Comparison of Radical Prostatectomy and Iodine 125 Interstitial Radiotherapy for the Treatment of Clinically Localized Prostate Cancer: A 7-Year Biochemical (PSA) Progression Analysis

Long-term oncologic outcomes of radiotherapy combined with maximal androgen blockade for localized, high-risk prostate cancer

Background

To assess the oncologic outcomes of radiation therapy (RT) combined with maximal androgen blockade (MAB) and prostate-specific antigen (PSA) kinetics in patients with localized, high-risk prostate carcinoma (PCa).

Methods

Three-hundred twenty individuals with localized PCa who underwent RT + MAB in 2001–2015 were evaluated retrospectively. All patients had received 36 months of MAB therapy and 45 Gy of pelvic irradiation, plus a dose-escalated external beam radiation therapy (DE-EBRT) boost to 76~81 Gy (MAB + EBRT group), or a low-dose-rate prostate permanent brachytherapy (LDR-PPB) boost to 110 Gy with I-125 (MAB + EBRT + PPB group).

Results

Follow-up median is 90 months, ranging from 12 to 186 months; 117 (36.6%) and 203 (63.4%) cases underwent MAB + EBRT and MAB + EBRT + PPB, respectively. Multivariate Cox regression showed that the PPB regimen and PSA kinetics were positive indicators of oncologic outcomes. Compared with MAB + EBRT, MAB + EBRT + PPB remarkably improved PSA kinetics more pronouncedly: PSA nadir (1.3 ± 0.7 vs 0.11 ± 0.06 ng/mL); time of PSA decrease to nadir (7.5 ± 1.8 vs 3.2 ± 2.1 months); PSA doubling time (PSADT; 15.6 ± 4.2 vs 22.6 ± 6.1 months); decrease in PSA (84.6 ± 6.2% vs 95.8 ± 3.4%). Additionally, median times of several important oncologic events were prolonged in the MAB + EBRT + PPB group compared with the MAB + EBRT group: overall survival (OS; 12.3 vs 9.1 years, P < 0.001), biochemical recurrence-free survival (BRFS; 9.8 vs 6.5 years, P < 0.001), skeletal-related event (SRE; 10.4 vs 8.2 years, P < 0.001), and cytotoxic chemotherapy (CCT; 11.6 vs 8.8 years, P = 0.007).

Conclusion

MAB + EBRT + PPB is extremely effective in patients with localized, high-risk PCa, indicating that PPB may play a synergistic role in improving PSA kinetics and independently predicts oncologic outcomes.

Meta-analysis of studies comparing oncologic outcomes of radical prostatectomy and brachytherapy for localized prostate cancer

Background

The aim of this study was to compare oncologic outcomes of radical prostatectomy (RP) with brachytherapy (BT).

Methods

A literature review was conducted according to the 'Preferred reporting items for systematic reviews and meta-analyses' (PRISMA) statement. We included studies reporting comparative oncologic outcomes of RP versus BT for localized prostate cancer (PCa). From each comparative study, we extracted the study design, the number and features of the included patients, and the oncologic outcomes expressed as all-cause mortality (ACM), PCa-specific mortality (PCSM) or, when the former were unavailable, as biochemical recurrence (BCR). All of the data retrieved from the selected studies were recorded in an electronic database. Cumulative analysis was conducted using the Review Manager version 5.3 software, designed for composing Cochrane Reviews (Cochrane Collaboration, Oxford, UK). Statistical heterogeneity was tested using the Chi-square test.

Results

Our cumulative analysis did not show any significant difference in terms of BCR, ACM or PCSM rates between the RP and BT cohorts. Only three studies reported risk-stratified outcomes of intermediate- and high-risk patients, which are the most prone to treatment failure.

Conclusions

our analysis suggested that RP and BT may have similar oncologic outcomes. However, the analysis included a limited number of studies, and most of them were retrospective, making it impossible to derive any definitive conclusion, especially for intermediate- and high-risk patients. In this scenario, appropriate urologic counseling remains of utmost importance.

Low-dose-rate Brachytherapy for Prostate Cancer in Low-resource Settings

PURPOSE

In areas with limited health care, it is important to identify and implement effective treatment methods and to optimize available resources. We investigated the implementation of a low-dose-rate (LDR) brachytherapy program for the treatment of prostate cancer (PCa) in a low-resource setting such as Puerto Rico (PR), where PCa is the main cause of cancer-associated death.

METHODS AND MATERIALS

After institutional approval, the medical records of patients with nonmetastatic PCa undergoing LDR brachytherapy from 2008 to 2013 were reviewed from PR. The factors analyzed included adequate D₉₀ (radiation dose delivered to 90% of the target volume) coverage (≥140 Gy), early and late toxicity (Common Terminology Criteria for Adverse Events grade >2), and prostate-specific antigen failure. Freedom from biochemical failure was evaluated using Kaplan-Meier analysis.

RESULTS

The barriers to implementation of LDR brachytherapy in a country with limited resources were identified. These included lack of access to funding for startup costs, specific referral patterns, lack of trained support staff, such as dosimetrists and physicists, and initial opposition from insurance companies for reimbursement. The initial results from 191 patients were included in the present study with a median follow-up period of 26 months. Prostate-specific antigen failure occurred in 6 patients (3%). No early or late gastrointestinal toxicity (grade >2) developed. Only 3 (2%) and 2 (1%) patients experienced early and late genitourinary toxicity (grade >2), respectively. The 2- and 3-year freedom from biochemical failure in this population was 97% and 95.9%, respectively.

CONCLUSIONS

At present, limited data are available delineating the barriers faced by low-resource settings in the implementation of LDR brachytherapy. Our data highlight the issues unique to this environment and support the use of LDR brachytherapy as a reliable and effective treatment modality for patients with PCa in low-resource settings.

Comparative analysis of short - term functional outcomes and quality of life in a prospective series of brachytherapy and Da Vinci robotic prostatectomy

Introduction

There is a growing interest in achieving higher survival rates with the lowest morbidity in localized prostate cancer (PC) treatment. Consequently, minimally invasive techniques such as low-dose rate brachytherapy (BT) and robotic-assisted prostatectomy (RALP) have been developed and improved. Comparative analysis of functional outcomes and quality of life in a prospective series of 51BT and 42Da Vinci prostatectomies DV

Materials and Methods

Comparative analysis of functional outcomes and quality of life in a prospective series of 93 patients with low-risk localized PC diagnosed in 2011. 51patients underwent low-dose rate BT and the other 42 patients RALP. IIEF to assess erectile function, ICIQ to evaluate continence and SF36 test to quality of life wee employed.

Results

ICIQ at the first revision shows significant differences which favour the BT group, 79% present with continence or mild incontinence, whereas in the DV group 45% show these positive results. Differences disappear after 6 months, with 45 patients (89%) presenting with continence or mild incontinence in the BT group vs. 30 (71%) in the DV group. 65% of patients are potent in the first revision following BT and 39% following DV. Such differences are not significant and cannot be observed after 6 months. No significant differences were found in the comparative analysis of quality of life.

Conclusions

ICIQ after surgery shows significant differences in favour of BT, which disappear after 6 months. Both procedures have a serious impact on erectile function, being even greater in the DV group. Differences between groups disappear after 6 months.

Dosimetric and radiobiological comparison of volumetric modulated arc therapy, high-dose rate brachytherapy, and low-dose rate permanent seeds implant for localized prostate cancer

To investigate the dosimetric and radiobiological differences among volumetric modulated arc therapy (VMAT), high-dose rate (HDR) brachytherapy, and low-dose rate (LDR) permanent seeds implant for localized prostate cancer. A total of 10 patients with localized prostate cancer were selected for this study. VMAT, HDR brachytherapy, and LDR permanent seeds implant plans were created for each patient. For VMAT, planning target volume (PTV) was defined as the clinical target volume plus a margin of 5mm. Rectum, bladder, urethra, and femoral heads were considered as organs at risk. A 78Gy in 39 fractions were prescribed for PTV. For HDR and LDR plans, the dose prescription was D90 of 34Gy in 8.5Gy per fraction, and 145Gy to clinical target volume, respectively. The dose and dose volume parameters were evaluated for target, organs at risk, and normal tissue. Physical dose was converted to dose based on 2-Gy fractions (equivalent dose in 2Gy per fraction, EQD2) for comparison of 3 techniques. HDR and LDR significantly reduced the dose to rectum and bladder compared with VMAT. The Dmean (EQD2) of rectum decreased 22.36Gy in HDR and 17.01Gy in LDR from 30.24Gy in VMAT, respectively. The Dmean (EQD2) of bladder decreased 6.91Gy in HDR and 2.53Gy in LDR from 13.46Gy in VMAT. For the femoral heads and normal tissue, the mean doses were also significantly reduced in both HDR and LDR compared with VMAT. For the urethra, the mean dose (EQD2) was 80.26, 70.23, and 104.91Gy in VMAT, HDR, and LDR brachytherapy, respectively. For localized prostate cancer, both HDR and LDR brachytherapy were clearly superior in the sparing of rectum, bladder, femoral heads, and normal tissue compared with VMAT. HDR provided the advantage in sparing of urethra compared with VMAT and LDR.

Development of a computational simulation tool to design a protocol for treating prostate tumours using transurethral laser photothermal therapy

OBJECTIVES

The objective of this study was to design laser treatment protocols to induce sufficient thermal damage to a tumour embedded in a prostate model, while protecting the surrounding healthy tissue.

METHODS

A computational Monte Carlo simulation algorithm of light transport in a spherical prostatic tumour containing gold nanorods was developed to determine laser energy deposition. The laser energy absorption was then used to simulate temperature elevations in the tumour embedded in an elliptical human prostate model. The Arrhenius integral was coupled with the heat transfer model to identify heating protocols to induce 100% damage to the tumour, while resulting in less than 5% damage to the surrounding sensitive prostatic tissue.

RESULTS

Heating time to achieve 100% damage to the tumour was identified to be approximately 630 s when using a laser irradiance of 7 W/cm2 incident on the prostatic urethral surface. Parametric studies were conducted to show how the local blood perfusion rate and urethral surface cooling affect the heating time to achieve the same thermal dosage. The heating time was shorter when cooling at the urethra was not applied and/or with heat-induced vasculature damage. The identified treatment protocols were acceptable since the calculated percentages of the damaged healthy tissue volume to the healthy prostatic volume were approximately 2%, less than the threshold of 5%. The approach and results from this study can be used to design individualised treatment protocols for patients suffering from prostatic cancer.

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.

Comparison of Health-Related Quality of Life 5 Years After SPIRIT: Surgical Prostatectomy Versus Interstitial Radiation Intervention Trial

Purpose

The American College of Surgeons Oncology Group phase III Surgical Prostatectomy Versus Interstitial Radiation Intervention Trial comparing radical prostatectomy (RP) and brachytherapy (BT) closed after 2 years due to poor accrual. We report health-related quality of life (HRQOL) at a mean of 5.3 years for 168 trial-eligible men who either chose or were randomly assigned to RP or BT following a multidisciplinary educational session.

Patients and Methods

After initial lack of accrual, a multidisciplinary educational session was introduced for eligible patients. In all, 263 men attended 47 sessions. Of those, 34 consented to random assignment, 62 chose RP, and 94 chose BT. Five years later, these 190 men underwent HRQOL evaluation by using the cancer-specific 50-item Expanded Prostate Cancer Index Composite, the Short Form 12 Physical Component Score, and Short Form 12 Mental Component Score. Response rate was 88.4%. The Wilcoxon rank sum test was used to compare summary scores between the two interventions.

Results

Of 168 survey responders, 60.7% had BT (9.5% randomly assigned) and 39.3% had RP (9.5% randomly assigned). Median age was 61.4 years for BT and 59.4 for RP (P = .05). Median follow-up was 5.2 years (range, 3.2 to 6.5 years). For BT versus RP, there was no difference in bowel or hormonal domains, but men treated with BT scored better in urinary (91.8 v 88.1; P = .02) and sexual (52.5 v 39.2; P = .001) domains, and in patient satisfaction (93.6 v 76.9; P < .001).

Conclusion

Although treatment allocation was random in only 19%, all patients received identical information in a multidisciplinary setting before selecting RP, BT, or random assignment. HRQOL evaluated 3.2 to 6.5 years after treatment showed an advantage for BT in urinary and sexual domains and in patient satisfaction.

Quality-of-Life Impact of Primary Treatments for Localized Prostate Cancer in Patients Without Hormonal Treatment

Purpose

Earlier studies evaluating the effect on quality of life (QoL) of localized prostate cancer interventions included patients receiving adjuvant hormone therapy, which could have affected their outcomes. Our objective was to compare the QoL impact of the three most common primary treatments on patients who were not receiving adjuvant hormonal treatment.

Patients and Methods

This was a prospective study of 435 patients treated with radical prostatectomy, external-beam radiotherapy, or brachytherapy. QoL was assessed before and after treatment with the Short Form-36 and the Expanded Prostate Cancer Index Composite. Differences between groups were tested by analysis of variance. Distribution of outcome at 3 years was examined by stratifying according to baseline status. Generalized estimating equation models were constructed to assess the effect of treatment over time.

Results

Compared with the brachytherapy group, the prostatectomy group showed greater deterioration on urinary incontinence and sexual scores but better urinary irritative-obstructive results (−18.22, −13.19, and +6.38, respectively, at 3 years; P < .001). In patients with urinary irritative-obstructive symptoms at baseline, improvement was observed in 64% of those treated with nerve-sparing radical prostatectomy. Higher bowel worsening (−2.87, P = .04) was observed in the external radiotherapy group, with 20% of patients reporting bowel symptoms.

Conclusion

Radical prostatectomy caused urinary incontinence and sexual dysfunction but improved pre-existing urinary irritative-obstructive symptoms. External radiotherapy and brachytherapy caused urinary irritative-obstructive adverse effects and some sexual dysfunction. External radiotherapy also caused bowel adverse effects. Relevant differences between treatment groups persisted for up to 3 years of follow-up, although the difference in sexual adverse effects between brachytherapy and prostatectomy tended to decline over long-term follow-up. These results provide valuable information for clinical decision making.

Comparison of two treatment approaches for prostate cancer: intensity-modulated radiation therapy combined with 125I seed-implant brachytherapy or 125I seed-implant brachytherapy alone

The purpose of the present study was to assess the results of two different treatment approaches for clinically localized prostate cancer: intensity‐modulated radiation therapy (IMRT) followed by I125 seed‐implant brachytherapy and I125 seed‐implant brachytherapy alone. We studied our 30 most recent consecutive patients. The sample population consisted of 15 cases treated with IMRT (50.4 Gy) followed by I125 seed‐implant boost (95 Gy), and 15 cases treated with I125 seed implant only (144 Gy). We analyzed established dosimetric indices and various clinical parameters. In addition, we also evaluated and compared the acute urinary morbidities of the two treatment approaches, as assessed by the international prostate symptom score (IPSS). In our series, acute urinary morbidity was slightly increased with IMRT followed by I125 seed‐implant brachytherapy as compared with I125 seed‐implant brachytherapy alone. In addition, we observed no statistically significant correlation between the IPSS and the maximum or mean urethral dose. The combination of IMRT and seed‐implant brachytherapy presents an alternative opportunity to treat clinically localized prostate cancer. The full potential of the procedure needs to be further investigated.

PACS number: 87.53.Tf

Permanent 125I-seed brachytherapy or radical prostatectomy: a prospective comparison considering oncological and quality of life results

OBJECTIVE

To assess the quality of life in patients with prostate cancer after permanent brachytherapy (BT) or radical perineal prostatectomy (RP).

PATIENTS AND METHODS

The American Brachytherapy Society recommends the permanent implantation of radioactive seeds as a monotherapy for patients with T1-T2aN0M0 prostate cancer and a prostate-specific antigen (PSA) level of < or = 10 ng/mL, a Gleason score of <7 and a prostate volume of <60 mL. Using these criteria, 132 patients with low-risk prostate cancer were selected; 52 had BT with 125I-seed implantation, 38 had RP with unilateral nerve-sparing (RP + NS) and 42 extended RP (RP group). Only patients with unilateral tumour on biopsy were considered. Before therapy and 6, 12 and 24 months afterward, patients completed questionnaires to assess perceived health and function. PSA relapse was diagnosed with a PSA of >0.1 ng/mL for patients in the RP groups, and three consecutive PSA increases for those after BT.

RESULTS

Extraprostatic tumours were found in 18% of specimens taken during RP, and bilateral tumours in 63% of patients. After a mean follow-up of 27 months, there was PSA relapse in two of the 80 patients in the RP and RP + NS groups, and six of the 52 patients in the BT group; a significant difference, with a hazard ratio of 5.2. The acute morbidity was low in all groups. At 1 year, more than two incontinence pads were used by 5% of patients after RP and by 4% after BT. Similarly, at 1 year 15% of patients after RP and 13% after BT were bothered by urinary incontinence. Newly-developed fecal soiling was reported by 4%, 5% and 11% of the RP, RP + NS and BT groups respectively; none of the patients after RP and 4% after BT were bothered by this symptom. The duration and stiffness of erection was assessed after 1 year and reported to be equal or slightly decreased by a third after RP + NS and 38% after BT. Taking a 5-10 point difference as clinically relevant, role, emotional and social functioning were improved considerably after RP + NS than after BT, but sexual activity was impaired significantly after RP + NS than after BT.

CONCLUSIONS

Both therapies showed typical acute and late morbidity; the most bothersome late symptoms were urinary incontinence for patients after RP and fecal soiling after BT. Sexual function was impaired significantly in patients who were potent before RP + NS, whereas after BT men reported only a minor change in sexual performance at 1 year. Tumour control after a median follow-up of 27 months was better after RP but biochemical recurrence may still occur after > or = 5 years; therefore the present results are not mature enough and there were too few patients to provide a more definitive statement. As approximately 18% of patients considered to be appropriate candidates for BT had tumours extending beyond the prostate capsule or invading the seminal vesicles, nomograms are needed for more accurate information before therapy.

Radical prostatectomy, external beam radiotherapy <72 Gy, external beam radiotherapy ≥72 Gy, permanent seed implantation, or combined seeds/external beam radiotherapy for stage T1–T2 prostate cancer

PURPOSE

To review the biochemical relapse-free survival (bRFS) rates after treatment with permanent seed implantation (PI), external beam radiotherapy (EBRT) <72 Gy (EBRT <72), EBRT > or =72 Gy (EBRT > or =72), combined seeds and EBRT (COMB), or radical prostatectomy (RP) for clinical Stage T1-T2 localized prostate cancer treated between 1990 and 1998.

METHODS AND MATERIALS

The study population comprised 2991 consecutive patients treated at the Cleveland Clinic Foundation or Memorial Sloan Kettering at Mercy Medical Center. All cases had pretreatment prostate-specific antigen (iPSA) levels and biopsy Gleason scores (bGSs). Neoadjuvant androgen deprivation for < or =6 months was given in 622 cases (21%). No adjuvant therapy was given after local therapy. RP was used for 1034 patients (35%), EBRT <72 for 484 (16%), EBRT > or =72 for 301 (10%), PI for 950 (32%), and COMB for 222 patients (7%). The RP, EBRT <72, EBRT > or =72, and 154 PI patients were treated at Cleveland Clinic Foundation. The median radiation doses in EBRT <72 and EBRT > or =72 case was 68.4 and 78.0 Gy, respectively. The median follow-up time for all cases was 56 months (range 12-145). The median follow-up time for RP, EBRT <72, EBRT > or =72, PI, and COMB was 66, 75, 49, 47, and 46 months, respectively. Biochemical relapse was defined as PSA levels >0.2 for RP cases and three consecutive rising PSA levels (American Society for Therapeutic Radiology Oncology consensus definition) for all other cases. A multivariate analysis for factors affecting the bRFS rates was performed using the following variables: clinical T stage, iPSA, bGS, androgen deprivation, year of treatment, and treatment modality. The multivariate analysis was repeated excluding the EBRT <72 cases.

RESULTS

The 5-year bRFS rate for RP, EBRT <72, EBRT > or =72, PI, and COMB was 81%, 51%, 81%, 83%, and 77%, respectively (p <0.001). The 7-year bRFS rate for RP, EBRT <72, EBRT > or =72, PI, and COMB was 76%, 48%, 81%, 75%, and 77%, respectively. Multivariate analysis, including all cases, showed iPSA (p <0.001), bGS (p <0.001), year of therapy (p <0.001), and treatment modality (p <0.001) to be independent predictors of relapse. Because EBRT <72 cases had distinctly worse outcomes, the analysis was repeated after excluding these cases to discern any differences among the other modalities. The multivariate analysis excluding the EBRT <72 cases revealed iPSA (p <0.001), bGS (p <0.001), and year of therapy (p = 0.001) to be the only independent predictors of relapse. Treatment modality (p = 0.95), clinical T stage (p = 0.09), and androgen deprivation (p = 0.56) were not independent predictors for failure.

CONCLUSION

The biochemical failure rates were similar among PI, high-dose (> or =72 Gy) EBRT, COMB, and RP for localized prostate cancer. The outcomes were significantly worse for low-dose (<72 Gy) EBRT.

Dosimetric consequences of increased seed strength for I-125 prostate implants

Based on the findings of an earlier planning study, we compared post-implant dose distributions for two groups of 20 consecutive patients treated to 145 Gy with 0.414 and 0.526 U I-125 seeds. Dosimetric coverage as measured by the key clinical index D(90) was significantly better for the higher-strength seeds, with no apparent deleterious effects.

Alternative therapies for localized prostate cancer

Prostate cancer is the leading malignancy in men; an increase in detected localized prostate cancers is expected in the years to come. Radical prostatectomy, although effective, is associated with a considerable morbidity. The aim of minimal invasive alternative treatment options should be equal efficacy, but a decrease in side effects. Cryosurgical ablation of the prostate, brachytherapy, high-intensity focused ultrasound, and radiofrequency interstitial tumor ablation were evaluated after a literature review from a MEDLINE search (1966-2002). When compared with treatments in the 1960s and 1970s, increased safety is observed in all of the alternative treatments available today. Sophisticated technology, including the latest ultrasonography devices for exact planning and monitoring of treatment, contributes largely to this safety. Five-year results of cryosurgical ablation of the prostate show a prostate-specific antigen lower than 1 ng/mL in 60% of the cases; in the third generation, there are no long-term data available on cryosurgical ablation of the prostate. Recent outcome data of brachytherapy come close to results of radical prostatectomy series. Brachytherapy is the only true alternative at this point in time. High-intensity focused ultrasound and radiofrequency interstitial tumor ablation are promising new technologies that have proven to be able to induce extensive necrosis; however, follow-up is too short to determine their definite places in the treatment of prostate cancer.

The current and potential role of cryoablation as a primary therapy for localized prostate cancer

Targeted cryoablation of the prostate has evolved significantly since its reintroduction in the early 1990s. This evolution stems from engineering advancements, procedural refinement, introduction of temperature monitoring, and greater understanding of cryobiology. Recent publications demonstrate durable efficacy for cryoablation, equivalent to other therapies for low-risk disease and possibly superior for moderate- and high-risk prostate cancer. Morbidity following the procedure is mild in comparison with other therapies, with the exception of sexual function impairment. However, longer-term quality-of-life studies show that a significant number of patients return to having intercourse, and late-onset morbidities are not observed. These results contrast with those for radiotherapy--specifically brachytherapy--for which several recent studies document a decline in sexual function, protracted morbidity, and the emergence of late-onset morbidity. Cryoablation is an effective therapy with acceptable morbidity that should be offered as a treatment option to all patients with localized prostate cancer. Furthermore, cryoablation has the potential ability to be tailored to an individual patient's disease. As diagnostic tools and methods continue to advance, it may become possible to target the less aggressive forms of prostate cancer. Focal cryoablation may prove to be an ideal treatment modality in this setting.

Localized prostate cancer: radiation or surgery?

The treatment of localized prostate cancer remains controversial because of the lack of conclusive well-controlled or randomized studies comparing outcomes of radiotherapy to outcomes of radical prostatectomy. A comparison of different therapies should include issues of cancer control, morbidity, quality of life (QOL), salvage of primary treatment failures, late effects, and cost. The available data suggest that these two modalities provide similar rates of cancer control at 10 years, and that except for the youngest patients, choice of therapy should be based on toxicity and QOL issues.

Impact of a novel neoadjuvant and adjuvant hormone-deprivation approach on quality of life, voiding function, and sexual function after prostate brachytherapy

BACKGROUND

Data demonstrate a benefit from neoadjuvant and adjuvant hormone-deprivation therapy with luteinizing hormone-releasing hormone agonists in patients who are treated with radiotherapy for localized prostate carcinoma; however, this approach has detrimental effects on quality of life (QOL). A cross-sectional study was undertaken to evaluate the impact on QOL, voiding function, and sexual function of an alternative hormone-deprivation approach.

METHODS

Three hundred fifty patients with clinical T1c-T2b prostate carcinoma were treated from March 1997 to August 2000 either with palladium 103 brachytherapy (BTM) without hormone therapy or with 8 months of adjuvant and neoadjuvant hormone-deprivation therapy with an antiandrogen and finasteride (BTM+H), were mailed the Functional Assessment of Cancer Therapy (FACT) global well being QOL instrument (FACT-G), the American Urological Association symptom score (AUASS), and specific items addressing urinary control and sexual function from validated instruments. Differences between treatment groups were assessed as a function of time since treatment.

RESULTS

Seventy-two percent of patients responded to the questionnaire. No differences in overall FACT-G scores, AUASS scores, or AUASS subscale scores between the BTM group and the BTM+H group were found. The BTM+H group initially had lower personal well being FACT-G subscale scores, more urinary incontinence, and lower odds of attaining an erection sufficient for intercourse initially, although these differences disappeared with longer follow-up.

CONCLUSIONS

The use of neoadjuvant and adjuvant antiandrogen and finasteride with brachytherapy is associated with QOL equal to that of brachytherapy alone for the treatment of patients with localized prostate carcinoma, allowing the advantages of hormone manipulation in terms of tumor control without its downside.

Is there a preferred strength for regularly spaced 125I seeds in inverse-planned prostate implants?

PURPOSE

To determine whether a preferred seed strength exists for 125I prostate implants preplanned using a fixed intraneedle seed spacing of 1 cm and an objective needle placement strategy within the planning target volume (PTV), and incorporating explicit dose-volume constraints for the PTV and tissues at risk.

METHODS AND MATERIALS

Prostate, urethra, and rectum contours for 10 patients were obtained from transrectal ultrasound studies. The PTV was defined in accordance with Radiation Therapy Oncology Group (RTOG) 0019 protocol. Inverse planning software was used to optimally arrange seeds of strength 0.3-0.8 U to cover the PTV to D(Rx) = 145 Gy, and limit urethra and rectum doses to 150% and 100% of D(Rx), respectively. Isodose distributions and dosimetric indices were calculated: V(200), V(150), V(100), V(90), D(100), D(90) for PTV; V(150) for urethra; and V(100) for rectum. For seeds of strength 0.414 and 0.6 U and three prostate sizes, the sensitivity of V(90) and D(90) to elementary perturbations of the optimal seed arrangement were examined.

RESULTS

For our planning scenario, 125I seeds of strength 0.5-0.6 U provided the best possible PTV coverage while maintaining V(200) at approximately 25%. The source arrangement for 0.6-U seeds was only modestly more sensitive to perturbations than that for 0.414-U seeds. These findings may not be applicable to implants planned manually or that involve needle placement outside the PTV.

CONCLUSION

Given a particular source arrangement, inverse planning aimed at maximizing dosimetric coverage of the prostate while limiting doses to the urethra and rectum can be used to search for a preferred seed strength. For regularly spaced sources within the PTV, higher strength seeds can provide better dose coverage and better urethral protection than lower strength seeds.

A critical analysis of the interpretation of biochemical failure in surgically treated patients using the American Society for Therapeutic Radiation and Oncology criteria

PURPOSE

The use of prostate specific antigen (PSA) to indicate biochemical failure has become an accepted procedure to measure the effectiveness of therapy. Because long-term randomized studies comparing radiation modalities to radical prostatectomy are not available, use of biochemical recurrence as a surrogate measure of efficacy is increasing. Unfortunately, the definition of failure is not uniform among therapies. We evaluate how the American Society for Therapeutic Radiation and Oncology (ASTRO) criteria affect the interpretation of failure when applied to radical prostatectomy.

MATERIALS AND METHODS

We retrospectively reviewed data from 2,691 men who underwent anatomical radical prostatectomy for localized disease between 1985 and 2000. All patients had regular followup visits ranging from 6 months to 15 years (mean 6). No patients were treated with radiation or hormonal therapy preoperatively or postoperatively until clinical recurrence. Biochemical failure was defined as any measurable PSA 0.2 ng./ml. or greater. We evaluated how elements of the ASTRO criteria affected the failure rate when applied to this series. We looked at 1) backdating the failure date to the midpoint between nadir and first PSA greater than 0.2 ng./ml., 2) early censoring if only 1 or 2 increasing values were available and 3) defining failure after 3 consecutive PSA increases and backdating failure time (midpoint of nadir and first PSA increase).

RESULTS

Using actuarial analysis of the data defining failure as the first PSA 0.2 ng./ml. or greater, biochemical freedom from failure at 5, 10 and 15 years was 85%, 77% and 68%, respectively. In contrast, when backdating was used in this series, almost all failures occurred early with rare late failures (freedom from failure 82%, 80% and 80% at 5, 10 and 15 years, respectively). The difference in failure became even more pronounced when ASTRO criteria were applied requiring 3 consecutive increases, and backdating failure to the midpoint between nadir and first PSA (freedom from failure 90%, 90% and 90% at 5, 10 and 15 years, respectively).

CONCLUSIONS

The application of ASTRO criteria to a mature series of surgically treated patients with localized prostate cancer produced an apparent improvement in the probability of being biochemically free of disease at 15 years from 68% to 90%. Until prospective trials comparing these different therapies become available, caution should be exercised when interpreting outcomes between series due to the inherent differences in definition of biochemical failure.

Radical prostatectomy in the management of clinically localized prostate cancer

BACKGROUND

Several management options are available when prostate cancer is diagnosed at an early stage. However, the optimal treatment for localized prostate cancer is unknown, and reports in the literature are controversial regarding the best treatment modality for this early presentation.

METHODS

The authors review improvements in surgical technique that have decreased complications, and they address long-term outcomes of surgery related to cancer control.

RESULTS

Improvements in surgical techniques allow for decreased intraoperative complications. The incidence of long-term complications such as incontinence and impotency is also reduced. The 5- and 10-year progression-free survival with radical prostatectomy has improved.

CONCLUSIONS

Surgery today is safer with improvements in techniques. The long-term outcomes with surgery are excellent and, in several series, better than outcomes achieved with other treatment modalities.

Indications and contraindications for nerve-sparing radical prostatectomy

Nerve-sparing radical prostatectomy can be performed safely in most men undergoing radical prostatectomy. As is true in many aspects of prostate cancer diagnosis and therapy, the key element is patient selection. With many prostate tumors diagnosed at an earlier stage, the authors have seen a shift toward more favorable pathologic findings at the time of surgery. Concomitant with the success of early detection of prostate cancer is the realization that men are younger at the time of diagnosis and more interested in preserving sexual function. This article has described factors associated with an increased risk for extraprostatic tumor and, subsequently, an increased possibility of postprostatectomy cancer recurrence. Except for the previously mentioned absolute contraindications, none of these factors, by themselves, should be used to exclude a patient from nerve-sparing prostatectomy. Instead, meticulous attention must be given to the surgical dissection. If any doubt remains regarding residual tumor, the surgeon should err on the side of caution and remove the neurovascular bundle. The use of standardized intraoperative frozen-section analysis can help guide these decisions. The patient must be informed before surgery regarding the risks of nerve-sparing surgery, the potency rates of the surgeon, and the possibility that, to ensure adequate cancer control, the nerves may be sacrificed despite any preoperative optimism favoring the potential for their salvage.

Prospective assessment of voiding and sexual function after treatment for localized prostate carcinoma: comparison of radical prostatectomy to hormonobrachytherapy with and without external beam radiotherapy

BACKGROUND

Voiding and sexual function after treatment are major determinants of quality of life in prostate carcinoma patients. Erectile dysfunction, incontinence, and urinary symptoms, both obstructive and irritative, have a significant negative impact on patient quality of life. This prospective study was undertaken to evaluate voiding, sexual function, and their impact on patients with localized prostate carcinoma who were treated with radical retropubic prostatectomy (RP) and to compare these patients with patients who were undergoing hormonobrachytherapy with external bean radiotherapy (HBTC) and patients who were undergoing hormonobrachytherapy without external beam radiotherapy (HBT).

METHODS

Patients treated for localized prostate carcinoma with either RP or interstitial palladium-103 (103Pd) HBTC or HBT were prospectively administered a voiding and sexual function questionnaire before any treatment was initiated and at posttreatment visits. Questionnaire components included the American Urological Association Symptom Score (AUASS) and specific items that addressed urinary control and sexual function from the University of California at Los Angeles Prostate Cancer Index. Questionnaire results were compiled, and differences among treatment groups were assessed over time.

RESULTS

From January 1997 to November 1999, 127 consecutive patients were treated with either unilateral or bilateral nerve-sparing RP (42 patients), HBTC (40 patients) or HBT (45 patients) by 2 surgeons proficient in all procedures. Using the overall score and the obstructive subscale (OAUA) of the AUASS, the RP group showed a posttreatment decrease in scores compared with both HBTC and HBT groups. OAUA scores of HBTC and HBT groups were significantly greater than scores in RP patients over the course of the study. HBTC patients had increased irritative symptoms initially when compared with RP patients, and, although not statistically significant, the magnitude of the difference persisted over the course of the study. Total AUASS and subscale scores for the RP group returned to near baseline levels within 12 months. The use of incontinence pads was a criterion for urinary incontinence, and the proportion of patients returning to baseline continence was lower in RP patients over the course of the study. No notable differences in Voiding Bother (VB) scores were found. Initially RP patients experienced worse Sexual Function (SF) scores; however, scores for RP patients changed over time and approached the levels seen in HBTC patients at 18 months. The Sexual Function Bother (SFB) scores also were higher initially in the RP group but then decreased to similar levels observed for HBTC patients by 18 months. None of the treatment groups returned to near baseline SF or SFB scores during the course of this study.

CONCLUSIONS

Comparison of voiding function indicated that HBTC and HBT patients initially have more obstructive voiding symptoms, whereas urinary incon- tinence is initially worse in RP patients. Initially RP patients demonstrated worse SF and SFB scores, but RP patients returned to HBTC levels within 18 months.

The place of radical prostatectomy in the treatment of early localized prostate cancer

Today a number of treatment options exist for men diagnosed with early localized prostate carcinoma, of which the most important are radical prostatectomy, external beam radiotherapy and brachytherapy. New advances in brachytherapy using the implantation of iodine-125 and palladium-103 seeds have significantly altered its place in the treatment of localized disease and provided an alternative to external beam radiotherapy and potentially radical prostatectomy. Drawing on recently published data and our own experiences of retropubic radical prostatectomy in 100 consecutive men with localized disease, we review the place of radical prostatectomy in the treatment of early prostate cancer today. For many urologists radical prostatectomy remains the treatment of choice for men aged 70 years or less, with localized disease, a life expectancy of over 10 years and no co-morbidity. However, this has to be balanced against recent advances in brachytherapy, which now provides a minimally invasive alternative therapy for some patients with organ-confined disease and for those in whom surgery is contraindicated.

Prostatourethral-rectal fistula after prostate brachytherapy

BACKGROUND

Brachytherapy (BT) has seen increased utilization as a potentially curative treatment for patients with localized initial or recurrent prostate carcinoma. This modality can be delivered by palladium 103 (Pd(103)) or iodine 125 (I(125)) implant with or without external beam radiotherapy (EBRT). Prostatourethral-rectal fistula (PRF) is a serious complication of this approach, and its incidence, clinical presentation, and risk factors for occurrence have not been documented thoroughly. Thus, the authors sought to determine these factors in a large series of patients who were treated at two institutions.

METHODS

Seven hundred sixty-five patients received outpatient BT using a computed tomography (CT)-guided or transrectal ultrasound (TRUS)-guided technique between July 1994 and June 1999 using either Pd(103) or I(125) implants. Of the 754 patients with follow-up, 640 patients received BT monotherapy, 69 patients received BT monotherapy as a boost after EBRT, and 45 patients received BT as salvage therapy after locally recurrent prostate carcinoma that was treated initially with BT (20 patients), EBRT (20 patients), surgery plus EBRT (3 patients), surgery and high dose rate radiotherapy (HDR) (1 patient), or EBRT plus HDR (1 patient). CT dosimetry of the TRUS-guided implants was carried out in all patients 1-7 days postprocedure. Patient follow-up and clinical status were compiled in a data base.

RESULTS

Seven PRFs developed in 754 patients (1%) between 9 months and 12 months after treatment. One PRF (0.2%) occurred in patients who were treated with BT monotherapy. PRFs occurred in patients who were treated with combination therapy (2 of 69 patients; 2.9%) and in patients who underwent salvage BT (4 of 45 patients; 8.8%) patients. All six patients who developed fistulas in the context of combination BT/EBRT or salvage BT had biopsy of an anterior rectal lesion overlying the prostate noted on physical examination during routine follow-up. Gastrointestinal endoscopic evaluation alone was not associated with any PRF. Five of the seven PRFs resolved with either surgical repair (3 patients) or conservative management (2 patients).

CONCLUSIONS

There is a low incidence of PRF formation after BT monotherapy. Because all patients who developed PRF did so subsequent to prior rectal biopsies, the authors currently are discouraging such practices strongly if the rectal lesion is consistent with radiation-induced effects.

Prostate tumor progression and prognosis. interplay of tumor and host factors

The prognosis for prostate cancer is largely dependent on the probability of metastatic dissemination. Prognostic markers currently in use are very poor predictors of metastatic potential, and as of yet none of the battery of new molecular markers has proven greatly superior. This may be due in part to their inability to assess the degree of interaction of subpopulations of prostate cancer cells with each other and with their microenvironment. A growing body of evidence indicates that these types of interactions are a major factor in the eventual genesis of cancer cells capable of metastasis. Recent research has demonstrated that specialized components of prostate tumors may play a critical supporting role for the overall growth of the larger tumor. The multifocal nature and apparent polyclonal origins of prostate tumors suggest that carcinogenesis and tumor progression are promoted by global influences or "field effects." It appears that these effects extend beyond the proliferating epithelial component to the tissue stroma. Prostate cancer cells and stromal cells seem to act in concert to modify the microenvironment, leading to metastasis. An understanding of this synergy may provide a new class of prognostic markers which more accurately measure the complex set of interactions that determine tumor behavior.

Surgical and postoperative factors affecting length of hospital stay after radical prostatectomy

BACKGROUND

Radical prostatectomy continues to comprise the mainstay of therapy for localized prostate carcinoma. However, caring for radical prostatectomy patients accounts for approximately half of the $1.7 billion annual cost of prostate carcinoma treatment. Length of stay (LOS) after surgery appears to be one of the main components of this cost. The first step in reducing cost is to identify those variables associated with LOS. Radical prostatectomy can be performed using two very different surgical techniques and with each technique different costs are incurred. The objective of the current study was to identify factors associated with LOS as a function of surgical approach. To reduce potential biases due to patient requests for longer hospitalization or physician preferences in that regard, secondary objectives were to identify factors associated with time to fluid intake (TTF) and time to consume solid foods (TTS).

METHODS

An institutional-based, retrospective chart review of 313 men with clinically localized prostate carcinoma who underwent either a perineal (RPP) or retropubic (RRP) prostatectomy at a single university center from March 1988 to October 1996 was undertaken. Information regarding LOS was available for 311 patients. Linear regression models were used to assess the association between covariables and LOS. Poisson regression models for count data were used to assess associations between covariables and the secondary endpoints of TTF and TTS. Covariables included: preoperative (age, race, prostate specific antigen, Gleason score, clinical stage, lymph node resection, comorbidity, and admission time), intraoperative (surgical approach, surgeon, operative time, estimated blood loss, transfusion requirement, anesthetic approach, and American Society of Anesthesiologists score), and postoperative (pain management complications and transfusions) parameters.

RESULTS

The median LOS was 4 days (range, 1-19 days) for RPP and 5 days (range, 3-16 days) for RRP approaches. The final model included six main effects and three interaction terms. Overall, LOS decreased over time with LOS decreasing at a faster rate in patients who underwent RPP. In general, patients who underwent RRP had an increased LOS compared with patients who underwent RPP. Complications from surgery and age increased the LOS for all patients; however, the increase was greater in patients who underwent RPP. In addition, the use of intraoperative epidural anesthesia and the increased use of postoperative narcotics were associated with increased LOS for patients undergoing both surgical approaches. TTF and TTS were significantly longer for patients who underwent the retropubic approach compared with those patients who underwent the perineal approach. After adjustment for surgical approach no other covariables were found to be associated with TTF. After adjustment for surgical approach, the occurrence of complications was found to be associated with TTS, indicating that patients who experienced complications took longer before they could tolerate solid foods.

CONCLUSIONS

In view of the importance of clinical care pathways in reducing medical expenditures from radical prostatectomy, the results of the current study may contribute to the further refining of these pathways by highlighting the differences and similarities among the variables affecting LOS as a function of surgical approach.

[Prostatic brachytherapy: an alternative therapy. Review of the literature]

Radical prostatectomy remains the 'golden standard' therapy for localized prostate carcinoma for patients with a survival rate of more than ten years. However, because of the complications inherent in this surgical procedure, prostatectomy is presently increasingly challenged by various radiotherapy procedures. In the last decade, more sophisticated conformal therapy techniques have been proposed for prostate cancer patients. In parallel, for highly selected patients, brachytherapy is being promoted by an increasing number of medical centers. In fact, brachytherapy techniques for prostate cancers can be traced back to 1911, but recently developed techniques offer reliability and reproducibility, with satisfactory results in terms of tumor control and reduced toxicity, in selected patients. We present here the different techniques that are available today in prostate cancer brachytherapy.

Cryosurgery for prostate cancer: new technology and indications

Patients diagnosed with prostate cancer who elect to pursue active treatment of their disease must choose among the many available treatment alternatives. Several treatment options now exist for similar-stage disease (clinical T1-3N0M0), including radical prostatectomy, external beam radiation, prostate brachytherapy (PB), and cryosurgical ablation of the prostate (CSAP). This article reviews the current role of CSAP in the treatment of clinically localized prostate cancer. CSAP has a role in the primary treatment of men with high-risk, clinically localized prostate cancer (defined as PSA >10, Gleason score >or=7, or clinical stage >or= cT2B). CSAP (occasionally followed by external beam radiotherapy) appears to offer improved rates of cancer control over other types of single or combination therapies for this high-risk prostate cancer, and it is associated with an acceptable side-effect profile. CSAP should also be the treatment of choice for men with recurrent local disease who have undergone external beam radiotherapy or PB.

Salvage radical prostatectomy after radiation therapy and brachytherapy

Local recurrence after any type of radiation therapy presents the clinician with a significant challenge. If there is no evidence of metastatic disease, patients can be offered a potentially curative salvage prostatectomy. To qualify for such surgery, patients should be at least 12 months from the completion of radiation and have at least a 10-year life expectancy; ideally, they will have a serum prostate specific antigen concentration <10 ng/mL and a Gleason score of 7 or less. Perioperative complications are substantial, with urinary incontinence rates of 40% to 50% and rectal injury rates of 10% to 15%. Long-term disease-free survival rates of 30% to 40% can be expected.

Radical prostatectomy versus brachytherapy for early-stage prostate cancer

BACKGROUND AND PURPOSE

The considerations in choosing a treatment for prostate cancer are potential for cure, acute toxicity, long-term morbidity, quality of life, and direct and indirect costs. The classic options are radical prostatectomy, external-beam radiation, and watchful waiting. During the last decade, technological advances have fostered another: brachytherapy.

METHODS

This article compares brachytherapy and radical prostatectomy in terms of cancer control, complications, and cost using series from medical centers that have pioneered and advocated particular procedures.

RESULTS

In the surgical series from Johns Hopkins, the 7-year success rate (no PSA >0.2 ng/mL) of anatomic radical prostatectomy was 97.8% in patients with stage T(2c) or lower disease and a Gleason score of < or =6. In the brachytherapy series from Seattle, the 7-year success rate (PSA < or =0.5 ng/mL) was 79%. Postoperatively, 68% of the patients who were potent preoperatively maintained erectile function, and 92% were fully continent. Urethral toxicity is slightly more common in patients treated by brachytherapy, but in the authors' series, no patient remained incontinent after 6 months. Some patients became impotent during follow-up. The cost of brachytherapy ($16,200) is less than that of ($27,000), although the difference may be reduced by the use of neoadjuvant hormonal therapy with the former.

CONCLUSION

Patients receiving brachytherapy appear to have a slightly higher rate of disease progression. The side effects generally are acceptable and may be less severe than those of surgery. Further follow-up data are needed to define the roles of these two treatments for early-stage prostate cancer.

Brachytherapy for clinically localized prostate cancer

Prostate brachytherapy is an effective treatment option for clinically organ-confined prostate carcinoma. Observed 5- and 10-year follow-up have documented prostate-specific antigen (PSA) levels that were comparable to published radical prostatectomy series and were better than several published external-beam radiation series. Between January 1987 and June 1988, a total of 152 consecutive patients with Stage T1 to T3 low to high Gleason grade prostate cancer were studied at Northwest Hospital in Seattle, Washington. Patients' median age was 70 years (range, 53 to 92 years). All patients received Iodine-125 prostate brachytherapy with or without a 45 Gy dose of external-beam radiation. The average preoperative PSA, clinical stage, and prostate needle biopsy Gleason sum were 11 ng/ml, T2, and (5), respectively, and were known in all but five patients. PSA follow-up, clinical examination, and biopsy results judged disease-free survival at 5 and 10 postoperative years. Elevation of PSA above 0.5 ng/ml or a positive biopsy or a positive bone scan was considered treatment failure. The authors provide an historical review of prostate brachytherapy in conjunction with up-to-date implant techniques and long-term outcome results.

Caution in interpreting biochemical control rates after treatment of prostate cancer: length of follow-up influences results

OBJECTIVES

Prostate-specific antigen (PSA) based end points are commonly used to report outcomes after treatment for prostate cancer. This study examines the influence of follow-up length on biochemical control (bNED) rates.

METHODS

We reviewed 437 patients with clinically localized prostate cancer treated with conformal radiotherapy without neoadjuvant androgen deprivation. Biochemical failure was defined as three consecutive PSA increases or an increase large enough to prompt androgen deprivation therapy. The failure date was projected back to the midpoint between the PSA nadir and the first PSA increase (or between the nadir and the initiation of androgen deprivation therapy). The analysis was performed by censoring patients with longer follow-up in a stepwise fashion, thus creating smaller subgroups with shorter follow-up intervals. Subgroup 1 (n = 191) and subgroup 2 (n = 273) were defined to include those patients monitored for up to 2 years and up to 3 years, respectively.

RESULTS

The median follow-up intervals for subgroup 1, subgroup 2, and the original study population were 1.1, 1.5, and 2.5 years. No significant differences were seen in pretreatment prognostic factors among the three groups. The 2-year bNED of subgroup 1, subgroup 2, and the original population was 86%, 77%, and 73%, respectively. Although subgroup 1 had a superior bNED compared with the original population (P = 0.04), no differences in clinical recurrence rates were seen among any of the three groups.

CONCLUSIONS

Because of projecting the biochemical failure dates back according to commonly used bNED definitions, control rates are highly dependent on the length of follow-up.