Prostate Brachytherapy Patients Research Articles

Dosimetric quality endpoints for low-dose-rate prostate brachytherapy using biological effective dose (bed) vs. conventional dose

The purpose of this study was to compare conventional low-dose-rate prostate brachytherapy dosimetric quality parameters with their biological effective dose (BED) counterparts. To validate a model for transformation from conventional dose to BED, the postimplant plans of 31 prostate brachytherapy patients were evaluated using conventional dose-volume histogram (DVH) quality endpoints and analogous BED-DVH endpoints. Based on CT scans obtained 4 weeks after implantation, DVHs were computed and standard dosimetric endpoints V100 (volume receiving 100% of the prescribed dose), V150, V200, HI (1−[V150/V100]), and D90 (dose that 90% of the target volume received) were obtained for quality analysis. Using known and reported transformations, dose grids were transformed to BED-early (α/β = 10 Gy) and BED-late (α/β = 3 Gy) grids, and the same dosimetric endpoints were analyzed. For conventional, BED-early and BED-late DVHs, no differences in V100 were seen (0.896, 0.893, and 0.894, respectively). However, V150 and V200 were significantly higher for both BED-early (0.582 and 0.316) and BED-late (0.595 and 0.337), compared with the conventional (0.539 and 0.255) DVHs. D90 was significantly lower for the BED-early (103.1 Gy) and BED-late transformations (106.9 Gy) as compared with the conventional (119.5 Gy) DVHs. The conventional prescription parameter V100 is the same for the corresponding BED-early and BED-late transformed DVHs. The toxicity parameters V150 and V200 are slightly higher using the BED transformations, suggesting that the BED doses are somewhat higher than predicted using conventional DVHs. The prescription/quality parameter D90 is slightly lower, implying that target coverage is lower than predicted using conventional DVHs. This methodology can be applied to analyze BED dosimetric endpoints to improve clinical outcome and reduce complications of prostate brachytherapy.

Late rectal function after prostate brachytherapy

Purpose Using a patient-administered quality of life instrument, to evaluate the effect of permanent prostate brachytherapy on late rectal function. Methods and materials One hundred eighty-nine prostate brachytherapy patients were mailed the Rectal Function Assessment Score (R-FAS), with a prestamped return envelope. The R-FAS consists of nine questions and a scoring range of 0–27, with higher scores indicative of poorer bowel function. One hundred eighty-seven (98.4%) surveys were returned. The median follow-up was 66.3 months (range 54–92 months). Clinical, treatment, and dosimetric parameters evaluated for bowel dysfunction included patient age, diabetes, hypertension, tobacco consumption, clinical T-stage, elapsed time since implant, prostate ultrasound volume, planning target volume, hormonal status, supplemental external beam radiation therapy (EBRT), isotope, average, median and maximum rectal doses, total implanted seed strength, values of the minimum dose received by 90% of the prostate gland (D 90), and the percent prostate volume receiving 100%, 150%, and 200% of the minimum prescribed dose (V 100/150/200). Results The R-FAS score for the evaluated cohort was 3.92, which represented a slight improvement from the 1999 survey score of 4.15 ( p = 0.29). Of the evaluated clinical, treatment, and dosimetric parameters, the number of preimplant bowel movements, a history of tobacco consumption, and the median rectal dose correlated with the R-FAS. Although lower rectal doses were noted with Pd-103, isotope did not predict for bowel function. Only 12% (23/187) of patients reported their bowel function to be worse after implantation. Patient perception of overall rectal quality of life was inversely related to the use of supplemental EBRT ( p = 0.007). Conclusion Minor bowel changes are noted following prostate brachytherapy. The vast majority of patients did not report any deterioration in bowel function. In addition, the R-FAS continue to improve with time.

Nursing assessment of sexual function following permanent prostate brachytherapy for patients with early-stage prostate cancer.

Assessment of sexual function following potentially curative local treatment for carcinoma of the prostate gland has resulted in wide ranges of potency preservation rates, which may be because of differences in the evaluated patient populations, mode of data collection, and length of patient follow-up. Quality-of-life data are most reliable when obtained by patient-administered and validated quality-of-life instruments. In the Schiffler Cancer Center's prostate brachytherapy unit, healthcare professionals utilize the specific erectile questions of the International Index of Erectile Function to ascertain pre- and post-treatment erectile function. Documentation of sexual function following all local treatments, including prostate brachytherapy, may help to clarify the etiology of treatment-induced erectile dysfunction (ED), improve treatment for ED, and, ultimately, improve quality-of-life outcomes. Fortunately, the majority of patients with brachytherapy-induced ED respond favorably to sildenafil citrate.

Comparison of methods for calculating rectal dose after 125I prostate brachytherapy implants

Purpose : To compare several different methods of calculating the rectal dose and examine how accurately they represent rectal dose surface area measurements and, also, their practicality for routine use. Methods and Materials : This study comprised 55 patients, randomly selected from 295 prostate brachytherapy patients implanted at the Vancouver Cancer Center between 1998 and 2000. All implants used a nonuniform loading of 0.33 mCi (NIST-99) 125I seeds and a prescribed dose of 144 Gy. Pelvic CT scans were obtained for each patient ∼30 days after implantation. For the purposes of calculating the rectal dose, several structures were contoured on the CT images: ( 1) a 1-mm-thick anterior rectal wall, ( 2) the anterior half rectum, and ( 3) the whole rectum. Point doses were also obtained along the anterior rectal surface. The thin wall contour provided a surrogate for a dose-surface histogram (DSH) and was our reference standard rectal dose measurement. Alternate rectal dose measurements (volume, surface area, and length of rectum receiving a dose of interest [DOI] of ≥144 Gy and 216 Gy, as well as point dose measures) were calculated using several methods (VariSeed software) and compared with the surrogate DSH measure ( SA DOI ). Results : The best correlation with SA 144 Gy was the dose volumes (whole or anterior half rectum) ( R = 0.949). The length of rectum receiving ≥144 Gy also correlated well with SA 144 Gy ( R ≥0.898). Point dose measures, such as the average and maximal anterior dose, correlated poorly with SA 144 Gy ( R ≤0.649). The 216-Gy measurements supported these results. In addition, dose-volume measurements were the most practical (∼6 min/patient), with our surrogate DSH the least practical (∼20 min/patient). Conclusion : Dose-volume measurements for the whole or anterior half rectum, because they were the most practical measures and best represented the DSH measurements, should be considered a standard method of reporting the rectal dose when calculating the DSH is not practical. Average or maximal anterior rectal doses are not reliable indicators of surface area dosimetry.

Safety and efficacy of prostate brachytherapy in patients with prior turp

Safety and efficacy of prostate brachytherapy in patients with prior turp

External radiotherapy and permanent prostate brachytherapy in patients with localized prostate cancer •

We examined the difference in prostate-specific antigen (PSA)–freedom from recurrence (FFR) in patients with localized prostate cancer treated with permanent prostate brachytherapy (PPB) alone or external radiotherapy combined with PPB (RT-PPB). A total of 1476 patients with prostate cancer (T1/T2) were treated with PPB by following the American Brachytherapy Society criteria. Patient self-selection and preference allowed for an overlap of treatment methodologies and risk factors. Monotherapy consisted of 125I or 103Pd. RT-PPB consisted of RT followed by PPB. PSA-FFR was based on a published modification of the American Society for Therapeutic Radiology and Oncology definition. Cox regression analysis was performed to assess the role of Gleason sum, pretreatment PSA value, clinical stage, RT-PPB, the addition of hormones, and the minimum dose covering 90% of the prostate volume (D90 dose). Monotherapy was used for 1016 patients (79%), and RT-PPB was used for 281 patients (21%), with an overall 6-year PSA-FFR of 83.2% (median follow-up of 34.7 months; range, 6–91 months). Multivariate Cox regression analysis to predict PSA-FFR identified the following highly significant variables: pretreatment PSA value, Gleason sum, and the addition of hormones. When the D90% (D90 dose relative to the prescribed dose) was included as a variable, Cox regression identified only the following significant variables: D90%, pretreatment PSA, and Gleason sum. Cox regression failed to identify an improvement in PSA-FFR with RT-PPB or the addition of hormones. Although these conclusions question the role for RT-PPB, only a comparative trial will be able to answer this question definitively.

Urinary morbidity in brachytherapy patients with median lobe hyperplasia

Purpose: To investigate clinical course of prostate brachytherapy patients with radiographic evidence of median lobe hyperplasia (MLH). Methods and Materials: Fifteen patients with median lobe hyperplasia were identified during our routine brachytherapy practice and implanted between June 1998 and March 2000, representing approximately 6% of the 245 brachytherapy patients treated during that time. Each patient was contacted at the time of this report preparation to update postimplant morbidity information, with follow-up ranging from 6 to 30 months (median: 18 months). Results: Three of the 15 patients developed acute, postimplant urinary retention. The preimplant prostate volume, dMLH, and preimplant AUA scores were similar between patients who did or did not develop prolonged urinary retention. Compared with a control group of 62 control patients treated during a similar time interval at the University of Washington, patients with MLH had significantly higher AUA scores at last follow-up. There was no correlation between the change in AUA scores at last follow-up. Conclusions: Based on the data reported here, we consider MLH to be a weak contraindication to prostate brachytherapy. Considering that even patients with prolonged retention have gradually improved spontaneously, we do not advocate prophylactic prebrachytherapy resection of hypertrophic tissue in MLH patients.

Incidence of urinary incontinence after I 125/Pd 103 prostate brachytherapy in patients with prior TURP

Purpose: Early reports of prostate brachytherapy using 2D planning and homogenous seed loading technique were significant for an increased incidence of urinary incontinence (UI) in patients with previous TURP. This study examines the incidence of urinary incontinence after radioactive seed implantation in patients with prior TURP who underwent 3D pretreatment planning and a modified peripheral loading technique.Materials and Methods: 1959 patients underwent permanent I125/Pd103 prostate brachytherapy as primary or boost treatment for adenocarcinoma of the prostate at a single institution. 152 (7.8%) patients had a TURP prior to brachytherapy. Preplanning philosophy was to place seeds >5mm from the TURP defect as outlined on the US volume study, to limit dose to TURP to <140% of prescribed dose, and to use modified peripheral loading. 120 patients were available for telephone questionnaire by the treating physician. Time from TURP to implant ranged from 1 to 312 months with a median of 72 months. Age ranged from 60 to 84 years with a median of 75 years. AUA symptom score ranged from 0 to 26 with a median of 6. 1 patient was excluded secondary to incontinence prior to implant. Median follow up is 16 months. Patients were questioned as to the presence of any leakage (UI). If there was any UI, it was then identified as either stress incontinence, urge incontinence, or both.Results: Refer to Table 1.Conclusion: We believe that prostate brachytherapy using 3D preplanning and modified peripheral loading technique can be performed safely in patients who have had previous TURP. Early follow up shows a crude incontinence rate of 11/119 (9.2%). If a stricter definition of incontinence - incontinence requiring >1 pad per day is used, the crude incontinence rate is 4/119 (3.4%). Tabled 1Time of Follow-Up Call from ImplantStress IncontinenceUrge IncontinenceBoth<6 months1/181/180/186-12 months2/250/250/25>12 months2/761/764/76 Open table in a new tab Purpose: Early reports of prostate brachytherapy using 2D planning and homogenous seed loading technique were significant for an increased incidence of urinary incontinence (UI) in patients with previous TURP. This study examines the incidence of urinary incontinence after radioactive seed implantation in patients with prior TURP who underwent 3D pretreatment planning and a modified peripheral loading technique. Materials and Methods: 1959 patients underwent permanent I125/Pd103 prostate brachytherapy as primary or boost treatment for adenocarcinoma of the prostate at a single institution. 152 (7.8%) patients had a TURP prior to brachytherapy. Preplanning philosophy was to place seeds >5mm from the TURP defect as outlined on the US volume study, to limit dose to TURP to <140% of prescribed dose, and to use modified peripheral loading. 120 patients were available for telephone questionnaire by the treating physician. Time from TURP to implant ranged from 1 to 312 months with a median of 72 months. Age ranged from 60 to 84 years with a median of 75 years. AUA symptom score ranged from 0 to 26 with a median of 6. 1 patient was excluded secondary to incontinence prior to implant. Median follow up is 16 months. Patients were questioned as to the presence of any leakage (UI). If there was any UI, it was then identified as either stress incontinence, urge incontinence, or both. Results: Refer to Table 1. Conclusion: We believe that prostate brachytherapy using 3D preplanning and modified peripheral loading technique can be performed safely in patients who have had previous TURP. Early follow up shows a crude incontinence rate of 11/119 (9.2%). If a stricter definition of incontinence - incontinence requiring >1 pad per day is used, the crude incontinence rate is 4/119 (3.4%). Tabled 1Time of Follow-Up Call from ImplantStress IncontinenceUrge IncontinenceBoth<6 months1/181/180/186-12 months2/250/250/25>12 months2/761/764/76 Open table in a new tab

The role of external radiotherapy and permanent prostate brachytherapy in patients with localized prostate cancer: a matched pair analysis

The role of external radiotherapy and permanent prostate brachytherapy in patients with localized prostate cancer: a matched pair analysis

Relationship between the transition zone index of the prostate gland and urinary morbidity after brachytherapy

Objectives. To evaluate whether urinary symptomatology after prostate brachytherapy is related to the preimplant transition zone index (TZI = transition zone volume/prostate gland volume). Methods. A total of 170 consecutive patients without a prior history of transurethral resection of the prostate gland (TURP) underwent transperineal ultrasound-guided prostate brachytherapy for clinical T1c-T3a carcinoma of the prostate gland. Prostate gland and transition zone dimensions and volumes were measured by prolate ellipsoid calculation from the static ultrasound images. The relationship between TZI and various measures of urinary dysfunction including normalization of International Prostate Symptom Scores (IPSS), catheter dependency, the need for a subsequent TURP, and the duration of alpha-blocker dependency were evaluated. Additional clinical parameters evaluated included the relationship between TZI and patient age, clinical T stage, prostate ultrasound volume, neoadjuvant hormonal manipulation, and preimplant IPSS. For all indices of urinary dysfunction other than serial IPSS, the median patient follow-up was 89.3 weeks. The median follow-up for serial IPSS evaluations was 37.3 weeks with a mean of 11.2 questionnaires per patient. Results. The mean TZI for the 170 patients was 0.23 ± 0.06 (prostate gland volume 30.3 ± 8.7 cm 3, transition zone volume 7.3 ± 3.6 cm 3). The TZI correlated with the time for IPSS normalization, the maximum IPSS after brachytherapy, and the maximum increase in IPSS. Conversely, the TZI did not correlate with either catheter dependency or alpha-blocker dependency. Two of 170 patients (1.2%) required a postimplant TURP. The TZI in these 2 patients (0.34) was statistically different ( P = 0.016) from the mean. Conclusions. In prostate brachytherapy patients, the preimplant TZI predicted the need for a subsequent transurethral resection. The TZI also correlated with multiple variants of IPSS. Conversely, TZI did not correlate with either catheter dependency or alpha-blocker dependency.

Rectal function following prostate brachytherapy

Purpose: Quality of life following therapeutic intervention for carcinoma of the prostate gland has not been well documented. In particular, a paucity of data has been published regarding bowel function following prostate brachytherapy. This study evaluated late bowel function in 209 consecutive prostate brachytherapy patients via a one-time questionnaire administered 16–55 months postimplant. Materials and Methods: Two hundred nineteen consecutive patients underwent permanent prostate brachytherapy from April 1995 through February 1998 using either 125I or 103Pd for clinical T1c–T3a carcinoma of the prostate gland. Of the 219 patients, 7 had expired. Of the remaining 212 patients (median follow-up, 28 months), each patient was mailed a self-administered questionnaire (10 questions) with a prestamped return envelope; 209 (98.6%) surveys were returned. Clinical parameters evaluated for bowel dysfunction included patient age, diabetes, hypertension, history of tobacco consumption, clinical T-stage, elapsed time since implant, and prostate ultrasound volume. Treatment parameters included utilization of neoadjuvant hormonal manipulation, utilization of moderate dose external beam radiation therapy prior to implantation, choice of isotope ( 125I vs. 103Pd), rectal dose (average, median and maximum doses), total implanted seed strength, values of the minimum dose received by 90% of the prostate gland (D 90), and the percent prostate volume receiving 100%, 150%, and 200% of the prescribed minimum peripheral dose (V 100, V 150 and V 200, respectively). Because detailed baseline bowel function was not available for these patients, a cross-sectional survey was performed in which 30 newly diagnosed prostate cancer patients of comparable demographics served as controls. Results: The total rectal function scores for the brachytherapy and control patients were 4.3 and 1.6, respectively, out of a total 27 points ( p < 0.001). Of the evaluated clinical parameters, only the preimplant number of bowel movements per day were correlated with the total survey score ( p < 0.01). None of the treatment parameters were significantly correlated with the total survey score. Despite the fact that implantation with 103Pd resulted in lower radiation doses to the rectum, the choice of isotope was not predictive of bowel function scores. A trend toward increased rectal scores was noted for older patients, and a nonsignificant improvement in rectal survey scores was noted with elapsed time from implantation. Only 19.2% (40/208) of the treatment group reported a worsening of bowel function following implantation. Patient perception of overall rectal quality of life, however, was inversely related to the utilization of external beam radiation therapy ( p = 0.034). Conclusion: To date, no severe changes in late bowel function have been noted following prostate brachytherapy. Although the survey scores indicate bowel function is worse after an implant, the minor changes are not significant enough to bother most individuals. Less than 20% of patients reported that their bowel function was worse following prostate brachytherapy.

Prostate brachytherapy in patients with median lobe hyperplasia

Our aim was to document the technical and clinical course of prostate brachytherapy patients with radiographic evidence of median lobe hyperplasia (MLH). Eight patients with MLH were identified during our routine brachytherapy practice, representing 9% of the 87 brachytherapy patients treated during a 6-month period. No effort was made to avoid brachytherapy in patients noted to have MLH on diagnostic work-up. Cystoscopic evaluation was not routinely performed. Postimplant axial computed tomographic (CT) images of the prostate were obtained at 0.5 cm intervals. Preimplant urinary obstructive symptoms were quantified by the criteria of the American Urologic Association (AUA). Each patient was contacted during the writing of this report to update postimplant morbidity information. There was no apparent association between the degree of MLH and preimplant prostate volume or AUA score. Intraoperatively, we were able to visualize MLH by transrectal ultrasound and did not notice any particular difficulty placing sources in the MLH tissue or migration of sources out of the tissue. The prescription isodose covered from 81% to 99% of the postimplant CT-defined target volume, achieving adequate dose to the median lobe tissue in all patients. Two of the eight patients developed acute, postimplant urinary retention. The first patient required intermittent self-catheterization for 3 months and then resumed spontaneous urination. MLH does not appear to be a strong contraindication to prostate brachytherapy, and prophylactic resection of hypertrophic tissue in such patients is probably not warranted. Int. J. Cancer (Radiat. Oncol. Invest.) 90, 152–156 (2000). © 2000 Wiley-Liss, Inc.

Prostate brachytherapy in patients with median lobe hyperplasia

Our aim was to document the technical and clinical course of prostate brachytherapy patients with radiographic evidence of median lobe hyperplasia (MLH). Eight patients with MLH were identified during our routine brachytherapy practice, representing 9% of the 87 brachytherapy patients treated during a 6-month period. No effort was made to avoid brachytherapy in patients noted to have MLH on diagnostic work-up. Cystoscopic evaluation was not routinely performed. Postimplant axial computed tomographic (CT) images of the prostate were obtained at 0.5 cm intervals. Preimplant urinary obstructive symptoms were quantified by the criteria of the American Urologic Association (AUA). Each patient was contacted during the writing of this report to update postimplant morbidity information. There was no apparent association between the degree of MLH and preimplant prostate volume or AUA score. Intraoperatively, we were able to visualize MLH by transrectal ultrasound and did not notice any particular difficulty placing sources in the MLH tissue or migration of sources out of the tissue. The prescription isodose covered from 81% to 99% of the postimplant CT-defined target volume, achieving adequate dose to the median lobe tissue in all patients. Two of the eight patients developed acute, postimplant urinary retention. The first patient required intermittent self-catheterization for 3 months and then resumed spontaneous urination. MLH does not appear to be a strong contraindication to prostate brachytherapy, and prophylactic resection of hypertrophic tissue in such patients is probably not warranted. Int. J. Cancer (Radiat. Oncol. Invest.) 90, 152-156 (2000).

Temporal resolution of urinary morbidity following prostate brachytherapy

Purpose: To report the short-term urinary morbidity for prostate brachytherapy patients without a preimplant history of a transurethral resection of the prostate gland and who received prophylactic and prolonged α-blockers. α-blockers may decrease radiation-induced urethritis and increase urinary flow. Multiple clinical and treatment parameters were evaluated to identify factors associated with increased acute urinary morbidity. Materials and Methods: One hundred seventy consecutive patients without a prior history of a transurethral resection of the prostate gland underwent transperineal ultrasound guided prostate brachytherapy for clinical T1c-T3a carcinoma of the prostate gland. For all patients, an α-blocker was initiated prior to implantation and continued at least until the international prostate symptom score (IPSS) returned to baseline levels. Clinical parameters evaluated for short-term urinary morbidity included patient age, clinical T stage, preimplant IPSS (obtained within 3 weeks of implantation), and prostate ultrasound volume. Treatment parameters included the utilization of neoadjuvant hormonal manipulation, the utilization of moderate dose external beam radiation therapy before implantation, the choice of isotope, the urethral dose, the total implant activity in millicuries, and a variety of dosimetric quality indicators (D 90 and V 100/V 150/V 200). Catheter dependency and the duration of α-blocker dependency was also evaluated. On average, 11.2 IPSS surveys were obtained for each patient. Results: One hundred fifty of the 170 patients (88.2%) had the urinary catheter permanently removed on day 0. Only one patient required an urinary catheter for > 5 days. Two patients (1.2%) required a subsequent transurethral resection of the prostate gland because of prolonged obstructive/irritative symptoms. To date, no patient has developed an urinary stricture or urinary incontinence. The IPS score on average peaked at 2 weeks following implantation. This score returned to within 1 point of the antecedent value at a median of 6 weeks and a mean of 13.3 weeks. At 26 and 50 weeks, 85% and 56% of the patients, respectively, continued with α-blockers. Of the clinical and treatment parameters evaluated for short-term urinary morbidity, only variants of the IPSS such as the maximum, maximum increase, and preimplant IPSS values correlated with time to return to the referent zone with p < 0.05. Conclusion: The return of the IPS score to baseline occurred more rapidly in our series than what has previously been reported. The 1.2% incidence of transurethral resections also compares favorably with the published literature. We believe these results may be due to maintaining the average urethral dose to approximately 115% of the prescribed dose and the prophylactic and long-term use of α-blockers.

Prostate brachytherapy in patients with prostate volumes ≥ 50 cm 3: dosimetic analysis of implant quality

Objectives: Permanent implantation with 125I in patients with localized prostate cancer who have prostate volumes ≥ 50 cm 3 is often technically difficult owing to pubic arch interference. The objective of this study was to describe dosimetry outcomes in a group of patients who were implanted using the real-time ultrasound-guided technique who had prostate volumes ≥ 50 cm 3. Materials and Methods: A total of 331 patients received an 125I prostate seed implant from January 1, 1995, to June 1, 1999, of whom 66 (20%) had prostate volumes ≥ 50 cm 3 at the time of the procedure. The real-time seed implant method was used in all patients and consisted of intraoperative planning and real-time seed placement using a combination of axial and sagittal ultrasound imaging. Pubic arch interference was managed using an extended lithotomy position or by angling the tip of the ultrasound probe in an anterior direction. No preimplant pubic arch CT scan study was performed and no patients were excluded from treatment because of prostate size. Implant quality was assessed using CT-based dosimetry performed 1 month postimplant. Dose–volume histograms for the prostate, bladder, rectum, and urethra volumes were generated. The target dose for these implants was 160 Gy and an adequate implant was defined as the dose delivered to 90% of the prostate (D90) ≥ 140 Gy. The dose delivered to 95% of the prostate (D95) and doses to 30% of the rectal (DRECT30) and urethral (DURE30) volumes were also calculated. Results: Prostate volumes in the 66 patients ranged from 50 to 93 cm 3 (median 57, mean 61 cm 3). Total activity implanted was 27.8–89.1 mCi (median 57 mCi), with a range in activity per seed of 0.36–0.56 mCi (median 0.4 mCi). The prostate D90s and D95s ranged from 13,245 to 22,637 cGy (median 18,750) and 11,856 to 20,853 cGy (median 16,725), respectively. Only one patient (1.5%) had a D90 < 140 Gy. The DURE30 values ranged from 15,014 to 27,800 cGy (median 20,410) and the DRECT30 values were 3137–9910 cGy (median 5515). Conclusion: Implantation of the large prostate can be accomplished using the real-time method. A total of 98.5% of the patients receive a high-quality implant. In addition, these implants should not put patients at increased risk for significant urinary and bowel complications because urethral and rectal doses can be kept at acceptable levels.

Prostate brachytherapy in patients with median lobe hyperplasia

Prostate brachytherapy in patients with median lobe hyperplasia

Prostate brachytherapy in patients with prior evidence of prostatitis

Purpose: To refute a misconception that a prior history of prostatitis is a contraindication to prostate brachytherapy. Methods and Materials: Five patients with clinical or pathologic evidence of prior prostatitis were treated with transperineal brachytherapy. Four of the patients received a single i.v. dose of ciprofloxacin (500 mg) intraoperatively. Postimplant antibiotics were not given. The pretreatment biopsy slides were reviewed. Results: Two of the five patients developed postimplant urinary retention requiring short-term catheterization, and both resolved spontaneously. One patient developed what appeared to be an exacerbation of his chronic prostatitis. Conclusion: We continue to recommend prostate brachytherapy for the treatment of clinically organ-confined cancer, with no concern about prior clinical or pathologic evidence of prostatitis.

The dependence of prostate postimplant dosimetric quality on CT volume determination

Purpose: The postoperative evaluation of permanent prostate brachytherapy requires a subjective determination of the implant volume. This work investigates the magnitude of the effect that various methods of treatment volume delineation have on dosimetric quality parameters for a treatment planning philosophy that defines a target volume as the prostate with a periprostatic margin. Methods and Materials: Eight consecutive prostate brachytherapy patients with a prescribed dose of 145 Gy from 125I as monotherapy comprised the study population. The prostate ultrasound volume was enlarged to a planning volume by an average factor of 1.8 to encompass probable extracapsular extension in the periprostatic region. For this cohort, the mean pretreatment parameters were 30.3 cm 3 ultrasound volume, 51.8 cm 3 planning volume, 131 seeds per patient, and 42.9 mCi total activity. On CT study sets obtained less than 2 hours postoperatively, target volumes were drawn using three methods: prostate plus a periprostatic margin, prostate only which excluded the puborectalis muscles, the periprostatic fat and the periprostatic venous plexus, and the preplanning ultrasound magnified to conform to the magnification factor of the postimplant CT scan. Three sets of 5 dosimetric quality parameters corresponding to the different volumetric approaches were calculated: V100, V150, and V200 which are the fractions of the target volume covered by 100, 150, and 200% of the prescribed dose, and D90 and D100, which are the minimal doses covering 90 and 100% of the target volume. Results: The postoperative CT volume utilizing the prostate plus margin technique was comparable to the initial planning volume (mean 55.5 cm 3 vs. 51.8 cm 3, respectively) whereas those determined via superimposing the preplan ultrasound resulted in volumes nearly identical to the initial ultrasound evaluation (mean 32.4 cm 3 vs. 30.3 cm 3). The prostate only approach resulted in volumes approximately 25% larger than the ultrasound volume approach. Despite the volume determinations being markedly different, no significant differences between the approaches were appreciated for V100, V150, V200, and D90. Large variations seen in D100 were uncorrelated to any of the other parameters and make D100 unsuitable as a quality indicator. Conclusions: In terms of a logarithmic measure, the variation between volumetric approach for V100, V150, V200, and D90 was less than one-fifth the variation of the CT volumes. These results which indicate relative independence of postimplant CT volume determination and dosimetric quality are only valid for a planning philosophy that includes the prostate with a periprostatic margin as the target volume.

Efficacy of sildenafil citrate in prostate brachytherapy patients with erectile dysfunction

Objectives. To ascertain the efficacy of sildenafil citrate (Viagra) in patients with erectile dysfunction (ED) either before or after prostate brachytherapy by an open-label, nonrandomized study. Methods. Sixty-two patients who underwent prostate brachytherapy between March 1995 and July 1998, had ED either before or after brachytherapy, and were interested in treatment with sildenafil comprised the patient population. Clinical and treatment parameters evaluated for medication efficacy included patient age at brachytherapy and at medication administration, hypertension, diabetes, smoking history, onset of ED, potency status before implant, frequency of intercourse before brachytherapy (if potent), use of neoadjuvant hormonal manipulation, use of moderate dose external beam radiation therapy before implantation, choice of isotope, V100 (the percentage of the prostate volume receiving at least 100% of the prescribed minimal peripheral dose), and sildenafil dose. Results. Fifty (80.6%) of 62 patients responded favorably to sildenafil. None of the treatment parameters predicted medication failure, and among the clinical parameters, only diabetes predicted failure (3 of 5) and only with borderline statistical validity ( P = 0.046). Conclusions. Our results suggest brachytherapy-induced impotence is as amenable to sildenafil treatment as ED from other causes. In addition, our 80.6% success rate is comparable to reported results for patients who underwent bilateral nerve-sparing radical prostatectomy and significantly better than patients who underwent unilateral nerve-sparing or non-nerve-sparing approaches.

Potential role of various dosimetric quality indicators in prostate brachytherapy

Purpose: Postoperative CT-based dosimetric analysis provides detailed information regarding the coverage and uniformity of an implant, but the assessment of implant quality remains an unanswered and controversial issue. There is no disagreement that a good implant should cover the target volume with an adequate dose, but there is no consensus as to what represents an adequate dose.Materials and Methods: The American Brachytherapy Society has recently proposed that prostate brachytherapy quality be measured in terms of the following parameters: D90, V100, and V150 where D90 is defined as the minimal dose covering 90% of the prostate volume and V100 and V150 are defined as the percent volume of the prostate receiving at least 100% or 150% of the prescribed minimal peripheral dose (mPD), respectively. We report detailed day 0 dosimetric evaluation for 60 consecutive prostate brachytherapy patients implanted via a standard transperineal ultrasound guided approach in terms of D90, D100, V90, V100, and V150 and also the maximal and average rectal and urethral dose.Results: Dosimetric evaluation resulted in a V100 greater than 80% of the prostate volume and a D90 greater than 90% of the mPD in the entire patient population. There was a statistically significant difference between the quality scores of 125I implants and 103Pd implants with the 125I mean V100 and D90 at 95.3% volume and 109.9% mPD, respectively, vs. 103Pd at 91.8% volume and 103.7% mPD. Likewise, the rectal and urethral doses as a fraction of mPD were significantly lower in 103Pd than in 125I implants. This occurred despite the fact that palladium implants were typically preplanned with significantly better coverage and hotter V150 than iodine implants. We consider V150 to be an important parameter for determining dose homogeneity although the clinical utility of dose homogeneity remains unknown. The mean V150 was 45.6 ± 9.6% volume. There was no additional dosimetric utility from a determination of V90 while D100 was found to be overly sensitive to steep dose gradients at the periphery of the prostate.Conclusions: This report represents the first detailed postimplant day 0 dosimetric evaluation comparing ABS recommended quality parameters used to evaluate prostate brachytherapy. At the present time, no long-term clinical outcomes are available because of short follow-up. As PSA based follow-up data becomes available, however, this report may help define what represents an adequate implant.