Should brachytherapy be considered a therapeutic option in localized prostate cancer?

Radical prostatectomy versus brachytherapy for clinically localized prostate cancer on oncological and functional outcomes: a meta-analysis

Background

Prostate cancer (PCa) is a form of malignancy that harms the health status of elderly men worldwide. It is unclear which of radical prostatectomy (RP) or brachytherapy (BT) is the more effective treatment for PCa. This study presents the first highly comprehensive and up-to-date comparative analysis of the overall outcomes of RP versus BT.

Methods

We conducted a systematic literature search for studies published on PubMed, EMBASE, and the Cochrane Library on the outcomes of RP versus BT in clinically localized PCa. The cumulative analysis was performed using Review Manager Version 5.3 software, and the Chi-square test was employed to test the statistical heterogeneity. The summary odds ratio (OR) and standard mean difference (SMD) was estimated using random effects models at 95% confidence intervals (CIs).

Results

In total, 2 randomized, 2 prospective, and 21 retrospective comparative studies were included. No significant differences in biochemical recurrence rate (BCR) (OR: 1.24; 95% CI: 0.91, 1.68) and prostate cancer-specific mortality (PCSM) (OR: 1.62; 95% CI: 0.86, 3.04) between RP and BT were noted. With erectile dysfunction and urinary incontinence, BT was more protective than RP in both short-term post-operative reports (OR: 2.06; 95% CI: 1.15, 3.70 and OR: 4.62; 95% CI: 2.33, 9.16) and long-term patient outcome reports (SMD: -5.62; 95% CI: -13.81, 2.57 and SMD: -11.52; 95% CI: -18.32, -4.72).

Conclusions

BT and RP for PCa therapy pose comparable risks of PCSM and BCR, while BT is associated with a lower incidence of erectile dysfunction and urinary incontinence. This study tentatively confirms that BT is an alternative to RP for patients seeking a curative treatment with minimal risks of urinary incontinence and sexual dysfunction.

Low dose rate prostate brachytherapy

Low dose rate (LDR) prostate brachytherapy is an evidence based radiation technique with excellent oncologic outcomes. By utilizing direct image guidance for radioactive source placement, LDR brachytherapy provides superior radiation dose escalation and conformality compared to external beam radiation therapy (EBRT). With this level of precision, late grade 3 or 4 genitourinary or gastrointestinal toxicity rates are typically between 1% and 4%. Furthermore, when performed as a same day surgical procedure, this technique provides a cost effective and convenient strategy. A large body of literature with robust follow-up has led multiple expert consensus groups to endorse the use of LDR brachytherapy as an appropriate management option for all risk groups of non-metastatic prostate cancer. LDR brachytherapy is often effective when delivered as a monotherapy, although for some patients with intermediate or high-risk disease, optimal outcome are achieved in combination with supplemental EBRT and/or androgen deprivation therapy (ADT). In addition to reviewing technical aspects and reported clinical outcomes of LDR prostate brachytherapy, this article will focus on the considerations related to appropriate patient selection and other aspects of its use in the treatment of prostate cancer.

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.

The evolution of brachytherapy for prostate cancer

Brachytherapy (BT), using low-dose-rate (LDR) permanent seed implantation or high-dose-rate (HDR) temporary source implantation, is an acceptable treatment option for select patients with prostate cancer of any risk group. The benefits of HDR-BT over LDR-BT include the ability to use the same source for other cancers, lower operator dependence, and - typically - fewer acute irritative symptoms. By contrast, the benefits of LDR-BT include more favourable scheduling logistics, lower initial capital equipment costs, no need for a shielded room, completion in a single implant, and more robust data from clinical trials. Prospective reports comparing HDR-BT and LDR-BT to each other or to other treatment options (such as external beam radiotherapy (EBRT) or surgery) suggest similar outcomes. The 5-year freedom from biochemical failure rates for patients with low-risk, intermediate-risk, and high-risk disease are >85%, 69-97%, and 63-80%, respectively. Brachytherapy with EBRT (versus brachytherapy alone) is an appropriate approach in select patients with intermediate-risk and high-risk disease. The 10-year rates of overall survival, distant metastasis, and cancer-specific mortality are >85%, <10%, and <5%, respectively. Grade 3-4 toxicities associated with HDR-BT and LDR-BT are rare, at <4% in most series, and quality of life is improved in patients who receive brachytherapy compared with those who undergo surgery.

Electroplating/electrodissolution/recovery cycle for rhodium target used for an industrial scale cyclotron production of palladium-l03

Electrodeposition of rhodium metal on a copper backing was performed in acidic sulfate media using RhCl3 · 3 H2O, Rh2(SO4)3 (recovered from hydrochloric acid solution) and also the commercially available Rhodex plating baths. This work describes the development of a high current density (2.4 A·cm-2) electrodissolution system that allows solubilisation of rhodium fragments, powder and pieces of foils and wires in the presence of hydrochloric and chlorine gas. Solvent-solvent extraction of no-carrier-added 103Pd from the irradiated rhodium target with a-furyldioxime into chloroform under the influence of hydrochloric acid concentration was investigated. The extraction yield was 85.3% for a single extraction with 0.37 M HCl, and 103Pd was more than 99% pure.

Canine prostate: contrast-enhanced US-guided radiofrequency ablation with urethral and neurovascular cooling--initial experience

PURPOSE

To prospectively evaluate in a canine model contrast material-enhanced ultrasonography (US) for guiding and monitoring radiofrequency (RF) ablation of the entire prostate, with urethral and vascular cooling to protect the surrounding structures.

MATERIALS AND METHODS

After approval by the institutional animal use and care committee, an RF electrode was used to ablate the entire prostate in 15 dogs. During ablation, pulse-inversion harmonic US was performed by using an endocavitary probe after an intravenous bolus injection (0.04 mL/kg) and infusion (0.015 muL/kg/min) of a US contrast agent. In group 1 (n = 4), no cooling protection was used during ablation. In group 2 (n = 5), urethral and bladder protection was provided by inserting a 12-F catheter infused with cold saline (8 degrees C +/- 4 [standard deviation]) at a rate of 100 mL/min. In group 3 (n = 6), further protection of the neurovascular bundles (NVBs) was provided by infusing cold saline (8 degrees C +/- 4) into the iliac arteries at a rate of 50 mL/min by means of catheterization of the femoral artery. Pathologic findings among the three groups were compared by using the Wilcoxon rank sum test.

RESULTS

The average volumes of prostate ablation achieved in the three groups were 96.6%, 91.9%, and 92%. Contrast-enhanced pulse-inversion harmonic US allowed visualization and monitoring of urethral and NVB blood flow during the ablation. Without protection, damage to the urethra and the NVB was demonstrated at both US and pathologic examination. There was highly significant difference in urethral damage between groups with and the group without urethral cooling (P = .002), while intraarterial cooling demonstrated a nonsignificant trend toward a decreased NVB damage (P = .069).

CONCLUSION

Contrast-enhanced US can guide RF ablation of the entire prostate. Infusion of cold saline provides effective protection for the urethra during such procedures. The application of intraarterial cooling did not provide a significant improvement in the protection of the NVB in this small study.

[Brachyterapy in localized prostate cancer]

INTRODUCTION AND OBJECTIVES

Considering the high frequency of localized prostate cancer in stages, at the moment there are minimally invasive techniques that compete with the classic surgery. One of them is the Low Dose Rate (LDR) Brachytherapy with permanent implants of 1125 seeds. The objective of the present study is to expose our experience from the year 1998, when we made the first treatment, until today. The results and the morbidity of the patients over a 7 and a half years period are analyzed.

MATERIAL AND METHODS

A total of 800 patients were treated with LDR brachytherapy, with average age of 68 years and range between 48 and 83 years. In all patients the 1125 seeds were used with Rapid-Strand and peripheral load by means of intraoperative planning.

RESULTS

The urinary rate of complications was of 3% of AUR, and 0.2% of urinary incontinence. The morbidity on the digestive apparatus was of a 12% intermittent bleeding, 2% of proctitis, and a 0.3% of rectal fistulas.

Semiautomatic 3-D prostate segmentation from TRUS images using spherical harmonics

Prostate brachytherapy quality assessment procedure should be performed while the patient is still on the operating table since this would enable physicians to implant additional seeds immediately into the prostate if necessary thus reducing the costs and increasing patient outcome. Seed placement procedure is readily performed under fluoroscopy and ultrasound guidance. Therefore, it has been proposed that seed locations be reconstructed from fluoroscopic images and prostate boundaries be identified in ultrasound images to perform dosimetry in the operating room. However, there is a key hurdle that needs to be overcome to perform the ultrasound and fluoroscopy-based dosimetry: it is highly time-consuming for physicians to outline prostate boundaries in ultrasound images manually, and there is no method that enables physicians to identify three-dimensional (3-D) prostate boundaries in postimplant ultrasound images in a fast and robust fashion. In this paper, we propose a new method where the segmentation is defined in an optimization framework as fitting the best surface to the underlying images under shape constraints. To derive these constraints, we modeled the shape of the prostate using spherical harmonics of degree eight and performed statistical analysis on the shape parameters. After user initialization, our algorithm identifies the prostate boundaries on the average in 2 min. For algorithm validation, we collected 30 postimplant prostate volume sets, each consisting of axial transrectal ultrasound images acquired at 1-mm increments. For each volume set, three experts outlined the prostate boundaries first manually and then using our algorithm. By treating the average of manual boundaries as the ground truth, we computed the segmentation error. The overall mean absolute distance error was 1.26 +/- 0.41 mm while the percent volume overlap was 83.5 +/- 4.2. We found the segmentation error to be slightly less than the clinically-observed interobserver variability.

3D TRUS guided robot assisted prostate brachytherapy

This paper describes a system for dynamic intraoperative prostate brachytherapy using 3D ultrasound guidance with robot assistance. The system consists of 3D transrectal ultrasound (TRUS) imaging, a robot and software for prostate segmentation, 3D dose planning, oblique needle segmentation and tracking, seed segmentation, and dynamic re-planning and verification. The needle targeting accuracy of the system was 0.79 mm +/- 0.32 mm in a phantom study.

Permanent prostate brachytherapy: a century of technical evolution

PURPOSE

To summarise the practical aspects of the development of techniques of interstitial permanent prostate brachytherapy (PPB) implantation. Prostate brachytherapy dates back to Pasteau's publication in 1913 describing the insertion of a radium capsule into the prostatic urethra to treat carcinoma of the prostate. Various implantation methods were employed but with unsatisfactory results until the development of the transrectal ultrasound in the 1980s. The subsequent two-stage Seattle technique allowed for a planned homogenous distribution of radioactive sources throughout the gland resulting in biochemical control comparable to surgical and external beam radiotherapy series. With the advent of advanced computer software and improved imaging, the technique has developed accordingly to a single stage procedure with on-table dosimetric assessment. The principles of targeting dose to the prostate while avoiding surrounding organs at risk remain as relevant today as nearly a century ago. There is an array of techniques to consider for the novice PPB provider. Whether the evolution of PPB techniques will translate into improved biochemical control is yet to be seen.

Efficacy of High Dose Per Fraction Radiation for Implanted Human Prostate Cancer in a Nude Mouse Model

PURPOSE

SBRT is a new therapeutic paradigm using large dose per fraction treatments (aggressive hypofractionation). While SBRT has shown efficacy for treating patients with lung, liver and spine tumors, to our knowledge there have been no preclinical studies evaluating the efficacy of this treatment for prostate cancer. We investigated the dose-response characteristics of SBRT for treating human prostate cancer in a nude mouse model.

MATERIALS AND METHODS

Nude mice were injected subcutaneously into the right flank with C4-2 prostate cancer cells grown in culture. A dose escalation trial was performed to assess toxicity and response. Tumor bearing animals were radiated with 3 fractions (1 per week) for a total dose of 15 Gy in 11, 22.5 Gy in 9 and 45 Gy in 10, while 8 untreated animals served as controls. The mice were weighed, and tumor volume and PSA measurements were performed at baseline and weekly until 4 weeks after treatment.

RESULTS

There was no treatment related toxicity. There was a significant difference in the tumor response to higher radiation doses. In the 15 and 22.5 Gy groups mean tumor volume decreased to 58% and 90% of the original volume, respectively, but the rats experienced progressive tumor regrowth within 1 week after the completion of therapy. The 45 Gy group had a mean tumor volume and PSA decrease of greater than 90%, which was sustained 1 month after treatment in all except 2 mice.

CONCLUSIONS

SBRT dose level treatments were able to significantly decrease tumor volume and PSA. However, using 15 and 22.5 Gy durable responses were not achieved except in a few mice. The 45 Gy group demonstrated sustained PSA and tumor volume decreases in most mice. These results clearly show an increasing dose-response relationship for a range of hypofractionated dose levels, as used in SBRT.

An Evaluation of General and Spinal Anesthesia Techniques for Prostate Brachytherapy in a Day Surgery Setting

We evaluated four anesthetic techniques for transperineal brachytherapy of the prostate in a day-surgery setting: general anesthesia with either fentanyl and propofol total IV anesthesia (TIVA) or with fentanyl, thiopental, and isoflurane (F-P-I), versus spinal block using 5 mg of 0.5% large-dose spinal hyperbaric bupivacaine (LDS) or 2.5 mg of 0.5% hyperbaric bupivacaine plus fentanyl 25 mug small-dose spinal (SDS). Operating room time was shorter in the general anesthesia groups. TIVA patients voided earlier (103 +/- 41 min) than F-P-I patients (131 +/- 65 min), SDS (126 +/- 55 min), and LDS patients (169 +/- 65 min; P < 0.05 TIVA versus all groups and between spinal groups). TIVA patients were discharged earlier (119 +/- 42 min) than F-P-I patients (160 +/- 69 min) and SDS or LDS patients (132 +/- 53 and 186 +/- 72 min, respectively; P < 0.05 versus all groups and between the spinal groups). There were no intergroup differences regarding postanesthesia nausea or vomiting, pain score, return to normal function at home, or overall satisfaction. Whereas all four techniques are suitable for this procedure, TIVA provides the earliest voiding and consequently fastest discharge. Between spinal techniques, the SDS technique requires more intraoperative sedation but provides earlier voiding and consequently earlier discharge. TIVA, general anesthesia with isoflurane and fentanyl, and two spinal techniques (5 mg of bupivacaine 0.5% or 2.5 mg of bupivacaine 0.5% plus 25 mug of fentanyl) are suitable techniques for transperineal brachytherapy in the day-surgery setting. TIVA allows for earliest voiding and therefore fastest discharge home. Spinal block with 2.5 mg of bupivacaine plus 25 mug of fentanyl provides earlier voiding and consequently earlier discharge than 5 mg of bupivacaine alone.

Long-term outcomes among localized prostate cancer survivors: health-related quality-of-life changes after radical prostatectomy, external radiation, and brachytherapy

PURPOSE

We sought to elucidate long-term changes in health-related quality-of-life (HRQOL) outcomes by prospectively re-evaluating a well-characterized cohort of prostate cancer (PC) survivors 4 to 8 years after primary treatment.

PATIENTS AND METHODS

Patients who had been evaluated previously at a median of 2.6 years after radical prostatectomy (RP), external radiation (three-dimensional conformal radiation therapy [3-D CRT]), or brachytherapy (BT) were recontacted at a median of 6.2 years after treatment. The clinical relevance of long-term HRQOL impairment among survivors was established by comparison with controls of similar age. Factors associated with HRQOL changes during this interval were evaluated.

RESULTS

Of the 964 eligible men, 709 (73.5%) completed measurable questionnaires. In four domains (urinary irritative-obstructive, urinary incontinence, bowel, and sexual), significant HRQOL differences were detected for at least one of the therapy groups, compared with controls (all P < .05). During the 4-year interval, significant improvement was observed for the urinary irritative-obstructive (P < .0001) and bowel (P < .0001) domains among BT patients, whereas urinary incontinence HRQOL worsened for both the BT (P = .0017) and 3-D CRT (P = .0008) treatment groups. Overall sexual HRQOL deteriorated for the 3-D CRT cohort (P = .0017), as well as for controls (P = .0136). Among RP patients, significant HRQOL changes were not observed.

CONCLUSION

During a 4-year interval from earlier to longer-term phases of PC treatment survivorship, sexual, urinary, and bowel dysfunction remain significant concerns among early-stage PC treatment survivors, compared with control men. Although postprostatectomy HRQOL remains relatively stable during this interval, disease-specific HRQOL continues to evolve among men treated with BT and 3-D CRT.

Gonadotropin-releasing hormone agonists in the treatment of prostate cancer

In 1979, the first prostate cancer patient was treated with a GnRH agonist at the Laval University Medical Center in Quebec City, Canada, thus rapidly leading to the worldwide replacement of surgical castration and high doses of estrogens. The discovery of medical castration with GnRH agonists was soon followed by fundamental changes in the endocrine therapy of prostate cancer. Most importantly, the excellent tolerance accompanying the treatment with GnRH agonists has been a key factor that permitted a series of studies demonstrating a major reduction in the death rate from prostate cancer ranging from 31 to 87% at 5 yr of follow-up in patients with localized or locally advanced prostate cancer. In fact, a one third reduction in prostate cancer deaths has been calculated in the metaanalysis of all available studies. The general acceptance of this discovery by patients and physicians is illustrated by world sales above 3.0 billion U.S. dollars in 2003. Although extremely efficient in achieving complete medical castration and well tolerated, with no other side effects than the expected hypoandrogenicity, GnRH agonists should not be administered alone. In fact, shortly after discovery of the castration effects of GnRH agonists, we observed that approximately 50% of androgens remain in the prostate after castration, thus leading to the recognition of the role of adrenal dehydroepiandrosterone as an important source of the androgens synthesized locally in the prostate and in many peripheral target tissues. We therefore developed combined androgen blockade (CAB), whereby the androgens of both testicular and adrenal origins are blocked simultaneously at start of treatment with the combination of a GnRH agonist to block the testis and a pure antiandrogen to block the action of the androgens produced locally. CAB, first used in advanced metastatic disease, has been the first treatment shown to prolong life in prostate cancer. Most interestingly, in 2002, we made the observation that CAB alone given continuously for 6.5 yr or more leads to cure of the disease in at least 90% of cases, thus suggesting that androgen blockade combining a GnRH agonist and a pure antiandrogen could well be the most efficient treatment of localized prostate cancer, and thus offering the possibility of practically eliminating death from prostate cancer.

Detection and correction of patient movement in prostate brachytherapy seed reconstruction

Intraoperative dosimetry of prostate brachytherapy can help optimize the dose distribution and potentially improve clinical outcome. Evaluation of dose distribution during the seed implant procedure requires the knowledge of 3D seed coordinates. Fluoroscopy-based seed localization is a viable option. From three x-ray projections obtained at different gantry angles, 3D seed positions can be determined. However, when local anaesthesia is used for prostate brachytherapy, the patient movement during fluoroscopy image capture becomes a practical problem. If uncorrected, the errors introduced by patient motion between image captures would cause seed mismatches. Subsequently, the seed reconstruction algorithm would either fail to reconstruct or yield erroneous results. We have developed an algorithm that permits detection and correction of patient movement that may occur between fluoroscopy image captures. The patient movement is decomposed into translational shifts along the tabletop and rotation about an axis perpendicular to the tabletop. The property of spatial invariance of the co-planar imaging geometry is used for lateral movement correction. Cranio-caudal movement is corrected by analysing the perspective invariance along the x-ray axis. Rotation is estimated by an iterative method. The method can detect and correct for the range of patient movement commonly seen in the clinical environment. The algorithm has been implemented for routine clinical use as the preprocessing step for seed reconstruction.

10-YEAR DISEASE-FREE SURVIVAL RATES AFTER SIMULTANEOUS IRRADIATION FOR PROSTATE CANCER WITH A FOCUS ON CALCULATION METHODOLOGY

PURPOSE

We documented the 10-year disease-free survival rate after simultaneous irradiation for prostate cancer and suggested standards for outcome calculation methodology.

MATERIALS AND METHODS

From 1992 to 1998, 1,469 consecutive men with clinical stage T1T2NxM0 prostate cancer who did not receive neoadjuvant hormones were treated with simultaneous irradiation, an ultrasound guided transperineal prostate I seed implant followed by external irradiation. Median pretreatment prostate specific antigen (PSA) was 7.1 ng/ml (range 0.3 to 88). All men were treated 5 or more years ago. Median followup was 6 years (range 3 months to 11 years). Disease freedom was defined as the achievement and maintenance of PSA 0.2 ng/ml or less, and treatment failure was defined as a PSA nadir greater than 0.2 ng/ml or a subsequent PSA increase above this level.

RESULTS

The overall 10-year disease-free survival rate was 83%. Median time to recurrence was 30 months (range 3 months to 8 years) and 24% of recurrences were after 5-year followup. The 10-year outcome according to low, intermediate and high risk group was 93%, 80% and 61%, respectively (p <0.0001). Multivariate analysis of factors related to disease freedom documents that pretreatment PSA, Gleason score and percent positive biopsies were significant but stage and age were not.

CONCLUSIONS

By calculating outcome with PSA cut point 0.2 ng/ml and evaluation only of men treated 5 or more years ago, the 10-year disease-free survival rates from this study can be reasonably compared with the outcome of radical prostatectomy performed in the PSA era.

Tomosynthesis-based localization of radioactive seeds in prostate brachytherapy

Accurately assessing the quality of prostate brachytherapy intraoperatively would be valuable for improved clinical outcome by ensuring the delivery of a prescribed tumoricidal radiation dose to the entire prostate gland. One necessary step towards this goal is the robust and rapid localization of implanted seeds. Several methods have been developed to locate seeds from x-ray projection images, but they fail to detect completely-overlapping seeds, thus necessitating manual intervention. To overcome this limitation, we have developed a new method where (1) a three-dimensional volume is reconstructed from x-ray projection images using a brachytherapy-specific tomosynthesis reconstruction algorithm with built-in blur compensation and (2) the seeds are located in this reconstructed volume. In contrast to other projection-based methods, our method can detect completely overlapping seeds. Our simulation results indicate that we can locate all implanted seeds in the prostate using a tomosynthesis angle of 30 degrees and seven projection images. The mean localization error is 1.27 mm for a case with 100 seeds. We have also tested our method using a prostate phantom with 61 implanted seeds and succeeded in locating all seeds automatically. We believe this new method can be useful for the intraoperative quality assessment of prostate brachytherapy in the future.

High-dose rate iridium-192 brachytherapy and external beam radiation therapy for prostate cancer with or without androgen ablation

AIM

To report the results of our feasibility study incorporating iridium-192 high-dose-rate (HDR) afterloading brachytherapy and external beam radiation therapy (EBRT) for the treatment of prostate carcinoma and to assess the role of androgen ablation in conjunction with this treatment option.

METHODS

From July 2000 to June 2002, 42 patients with clinically localized or locally extensive prostate carcinoma were treated with HDR iridium-192 brachytherapy and EBRT with or without androgen ablation. The median follow up was 16.5 months.

RESULTS

The technique of HDR brachytherapy and EBRT proved to be feasible with acceptable morbidities. Continuous prostate-specific antigen (PSA) reduction was noted in all patients and no PSA failure was noted during follow up. Within 1 year, the decline of PSA nadir values less than 1 ng/mL was faster in patients with the addition of androgen blockade (P = 0.001). However, within 1 year, PSA nadir values less than 1.0 ng/mL can be achieved in all patients whose initial PSA is less than 20 ng/mL, with or without hormone blockade.

CONCLUSIONS

The need for hormonal therapy in favorable-risk brachytherapy patients (PSA < 20 ng/mL) might be less than the need for intermediate- or high-risk patients. The use of hormonal therapy in intermediate-risk patients (PSA >/= 20 ng/mL) treated with HDR brachytherapy and pelvic EBRT is appealing, considering the favorable results. High dose rate brachytherapy appears to be an effective treatment for clinically localized and locally extensive prostate cancer, with minimal morbidity.

Intraoperative dynamic dose optimization in permanent prostate implants

PURPOSE

With the advent of intraoperative optimized planning, the treatment of prostate cancer with permanent implants has reached an unprecedented level of dose conformity. However, because of well-documented (and unavoidable) inaccuracies in seed placement into the gland, carrying out a plan results in a large degree of variability relative to the intended dose distribution. This brings forth the need to periodically readjust the plan to allow for the real positions of seeds already implanted. In this paper, an algorithm for performing this task, hereby described as intraoperative dynamic dose optimization (IDDO), is presented and assessed.

METHODS AND MATERIALS

The general scheme for performing IDDO consists of three steps: (1) at some point during the implant, coordinates of implanted seeds are identified; (2) seed images are projected onto the reference frame of the ultrasound images for planning; and (3) the plan is reoptimized. Work on the first two steps is reported elsewhere. Here, we focus on the strategy for implementing the reoptimization step. An optimal treatment plan is first obtained based on initial operating room-acquired ultrasound images. We analyze the sensitivity and effect of the IDDO procedure with respect to the total number of reoptimizations performed. Specifically, we consider reoptimizing 2, 3, and 4 times. When two reoptimizations are used, half of the seeds from the initial optimal plan are implanted. The first reoptimization is performed on the remaining possible seed positions, and all the seeds designated in this reoptimized plan are implanted. The second (final) reoptimization is done on the remaining unused seed positions to ensure 100% coverage of the gland and to eliminate possible cold spots in the gland. Similarly, when three reoptimization steps are used, one-third of the seeds from the initial optimized plan, one-half of the seeds from the first reoptimization, and all seeds from the second reoptimization are implanted. The third (final) reoptimization is performed to assist in eliminating possible cold spots. Reoptimizing four times proceeds in a like manner. Fifteen patient cases are used for comparison. Strict dose bounds of 100% and 120% of the prescription dose are imposed on the urethra, and 100% coverage is imposed on the prostate volume. To assist in achieving good conformity, prostate contour points are assigned a target upper dose bound of 150% of the prescription dose.

RESULTS

A two-way comparison is performed: (a) initial optimized plan, (b) IDDO plan. Postimplant dose analysis, coverage and conformity measures, as well as actual dose received by urethra and rectum are used to gauge the results. The initial optimized plan consistently provides 93% prescription dose coverage to the gland with average conformity index of 1.32. The urethra dose ranges within 100% to 150%, and the maximum dose delivered to the rectum reaches 91% of the prescription dose. On average, about 50% of the urethra receives more than 120% of the prescription dose, and 19% of the rectum volume receives more than the 78% upper dose limit. For the IDDO plan, 100% postimplant coverage with 1.16 conformity is achieved. Urethra and rectum dose is maintained within the prescribed 100% to 120% range and 78% upper bound, respectively.

CONCLUSIONS

With real-time treatment planning, it is possible to dynamically reoptimize treatment plans to account for actual seed positions (as opposed to planned positions) and needle-induced swelling to the gland during implantation. Postimplant analysis shows that the final seed configuration resulting from the IDDO method yields improved dosimetry. The algorithmic design ensures that one can achieve complete coverage while maintaining good conformity, thus sparing excess radiation to external tissue. The study also provides evidence of the possibility of morbidity reduction to urethra and rectum (because of reduced dose delivered to these structures) via the use of IDDO planning. Clinical studies are needed to validate the importance of our approach.

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.

Determinants of long-term sexual health outcome after radical prostatectomy measured by a validated instrument

PURPOSE

We combined the strengths of previous patient reported studies (that is use of a validated instrument) with the assets of previous single surgeon, physician reported series (that is prospective collection of operative data) by performing a multiple surgeon study to identify demographic and operative determinants of post-prostatectomy sexual health related quality of life outcomes.

MATERIALS AND METHODS

Sexual outcome was measured after prostatectomy in 671 prostate cancer cases with a followup of 4 to 52 months treated by any of 7 urologists at a high volume medical center and 112 age matched controls by cross-sectional health related quality of life assessment using the Expanded Prostate Cancer Index Composite validated questionnaire. Multivariable ANCOVA was done to identify the baseline determinants affecting post-prostatectomy sexual health outcomes among 17 clinical and demographic factors.

RESULTS

Factors independently associated with better sexual health outcome in patients included younger age (p <0.0001), nerve sparing technique (p <0.0001), time since prostatectomy (p = 0.0001), smaller prostate size (p = 0.003), higher education level (p = 0.02), and higher household income (p = 0.02). Orgasm was achieved at a higher rate than erection. In controls only age (p = 0.0004) and having a partner (p = 0.04) were significantly associated with sexual health.

CONCLUSIONS

Larger prostate size adversely affected sexual health outcome after radical prostatectomy independent of all other measured factors. Patient sexual outcome did not differ significantly among surgeons who performed a broad range of such procedures yearly, suggesting that surgical expertise cannot be measured simply by the number of such operations that a surgeon performs. Stratifying patient reported sexual function by the principal determinants of age, nerve sparing and prostate size provides a basis for counseling patients.

A medical needle drive for the study of interstitial implant mechanics

We describe the construction and test performance of a computer-controlled medical needle drive. The drive represents one facet of a larger project whose aim is to investigate experimentally the mechanics of needle introduction in radioactive 'seed' prostate implants, with a view to identifying ways of making incremental improvements in needle placement accuracy. It is capable of mimicking a range of motions imparted to a needle by a clinical practitioner, and of monitoring the compressive force at the needle tip in real time via an in-line load cell. Tests involving driving needles into porcine gelatin samples using a variety of velocity profiles confirm intended operation. The drive will permit us to introduce needles in a controlled and reproducible manner into a realistic prostate phantom currently being designed.

Prospective assessment of patient-reported long-term urinary morbidity and associated quality of life changes after 125I prostate brachytherapy

PURPOSE

Prostate brachytherapy has been reported to have less morbidity for patients than radical prostatectomy or external beam irradiation. However, to date there have been no long-term data to support these claims. With radiation doses in excess of 140 Gy required to control the tumor, disabling chronic urinary symptoms and associated quality of life (QOL) changes might be expected to occur. This study prospectively assessed the long-term effects of (125)I prostate brachytherapy on urinary morbidity.

METHODS AND MATERIALS

A total of 248 patients with a median age of 67 years (range, 43-83 years) who presented with T1-T2 prostate cancer were treated with (125)I seed implantation and followed up for a minimum of 18 months after treatment (range, 18 to 108 months; median, 31 months). There were 177 T1b-T2a cases and 41 patients with prostate-specific antigen >10 ng/ml; 20.2% were treated with hormonal therapy. All patients prospectively reported their urinary symptoms and QOL assessment on American Urological Association symptom score records before treatment and at each follow-up visit. Urinary symptoms at last follow-up were compared with pretreatment scores. Radiation doses to the prostate (dose delivered to 90% of the gland; D(90)) and urethra (D(30)) were determined by CT-based dosimetry.

RESULTS

The median prostate D(90) was 165 Gy (range, 16.5-260 Gy), and the median urethra D(30) was 192 Gy (range, 23.5-306 Gy). Mean individual scores and QOL ranged from 0.31 to 1.65 before implantation and 0.39 to 1.73 afterward. There were no significant differences between pretreatment and last mean scores for any of the categories except for a small but significant increase in urgency (p=0.01) and weak stream (p=0.03). The cohort of patients who initially presented with marked urinary symptoms (initial score >or=3) had improvement in individual scores by 31.4% to 58.2%, total score by 31.1% (p=0.0005), and QOL by 40.6% (p<0.0001).

CONCLUSIONS

This study suggests that prostate brachytherapy is associated with minimal long-term urinary morbidity. The subgroup of patients who present with marked urinary symptoms before implantation has improvement in symptoms and QOL after implantation. These data substantiate the favorable long-term QOL outcomes associated with modern brachytherapy techniques.

The relevance of prostatectomy findings for brachytherapy selection in patients with localized prostate carcinoma

BACKGROUND

The efficacy of brachytherapy for patients with localized prostate carcinoma depends on adequate radiotherapeutic coverage of the primary tumor and its subclinical extraprostatic extensions. Predictive models based on pretherapy factors may be useful to estimate the likelihood for clinically relevant extraprostatic disease and may be incorporated into selection criteria for this procedure.

METHODS

Multivariate logistic regression model building was performed using pretherapy factors in 2905 surgically staged patients with localized prostate carcinoma to estimate the probability of seminal vesicle and/or lymph node involvement. Bootstrap methods were employed to assess the stability of the final model parameters and to determine the sensitivity and specificity of the final model.

RESULTS

Clinical tumor classification, biopsy Gleason score groupings, and serum prostate specific antigen (PSA) levels were associated with seminal vesicle and/or pelvic lymph node involvement. These factors were incorporated into a multivariate model that predicted for these adverse histopathologic features. Allowing for up to a 10% likelihood for seminal vesicle and/or pelvic lymph node involvement, patients with tumors classified as T1c-T2a, Gleason scores of 2-6, and PSA < or = 16 ng/mL; or with tumors classified as T1c-T2a, Gleason scores of 7-10, and PSA < or = 4 ng/mL; or with tumors classified as T2b-T2c, Gleason scores of 2-6, and PSA < or = 6 ng/mL would be potential candidates for brachytherapy alone.

CONCLUSIONS

The predictive model presented may provide criteria whereby an adequately performed prostate brachytherapy procedure is expected to encompass the intraprostatic and adjacent extraprostatic disease. Prostate brachytherapy alone may be considered in these circumstances, whereas the addition of external beam radiotherapy may be reserved for patients with disease that is apt to extend beyond the brachytherapy target volume.

Brachytherapy for carcinoma of the prostate: techniques, patient selection, and clinical outcomes

Brachytherapy for prostate carcinoma has developed as either low dose rate permanent implants or high dose rate afterloading. Both approaches offer unsurpassed dose escalation and, particularly with permanent implants, the convenience of a single outpatient treatment. These therapies have now entered the mainstream of treatment options and are in the refinement phase of development. Techniques of implantation, treatment planning approaches, innovative fractionation schemes, and appropriate patient selection are the subject of current investigation. Treatment results are available beyond 10 years and appear equivalent or superior to other modalities. Although short term morbidity can be significant with brachytherapy, most current series report low long-term urinary and rectal complications. Meaningful quality of life studies and randomized cooperative group trials are now underway and should help define the role of brachytherapy in the near future.

High-dose-rate brachytherapy in the treatment of carcinoma of the prostate

BACKGROUND

Although radical prostatectomy for localized disease is considered as a standard of care, external-beam radiotherapy and brachytherapy are equally effective. We report on the technique and preliminary results of high-dose-rate (HDR) brachytherapy using a temporary iridium-192 implant technique.

METHODS

The authors reviewed the literature on the techniques, treatment protocols, and results of HDR brachytherapy in the treatment of carcinoma of the prostate, and they report their own protocols, technique, and results.

RESULTS

The combination of HDR brachytherapy and external irradiation has been well tolerated by all 200 patients in our series, with less than 3% grade 3 late complications and with 95% PSA relapse-free survival with a median follow-up of 24 months.

CONCLUSIONS

HDR brachytherapy may be the most conformal type of irradiation in the treatment of carcinoma of the prostate regardless of tumor size, anatomical distortion, and organ mobility.

A prospective quality-of-life study in men with clinically localized prostate carcinoma treated with radical prostatectomy, external beam radiotherapy, or interstitial brachytherapy

PURPOSE

To prospectively assess the health-related quality of life (HRQOL) and changes in HRQOL during the first year after 3 different treatments for clinically localized prostate cancer.

METHODS AND MATERIALS

Ninety men with T1-T2 adenocarcinoma of the prostate were treated with curative intent between May 1998 and June 1999 and completed a quality-of-life Functional Assessment of Cancer Therapy-Prostate (FACT-P) questionnaire before treatment (T0) and 1 month (T1), 3 months (T3), and 12 months (T12) after treatment. Forty-four men were treated with permanent source interstitial brachytherapy (IB), 23 received external beam radiotherapy (EBRT), and 23 men were treated with radical prostatectomy (RP). The mean age of the entire study population was 65.9 years (median 67, range 42-79). The mean pretreatment prostate-specific antigen level of the entire study population was 6.81 ng/mL (median 6.25, range 1.33-19.6). The Gleason score was <or=6 in 65 (72%) of 90. The repeated measures analysis of variance and analysis of covariance were conducted on all quality-of-life and urinary outcome measures.

RESULTS

A comparison of the demographic characteristics of the 3 treatment groups demonstrated significant differences. The men treated with RP were significantly younger than the men in either the IB or EBRT group (median age 61.0 RP, 67.1 IB, 68.8 EBRT; p = 0.0006). The men in the IB group were more likely to have a Gleason score of <or=6 than the EBRT group (Gleason score <or=6, 86% IB and 48% EBRT; p = 0.015). The mean score (standard deviation) at T0, T1, T3, and T12 for the FACT-P questionnaire for each group was as follows: IB 138.4 (17.0), 120.5 (21.7), 130.0 (18.4), and 138.5 (14.2); EBRT 137.1 (12.1), 129.5 (21.0), 134.4 (19.2), and 136.9 (15.6); and RP 138.3 (14.7), 117.7 (18.3), 134.4 (17.8), and 140.4 (14.9), respectively. Statistically significant differences over time were observed for the FACT-P in the IB and RP groups (p <0.0001), but not for the EBRT group (p = 0.08). The examination of the subscales within the FACT-P instrument demonstrated statistically significant changes over time in the IB and RP groups for the following: physical well-being, functional well-being, and prostate cancer symptoms. After adjusting for age, race, T stage, Gleason score, use of hormonal therapy, and baseline FACT-P scores, statistically significant differences in the FACT-P score at T1 according to treatment group were observed. At T12, the FACT-P scores were not significantly different than the baseline FACT-P scores for any group.

CONCLUSIONS

The results of this analysis suggest that significant decreases in HRQOL, as measured by the FACT-P instrument, are evident in the first month after IB or RP, but not after EBRT. One year after treatment, however, the FACT-P scores were not statistically different from the baseline measures for any group. For all treatment groups, most of the HRQOL decreases were observed in the physical, functional, and prostate cancer-specific domains. These results suggest that the HRQOL changes are likely to be treatment-specific, further emphasizing the importance of a randomized trial comparing the different treatment options in this population of men.

Defining the risk of developing grade 2 proctitis following 125I prostate brachytherapy using a rectal dose-volume histogram analysis

OBJECTIVE

To determine the rectal tolerance for developing Grade 2 radiation proctitis after 125I prostate implantation based on the rectal dose-volume histogram.

METHODS AND MATERIALS

Two hundred twelve patients with T1-T2 prostate cancer underwent 125I implantation without external beam irradiation. One month after the procedure, all patients underwent CT-based postimplant dosimetry (3-mm abutting slices). The rectal volumes, defined by an inner and outer wall, were determined from 9 mm above the seminal vesicles to 9 mm below the prostate apex. All doses were calculated by TG43 formalism. The prostate prescription dose was 160 Gy. A dose response analysis was undertaken for volumes of rectal tissue receiving a given dose. Dose levels examined were 80 Gy, 100 Gy, 120 Gy, 140 Gy, 160 Gy, 180 Gy, 200 Gy, 220 Gy, and 240 Gy. Grade 2 proctitis was defined as rectal bleeding occurring at least once a week for a minimum period of one month. The risk of proctitis was calculated using actuarial methods. For each dose level, a critical volume cutpoint was chosen to define a low and high volume group of patients. The cutpoint was determined based on two goals: minimizing thep value and finding a < or =5% risk of proctitis in the low volume group. Patients were followed from 12 to 61 months (median: 28 months) after implantation.

RESULTS

Twenty-two patients developed Grade 2 proctitis: 14% within the first year, 72% between the first and second year, and 14% during the third year after the implant date. After the third year postimplantation, no cases of proctitis were reported. Proctitis was found to be significantly volume dependent for a given dose. The prescription dose (160 Gy) delivered to < or =1.3 cc of rectal tissue resulted in a 5% rate of proctitis at 5 years vs. 18% for volumes >1.3 cc (p = 0.001). Similar results were found for all doses examined. As the rectal volume receiving the prescription dose (160 Gy) increased, so did the proctitis rate: 0% for < or =0.8 cc, 7% for >0.8-1.3 cc, 8% for >1.3-1.8 cc, 24% for >1.8-2.3 cc, and 25.5% for >2.3cc (p = 0.002).

CONCLUSIONS

Rectal dose-volume histogram analysis is a practical and predictive method of assessing the risk of developing Grade 2 proctitis after 125I prostate implantation. Delivered dose should be kept below defined rectal volume thresholds to minimize this risk. This information can allow one to decrease rectal morbidity by modifying prostate implant technique.

Retrospective stratification of a consecutive cohort of prostate cancer patients treated with a combined regimen of external-beam radiotherapy and brachytherapy

PURPOSE

The evaluation of clinical variables that influence biochemical relapse-free survival in a cohort of patients treated by combined radiotherapy over a fixed interval.

METHODS AND MATERIALS

Three hundred forty-eight patients diagnosed with clinical Stage T1--T3a prostate cancer were treated with a course of (103)Pd or (125)I brachytherapy followed by a limited course of external beam radiation formed the basis for study. All censored patients had a minimum 2-year follow-up. Biochemical relapse-free survival (BRFS) was estimated using a modified American Society for Therapeutic Radiology and Oncology consensus definition. Discrete "risk groups" were developed based on BRFS as influenced by pretreatment parameters.

RESULTS

Significant risk factors contributing to biochemical failure were serum prostate-specific antigen (PSA) greater than 20 ng/mL, Gleason sum of 7 or greater, or clinical stage T2c or greater. Five-year biochemical control for those exhibiting no risk factor was 88%; one risk factor, 75%; two or more risk factors, 51%. The differences in BRFS among all three risk groups were statistically significant. Outcomes for patients presenting with PSA 10 to 20 ng/mL, but otherwise low-risk disease, fared no differently from those low risk patients presenting with PSA less than 10 ng/mL.

CONCLUSIONS

Combined radiotherapy with (103)Pd or (125)I followed by external beam radiotherapy achieves a high rate of biochemical and clinical control in patients with low- to intermediate-risk clinically organ confined disease.

Radioimmunoguided imaging of prostate cancer foci with histopathological correlation

PURPOSE

We have previously presented a technique that fuses ProstaScint and pelvic CT images for the purpose of designing brachytherapy that targets areas at high risk for treatment failure. We now correlate areas of increased intensity seen on ProstaScint-CT fusion images to biopsy results in a series of 7 patients to evaluate the accuracy of this technique in localizing intraprostatic disease.

METHODS AND MATERIALS

The 7 patients included in this study were evaluated between June 1998 and March 29, 1999 at Metrohealth Medical Center and University Hospitals of Cleveland in Cleveland, Ohio. ProstaScint and CT scans of each patient were obtained before transperineal biopsy and seed implantation. Each patient's prostate gland was biopsied at 12 separate sites determined independently of Prostascint-CT scan results.

RESULTS

When correlated with biopsy results, our method yielded an overall accuracy of 80%: with a sensitivity of 79%, a specificity of 80%, a positive predictive value of 68%, and a negative predictive value of 88%.

CONCLUSION

The image fusion of the pelvic CT scan and ProstaScint scan helped identify foci of adenocarcinoma within the prostate that correlated well with biopsy results. These data may be useful to escalate doses in regions containing tumor by either high-dose rate or low-dose rate brachytherapy, as well as by external beam techniques such as intensity modulated radiotherapy (IMRT).

Penile erectile function after permanent radioactive seed implantation for treatment of prostate cancer

PURPOSE

We assess erectile function after prostate brachytherapy and analyze those factors affecting potency preservation.

MATERIALS AND METHODS

A total of 416 patients treated from October 1990 to September 1998 with permanent radioactive seed implantation for T1 to T2 prostate cancer had erectile function assessed before and after treatment. Erectile function was assessed using the scoring system of 0-complete inability to have erections, 1-able to have erections but insufficient for intercourse, 2-can have erections sufficient for intercourse but considered suboptimal and 3-has normal erectile function. Implant dose was defined as the D90, which was the dose delivered to 90% of the gland on a dose volume histogram from the 1-month computerized tomography based dosimetric analysis.

RESULTS

Pretreatment erectile function assessment revealed scores of 0 in 57 (14%), 1 in 46 (11%), 2 in 77 (18%) and 3 in 236 (57%) patients. In 313 patients who were potent with a score 2 or greater before therapy the actuarial freedom from any decrease in erectile function score was 64% and 30% at 3 and 6 years, respectively. The actuarial preservation of potency, with a score 2 or greater, was 79% and 59% at 3 and 6 years, respectively. The 2 factors found to have a significant negative effect on potency in univariate and multivariate analyses were high implant dose (D90 greater than 160 Gy. for I-125 and D90 greater than 100 Gy. for Pd-103) and a pretreatment erectile function score of 2 versus 3.

CONCLUSIONS

The rate of potency preservation after brachytherapy is high, although a decrease occurs from 3 to 6 years. Pretreatment erectile dysfunction as well as higher implant dose are associated with greater impotency.

I-125 implantation for localized prostate cancer: the Utrecht University experience

BACKGROUND AND PURPOSE

I-125 seed implantation is one of the treatment modalities for localized prostate carcinoma. It has few side-effects compared with radical prostatectomy and beam irradiation.

MATERIALS AND METHODS

At the University Medical Centre, Utrecht, 249 naive patients were treated by perineal implantation between December 1989 and December 1998. Mean age was 69 years (range 45-91 years). Stage and grade were: T(1), 121; T(2), 126; T(3), 2; well differentiated, 136; moderate, 100; undifferentiated, 15; not established, 8. Mean initial PSA level was 16.1 ng/ml (range <1.0-165). Mean prostate volume was 33 cm(3). Sixty-two patients had had previous surgical intervention for voiding problems. Treatment evolved from single seeds to RAPID Strand, and from a probe-mounted template to stepping unit and pre-planning. The introduction of RAPID Strand considerably increased the number of seeds (mean 41->65 seeds). Mean follow-up was 32.8 months, median 29.2 months (range 6-94 months).

RESULTS

A total of 195 patients had no evidence of disease (18 died of intercurrent causes) and 54 had evidence of disease (13 died with prostate cancer). Toxicity was found in 22 patients. Urinary side-effects occurred in 18 patients, in nine cases after previous TURP. Four patients had intestinal problems, but only one had a rectal ulcer, which healed after hormonal therapy for local recurrence.

CONCLUSIONS

Our findings indicate a correlation between the number of seeds implanted per cm(3) prostate volume and the final result. This is also reflected in a better volume coverage from MRI studies.

Edge-guided boundary delineation in prostate ultrasound images

Accurate detection of prostate boundaries is required in many diagnostic and treatment procedures for prostate disease. In this paper, a new paradigm for guided edge delineation is described, which involves presenting automatically detected prostate edges as a visual guide to the observer, followed by manual editing. This approach enables robust delineation of the prostate boundaries, making it suitable for routine clinical use. The edge-detection algorithm is comprised of three stages. An algorithm called sticks is used to enhance contrast and at the same time reduce speckle in the transrectal ultrasound prostate image. The resulting image is further smoothed using an anisotropic diffusion filter. In the third stage, some basic prior knowledge of the prostate, such as shape and echo pattern, is used to detect the most probable edges describing the prostate. Finally, patient-specific anatomic information is integrated during manual linking of the detected edges. The algorithm was tested on 125 images from 16 patients. The performance of the algorithm was statistically evaluated by employing five expert observers. Based on this study, we found that consistency in prostate delineation increases when automatically detected edges are used as visual guide during outlining, while the accuracy of the detected edges was found to be at least as good as those of the human observers. The use of edge guidance for boundary delineation can also be extended to other applications in medical imaging where poor contrast in the images and the complexity in the anatomy limit the clinical usability of fully automatic edge-detection techniques.

The role of external beam radiotherapy with I-125/Pd-103 brachytherapy for prostate carcinoma

BACKGROUND AND PURPOSE

To compare the biochemical outcomes of patients treated with Pd-103/I-125 brachytherapy alone vs. brachytherapy combined with external beam radiotherapy for early stage prostate carcinoma.

METHODS

Brachytherapy monotherapy was used in 403 patients. Brachytherapy was combined with 45 Gy of external beam radiotherapy in 231 patients. Median follow-up was 58 months. To compare the biochemical outcomes of these two treatment approaches, patients were stratified into three relative risk groups: low risk, T(1)-T(2), Gleason 2-6/10, PSA< or =10.0; intermediate risk, T(3), Gleason 7-10/10, PSA>10.0 (one factor); high risk, T(3), Gleason 7-10/10, PSA>10.0 (two factors).

RESULTS

The actuarial biochemical progression-free rate (bNED) for the entire 634 patients was 85% at 10 years. The bNED outcomes by risk group for monotherapy vs. combined therapy respectively were: low risk, 94 vs. 87%; intermediate risk, 84 vs. 85%; high risk, 54 vs. 62%. These differences did not reach statistical significance for any risk group. Rectal morbidity was slightly greater in the combined treatment patients.

CONCLUSION

Although the addition of external beam irradiation to brachytherapy is conceptually appealing for patients with higher risk prostate carcinoma, we were unable to demonstrate a benefit. Whether this is because of patient selection biases within the risk groupings, an artefact of retrospective review, or because external radiotherapy does not offer additional benefit is uncertain.

High-dose-rate interstitial brachytherapy as a monotherapy for localized prostate cancer: treatment description and preliminary results of a phase I/II clinical trial

PURPOSE

To improve results for localized prostate cancer, a prospective clinical trial of hyperfractionated Iridium-192 high-dose-rate (HDR) brachytherapy as a monotherapy was initiated.

METHODS AND MATERIALS

Between May 1995 and September 1998, 22 implants were performed on 22 patients with localized prostate cancer (T1:T2:T3:T4 = 4:6:9:3) at Osaka University Hospital. Nineteen patients, who had T3-T4 tumors or pretreatment PSA >/= 20.0 ng/mL, received hormone therapy. No patient had external beam radiation. Transperineal needle implants using real-time ultrasound guidance were performed, followed by dose optimization program. Patients were irradiated twice a day, with a time interval of more than 6 h. Total dose was 48 Gy/8 fractions/5 days or 54 Gy/9 fractions/5 days. Acute toxicity was scored using the Radiation Therapy Oncology Group (RTOG) radiation morbidity scoring criteria. Median follow-up time was 31 months.

RESULTS

HDR brachytherapy as a monotherapy was well-tolerated. No significant intra- or peri-operative complications occurred. No patient experienced acute toxicity of grade 3 or more. PSA levels normalized in 95% of patients within 20 months after irradiation. Four-year clinical and biochemical relapse-free rates were 95% and 55%, respectively.

CONCLUSION

Acute toxicity with this method was acceptable. Further patient accrual and longer follow-up will allow comparison to other techniques.

Evaluation of prostatic specific antigen and digital rectal examination as screening tests for prostate cancer

BACKGROUND

The 11,811 first visits and 46,751 annual follow-up visits performed since 1988 were analyzed in order to assess the efficacy of serum prostatic specific antigen (PSA) and digital rectal examination (DRE) for diagnosis of prostate cancer.

METHODS

At first visit, screening included DRE and measurement of PSA using 3.0 ng/ml as upper limit of normal, demonstrated as optimal value in the course of the study. Transrectal echography of the prostate (TRUS) was performed only if PSA and/or DRE was abnormal. For elevated PSA, biopsy was performed only if PSA was above the value predicted from prostatic volume measured by TRUS. At follow-up visits, it was decided during the course of the study to use PSA alone.

RESULTS

PSA was above 3.0 ng/ml in 16.6% and 15.6% of men at first and follow-up visits, respectively. Prostate cancer was found in 2.9% of men invited for screening at first visit and in only 0.4% of men at follow-up visits for a 7.1-fold decrease at follow-up visits done up to 11 years. PSA alone allowed to find 90.5% and 90. 0% of cancers at first and follow-up visits, respectively, compared to 41.1% and 25.0% by DRE alone. In the presence of normal PSA, 344 and 1,919 DREs are needed to find one prostate cancer at first and follow-up visits, respectively. A significant improvement in stage of the disease is found at follow-up (215 cancers) compared to first visits (337 cancers). Comparison made between men invited for screening and those who were not invited but screened showed no significant difference in terms of incidence and prevalence of prostate cancer as well as diagnosis of cancer as a function of age or as a function of PSA, DRE, and TRUS data. The cost for finding one case of prostate cancer is estimated at Can $2,420 and Can $7, 105 (first and follow-up visits, respectively, when PSA is used as prescreening).

CONCLUSIONS

PSA used as prescreening and followed by DRE and TRUS when PSA is abnormal is highly efficient in detecting prostate cancer at a localized (potentially curable) stage since 99% of the cancers diagnosed were at such a localized stage, thus practically eliminating the diagnosis of metastatic and noncurable prostate cancer. The approach used is highly reliable, sensitive, efficient, and acceptable by the general population. The detection of clinically nonsignificant cancer is an exception.

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.

Health-related quality of life and morbidity in patients receiving brachytherapy for clinically localized prostate cancer

Health-related quality of life must be a factor when treatment options are discussed with a patient. Quality of life is measured by validated questionnaires that include generic and disease-targeted measures. Urinary and rectal symptoms and sexual function are evaluated after treatment for prostate cancer. Quality of life is adversely affected in the early post-brachytherapy period primarily by the urinary morbidity. Urinary symptoms peak 2 months after treatment and decline thereafter, although severe long-term urinary toxicity occurs in 3% to 12% of patients. Urinary symptoms are generally treated with alpha-blocker and anticholinergic drugs, but 2% to 5% of patients require transurethral resection of the prostate to relieve persistent obstruction. However, 6 months after treatment, overall satisfaction is excellent, and the majority of patients would recommend the procedure to a friend.

Biopsy results after real-time ultrasound-guided transperineal implants for stage T1-T2 prostate cancer

PURPOSE

To analyze the results of ultrasound-guided brachytherapy for stage T1-T2 prostate cancer, as shown by biopsy results.

PATIENTS AND METHODS

The 268 patients (mean age 66 years; range 41-83 years) underwent real-time ultrasound-guided implantation of either iodine-125 (N = 186) or palladium-103 (N = 82) seeds. Of these patients, 96 (36%) received total androgen suppression for 3 months prior to and 3 months after implantation. Prostate biopsy was performed 24 months later, with the six to eight cores all being interpreted by the same pathologist. Each specimen was rated either positive or negative for cancer.

RESULTS

Of the 268 patients, 238 (89%) had a negative biopsy at 24 months. Among the patients receiving androgen suppression, 2% were found to have positive biopsies compared with 16% of those not given hormones (P = 0.004). Of the 155 patients with stage T1-T(2a) cancer, 6% had a positive biopsy compared with 19% of patients with stage T(2b) or T(2c) cancer (P = 0.001). In the entire series, the pretreatment serum concentration of prostate specific antigen, Gleason score, and isotope (I v Pd) were not significant predictors of a positive biopsy. However, among the 172 patients who did not receive androgen suppression, all three factors were predictive: 42% for Gleason score of 7 to 10 v 13% for Gleason score < or =6 (P = 0.001): 25% for pretreatment PSA concentration >10 ng/mL v 13% for PSA < or = 10 ng/mL (P = 0.05); and 27% for stage T(2b) or T(2c) v 9% for stage T1 or T(2a) (P = 0.001). The isotope used and the last PSA value were not significant predictors.

CONCLUSION

Brachytherapy provides excellent local control of prostate cancer, with 89% of patients having negative biopsies 2 years after treatment. High-risk patients may benefit from the addition of androgen suppression.

Role of brachytherapy in patients with stage T1c, T2a adenocarcinoma of the prostate

The precise role of brachytherapy in treating patients with adenocarcinoma of the prostate remains unclear. Recent literature suggests that the long-term disease-free survival of patients with well-differentiated and localized tumors who receive brachytherapy is comparable to that of patients with similar tumors who are treated with radical prostatectomy or external-beam radiation. Advances in imaging technology, treatment planning software, and delivery apparatus have resulted in a technique that is accurate and reproducible. We explore the development of contemporary brachytherapy and examine the current published data relating to its emergence as a medically successful, cost-effective, and low-morbidity therapeutic modality for patients with stage T(1c), T(2a) prostate cancer.

Prostate brachytherapy in patients with prostate volumes >/= 50 cm(3): dosimetic analysis of implant quality

OBJECTIVES

Permanent implantation with (125)I 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 (125)I 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.

Palladium-103 brachytherapy for prostate carcinoma

PURPOSE

A report of biochemical outcomes for patients treated with palladium-103 (Pd-103) brachytherapy over a fixed time interval.

METHODS AND MATERIALS

Two hundred thirty patients with clinical stage T1-T2 prostate cancer were treated with Pd-103 brachytherapy and followed with prostate-specific antigen (PSA) determinations. Kaplan-Meier estimates of biochemical failure on the basis of two consecutive elevations of PSA were utilized. Multivariate risk groups were constructed. Aggregate PSA response by time interval was assessed.

RESULTS

The overall biochemical control rate achieved at 9 years was 83.5%. Failures were local 3.0%; distant 6.1%; PSA progression only 4.3%. Significant risk factors contributing to failure were serum PSA greater than 10 ng/ml and Gleason sum of 7 or greater. Five-year biochemical control for those exhibiting neither risk factor was 94%; one risk factor, 82%; both risk factors, 65%. When all 1354 PSA determinations obtained for this cohort were considered, the patients with a proportion of PSAs < or = 0.5 ng/ml continued to increase until at least 48 months post-therapy. These data conformed to a median PSA half-life of 96.2 days.

CONCLUSIONS

Prostate brachytherapy with Pd-103 achieves a high rate of biochemical and clinical control in patients with clinically organ-confined disease. PSA response following brachytherapy with low-dose-rate isotopes is protracted.