American Brachytherapy Society (ABS) recommendations for transperineal permanent brachytherapy of prostate cancer

Differences between intraoperative ultrasound-based dosimetry and postoperative computed tomography-based dosimetry for permanent interstitial prostate brachytherapy

PURPOSE

To compare the results of intraoperative ultrasound (US)-based dosimetry with those of postimplant computed tomography (CT)-based dosimetry after (125)I prostate brachytherapy.

METHODS AND MATERIALS

Subjects comprised 160 patients who underwent prostate brachytherapy using (125)I seed implants. Prescribed dose was set as 145 Gy to the periphery of the prostate. Implantation was performed using an intraoperative interactive technique. Postimplant dosimetry was performed on Days 1 and 30 after implantation using CT. Dosimetric results for the prostate, urethra, and rectum were compared among intraoperative US and CT on Day 1 (CT(1)) and Day 30 (CT(30)).

RESULTS

Mean minimal dose received by 90% of prostate volume was 133.7%, 115.6%, and 125.8% of the prescribed dose on US, CT(1), and CT(30), respectively: This value temporarily decreased on Day 1 and increased on Day 30. Other parameters for the prostate and urethra showed similar trends. Conversely, mean rectal volume receiving 100% of the prescribed dose was 0.69, 0.46, and 1.02 mL on US, CT(1), and CT(30), respectively. Rectal parameters tended to be underestimated on US relative to CT(30)-based dosimetry. A positive linear relationship was identified between US and CT observations for every prostate parameter and the dose covering 30% of the urethra.

CONCLUSIONS

Our results demonstrate significant differences between dosimetric parameters obtained by US, CT(1), and CT(30). However, significant correlations also exist between US and CT, at least in prostate and urethral parameters. Clarification of the degrees of difference might make US planning more feasible.

MRI signal intensity based B-spline nonrigid registration for pre- and intraoperative imaging during prostate brachytherapy

PURPOSE

To apply an intensity-based nonrigid registration algorithm to MRI-guided prostate brachytherapy clinical data and to assess its accuracy.

MATERIALS AND METHODS

A nonrigid registration of preoperative MRI to intraoperative MRI images was carried out in 16 cases using a Basis-Spline algorithm in a retrospective manner. The registration was assessed qualitatively by experts' visual inspection and quantitatively by measuring the Dice similarity coefficient (DSC) for total gland (TG), central gland (CG), and peripheral zone (PZ), the mutual information (MI) metric, and the fiducial registration error (FRE) between corresponding anatomical landmarks for both the nonrigid and a rigid registration method.

RESULTS

All 16 cases were successfully registered in less than 5 min. After the nonrigid registration, DSC values for TG, CG, PZ were 0.91, 0.89, 0.79, respectively, the MI metric was -0.19 +/- 0.07 and FRE presented a value of 2.3 +/- 1.8 mm. All the metrics were significantly better than in the case of rigid registration, as determined by one-sided t-tests.

CONCLUSION

The intensity-based nonrigid registration method using clinical data was demonstrated to be feasible and showed statistically improved metrics when compare to only rigid registration. The method is a valuable tool to integrate pre- and intraoperative images for brachytherapy.

Relationship between Day 0 dosimetric parameters and biochemical relapse-free survival in patients treated with transperineal permanent prostate interstitial brachytherapy with (125)I seeds

OBJECTIVES

To determine the relationship between dosimetric parameters obtained on postimplantation Day 0 and biochemical relapse-free survival (bRFS) in patients treated with (125)I transperineal interstitial permanent prostate brachytherapy (TIPPB).

METHODS

Two-hundred twenty men with low-risk (n=155, 70.4%), low-volume intermediate-risk (n=63, 28.7%), or high-risk (n=2, 0.9%) prostate cancer were treated with TIPPB between December 2000 and June 2006. Seventy-four (33.6%) patients received short-term (3-6 months) androgen suppression therapy before TIPPB. The median followup for patients free of biochemical failure was of 37.9 months (range, 24.0-84.5 months).

RESULTS

The receiver operating characteristic (ROC) analysis established a best-fit cutoff value for the quantifiers D(90) and V(100) of 147Gy and 92%, respectively. The Kaplan-Meier analysis of bRFS at the cutoff value of D(90)=147Gy using the ASTRO, nadir+2, and combined (ASTRO and nadir+2) definitions showed a trend toward statistical significance for the ASTRO (p=0.076) and nadir+2 (p=0.064) definitions and a statistically significant correlation for the combined definition (p=0.033). The corresponding 7-year bRFS for the D(90) >147Gy and D(90) </=147Gy subsets using the ASTRO, nadir+2, and combined definitions were 96.5% vs. 89.7% (ASTRO, p=0.076); 93.7% vs. 70.5% (nadir+2, p=0.064); and 94.4 vs. 75.5% (combined, p=0.033). The V(100) (%) cutoff value of 92% predicted by the ROC analysis was not significant. Among other cutoff values, only D(90)=140Gy (p=0.050) and D(90)=160Gy (p=0.098) showed a trend toward statistical significance when the nadir+2 and the ASTRO definitions were used. The rest of dosimetric, tumor, and patient parameters did not show statistical correlation with bRFS in the Kaplan-Meier analysis.

CONCLUSIONS

The cutoff value of D(90)=147Gy obtained on postimplantation Day 0 showed a trend toward significant correlation with bRFS when the standard ASTRO and nadir+2 definitions were used and a weak but statistically significant correlation with bRFS as per the nonstandard combined definition in a series of patients with predominantly low-risk disease (70.4%) treated at high radiation doses (median D(90)=152.9Gy, median V(100)=92.5%).

Cross section measurements of proton and deuteron induced formation of103Ag in natural palladium

Proton and deuteron induced nuclear reactions for generation of the103Pd parent103Ag were investigated using the stacked-foil activation technique on natural palladium targets up to Ep=37.3 MeV and Ed=20.5 MeV, respectively. Excitation functions are reported for the first time for the reactionsnatPd(p,xn)103Ag andnatPd(d,xn)103Ag.

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.

Rectal morbidity after permanent interstitial brachytherapy for prostate cancer--impact of day 1 vs. day 30 computed tomography-based postimplant dosimetry

PURPOSE

The aim of the study was to evaluate bowel quality-of-life changes after prostate brachytherapy and the impact of Day 1 vs. Day 30 postimplant dosimetry.

METHODS AND MATERIALS

In 61 patients, computed tomography (CT) scans were performed at Days 1 and 30 after (125)I brachytherapy. The patients have been surveyed prospectively before (time A), 1 month (time B), and >1 year after treatment (time C) using a validated questionnaire (Expanded Prostate Cancer Index Composite). Different parameters were tested for their predictive value on bowel quality-of-life changes (bowel bother score decrease >20 points at time B=BB20; bowel bother score decrease >10 points at time C=BC10), including seed displacements.

RESULTS

Mean bowel function/bother score decreased 13/13 points at time B (p<0.01) and 1/4 points at time C (change not significant). BB20 and BC10 were found in 25% and 20% of patients, respectively. Bowel bother score declines at time B correlated well with declines at time C (r=0.53; p<0.01). Prostate volume before implantation and the number of seeds per cubic centimeters were found to be predictive for BB20 and BC10. Smaller rectal wall volumes covered by the 60-100% isodoses at Day 1 were (paradoxically) found to be significantly predictive for BC10. Larger posterior seed displacements between Days 1 and 30 were significantly associated with BB20.

CONCLUSIONS

Quality-of-life scores have not been found to change significantly >1 year after brachytherapy. Larger rectal wall volumes within higher isodoses at Day 1 or 30 were not found to be predisposing for adverse quality-of-life changes.

[Retrospective evaluation of urinary continence in patients submitted to brachytherapy after transurethral resection of the prostate gland]

INTRODUCTION AND OBJECTIVE

Some candidates for brachytherapy present with a previous history of prostate transurethral resection (TURP). Nonetheless, TURP generates a cavity that may lead to technical difficulties in performing brachytherapy. Such condition make a history of previous TURP a relative contra-indication for brachytherapy. The aim of this study is to evaluate the role of brachytherapy in urinary continence, in a group of patients with previous history of TURP.

MATERIALS AND METHODS

In our study, we analysed a group of 16 patients submitted to TURP pre-brachytherapy. The mean quality of life score from ICSmaleSF questionnaire ranged from 0 to 1 before and after brachytheraphy (average: 0,18 -- before; average: 0,20 -- after). There was no estatistically significant difference between the former values (p<0,001). After brachytherapy patients were evaluated for lower urinary tract symptoms. The time interval between TURP and brachytherapy ranged from 30 to 90 days (average: 60 days). Post-brachytherapy follow-up varied between 3 and 60 months (average: 30 months).

RESULTS

None of the 16 patients evaluated presented lower urinary tract symptoms nor urinary incontinence. Medical complications observed in patients were: dysuria, erectile dysfunction, scrotal ecchymosis and urinary retention. The cases of dysuria, scrotal ecchymosis and urinary retention observed were of short-duration, the last one with spontaneous resolution after 7 days of vesical catheterism. The patient presenting erectile dysfunction had a good response to oral type 5 fosfodiesterase inhibitor three times a week, after a six month period.

CONCLUSION

In accordance with other studies, we believe that with some strategy TURP should not be considered a relative contra-indication for brachytherapy.

Is seminal vesiculectomy necessary in all patients with biopsy Gleason score 6?

BACKGROUND AND PURPOSE

Radiotherapists are excluding the seminal vesicles (SVs) from their target volume in cases of low-risk prostate cancer. However, these glands are routinely removed in every radical prostatectomy. Dissection of the SVs can damage the pelvic plexus, compromise trigonal, bladder neck, and cavernosal innervation, and contribute to delayed gain of continence and erectile function. In this study we evaluated the oncological benefit of routine removal of the SVs in currently operated patients.

MATERIALS AND METHODS

A total of 1003 patients (mean age, 59.7 years) with prostate cancer underwent robot-assisted radical prostatectomy between February 2003 and July 2007.

RESULTS

Seminal vesicle invasion (SVI) was found in 46 of the operated patients (4.6%). Biopsy Gleason score (BGS), preoperative serum PSA, clinical tumor stage, percent of positive cores, and maximal percentage of cancer in a core had all a significant impact on the risk of SVI. Only 4/634 patients (0.6%) with BGS < or =6 suffered from SVI, as opposed to 42/369 (11.4%) with higher Gleason scores.

CONCLUSIONS

Seminal vesiculectomy does not benefit more than 99% of the patients with BGS < or =6. Considering the potential neural and vascular damage associated with seminal vesiculectomy, we suggest that routine removal of these glands during radical prostatectomy in these cases is not necessary.

Neoadjuvant androgen deprivation for prostate volume reduction: the optimal duration in prostate cancer radiotherapy

OBJECTIVES

For locally advanced prostate cancer, the results of radiotherapy are improved by combination with androgen deprivation therapy. Volume reduction achieved with neoadjuvant hormonal treatment can facilitate dose escalation without increasing the toxicity. The optimal duration of hormonal treatment, however, is unknown. The endpoint of this study is the optimal duration of androgen deprivation for prostate volume reduction in a cohort of patients scheduled for external beam radiotherapy.

PATIENTS AND METHODS

Twenty patients scheduled for external beam radiotherapy with cT2-3No/xMo prostate cancer were treated with a luteinizing hormone releasing hormone agonist (busereline) and nonsteroidal anti-androgen (nilutamide) for 9 months consecutively. Repeated CT scan examination was performed 3-monthly to measure prostate volumes until the start of radiation therapy. The analysis of volume reduction was performed with the Wilcoxon signed ranks test.

RESULTS

The baseline median prostate volume for the cohort of patients was 82 cc (95% CI: 61-104 cc) with a median volume reduction of 31% (95% CI: 26%-35%) (P < 0.0001) after 3 months of androgen deprivation. Between 3 and 6 months, a median volume reduction of 9% (95% CI: 4%-14%) (P < 0.0001) was observed. The effect was more pronounced in large prostates (>60 cc) than in small prostates (≤60 cc). In the total cohort of patients no significant volume reduction occurred between 6 and 9 months of maximal androgen blockade (MAB).

CONCLUSIONS

In this study, we have shown that the most significant prostate volume reduction is achieved after 3 months of MAB with a maximum reduction after 6 months. Therefore, the optimal duration of neoadjuvant androgen deprivation to reduce prostate volume before prostate cancer radiotherapy is 6 months. In small prostates 3 months of hormonal treatment may be enough for maximal volume reduction.

A New Scheme for Curved Needle Segmentation in Three-Dimensional Ultrasound Images

Ultrasound image guided needle insertion is the method of choice for a wide variety of medical diagnostic and therapeutic procedures. When flexible needles are inserted in soft tissue, these needles generally follow a curved path. Segmenting the trajectory of the needles in ultrasound images will facilitate guiding them within the tissue. In this paper, a novel algorithm for curved needle segmentation in three-dimensional (3D) ultrasound images is presented. The algorithm is based on the projection of a filtered 3D image onto a two-dimensional (2D) image. Detection of the needle in the resulting 2D image determines a surface on which the needle is located. The needle is then segmented on the surface. The proposed technique is able to detect needles without any previous assumption about the needle shape, or any a priori knowledge about the needle insertion axis line.

Technical acquisition and dosimetric assessment of iodine-125 permanent brachytherapy in localized prostate cancer: our first series of 100 patients

OBJECTIVES

To assess our initial experience in the treatment of localized prostate cancer using low-dose-rate brachytherapy (LDR-brachytherapy) with iodine-125.

METHODS

One-hundred consecutive patients received LDR-brachytherapy between July 2004 and October 2006. Seventy-six patients were treated with seed implantation alone, whereas 24 patients were treated with a combination of brachytherapy and external beam radiotherapy. The minimal percentage of the dose received by 90% of the prostate gland (%D90), the percentage prostate volume receiving 100% of the prescribed minimal peripheral dose (V100), and the operation time were compared among every 10 consecutive patients.

RESULTS

The means of %D90 and V100 were 109.6% and 93.4%, respectively. When compared with the first 10 patients, both D90 and V100 showed significant improvement in the following 10 consecutive patients. Similarly, the mean operation time decreased significantly according to the accumulated number of patients.

CONCLUSIONS

Our initial experience with the first 100 cases suggests that LDR-brachytherapy needs accumulation of many more patients to obtain high-quality post-implant dosimetric outcomes.

Vibro-acoustography imaging of permanent prostate brachytherapy seeds in an excised human prostate--preliminary results and technical feasibility

OBJECTIVE

The objective in this work is to investigate the feasibility of using a new imaging tool called vibro-acoustography (VA) as a means of permanent prostate brachytherapy (PPB) seed localization to facilitate post-implant dosimetry (PID).

METHODS AND MATERIALS

Twelve OncoSeed (standard) and eleven EchoSeed (echogenic) dummy seeds were implanted in a human cadaver prostate. Seventeen seeds remained after radical retropubic prostatectomy. VA imaging was conducted on the prostate that was cast in a gel phantom and placed in a tank of degassed water. 2-D magnitude and phase VA image slices were obtained at different depths within the prostate showing location and orientation of the seeds.

RESULTS

VA demonstrates that twelve of seventeen (71%) seeds implanted were visible in the VA image, and the remainder were obscured by intra-prostatic calcifications. Moreover, it is shown here that VA is capable of imaging and locating PPB seeds within the prostate independent of seed orientation, and the resulting images are speckle free.

CONCLUSION

The results presented in this research show that VA allows seed detection within a human prostate regardless of their orientation, as well as imaging intra-prostatic calcifications.

Genitourinary toxicity after high-dose-rate (HDR) brachytherapy combined with Hypofractionated External beam radiotherapy for localized prostate cancer: an analysis to determine the correlation between dose-volume histogram parameters in HDR brachytherapy and severity of toxicity

PURPOSE

To evaluate the severity of genitourinary (GU) toxicity in high-dose-rate (HDR) brachytherapy combined with hypofractionated external beam radiotherapy (EBRT) for prostate cancer and to explore factors that might affect the severity of GU toxicity.

METHODS AND MATERIALS

A total of 100 Japanese men with prostate cancer underwent (192)Ir HDR brachytherapy combined with hypofractionated EBRT. Mean (SD) dose to 90% of the planning target volume was 6.3 (0.7) Gy per fraction of HDR. After 5 fractions of HDR treatment, EBRT with 10 fractions of 3 Gy was administrated. The urethral volume receiving 1-15 Gy per fraction in HDR brachytherapy (V1-V15) and the dose to at least 5-100% of urethral volume in HDR brachytherapy (D5-D100) were compared between patients with Grade 3 toxicity and those with Grade 0-2 toxicity. Prostate volume, patient age, and International Prostate Symptom Score were also compared between the two groups.

RESULTS

Of the 100 patients, 6 displayed Grade 3 acute GU toxicity, and 12 displayed Grade 3 late GU toxicity. Regarding acute GU toxicity, values of V1, V2, V3, and V4 were significantly higher in patients with Grade 3 toxicity than in those with Grade 0-2 toxicity. Regarding late GU toxicity, values of D70, D80, V12, and V13 were significantly higher in patients with Grade 3 toxicity than in those with Grade 0-2 toxicity.

CONCLUSIONS

The severity of GU toxicity in HDR brachytherapy combined with hypofractionated EBRT for prostate cancer was relatively high. The volume of prostatic urethra was associated with grade of acute GU toxicity, and urethral dose was associated with grade of late GU toxicity.

The fate of the seminal vesicle remnant after proximal transection or ligation: an animal model

PURPOSE

Dissection of the seminal vesicles during radical prostatectomy has the potential to damage the pelvic plexus, thus compromising trigonal, bladder neck and cavernous innervation, and contributing to delayed gain of continence and erectile function. The rate of prostate cancer invasion into the seminal vesicles in currently operated patients is low and in most it may be predicted preoperatively. This situation calls for seminal vesicle sparing radical prostatectomy in select patients, leaving a distal remnant of the seminal vesicles in place. We investigated the fate of the seminal vesicle remnant after proximal transection or ligation in an animal model.

MATERIALS AND METHODS

The right seminal vesicle in 36 anesthetized male rats was divided by suture ligation or by transection. The left seminal vesicle served as a control. Six rats per group were sacrificed 1, 2 and 4 weeks after division, respectively. Seminal vesicle morphology was evaluated macroscopically and microscopically.

RESULTS

All rats tolerated surgery well and gained weight postoperatively. Transected seminal vesicles were similar in weight and morphology to control contralateral glands. One week after seminal vesicle ligation the remnants became significantly heavier and showed balloon dilatation of the hollow spaces, while the lining epithelium became significantly flattened. Two and 4 weeks after ligation half of the animals showed gland shrinkage and half demonstrated persistent dilatation.

CONCLUSIONS

Seminal vesicle transection preserves the gland remnant in a relatively normal morphology, while ligation leads to severe and inconsistent morphological changes. When considering seminal vesicle sparing radical prostatectomy, seminal vesicle transection may be preferred to ligation.

In vitro comparative study of vibro-acoustography versus pulse-echo ultrasound in imaging permanent prostate brachytherapy seeds

BACKGROUND

Permanent prostate brachytherapy (PPB) is a common treatment for early stage prostate cancer. While the modern approach using trans-rectal ultrasound guidance has demonstrated excellent outcome, the efficacy of PPB depends on achieving complete radiation dose coverage of the prostate by obtaining a proper radiation source (seed) distribution. Currently, brachytherapy seed placement is guided by trans-rectal ultrasound imaging and fluoroscopy. A significant percentage of seeds are not detected by trans-rectal ultrasound because certain seed orientations are invisible making accurate intra-operative feedback of radiation dosimetry very difficult, if not impossible. Therefore, intra-operative correction of suboptimal seed distributions cannot easily be done with current methods. Vibro-acoustography (VA) is an imaging modality that is capable of imaging solids at any orientation, and the resulting images are speckle free.

OBJECTIVE AND METHODS

The purpose of this study is to compare the capabilities of VA and pulse-echo ultrasound in imaging PPB seeds at various angles and show the sensitivity of detection to seed orientation. In the VA experiment, two intersecting ultrasound beams driven at f(1)=3.00 MHz and f(2)=3.020 MHz respectively were focused on the seeds attached to a latex membrane while the amplitude of the acoustic emission produced at the difference frequency 20 kHz was detected by a low frequency hydrophone.

RESULTS

Finite element simulations and results of experiments conducted under well-controlled conditions in a water tank on a series of seeds indicate that the seeds can be detected at any orientation with VA, whereas pulse-echo ultrasound is very sensitive to the seed orientation.

CONCLUSION

It is concluded that vibro-acoustography is superior to pulse-echo ultrasound for detection of PPB seeds.

125I seed implant brachytherapy-assisted surgery with preservation of the facial nerve for treatment of malignant parotid gland tumors

The surgical treatment of malignant parotid gland tumors combined with (125)I seed implant brachytherapy and preservation of the facial nerve is described. Tumor and parotid gland resection with preservation of the facial nerve was carried out in 12 patients with malignant parotid gland tumors. (125)I seeds were implanted into the target area intra- or postoperatively. The extent of regional control of the tumor was followed up, and facial nerve function was evaluated. None of the patients had tumor recurrence during the follow-up period of 50-74 months (median follow-up period, 66 months). Facial nerve function had recovered to normal by 6 months postoperatively in all patients. A limited surgical resection combined with (125)I seed implant brachytherapy is therefore considered to be an alternative treatment for local control of malignant parotid gland tumors with preservation of the facial nerve.

Technology Insight: Combined external-beam radiation therapy and brachytherapy in the management of prostate cancer

External-beam radiation therapy (EBRT) combined with brachytherapy is an attractive treatment option for selected patients with clinically localized prostate cancer. This therapeutic strategy offers dosimetric coverage if local-regional microscopic disease is present and provides a highly conformal boost of radiation to the prostate and immediate surrounding tissues. Either low-dose-rate (LDR) permanent brachytherapy or high-dose-rate (HDR) temporary brachytherapy can be combined with EBRT; such combined-modality therapy (CMT) is typically used to treat patients with intermediate-risk to high-risk, clinically localized disease. Controversy persists with regard to indications for CMT, choice of LDR or HDR boost, isotope selection for LDR, and integration of EBRT and brachytherapy. Initial findings from prospective, multicenter trials of CMT support the feasibility of this strategy. Updated results from these trials as well as those of ongoing and new phase III trials should help to define the role of CMT in the management of prostate cancer. In the meantime, long-term expectations for outcomes of CMT are based largely on the experience of single institutions, which demonstrate that CMT with EBRT and either LDR or HDR brachytherapy can provide freedom from disease recurrence with acceptable toxicity.

Secondary effects and biochemical control in patients with early prostate cancer treated with (125)-I seeds

OBJECTIVE

To retrospectively evaluate the toxicity of low-dose-rate brachytherapy and to relate it to the dose-volume to organs at risk.

MATERIAL AND METHODS

We study 160 patients with early prostate cancer, treated with (125)-I implants. Most of them were T1c (63.1%), T2a (35.6%) and Gleason < or =6 (96.2%). Median PSA was 7.2 ng/ml (2.3-13.5); 85.6% were lowrisk cases and 14.4% high-risk cases. Mean follow-up was 24 months (7-48).

RESULTS

Acute urinary toxicity related to urological quality of life (UQL=CVU) was tolerable in 75% and unsatisfactory in 25%. Urinary retention was present in 6.9%. IPSS, V100 and D90 were related to the urinary toxicity grade. Rectal toxicity (RTOG) G2 was 0.6%. Sexual potency showed no changes with regard to the basal in 69%. Actuarial biochemical control was 89.8% at four years.

CONCLUSIONS

Brachytherapy with (125)-I seeds yields acceptable toxicity and excellent biochemical control.

Multicenter analysis of effect of high biologic effective dose on biochemical failure and survival outcomes in patients with Gleason score 7-10 prostate cancer treated with permanent prostate brachytherapy

PURPOSE

To investigate the biochemical control rates and survival for Gleason score 7-10 prostate cancer patients undergoing permanent prostate brachytherapy as a function of the biologic effective dose (BED).

METHODS AND MATERIALS

Six centers provided data on 5,889 permanent prostate brachytherapy patients, of whom 1,078 had Gleason score 7 (n = 845) or Gleason score 8-10 (n = 233) prostate cancer and postimplant dosimetry results available. The median prostate-specific antigen level was 7.5 ng/mL (range, 0.4-300). The median follow-up for censored patients was 46 months (range, 5-130). Short-term hormonal therapy (median duration, 3.9 months) was used in 666 patients (61.8%) and supplemental external beam radiotherapy (EBRT) in 620 (57.5%). The patients were stratified into three BED groups: <200 Gy (n = 645), 200-220 Gy (n = 199), and >220 Gy (n = 234). Biochemical freedom from failure (bFFF) was determined using the Phoenix definition.

RESULTS

The 5-year bFFF rate was 80%. The bFFF rate stratified by the three BED groups was 76.4%, 83.5%, and 88.3% (p < 0.001), respectively. Cox regression analysis revealed Gleason score, prostate-specific antigen level, use of hormonal therapy, EBRT, and BED were associated with bFFF (p < 0.001). Freedom from metastasis improved from 92% to 99% with the greatest doses. The overall survival rate at 5 years for the three BED groups for Gleason score 8-10 cancer was 86.6%, 89.4%, and 94.6%, respectively (p = 0.048).

CONCLUSION

These data suggest that permanent prostate brachytherapy combined with EBRT and hormonal therapy yields excellent bFFF and survival results in Gleason score 7-10 patients when the delivered BEDs are >220 Gy. These doses can be achieved by a combination of 45-Gy EBRT with a minimal dose received by 90% of the target volume of 120 Gy of (103)Pd or 130 Gy of (125)I.

Quality assurance/quality control issues for intraoperative planning and adaptive repeat planning of image-guided prostate implants

The quality assurance/quality control purpose is this. We design a treatment plan, and we wish to be as certain as reasonably possible that the treatment is delivered as planned. In the case of conventionally planned prostate brachytherapy, implementing to the letter the implantation plan is rarely attainable and therefore can require adaptive replanning (a quality control issue). The reasons for this state of affairs include changes in the prostate shape and volume during implantation and treatment delivery (e.g., edema resolution) and unavoidable inaccuracy in the placement of the seeds in the prostate. As a result, quality-control activities (e.g., the need to monitor-ideally, on the fly-the target and urethral and rectal dosage) must be also addressed.

The time gap between Pd-103 prostate brachytherapy and supplemental beam radiation does not impact on rectal morbidity or likelihood of cure

OBJECTIVE

To determine whether treatment gap between supplemental beam radiation and brachytherapy implant affects rectal morbidity and likelihood of cure in the treatment of intermediate-risk prostate cancer.

MATERIALS AND METHODS

Five hundred sixty-eight patients with AJCC clinical stage T1c-T2a prostate cancer, Gleason score 7 to 9 and/or prostate-specific antigen (PSA) 10 to 20 ng/mL, were randomized to implantation with Pd-103 (90 vs. 115 Gy) with 44 Gy versus 20 Gy preimplant supplemental beam radiation, respectively. Treatment-related morbidity was monitored by mailed questionnaires, using a modified Radiation Therapy Oncology Group rectal morbidity criteria at 1, 3, 6, 12, 18, and 24 months. Patients who reported grade 1 or worse rectal morbidity were interviewed by telephone to clarify details regarding their rectal bleeding.

RESULTS

Persistent rectal bleeding occurred in 36 of the 548 evaluable patients (7%). The mean gap among rectal bleeders was 3.8 days and among nonbleeders was 4.8 days (P = 0.236). Higher R100 and external beam dose of 44 Gy were significant predictors of rectal bleeding on univariate and multivariate analysis. Log-rank analysis did not demonstrate any improvement in biochemical failure free survival (BFFS) with shorter gap interval. On univariate analysis, Gleason score >7, PSA >10, D90 <100%, and treatment gap were all predictive of biochemical failure. On multivariate analysis, only Gleason score, PSA, and D90 remained significant predictors of BFFS.

CONCLUSION

Shorter gap intervals between supplemental beam radiation and brachytherapy implant are safe. Shorter gap intervals do not improve BFFS; however, they do allow for treatment completion in a more timely fashion.

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

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

PACS number: 87.53.Tf

Permanent prostate seed brachytherapy: a current perspective on the evolution of the technique and its application

This Review highlights current areas of controversy and development in the field of transperineal permanent prostate seed implantation brachytherapy (PPI), in particular the technological evolution of PPI treatment planning that has led to intra-operative treatment planning and execution, the use of MRI spectroscopy and ultrasonography to target intraprostatic tumor foci, and the introduction of (131)Cs as a new PPI isotope. Here we present a comprehensive review of mature data for PPI monotherapy and PPI combined with supplemental external beam radiation therapy, and a critical discussion of issues pertinent to supplemental EBRT. We also present our current policies in the treatment of prostate cancer at the University of California, San Francisco.