 57-171Gy), and in 16 (25%) of 63 patients, the calculated D(90) was >140 Gy. The median V(100) was 81% (range, 51-97%). Nine men developed evidence of biochemical relapse at a median of 19 months (range, 6-38 months). The 5-year estimate of bRFS was 85% (95% confidence interval, 80-90%). The 5-year estimates of bRFS according to D(90) were as follows: D(90) > or =140 Gy, 86%; D(90) <140 Gy, 84% (p = not statistically significant). No threshold value of D(90) was predictive of the 5-year estimates of bRFS until the D(90) was <80 Gy (D(90) > or =80 Gy, 89%; D(90) <80 Gy, 50%; p = 0.02). The 5-year estimates of bRFS according to V(100) were as follows: V(100) > or =85%, 87%; V(100) <85%, 84% (p = not statistically significant). No threshold value of V(100) was predictive of the 5-year estimates of BRFS unless the dosimetry was particularly poor. The 5-year BRFS was 89% if the V(100) was > or =65% compared with 40% if the V(100) was <65% (p = 0.006).

CONCLUSION

The dosimetric or quantifiers described in this report did not predict for bRFS after LDRPB unless the dosimetry was very poor. This finding is not in complete agreement with those of previous reports. Possible reasons for this observation are (1) the study in underpowered, (2) inherent measurement error, (3) dosimetric quantifiers are poor surrogates of the dose received by the cancer, and (4) length of follow-up. Additional work in the area of quality assessment after LDRPB is required.

Randomized trial of high- and low-source strength 125I prostate seed implants

PURPOSE

A range of (125)I isotope activities is used in permanent prostate implants. In this study, we compared the implant quality and cost in patients randomized to high-source or low-source strength permanent implants.

METHODS AND MATERIALS

Forty patients were randomized to receive high (0.76 microGy/m(2)/h) or low (0.4 microGy/m(2)/h) seed strength implants. The two treatment arms had a comparable mix of primary and boost patients and underwent implantation by the same team. The postimplant dosimetric evaluation was performed using CT (seed position) and T(2)-weighted MRI (prostate) scans registered using mutual information techniques. The implant quality parameters were assessed by dose indexes (ratio of achieved dose to planned dose) to quantify the relative error tolerance.

RESULTS

The high-source strength implants had better dose coverage as defined by the dose index; a larger percentage of volume receiving 100% of the prescribed dose as determined by CT (V(100)) (96.3% +/- 3.5% vs. 90.4% +/- 5.3%; p <0.002); lower seed cost (2400 US dollar vs. 3840 US dollar average/case); and took less operating room time on average (67 +/- 16 min vs. 85 +/- 20 min; p <0.004). Finally, the differences in the rectal and urethral doses were not statistically significant between the two treatment arms.

CONCLUSION

All 40 patients received an excellent implant as indicated by the CT V(100). Unless long-term toxicity differs, high-source strength seed implants improve the probability of excellent implant quality and decrease the average cost of permanent prostate implants.

Impact of supplemental external beam radiotherapy and/or androgen deprivation therapy on biochemical outcome after permanent prostate brachytherapy

PURPOSE

To evaluate the impact of supplemental external beam radiotherapy (EBRT) and/or androgen deprivation therapy (ADT) on 8-year biochemical outcome after permanent prostate brachytherapy.

METHODS AND MATERIALS

Between April 1995 and January 2001, 668 consecutive patients underwent brachytherapy using either (103)Pd or (125)I for clinical Stage T1b-T3aNxM0 (2002 American Joint Committee on Cancer) adenocarcinoma of the prostate gland. No patient underwent seminal vesicle biopsy or pathologic lymph node staging. The median follow-up was 58.6 months. Biochemical progression-free survival was defined by the American Society for Therapeutic Radiology and Oncology consensus definition. The clinical, treatment, and dosimetric parameters evaluated for biochemical progression-free survival included supplemental EBRT, ADT, patient age, clinical stage, Gleason score, preimplant prostate specific antigen (PSA), risk group, percentage of positive biopsies, isotope used, prostate volume, planning volume, percentage of target volume receiving 100%, 150%, and 200% of prescribed dose, minimal percentage of dose covering 90% of target volume, tobacco status, hypertension, and diabetes.

RESULTS

For the entire group, the actuarial 8-year biochemical progression-free survival rate was 98.2%, 98.4%, and 88.2% for low-, intermediate-, and high-risk patients, respectively, with a median PSA level of <0.1 ng/mL for all risk groups and ADT and EBRT subgroups. At last follow-up, only 5 patients (0.8%) had died of metastatic prostate cancer. In multivariate analysis, Gleason score, percentage of positive biopsies, and ADT predicted for biochemical outcome in high-risk patients. In low- and intermediate-risk patients, none of the evaluated variables predicted for biochemical outcome. For the entire population, pretreatment PSA level, Gleason score, ADT, and clinical stage predicted for 8-year biochemical progression-free survival, with the percentage of positive biopsies approaching statistical significance.

CONCLUSION

Prostate brachytherapy results in a high probability of 8-year biochemical progression-free survival for low-, intermediate-, and high-risk patients. Although the role of supplemental EBRT could not be adequately evaluated in high-risk patients, it did not improve biochemical outcome in low- and intermediate-risk patients. However, ADT resulted in a statistically significant improvement in progression-free survival for high-risk patients.

Image guided I125 prostate brachytherapy with Hybrid Interactive Mick technique in the community setting: How does it compare?

The aim of this study is to evaluate the target coverage, procedural techniques, and merits of Hybrid Interactive Mick (HIM) I125 transperineal permanent implantation (TPPI) of the prostate performed with 10 urologists in a community hospital. Detailed day 0 post-implant dosimetric evaluations of TPPI procedures were performed on 333 consecutive monotherapy patients treated between September 2000 and November 2003 at a single institution. All patients underwent TPPI with HIM. Pelvic and CXR films were obtained for a manual seed count at day 0 and again > day 90 on 175 patients. The HIM-prostate brachytherapy performed in a community hospital provided median D(90), V100, and V150 values of 157Gy, 94%, and 42.3%, respectively. 18% of patients had seed migration to the lungs while 2% had seed migration to the bladder. Only 7 patients (4%) had 2 or more seeds migrate to the lungs. Procedure times average 38 minutes and number of needles used averaged 18. The post-implant urinary retention rate was 2.1% Use of HIM-prostate brachytherapy in the community setting with multiple urologists reproducibly maintained excellent and consistent dosimetric coverage. Procedure times and number of needles used were minimized, and with careful attention to image-guided technique, seed migration to bladder and lung was also minimized.

Permanent interstitial brachytherapy in younger patients with clinically organ-confined prostate cancer

OBJECTIVES

To evaluate biochemical progression-free survival in hormone-naive men 62 years of age or younger with clinically organ-confined prostate cancer who underwent brachytherapy with or without supplemental external beam radiotherapy.

METHODS

From April 1995 through December 2000, 119 hormone-naive patients 62 years of age or younger underwent permanent interstitial brachytherapy for clinical T1b-T2cNxM0 (2002 American Joint Committee on Cancer) prostate cancer. No patient underwent seminal vesicle biopsy or pathologic lymph node staging. The median follow-up was 5.4 years. Biochemical progression-free survival was defined by either a prostate-specific antigen (PSA) level of 0.4 ng/mL or less after a nadir or by the American Society for Therapeutic Radiology and Oncology consensus definition. No patient was lost to follow-up. The clinical, treatment, and dosimetric parameters evaluated for biochemical progression-free survival included age, clinical T stage, Gleason score, pretreatment PSA level, risk group, percentage of positive biopsies, isotope, supplemental external beam radiotherapy, prostate volume, brachytherapy planning volume, percentage of the target volume receiving 100%, 150%, and 200% of the prescribed dose, minimal percentage of the prescribed dose covering 90% of the target volume, and tobacco status.

RESULTS

For the entire group, the actuarial 7-year biochemical progression-free survival rate was 96.1% and 98.3% for a PSA cutpoint of 0.4 ng/mL or less and for the American Society for Therapeutic Radiology and Oncology consensus definition, respectively. Using a PSA biochemical control definition of 0.4 ng/mL or less, 93.1%, 100%, and 95.2% of the low-risk, intermediate-risk, and high-risk hormone-naive patients were free of biochemical progression. The median post-treatment PSA level for the biochemically disease-free group was less than 0.1 ng/mL. In multivariate analysis, only the pretreatment PSA level predicted the biochemical outcome.

CONCLUSIONS

Hormone-naive patients 62 years of age or younger have a high probability of 7-year biochemical progression-free survival after permanent interstitial brachytherapy with or without supplemental external beam radiotherapy.

Transperineal interstitial permanent prostate brachytherapy for Japanese prostate cancer patients in Hawaii

BACKGROUND

Our aim was to report clinical and biochemical outcomes of transperineal interstitial permanent prostate brachytherapy in the treatment of Japanese patients with clinically organ-confined prostate cancer in Hawaii.

METHODS

Ninety-five Japanese patients underwent transperineal interstitial permanent prostate brachytherapy using either iodine-125 or palladium-103 for clinical T1c-T2b N0 M0 prostate cancer. These procedures were carried out between December 1998 and December 2002 at The Queen's Medical Center in Honolulu, Hawaii. Prostate-specific antigen measurements were collected from all patients at follow up. Biochemical failure was defined by three consecutive rises in prostate-specific antigen levels, based on the criteria of the American Society for Therapeutic Radiology and Oncology Consensus panel.

RESULTS

The median patient age was 71 years (range, 46-87 years). Thirty-six patients were implanted with either iodine-125 or palladium-103 as monotherapy; 59 patients received moderate-dose external beam irradiation first, followed by a prostate brachytherapy boost. The median follow-up length, calculated from the day of implantation, was 801 days (range, 237-1421 days). During this follow-up period, The Kaplan-Meier estimate of freedom from biochemical failure in this series was 94%. No major complications were observed.

CONCLUSIONS

Clinical and biochemical outcomes in the treatment of Japanese patients in Hawaii suffering from localized prostate cancer, using transperineal interstitial permanent prostate brachytherapy, with or without external beam irradiation, compared favorably to results in similarly treated patients in the general US population.

125I reimplantation in patients with poor initial dosimetry after prostate brachytherapy

PURPOSE

In this case report, we describe 7 patients with suboptimal dosimetry after (125)I prostate brachytherapy who underwent a second implant procedure to improve the dosimetric coverage of the prostate.

METHODS AND MATERIALS

Seven patients underwent second (125)I implants for suboptimal dosimetry after their initial implant for prostate cancer. The pretreatment characteristics (clinical stage, Gleason score, initial prostate-specific antigen level, location of positive cores, International Prostate Symptom Score, potency, use of androgen suppression, initial implant planning characteristics) were noted. The "Day 30" CT-based dosimetry parameters after the first implant and "Day 0" CT-based dosimetry after the reimplant were recorded (volumes of prostate and rectum covered by 100% and 150% of the dose and dose covering 90% of the prostate volume). The toxicity of the second procedure, International Prostate Symptom Scores before and after reimplantation, the clinical course, and prostate-specific antigen outcomes after reimplant were examined. We described our reimplant planning and intraoperative procedure.

RESULTS

In all 7 patients, we were able to achieve very favorable dosimetry after the second procedure. The acute toxicity of the reimplant procedure was reasonably low, and the short-term prostate-specific antigen outcome has been favorable.

CONCLUSION

It is possible to add more seeds safely to the dosimetrically cool area after the initial brachytherapy procedure and achieve excellent postimplant dosimetry with acceptable acute toxicity. The ultimate benefits and long-term toxicity of reimplantation are unknown.

Prognostic significance of percent positive biopsies in clinically organ-confined prostate cancer treated with permanent prostate brachytherapy with or without supplemental external-beam radiation

PURPOSE

The purpose of this paper was to evaluate the relationship between the percentage of positive biopsies and the biochemical outcome in hormone-naive patients undergoing permanent prostate brachytherapy with or without supplemental external-beam radiation therapy.

MATERIALS AND METHODS

Four hundred thirteen hormone-naive patients underwent prostate brachytherapy for clinical T1c-T2b NxM0 (1997 American Joint Committee on Cancer classification) adenocarcinoma of the prostate gland from April 1995 through June 2001. The median patient age was 66.9 years, and the median pretreatment prostate-specific antigen value was 6.8 ng/mL. The median follow-up was 52 months. Patients were stratified by percentage of positive biopsy results into the following cohorts: < 34%, 34%-50%, and > 50%. The influences of percentage of positive biopsy results, patient age, clinical T stage, Gleason score, pretreatment prostate-specific antigen value, risk group, prostate volume, supplemental external-beam radiation therapy, isotope, percentage of prescribed dose covering 90% of the target volume (D90), and volume receiving 100%, 150%, and 200% of the prescribed dose (V100/150/200) were evaluated. Biochemical disease-free survival was defined by the American Society of Therapeutic Radiology and Oncology consensus definition.

RESULTS

For all 413 patients, the 7-year actuarial freedom from biochemical progression rate was 99.4%, 94.3%, and 89.2% when stratified by percentage of positive biopsy results in the < 34%, 34%-50%, and > 50% groups, respectively. When low-, intermediate-, and high-risk patients were stratified by percentage of positive biopsy results, a nonsignificant trend for increased biochemical progression was noted with increasing positive biopsy results. In multivariate analysis, percentage of positive biopsy results and pretreatment prostate-specific antigen value were the only significant predictors of biochemical outcome. The median postimplantation prostate-specific antigen value for all biochemically disease-free patients was < 0.1 ng/mL, regardless of risk group or percentage of positive biopsy results cohort.

DISCUSSION

Multivariate analysis demonstrated that percentage of positive biopsy results and pretreatment prostate-specific antigen value were statistically significant predictors of 7-year biochemical progression-free survival. However, the relatively small absolute differences in biochemical outcome based on percentage of positive biopsy results may be a result of radiation dose escalation with the utilization of generous periprostatic treatment margins.

Cancer control after low-dose-rate prostate brachytherapy performed by a multidisciplinary team with no previous prostate brachytherapy experience

OBJECTIVES

To describe the biochemical disease-free survival observed in the first cohort men treated by a multidisciplinary team of clinicians with no previous experience in low-dose-rate prostate brachytherapy (LDRPB).

METHODS

The information in this report concerns the first 63 men treated with LDRPB alone at our institution between September 1997 and September 1998. All men had histologically confirmed, clinically localized prostate cancer. All men were treated with iodine 125 according to published methods. The prescription dose was 144 Gy according to the Task Group 43 formalism. LDRPB was performed jointly by a radiation oncologist and urologist. Three definitions of biochemical recurrence were used: the American Society for Therapeutic Radiology and Oncology consensus definition; prostate-specific antigen level greater than 0.4 ng/mL at last follow-up; and prostate-specific antigen level greater than 0.2 ng/mL at last follow-up. Biochemical relapse-free survival was estimated using the product-limit method. Putative covariates for biochemical relapse-free survival were examined using the proportional hazards regression model. All P values are two-sided.

RESULTS

The median follow-up for the entire cohort was 62 months. Of the 63 men, 45 (71%) had more than 60 months of follow-up. The median pretreatment prostate-specific antigen level was 6.68 ng/mL (range 1.1 to 23), and most men (44 of 63; 70%) had nonpalpable disease. The institutionally assigned Gleason score was less than 7 in 54 men (86%). Nine men developed evidence of biochemical relapse at a median of 19 months (range 6 to 38). The 5-year estimate of biochemical relapse-free survival was 85% (95% confidence interval 80% to 90%), 80% (95% confidence interval 74% to 86%), and 70% (95% confidence interval 64% to 76%) according to the three definitions given above.

CONCLUSIONS

The biochemical results achieved in the first cohort of men treated with LDRPB by a previously inexperienced multidisciplinary team of clinicians are similar to the results reported from centers with extensive LDRPB experience.

Relative influence of Gleason score and pretreatment PSA in predicting survival following brachytherapy for prostate cancer

PURPOSE

To evaluate 10-year survival rates after prostate brachytherapy and to assess the relative importance of pretreatment prostate-specific antigen (PSA) and Gleason score in predicting cancer death.

MATERIALS AND METHODS

A retrospective review was performed on all patients treated with permanent brachytherapy for stage T1 or T2 primary prostate cancer at a single institution from December 1988 through June 30, 1998. The study cohort consisted of 1266 patients with a median follow-up of 4.1 years and a maximum of 12.6 years. Actuarial survival and cause-specific survival rates were calculated as the primary endpoints, and compared at 5 and 10 years. Groups studied consist of PSA<or=4, PSA 4.1-10, and PSA>or=10 as well as Gleason 2-4, 5-6, and 7-10. Multivariate and univariate analysis were performed looking at stage, grade, PSA, and risk group as variables.

RESULTS

The median age at the time of treatment was 73 years and at the time of analysis 603 patients were known to be alive. Overall survival is 38% at 10 years, however most deaths were unrelated to prostate cancer. Cause specific survival at 5 and 10 years is 98% and 87%. Both grade (>or=Gleason 7) and PSA (>or=10 ng/ml) predict adversely for cancer death within 10 years. Patients with low grade or PSA at presentation reveal prostate cancer-specific survival of 91% and 98%, respectively. By contrast, men with high grade or high PSA presentation have survival of 66% and 69% at 10 years. In multivariate analysis, the presence of one of these adverse features carries a hazard ratio of cancer death of 4.7 and 6.4, while the presence of multiple risk factors places patients in an unfavorable risk group with a hazard ratio of 27.

CONCLUSIONS

Biochemical disease-free survival is a useful tool to assess prostate cancer treatments and is predicted based on established pretreatment risk groups. Long-term cancer-specific survival is ultimately a more important endpoint. Brachytherapy is reported here to be an excellent therapeutic alternative for selected early stage patients with prostate cancer. This is based on 10-year cause specific survival, which may also be predicted by stage, grade, PSA, and risk group. Of these, the risk group remains the most powerful parameter to identify those patients at highest risk of biochemical failure and death from prostate cancer.