The influence of isotope and prostate volume on urinary morbidity after prostate brachytherapy

Ultrahypofractionated Radiotherapy for Localised Prostate Cancer: How Far Can We Go?

Following adoption of moderately hypofractionated radiotherapy as a standard for localised prostate cancer, ultrahypofractioned radiotherapy delivered in five to seven fractions is rapidly being embraced by clinical practice and international guidelines. However, the question remains: how low can we go? Can radiotherapy for prostate cancer be delivered in fewer than five fractions? The current review summarises the evidence that radiotherapy for localised prostate cancer can be safely and effectively delivered in fewer than five fractions using high dose rate brachytherapy or stereotactic body radiotherapy. We also discuss important lessons learned from the single-fraction high dose rate brachytherapy experience.

Stereotactic Body Radiation Therapy (SBRT) for Prostate Cancer in Men With a High Baseline International Prostate Symptom Score (IPSS ≥ 15)

Background: Patients with a high pretreatment IPSS may have higher rates of late urinary morbidity after radiation therapy for prostate cancer (1). Stereotactic body radiation therapy (SBRT) delivers fewer high-dose fractions of radiation, which may be radiobiologically favorable to the conventional low-dose external beam fractions. The urinary toxicity associated with SBRT, however, remains unclear in patients with a high IPSS (1). We report our experience using SBRT for localized prostate cancer in patients with pretreatment IPSS ≥ 15.

Methods: Localized prostate cancer patients with a pre-treatment IPSS ≥ 15 treated with SBRT at Georgetown University Hospital from 2009 to 2016 were included in this retrospective review of prospectively collected data. These patients were treated to 35–36.25 Gy in five fractions delivered via CyberKnife (Accuray Inc., Sunnyvale, CA). Urinary toxicity was assessed using the Common Terminology Criteria for Adverse Events version 4.0 (CTCAE v4). Urinary quality of life was assessed using validated questionnaires (IPSS and EPIC-26).

Results: 53 patients at a median age of 71 years (range 57–89 years) received SBRT with a minimum follow up of 3 years. The median prostate size was 37 cm³ (range 12–100 cm³) and 30.2% patients received ADT. The 3-years incidence rate of Grade 3 urinary toxicity was 7.5% with median time to toxicity of 2.9 years. There were no Grade 4 or 5 toxicities. A mean baseline IPSS score of 19.8 significantly decreased to 12.9 at 3 months post-SBRT (p = 0.002) and remained stable at 36 months (13.7). A mean baseline EPIC-26 obstructive/irritative score of 64.1 significantly improved to 80.2 at 3 months (p = 0.002). This improvement was maintained to 36 months. There was no significant change from the mean baseline EPIC-26 urinary incontinence score at any point during follow up.

Conclusions: SBRT for clinically localized prostate cancer was well-tolerated in men with baseline IPSS ≥ 15 (1). Grade 3 toxicities occurred but resolved with time. Our data suggest that poor baseline urinary function does not worsen following SBRT and may even improve. High baseline IPSS score should not be considered a contraindication to SBRT.

Quantitative analysis of genitourinary toxicity after iodine-125 brachytherapy for localized prostate cancer: Followup of the International Prostate Symptom Score and Overactive Bladder Symptom Score

PURPOSE

To analyze genitourinary toxicity by followup of the International Prostate Symptom Score (IPSS) and Overactive Bladder Symptom Score (OABSS) after prostate brachytherapy.

METHODS AND MATERIALS

Six hundred eighty patients were treated with iodine-125 brachytherapy for localized prostate cancer. IPSS, OABSS, and two categories of IPSS questions (storage symptom score [IPSS-S] and voiding symptom score [IPSS-V]) were evaluated.

RESULTS

The median followup was 54 months (range, 24-108). All scales showed rapid increases followed by gradual decreases. The median times to IPSS peak and resolution were 1 and 6 months, respectively. The resolution rates of IPSS, IPSS-S, IPSS-V, and OABSS at the last followup were 84.2%, 86.3%, 89.5%, and 83.0%, respectively. The difference between IPSS baseline and peak was greater for larger preimplant prostate volumes (≥25 mL, p = 0.004). The time to resolution was longer for higher biologic effective dose (BED) (≥210 Gy, p = 0.019 [IPSS]), in those with larger prostate volumes (≥25 mL, p = 0.025 [OABSS]), in younger patients (younger than 70 years, p = 0.043 [IPSS-S]), and in those with androgen deprivation therapy (ADT) use (p = 0.049 [IPSS-V]). Urge incontinence, included in the OABSS, was observed more commonly in older patients (75 years and older, p = 0.018), with ADT use (p < 0.001), and for higher BED (≥210 Gy, p = 0.006).

CONCLUSIONS

The IPSS and OABSS showed similar patterns of change. Urinary symptoms improved more rapidly in those with high baseline IPSS levels. The OABSS was useful for following urinary symptoms after prostate brachytherapy. Age, ADT use, preimplant prostate volume, and BED were significantly associated with urinary outcomes.

Modified transurethral resection of the prostate (TURP) for men with moderate lower urinary tract symptoms (LUTS) before brachytherapy is safe and feasible

OBJECTIVE

To report the urinary toxicity outcomes for patients at greater risk of voiding symptoms and retention who received a modified limited transurethral resection of the prostate (TURP) before low-dose rate (LDR) brachytherapy.

PATIENTS AND METHOD

Data were analysed from patients receiving the above procedures between 2006 to present, taken from the prospective brachytherapy database of 2000 patients at the St. Luke's Cancer Centre. The limited TURP (TURP(BXT) ) was performed at a median (range) of 64 (25-205) days before seed implantation with a median resection weight of 1.15 g. Selection criteria were based on patients with moderate lower urinary tract symptoms, poor flow or post-void residual urine volume (PVR), or a prominent middle lobe or high bladder neck on transrectal ultrasonography. Baseline prostate cancer characteristics, uroflowmetry, International Prostate Symptom Score (IPSS) and quality-of-life QoL scores were collected and compared with follow-up IPSS and QoL scores.

RESULTS

Data for 112 patients was gathered from the database. The TURP(BXT) resulted in statistically significant improvements before LDR brachytherapy in maximum urinary flow rate (Qmax ) and PVR, IPSS and QoL scores (the mean Qmax before vs after the TURP(BXT) was 11.3 vs 16.7 mL/s). The IPSS and QoL scores at 6 months after seed implantation were increased compared with baseline values before the TURP(BXT) (mean IPSS at 6 months 11.7 vs 9.2 before TURP(BXT) ), but no difference at 1 year (mean IPSS 9), and improved scores at 2, 3, 4 and 5 years follow-up (mean IPSS of 7.9, 5.6, 5.3 and 7.4, respectively).

CONCLUSION

The present study suggests patients at increased risk of deteriorating voiding symptoms, including urinary retention, are no longer contraindicated against LDR brachytherapy if they receive a modified TURP before seed implantation. This procedure does not appear to carry the risk of urinary incontinence thought to be associated with a conventional TURP before LDR brachytherapy.

Stereotactic body radiation therapy (SBRT) for prostate cancer in men with large prostates (≥50 cm(3))

BACKGROUND

Patients with large prostate volumes have been shown to have higher rates of genitourinary and gastrointestinal toxicities after conventional radiation therapy for prostate cancer. The efficacy and toxicity of stereotactic body radiation therapy (SBRT), which delivers fewer high-dose fractions of radiation treatment, is unknown for large prostate volume prostate cancer patients. We report our early experience using SBRT for localized prostate cancer in patients with large prostate volumes.

METHODS

57 patients with prostate volumes ≥50 cm(3) prior to treatment with SBRT for localized prostate carcinoma and with a minimum follow up of two years were included in this retrospective review of prospectively collected data. Treatment was delivered using Cyberknife (Accuray) with doses of 35-36.25 Gy in 5 fractions. Biochemical control was assessed using the Phoenix definition. Toxicities were scored using the CTCAE v.4. Quality of life was assessed using the American Urological Association (AUA) Symptom Score and the Expanded Prostate Cancer Index Composite (EPIC)-26.

RESULTS

57 patients (23 low-, 25 intermediate- and 9 high-risk according to the D'Amico classification) at a median age of 69 years (range, 54-83 years) received SBRT with a median follow-up of 2.9 years. The median prostate size was 62.9 cm(3) (range 50-138.7 cm(3)). 33.3% of patients received ADT. The median pre-treatment prostate-specific antigen (PSA) was 6.5 ng/ml and decreased to a median PSA of 0.4 ng/ml by 2 years (p <0.0001). A mean baseline AUA symptom score of 7.5 significantly increased to 13 at 1 month (p = 0.001) and returned to baseline by 3 months (p = 0.21). 23% of patients experienced a late transient urinary symptom flare in the first two years following treatment. Mean baseline EPIC bowel scores of 95.8 decreased to 78.1 at 1 month (p <0.0001), but subsequently improved to 93.5 three months (p = 0.08). The 2-year actuarial incidence rates of GU and GI toxicity ≥ grade 2 were 49.1% and 1.8%, respectively. Two patients (3.5%) experienced grade 3 urinary toxicity, and no patient experienced grade 3 gastrointestinal toxicity.

CONCLUSIONS

SBRT for clinically localized prostate cancer was well tolerated in men with large prostate volumes.

Large prostate gland size is not a contraindication to low-dose-rate brachytherapy for prostate adenocarcinoma

PURPOSE

Prostate volume greater than 50cc is traditionally a relative contraindication to prostate seed implantation (PSI), but there is little consensus regarding prostate size and clinical outcomes. We report biochemical control and toxicity after low-dose-rate PSI and compare outcomes according to the prostate size.

METHODS AND MATERIALS

A total of 429 men who underwent low-dose-rate PSI between 1998 and 2009 were evaluated. Median followup was 38.7 months. Patients were classified by prostate volume into small, medium, and large subgroups. Differences were analyzed using the Mann-Whitney and Pearson's χ(2) tests for continuous and categorical variables, respectively. Cox proportional hazards regression models were used to evaluate effect of prostate size on outcomes.

RESULTS

Patient pretreatment factors were balanced between groups except for age (p=0.001). The 10-year actuarial freedom from biochemical failure for all patients treated with PSI was 96.3% with no statistically significant difference between large vs. small/medium prostate size (90% vs. 96.6%, p=0.47). In a multivariate analysis, plan type (hazard ratio [HR]=0.25, p=0.03), dose to 90% of the gland (D90: HR=0.98, p=0.02), volume receiving 200Gy (V200: HR=0.98, p=0.026), and biologic effective dose (HR=0.99, p=0.045), but not prostate size (HR=2.27, p=0.17) were significantly associated with freedom from biochemical failure. Prostate size was not significantly associated with time to maximum American Urologic Association score.

CONCLUSION

In men with large prostates, the PSI provides biochemical control and temporal changes in genitourinary toxicity that are comparable with men having smaller glands. Accurate dose optimization and delivery of PSI provides the best clinical outcomes regardless of gland size.

The use of a memokath prostatic stent for obstructive voiding symptoms after brachytherapy

INTRODUCTION

Brachytherapy may be complicated by serious obstructive voiding symptoms (OVS). Only conservative treatment options are available in the first 6 months after brachytherapy. We evaluated safety, efficacy and patient tolerance of the Memokath prostatic stent (MPS).

MATERIAL AND METHODS

A MPS was placed in 10 patients with OVS after brachytherapy. Evaluation included uroflowmetry, international prostate symptom score (IPSS), prostate volume and urethrocystoscopy before and 3 months after placement of the stent.

RESULTS

Both the IPSS and uroflowmetry results significantly improved after stent insertion. The mean IPSS decreased from 29/5 to 11/1 and the mean Qmax from the uroflowmetry improved from 4.7 to 11.2 ml/s. The 5 patients who were catheter dependent voided spontaneously with a mean Qmax of 15 ml/s. Two stents migrated towards the bladder, and those patients needed a second stent which was placed without complications. Removal of the stent was easy to perform. Adverse effects were minor with perineal pain and irritative voiding symptoms occurring in 5 patients mainly in the first weeks after insertion. This did not negatively influence quality of life and all patients were more satisfied with the stent than without.

CONCLUSIONS

The MPS provides a safe, effective, and completely reversible treatment for patients with OVS after brachytherapy and was well tolerated.

Predictive factors for acute and late urinary toxicity after permanent interstitial brachytherapy in Japanese patients

OBJECTIVES

To describe the frequency of and to determine predictive factors associated with Radiation Therapy Oncology Group urinary toxicity in prostate brachytherapy patients.

METHODS

From January 2004 to April 2011, 466 consecutive Japanese patients underwent permanent iodine-125-seed brachytherapy (median follow up 48 months). International Prostate Symptom Score and Radiation Therapy Oncology Group toxicity data were prospectively collected. Prostate volume, International Prostate Symptom Score before and after brachytherapy, and postimplant analysis were examined for an association with urinary toxicity, defined as Radiation Therapy Oncology Group urinary toxicity of Grade 1 or higher. Logistic regression analysis was used to examine the factors associated with urinary toxicity.

RESULTS

The rate of Radiation Therapy Oncology Group urinary toxicity grade 1 or higher at 1, 6, 12, 24, 36 and 48 months was 67%, 40%, 21%, 31%, 27% and 28%, respectively. Grade 2 or higher urinary toxicity was less than 1% at each time-point. International Prostate Symptom Score was highest at 3 months and returned to normal 12 months after brachytherapy. On univariate analysis, patients with a larger prostate size, greater baseline International Prostate Symptom Score, higher prostate V100, higher prostate V150, higher prostate D90 and a greater number of seeds had more acute urinary toxicities at 1 month and 12 months after brachytherapy. On multivariate analysis, significant predictors for urinary toxicity at 1 month and 12 months were a greater baseline International Prostate Symptom Score and prostate V100.

CONCLUSIONS

Most urinary symptoms are tolerated and resolved within 12 months after prostate brachytherapy. Acute and late urinary toxicity after brachytherapy is strongly related to the baseline International Prostate Symptom Score and prostate V100.

Factors influencing urinary symptoms 10 years after permanent prostate seed implantation

PURPOSE

We investigated the factors that influenced urinary symptoms in the first 10 years after prostate brachytherapy.

MATERIALS AND METHODS

A total of 1,932 men were treated with prostate brachytherapy alone or with external beam irradiation and followed a mean of 6.8 years. The influence of pretreatment American Urological Association symptom score (7 or less, 8 to 19, 20 or greater), external beam radiotherapy, (125)I or (103)Pd, biological effective dose, age, prostate size and hormone therapy on the change in American Urological Association symptom score (11,491) was compared.

RESULTS

The mean change from initial score (7.4) was 11.4, 5.5, 3.3, 2.7, 1.5, 1.2, 1, 1, 1, 1, 1.3 and 1.4 points at 3, 6 months and 1 to 10 years, respectively (p <0.001). Factors that resulted in a greater increase in urinary symptoms at year 1 were low pretreatment score (p <0.001), no hormonal therapy (p <0.001), younger age (p = 0.046) and higher biological effective dose (p = 0.025). At 10 years patients with an initial score of 20 or greater had an average decrease of 11 points compared to a decrease of 0.9 for an initial score of 8 to 19 and an increase of 2.7 for an initial score of 7 or less (p <0.001). On linear regression the scores at 1 year were influenced by initial score (p <0.001), biological effective dose (p = 0.022), prostate size (p <0.001) and hormonal therapy (p = 0.009). At 10 years only the pretreatment score remained significant (p <0.001).

CONCLUSIONS

There is minimal change in mean American Urological Association symptom score (1.4 points) 10 years after prostate brachytherapy. Patients presenting with high initial scores have the greatest improvement from baseline. Biological effective dose, external beam radiotherapy, hormonal therapy, isotope, patient age and prostate size do not appear to influence long-term urinary symptoms.

Changes in lower urinary tract symptoms after prostate brachytherapy

PURPOSE

To further define the bothersome lower urinary tract symptoms that occur after prostate brachytherapy (PB) by evaluating patient's responses to the individual questions of the urinary portion of the Expanded Prostate Cancer Index Composite (EPIC) survey and the AUA symptoms score in men undergoing PB.

MATERIAL AND METHODS

A longitudinal, prospective study of 170 patients who have undergone PB at a single institution was performed. All patients were asked to complete the EPIC survey pre-operatively and at 2 weeks, 4 weeks, 3 months, and 6 months post-operatively. Starting with the 75(th) patient in the cohort, patients were also asked to complete the AUA symptom score.

RESULTS

The pattern of changes for each question is similar for both the EPIC survey and the AUA symptom score, with a marked worsening of symptoms at 2 and 4 weeks and an improvement to baseline by 3 to 6 months. Hematuria questions had the quickest and dysuria questions had the longest return to baseline. The dysuria questions had the greatest change and the incontinence questions had the smallest change in magnitude. Obstructive symptoms had a greater magnitude of change when compared to irritative symptoms, but the irritative symptoms took longer to return to baseline.

CONCLUSIONS

The present study adds to the fund of knowledge regarding the bothersome lower urinary tract symptoms which occur after PB by analyzing the individual questions of both the urinary portion of the EPIC survey and the AUA symptom score.

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.

Preimplant factors affecting postimplant CT-determined prostate volume and the CT/TRUS volume ratio after transperineal interstitial prostate brachytherapy with 125I free seeds

Background

The aim was to identify preimplant factors affecting postimplant prostate volume and the increase in prostate volume after transperineal interstitial prostate brachytherapy with ¹²⁵I free seeds.

Methods

We reviewed the records of 180 patients who underwent prostate brachytherapy with ¹²⁵I free seeds for clinical T1/T2 prostate cancer. Eighty-one (45%) of the 180 patients underwent neoadjuvant hormonal therapy. No patient received supplemental external beam radiotherapy. Postimplant computed tomography was undertaken, and postimplant dosimetric analysis was performed. Univariate and multivariate analyses were performed to identify preimplant factors affecting postimplant prostate volume by computed tomography and the increase in prostate volume after implantation.

Results

Preimplant prostate volume by transrectal ultrasound, serum prostate-specific antigen, number of needles, and number of seeds implanted were significantly correlated with postimplant prostate volume by computed tomography. The increase in prostate volume after implantation was significantly higher in patients with neoadjuvant hormonal therapy than in those without. Preimplant prostate volume by transrectal ultrasound, number of needles, and number of seeds implanted were significantly correlated with the increase in prostate volume after implantation. Stepwise multiple linear regression analysis showed that preimplant prostate volume by transrectal ultrasound and neoadjuvant hormonal therapy were significant independent factors affecting both postimplant prostate volume by computed tomography and the increase in prostate volume after implantation.

Conclusions

The results of the present study show that preimplant prostate volume by transrectal ultrasound and neoadjuvant hormonal therapy are significant preimplant factors affecting both postimplant prostate volume by computed tomography and the increase in prostate volume after implantation.

The impact of pretreatment prostate volume on severe acute genitourinary toxicity in prostate cancer patients treated with intensity-modulated radiation therapy

PURPOSE

To assess the impact of pretreatment prostate volume on the development of severe acute genitourinary toxicity in patients undergoing intensity-modulated radiation therapy (IMRT) for prostate cancer.

METHODS AND MATERIALS

Between 2004 and 2007, a consecutive sample of 214 patients who underwent IMRT (75.6 Gy) for prostate cancer at two referral centers was analyzed. Prostate volumes were obtained from computed tomography scans taken during treatment simulation. Genitourinary toxicity was defined using the National Cancer Institute Common Terminology Criteria for Adverse Events Version 3.0 guidelines. Acute toxicity was defined as any toxicity originating within 90 days of the completion of radiation therapy. Patients were characterized as having a small or large prostate depending on whether their prostate volume was less than or greater than 50 cm(3), respectively. Genitourinary toxicity was compared in these groups using the chi-square or Fisher's exact test, as appropriate. Bivariate and multivariate logistic regression analysis was performed to further assess the impact of prostate volume on severe (Grade 3) acute genitourinary toxicity.

RESULTS

Patients with large prostates (>50 cm(3)) had a higher rate of acute Grade 3 genitourinary toxicity (p = .02). Prostate volume was predictive of the likelihood of developing acute Grade 3 genitourinary toxicity on bivariate (p = .004) and multivariate (p = .006) logistic regression. Every 27.0 cm(3) increase in prostate volume doubled the likelihood of acute Grade 3 genitourinary toxicity.

CONCLUSIONS

Patients with larger prostates are at higher risk for the development of severe acute genitourinary toxicity when treated with IMRT for prostate cancer.

Permanent prostate brachytherapy in prostate glands <20 cm(3)

PURPOSE

To investigate the dosimetry, treatment-related morbidity, and biochemical outcomes for brachytherapy in patients with prostate glands <20 cm(3).

METHODS AND MATERIALS

From November 1996 to October 2006, 104 patients with prostate glands <20 cm(3) underwent brachytherapy. Multiple prostate, urethral, and rectal dosimetric parameters were evaluated. Treatment-related urinary and rectal morbidity were assessed from patient questionnaires. Cause-specific survival, biochemical progression-free survival, and overall survival were recorded.

RESULTS

The median patient age, follow up, and pre-treatment ultrasound volume was 64 years, 5.0 years and 17.6cm(3), respectively. Median day 0 dosimetry was significant for the following: V100 98.5%, D90 126.1% and R100 <0.5% of prescription dose. The mean urethral and maximum urethral doses were 119.6% and 133.8% of prescription. The median time to International Prostate Symptom Score resolution was 4 months. There were no RTOG grade III or IV rectal complications. The cause-specific survival, biochemical progression-free survival, and overall survival rates were 100%, 92.5%, and 77.8% at 9 years. For biochemically disease-free patients, the median most recent postbrachytherapy PSA value was 0.02 ng/mL.

CONCLUSION

Our results demonstrate that brachytherapy for small prostate glands is highly effective, with an acceptable morbidity profile, excellent postimplant dosimetry, acceptable treatment-related morbidity, and favorable biochemical outcomes.

Urinary symptom flare in 712 125I prostate brachytherapy patients: long-term follow-up

PURPOSE

To describe the late transient worsening of urinary symptoms ("urinary symptom flare") in 712 consecutive prostate brachytherapy patients, associated predictive factors, association with rectal and urinary toxicity, and the development of erectile dysfunction.

METHODS AND MATERIALS

Patients underwent implantation between 1998 and 2003 (median follow-up, 57 months). International Prostate Symptom Score (IPSS), Radiation Therapy Oncology Group (RTOG) toxicity, and erectile function data were prospectively collected. Flare was defined as an increase in IPSS of > or =5 and of > or =8 points greater than the post-treatment nadir. The relationships between the occurrence of flare and the patient, tumor, and treatment characteristics were examined. The Cox proportional hazards method was used to test individual variables and the multivariate models.

RESULTS

The incidence of flare was 52% and 30% using the flare definition of an IPSS of > or =5 and > or =8 points greater than the postimplant nadir, respectively. Of the patients with symptoms, 65% had resolution of their symptoms within 6 months and 91% within 1 year. Flares most commonly occurred 16-24 months after implantation. On multivariate analysis, a greater baseline IPSS and greater maximal postimplant IPSS were the predictors of flare, regardless of the flare definition used. Androgen suppression was a predictor for fewer flares (IPSS > or =5). Diabetes and prostate edema predicted for more frequent flares (IPSS >/=8). Patients with flare had a greater incidence of RTOG Grade 3 urinary toxicity and RTOG Grade 2 or greater rectal toxicity. No association was found between erectile dysfunction and the occurrence of flare.

CONCLUSION

Urinary symptom flare is a common, transient phenomenon after prostate brachytherapy. A greater baseline IPSS and maximal postimplant IPSS were the strongest predictive factors. Flare was associated with a greater incidence of late RTOG Grade 3 urinary toxicity and greater rate of late RTOG Grade 2 or greater rectal toxicity.

Predictive factors for acute and late urinary toxicity after permanent prostate brachytherapy: long-term outcome in 712 consecutive patients

PURPOSE

To describe the frequency of acute and late Radiation Therapy Oncology Group (RTOG) urinary toxicity, associated predictive factors, and resolution of International Prostate Symptom Score (IPSS) in 712 consecutive prostate brachytherapy patients.

METHODS AND MATERIALS

Patients underwent implantation between 1998 and 2003 (median follow-up, 57 months). The IPSS and RTOG toxicity data were prospectively collected. The patient, treatment, and implant factors were examined for an association with urinary toxicity. The time to IPSS resolution was examined using Kaplan-Meier curves, and multivariate modeling of IPSS resolution was done using Cox proportional hazards regression analysis. Logistic regression analysis was used to examine the factors associated with urinary toxicity.

RESULTS

The IPSS returned to baseline at a median of 12.6 months. On multivariate analysis, patients with a high baseline IPSS had a quicker resolution of their IPSS. Higher prostate D90 (dose covering 90% of the prostate), maximal postimplant IPSS, and urinary retention slowed the IPSS resolution time. The rate of the actuarial 5-year late urinary (>12 months) RTOG Grade 0, 1, 2, 3, and 4 was 32%, 36%, 24%, 6.2%, and 0.1%, respectively. At 7 years, the prevalence of RTOG Grade 0-1 was 92.5%. Patients with a larger prostate volume, greater number of needles, greater baseline IPSS, and use of hormonal therapy had more acute toxicity. On multivariate analysis, the significant predictors for late greater than or equal to RTOG toxicity 2 were a greater baseline IPSS, maximal postimplant IPSS, presence of acute toxicity, and higher prostate V150 (volume of the prostate covered by 150% of the dose). More recently implanted patients had less acute urinary toxicity and patients given hormonal therapy had less late urinary toxicity (all p < 0.02).

CONCLUSION

Most urinary symptoms resolved within 12 months after prostate brachytherapy, and significant long-term urinary toxicity was very low. Refined patient selection and greater technical experience in prostate brachytherapy were associated with less urinary toxicity.

Bicalutamide alone prior to brachytherapy achieves cytoreduction that is similar to luteinizing hormone-releasing hormone analogues with less patient-reported morbidity

OBJECTIVES

To compare the impact of bicalutamide (B) vs. luteinizing hormone-releasing hormone analogues (LHRHa) on prostate volume, patient-reported side effects, and postimplant urinary toxicity in the setting of interstitial brachytherapy for early-stage prostate cancer.

METHODS

Between May 1998 and January 2004, 81 patients received androgen-deprivation therapy (ADT) for cytoreduction prior to interstitial brachytherapy alone. Fifty-six patients received LHRHa and 25 patients received B. Prostate volumes were measured prospectively prior to initiating therapy, and then intraoperatively at the time of implant by a single, blinded ultrasonographer. Patient-reported quality of life data were obtained prospectively, and postimplant urinary toxicity (catheter dependency and need for surgical intervention) was recorded during follow-up. Median follow-up was 53 (range 23-78) months.

RESULTS

The median percentage prostate volume reductions of 26% for B and 32% for LHRHa were not statistically different (P = 0.61). Decrements in libido (92% vs. 44%, P < 0.001) and erectile function (79% vs. 20%) were reported in more respondents treated with LHRHa than B. The incidence of recatheterization (28% vs. 24%, P = 0.34), and the need for subsequent surgical intervention (11% vs. 4%, P = 0.16) were similar for patients treated with LHRHa and B.

CONCLUSIONS

The degree of prostate downsizing with B is similar to that achieved with LHRHa. B was associated with fewer patient-reported sexual side effects and similar urinary morbidity. A randomized trial is needed to establish whether LHRHa or B should be the standard of care for prostate downsizing before interstitial brachytherapy.

Preimplant Predictive Factors of Urinary Retention After Iodine 125 Prostate Brachytherapy

OBJECTIVES

To assess the rate and predictive factors of urinary retention after iodine 125 brachytherapy for localized prostate cancer.

METHODS

Between 1998 and 2006, 655 patients with localized prostate cancer (T1-2, Gleason score 7 or less) were treated with brachytherapy at our institution. 42% received neoadjuvant hormonotherapy for prostate downsizing or when brachytherapy was combined with external beam radiation (10%). They underwent real-time interactive implantation (79%) or a preplanned technique (21%). Clinical, treatment-related and dosimetric factors were evaluated for catheterization requirement because of urinary retention. All patients received alpha1-blockers before and throughout at least 30 days posttreatment.

RESULTS

Twenty-one (3.2%) patients required catheterization because of urinary retention. Median time to retention onset was 1 day postimplantation. Univariate and multivariate analyses demonstrated that preimplant ultrasound (US)-based prostate volume and preimplant international prostate symptom scores (IPSS) were significant independent predictive factors for urinary retention (odds ratio [OR] = 6.8 and 3.1, 95% CI = 2.3-11.4 and 0.2-5.9, P = 0.02 and P = 0.03, respectively). Eight catheterized patients were successfully relieved from their catheter by nonsurgical means and 13 underwent minimal (channeling) transurethral resection of the prostate (TUR-P) not earlier than 6 months postimplant. Mean volume of resected prostate tissue was 9.9 mL (range 4.5-15). The perioperative and postoperative courses were uneventful. There was no TUR-P-related incontinence.

CONCLUSIONS

Catheterization for acute urinary retention after brachytherapy is an uncommon event. Our data suggest that preimplant US-based prostate volume and IPSS are the strongest predictors for catheterization. Catheterized patients who are refractory to medical therapy can safely undergo a minimal TUR-P.

Dynamic dose-feedback prostate brachytherapy in patients with large prostates and/or planned transurethral surgery before implantation

OBJECTIVE

To compare the quality of permanent prostate brachytherapy (PPB) implants, dosimetric outcomes and urinary morbidity between patients with large (>50 mL) and those with smaller prostates, treated with a dynamic dose-feedback technique as monotherapy for localized prostate cancer.

PATIENTS AND METHODS

The series included patients with pre-existing bladder outlet obstruction managed with planned transurethral resection or incision of the prostate; 155 consecutive men had PPB implants as monotherapy for localized prostate cancer using a dynamic dose-feedback approach. Dosimetric variables assessed included the implant volume, the minimum dose to 90% of the prostate (D90), and the volumes of prostate receiving 100% and 150% of the prescribed dose as a percentage of the total volume (V100 and V150), during and after implantation. Urinary morbidity was recorded in terms of acute urinary retention (AUR), the need for surgical intervention after implantation and the American Urologic Association (AUA) symptom score at baseline, 1.5, 3, 6, 9, 12 and 18 months.

RESULTS

In all, 38 patients had prostate volumes of >or=50 mL; prostate volume had no influence on any dosimetric variable assessed. Two patients with large prostates (>or=50 mL) had AUR and required delayed surgery. Three patients with small prostates (<50 mL) had transient retention; the differences were not statistically significant (Fisher's exact test). AUA symptom scores peaked at 6 weeks and returned to baseline within a year; there were no statistically significant differences between the groups. Eight patients had planned transurethral surgery at >or=4 months before implantation; they all had D90s of >130 Gy and had no incontinence.

CONCLUSION

Using the dynamic feedback technique, there was no adverse dosimetric and urinary morbidity in men having PPB and with prostates of >50 mL. Likewise, there were no impediments, e.g. pubic arch interference, which precluded a favourable dosimetric implant in men with a large prostate. Large prostates should not be a contraindication to PPB and require no hormonal cytoreduction. Patients with obstructive lower urinary tract symptoms can be managed with planned transurethral prostatic surgery before implantation, without compromising implant quality or morbidity.

The influence of geometrical changes on the dose distribution after I-125 seed implantation of the prostate

PURPOSE

After prostate implantation, dose calculation is usually based on a single imaging session, assuming no geometrical changes occur during the months of dose accumulation. In this study, the effect of changes in anatomy and implant geometry on the dose distribution was investigated.

MATERIALS AND METHODS

One day, 1 month and 312 months after seed implantation, a combined TRUS-CT scan was made of 13 patients. Based on these scans changes in dose rate distribution were determined in prostate, urethra and bladder and a 'geometry corrected' dose distribution was estimated.

RESULTS

When based on the day-1 scan, parameters representing high dose volumes in prostate and urethra were largely underestimated: V150 of the prostate 18+/-10% and V120 of the urethra 47+/-32%. The dose to a 2cm(3) hotspot in the bladder wall (D2cc), however, was overestimated by 31+/-35%. Parameters based on scans 1 month post-implant or later were all within +/-5% of geometry corrected values.

CONCLUSION

Values meant to indicate the adequacy of dose coverage of the prostate, V100 and D90, were not influenced by geometrical changes and were independent of the post-implant scan date. Other parameters representing high dose volumes changed strongly within the first month after implantation.