Four-year biochemical outcome after radioimmunoguided transperineal brachytherapy for patients with prostate adenocarcinoma

Long-term outcome of magnetic resonance spectroscopic image-directed dose escalation for prostate brachytherapy

PURPOSE

To report the long-term control and toxicity outcomes of patients with clinically localized prostate cancer, who underwent low-dose-rate prostate brachytherapy with magnetic resonance spectroscopic image (MRSI)-directed dose escalation to intraprostatic regions.

METHODS AND MATERIALS

Forty-seven consecutive patients between May 2000 and December 2003 were analyzed retrospectively. Each patient underwent a preprocedural MRSI, and MRS-positive voxels suspicious for malignancy were identified. Intraoperative planning was used to determine the optimal seed distribution to deliver a standard prescription dose to the entire prostate, while escalating the dose to MRS-positive voxels to 150% of prescription. Each patient underwent transperineal implantation of radioactive seeds followed by same-day CT for postimplant dosimetry.

RESULTS

The median prostate D90 (minimum dose received by 90% of the prostate) was 125.7% (interquartile range [IQR], 110.3-136.5%) of prescription. The median value for the MRS-positive mean dose was 229.9% (IQR, 200.0-251.9%). Median urethra D30 and rectal D30 values were 142.2% (137.5-168.2%) and 56.1% (40.1-63.4%), respectively. Median followup was 86.4 months (IQR, 49.8-117.6). The 10-year actuarial prostate-specific antigen relapse-free survival was 98% (95% confidence interval, 93-100%). Five patients (11%) experienced late Grade 3 urinary toxicity (e.g., urethral stricture), which improved after operative intervention. Four of these patients had dose-escalated voxels less than 1.0 cm from the urethra.

CONCLUSIONS

Low-dose-rate brachytherapy with MRSI-directed dose escalation to suspicious intraprostatic regions exhibits excellent long-term biochemical control. Patients with dose-escalated voxels close to the urethra were at higher risk of late urinary stricture.

A critical review of the analytical approaches for circulating tumor biomarker kinetics during treatment

Changes in serum tumor biomarkers may indicate treatment efficacy. Traditional tumor markers may soon be replaced by novel serum biomarkers, such as circulating tumor cells (CTCs) or circulating tumor nucleic acids. Given their promising predictive values, studies of their kinetics are warranted. Many methodologies meant to assess kinetics of traditional marker kinetics during anticancer treatment have been reported. Here, we review the methodologies, the advantages and the limitations of the analytical approaches reported in the literature. Strategies based on a single time point were first used (baseline value, normalization, nadir, threshold at a time t), followed by approaches based on two or more time points [half-life (HL), percentage decrease, time-to-events…]. Heterogeneities in methodologies and lack of consideration of inter- and intra-individual variability may account for the inconsistencies and the poor utility in routine. More recently, strategies based on a population kinetics approach and mathematical modeling have been reported. The identification of equations describing individual kinetic profiles of biomarkers may be an alternative strategy despite its complexity and higher number of necessary measurements. Validation studies are required. Efforts should be made to standardize biomarker kinetic analysis methodologies to ensure the optimized development of novel serum biomarkers and avoid the pitfalls of traditional markers.

Low-dose rate brachytherapy for men with localized prostate cancer

BACKGROUND

Localized prostate cancer is a slow growing tumor for many years for the majority of affected men. Low-dose rate brachytherapy (LDR-BT) is short-distance radiotherapy using low-energy radioactive sources. LDR-BT has been recommended for men with low risk localized prostate cancer.

OBJECTIVES

To assess the benefit and harm of LDR-BT compared to radical prostatectomy (RP), external beam radiotherapy (EBRT), and no primary therapy (NPT) in men with localized prostatic cancer.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 1950), and EMBASE (from 1980) were searched in June 2010 as well as online trials registers and reference lists of reviews.

SELECTION CRITERIA

Randomized, controlled trials comparing LDR-BT versus RP, EBRT, and NPT in men with clinically localized prostate cancer.

DATA COLLECTION AND ANALYSIS

Data on study methods, participants, treatment regimens, observation period and outcomes were recorded by two reviewers independently.

MAIN RESULTS

We identified only one RCT (N = 200; mean follow up 68 months). This trial compared LDR-BT and RP. The risk of bias was deemed high. Primary outcomes (overall survival, cause-specific mortality, or metastatic-free survival) were not reported. Biochemical recurrence-free survival at 5 years follow up was not significantly different between LDR-BT (78/85 (91.8%)) and RP (81/89 (91.0%)); P = 0.875; relative risk 0.92 (95% CI: 0.35 to 2.42).For severe adverse events reported at 6 months follow up, results favored LDR-BT for urinary incontinence (LDR-BT 0/85 (0.0%) versus RP 16/89 (18.0%); P < 0.001; relative risk 0) and favored RP for urinary irritation (LDR-BT 68/85 (80.0%) versus RP 4/89 (4.5%); P < 0.001; relative risk 17.80, 95% CI 6.79 to 46.66). The occurrence of urinary stricture did not significantly differ between the treatment groups (LDR-BT 2/85 (2.4%) versus RP 6/89 (6.7%); P = 0.221; relative risk 0.35, 95% CI: 0.07 to 1.68). Long-term information was not available.We did not identify significant differences of mean scores between treatment groups for patient-reported outcomes function and bother as well as generic health-related quality of life.

AUTHORS' CONCLUSIONS

Low-dose rate brachytherapy did not reduce biochemical recurrence-free survival versus radical prostatectomy at 5 years. For short-term severe adverse events, low-dose rate brachytherapy was significantly more favorable for urinary incontinence, but radical prostatectomy was significantly more favorable for urinary irritation. Evidence is based on one RCT with high risk of bias.

Image-guided radiotherapy for prostate cancer: a prospective trial of concomitant boost using indium-111-capromab pendetide (ProstaScint) imaging

PURPOSE

To evaluate, in a prospective study, the use of (111)In-capromab pendetide (ProstaScint) scan to guide the delivery of a concomitant boost to intraprostatic region showing increased uptake while treating the entire gland with intensity-modulated radiotherapy for localized prostate cancer.

METHODS AND MATERIALS

From September 2002 to November 2005, 71 patients were enrolled. Planning pelvic CT and (111)In-capromab pendetide scan images were coregistered. The entire prostate gland received 75.6 Gy/42 fractions, whereas areas of increased uptake in (111)In-capromab pendetide scan received 82 Gy. For patients with T3/T4 disease, or Gleason score ≥8, or prostate-specific antigen level >20 ng/mL, 12 months of adjuvant androgen deprivation therapy was given. In January 2005 the protocol was modified to give 6 months of androgen deprivation therapy to patients with a prostate-specific antigen level of 10-20 ng/mL or Gleason 7 disease.

RESULTS

Thirty-one patients had low-risk, 30 had intermediate-risk, and 10 had high-risk disease. With a median follow-up of 66 months, the 5-year biochemical control rates were 94% for the entire cohort and 97%, 93%, and 90% for low-, intermediate-, and high-risk groups, respectively. Maximum acute and late urinary toxicities were Grade 2 for 38 patients (54%) and 28 patients (39%) and Grade 3 for 1 and 3 patients (4%), respectively. One patient had Grade 4 hematuria. Maximum acute and late gastrointestinal toxicities were Grade 2 for 32 patients (45%) and 15 patients (21%), respectively. Most of the side effects improved with longer follow-up.

CONCLUSION

Concomitant boost to areas showing increased uptake in (111)In-capromab pendetide scan to 82 Gy using intensity-modulated radiotherapy while the entire prostate received 75.6 Gy was feasible and tolerable, with 94% biochemical control rate at 5 years.

Applications of SPECT/CT in nuclear radiology

OBJECTIVE

The purpose of this pictorial essay is to illustrate several clinical situations in which SPECT/CT can be effectively applied in nuclear radiology practice.

CONCLUSION

SPECT/CT has recently emerged as a valuable adjunct to standard techniques in clinical nuclear radiology. This technique provides significantly improved scintigraphic localization and characterization of disease, increasingly important in this era of minimally invasive surgery and targeted radiotherapy.

Focal therapy for localized prostate cancer: a critical appraisal of rationale and modalities

PURPOSE

Based on contemporary epidemiological and pathological characteristics of prostate cancer we explain the rationale for and concerns about focal therapy for low risk prostate cancer, review potential methods of delivery and propose study design parameters.

MATERIALS AND METHODS

Articles regarding the epidemiology, diagnosis, imaging, treatment and pathology of localized prostate cancer were reviewed with a particular emphasis on technologies applicable for focal therapy, defined as targeted ablation of a limited area of the prostate expected to contain the dominant or only focus of cancer. A consensus summary was constructed by a multidisciplinary international task force of prostate cancer experts, forming the basis of the current review.

RESULTS

In regions with a high prevalence of prostate specific antigen screening the over detection and subsequent overtreatment of prostate cancer is common. The incidence of unifocal cancers in radical prostatectomy specimens is 13% to 38%. In many others there is an index lesion with secondary foci containing pathological features similar to those found incidentally at autopsy. Because biopsy strategies and imaging techniques can provide more precise tumor localization and characterization, there is growing interest in focal therapy targeting unifocal or biologically unifocal tumors. The major arguments against focal therapy are multifocality, limited accuracy of staging, the unpredictable aggressiveness of secondary foci and the lack of established technology for focal ablation. Emerging technologies with the potential for focal therapy include high intensity focused ultrasound, cryotherapy, radio frequency ablation and photodynamic therapy.

CONCLUSIONS

Early detection of prostate cancer has led to concerns that while many cancers now diagnosed pose too little a threat for radical therapy, many men are reluctant to accept watchful waiting or active surveillance. Several emerging technologies seem capable of focal destruction of prostate tissue with minimal morbidity. We encourage the investigation of focal therapy in select men with low risk prostate cancer in prospective clinical trials that carefully document safety, functional outcomes and cancer control.

Central abdominal uptake of indium-111 capromab pendetide (ProstaScint) predicts for poor prognosis in patients with prostate cancer

OBJECTIVES

Central abdominal uptake (CAU) on immunoscintigraphy with capromab pendetide (CP) (ProstaScint) suggests the presence of metastases from prostate cancer, but tissue confirmation is difficult and invasive. We report the outcomes data from a cohort of patients with CAU on CP images obtained for staging.

METHODS

The records of 341 men with prostate cancer who underwent CP imaging at two institutions from 1994 to 1999 were reviewed. The patients were divided according to the presence or absence of CAU. Metastases were confirmed in 36 patients (52%) with CAU. The median follow-up was 4.1 years. Statistical analyses compared the differences in baseline characteristics, subsequent radiotherapy, intervention with androgen ablation, and survival.

RESULTS

CAU was detected in 69 patients (20%). A total of 262 patients underwent pelvic radiotherapy after the scan, 57 (83%) with CAU and 205 (75%) without (P = 0.2). Of the 69 patients with positive CAU findings and the 272 patients with negative CAU findings, 10 (14.5%) and 14 (5.1%) had died during the follow-up period (P = 0.007). Prostate cancer-specific death occurred in 5 (7.2%) of 69 patients with CAU-positive findings versus 2 of 272 with CAU-negative findings, for a rate 10 times greater in the CAU-positive group (P = 0.02). The results were independent of either the use or timing of androgen blockade.

CONCLUSIONS

The results of our study have shown that CAU on CP immunoscintigraphy is clinically important and correlates with a significantly greater risk of prostate cancer-specific death. These findings suggest that patients with CAU should be considered for earlier intervention with systemic therapy.

Prostate Postbrachytherapy Seed Distribution: Comparison of High-Resolution, Contrast-Enhanced, T1- and T2-Weighted Endorectal Magnetic Resonance Imaging Versus Computed Tomography: Initial Experience

PURPOSE

To compare contrast-enhanced, T1-weighted, three-dimensional magnetic resonance imaging (CEMR) and T2-weighted magnetic resonance imaging (T2MR) with computed tomography (CT) for prostate brachytherapy seed location for dosimetric calculations.

METHODS AND MATERIALS

Postbrachytherapy prostate MRI was performed on a 1.5 Tesla unit with combined surface and endorectal coils in 13 patients. Both CEMR and T2MR used a section thickness of 3 mm. Spiral CT used a section thickness of 5 mm with a pitch factor of 1.5. All images were obtained in the transverse plane. Two readers using CT and MR imaging assessed brachytherapy seed distribution independently. The dependency of data read by both readers for a specific subject was assessed with a linear mixed effects model.

RESULTS

The mean percentage (+/- standard deviation) values of the readers for seed detection and location are presented. Of 1205 implanted seeds, CEMR, T2MR, and CT detected 91.5% +/- 4.8%, 78.5% +/- 8.5%, and 96.1% +/- 2.3%, respectively, with 11.8% +/- 4.5%, 8.5% +/- 3.5%, 1.9% +/- 1.0% extracapsular, respectively. Assignment to periprostatic structures was not possible with CT. Periprostatic seed assignments for CEMR and T2MR, respectively, were as follows: neurovascular bundle, 3.5% +/- 1.6% and 2.1% +/- 0.9%; seminal vesicles, 0.9% +/- 1.8% and 0.3% +/- 0.7%; periurethral, 7.1% +/- 3.3% and 5.8% +/- 2.9%; penile bulb, 0.6% +/- 0.8% and 0.3% +/- 0.6%; Denonvillier's Fascia/rectal wall, 0.5% +/- 0.6% and 0%; and urinary bladder, 0.1% +/- 0.3% and 0%. Data dependency analysis showed statistical significance for the type of imaging but not for reader identification.

CONCLUSION

Both enumeration and localization of implanted seeds are readily accomplished with CEMR. Calculations with MRI dosimetry do not require CT data. Dose determinations to specific extracapsular sites can be obtained with MRI but not with CT.

The role of indium-111 radioimmunoscintigraphy in post-radical retropubic prostatectomy management of prostate cancer patients

Indium-111 radioimmunoscintigraphy (RIS) has an increasing role in the treatment of prostate cancer and is most commonly performed at this disease site using labeled monoclonal antibody against prostate-specific membrane antigen. There are many limitations of RIS, including low spatial resolution, low diagnostic yield and limited availability. Despite these limitations, the efficacy of RIS has been demonstrated in many clinical studies, including multi-institutional investigations. The highest sensitivity and specificity of RIS appears to be in the post-radical retropubic prostatectomy (post-RRP) setting. RIS has recently been explored for its role in clinical radiotherapy decision-making, and was found to have a significant impact in selecting patients for radiotherapy and for the general radiotherapy treatment volume definition. RIS has also recently been explored for its role in radiotherapy planning and was found to impact clinical target volume design. However, manual editing of the RIS volume is still necessary when projected into the radiotherapy-planning scan, as there is often overlap in the RIS-defined uptake regions with normal structures (rectum, bladder and symphysis bone marrow). The impact of RIS on biochemical control has been explored, with studies in this area yielding conflicting results. It appears that the maximum impact of RIS is possible when areas of labeled antibody uptake regions are co-registered with the radiotherapy-planning computed tomography scan. The larger RIS-guided target volumes do not appear to be prohibitive in increasing radiotherapy-related toxicity. Future directions of the use of RIS for post-RRP prostate cancer are discussed.

Biochemical disease-free survival rates following definitive low-dose-rate prostate brachytherapy with dose escalation to biologic target volumes identified with SPECT/CT capromab pendetide

PURPOSE

To report biochemical disease-free survival (bDFS) after conformal brachytherapy with dose escalation to biological target volumes (BTVs) identified by Capromab Pendetide with single photon emission computed tomography and computed tomography image fusion (SPECT/CT).

METHODS AND MATERIALS

Two hundred thirty-nine (T1c-T3b NxM0) consecutive patients were evaluated by SPECT/CT before treatment. Intraprostatic SPECT/CT BTVs were identified and targeted for 150% dose escalation during brachytherapy seed implant (SI). Patients received either SI alone (n = 150) or external beam radiation therapy (EBRT) plus SI boost (EBRT+SI) (n = 89), with (n = 50) and without (n = 189) neoadjuvant hormone ablation therapy. Risk factors (RF) (prostate-specific antigen [PSA] >10 ng/mL, Stage > or = T2b, and Gleason grade > or = 7) defined risk group (RG) categories [none, 1, and > or = 2 RF define low, intermediate, and high RG] for bDFS calculations using four failure criteria: American Society for Therapeutic Radiology and Oncology (ASTRO) consensus definition, PSA >1.0 ng/mL (PSA >1), PSA >0.5 ng/mL after nadir (PSA >0.5), and PSA nadir+2 ng/mL rise in PSA clinical nadir (CN+2). Median followup was 47.2 months (range, 24.8-96.1).

RESULTS

Seven-year actuarial bDFS rates were 88.0%, 82.1%, 80.4%, and 79.9% using the ASTRO, PSA >1, PSA >0.5, and CN+2 failure criteria, respectively. ASTRO-defined bDFS rates were 96.0%, 87.0%, and 72.5% for low, intermediate, and high RG's.

CONCLUSION

The data presented here demonstrate the feasibility of performing SPECT/CT BTV dose escalation in a mature series.

Rectal morbidity after permanent prostate brachytherapy with dose escalation to biologic target volumes identified by SPECT/CT fusion

PURPOSE

To evaluate rectal morbidity after dose escalation to biologic target volumes identified by capromab pendetide (ProstaScint) single-photon emission tomography images coregistered with computed tomography (SPECT/CT).

METHODS AND MATERIALS

Two hundred thirty-nine consecutive patients diagnosed with T1c-T3b NxM0 adenocarcinoma of the prostate were treated with brachytherapy seed implant (SI) dose escalation to SPECT/CT-identified biologic target volumes, from February 1997 through December 2002. Patients received SI (n=150) or external beam radiation therapy plus SI (n=89). Rectal morbidity was evaluated by clinician scoring using the modified Radiation Therapy Oncology Group criteria. The median followup was 47.2 (range 24.8-96.1) months.

RESULTS

The rate of acute Grades I and II toxicity was 29.9% and 3.7%, respectively, and chronic Grade I toxicity was 15.4%, 12.4%, 2.3%, and 1.8% at 1, 2, 3, and 4 years postimplant, respectively. Chronic Grade II toxicities were 1.8%, 1.9%, 1.5%, and 0.9% at 1, 2, 3, and 4 years, respectively. No Grade III rectal toxicity was reported. Chronic Grade IV rectal toxicity was 0.5% and 0.6% at 1.5 and 2.5 years, respectively. Ninety-six percent of patients reported freedom from all rectal toxicity after 3 years.

CONCLUSIONS

Dose intensification to occult tumor targets without increasing rectal toxicity may be achieved using SPECT/CT ProstaScint. Additional research to define the role of molecular imaging in prostate cancer is warranted.

PET/CT: form and function

Functional imaging with positron emission tomography (PET) is playing an increasingly important role in the diagnosis and staging of malignant disease, image-guided therapy planning, and treatment monitoring. PET with the labeled glucose analogue fluorine 18 fluorodeoxyglucose (FDG) is a relatively recent addition to the medical technology for imaging of cancer, and FDG PET complements the more conventional anatomic imaging modalities of computed tomography (CT) and magnetic resonance imaging. CT is complementary in the sense that it provides accurate localization of organs and lesions, while PET maps both normal and abnormal tissue function. When combined, the two modalities can help both identify and localize functional abnormalities. Attempts to align CT and PET data sets with fusion software are generally successful in the brain; other areas of the body is more challenging, owing to the increased number of degrees of freedom between the two data sets. These challenges have recently been addressed by the introduction of the combined PET/CT scanner, a hardware-oriented approach to image fusion. With such a device, accurately registered anatomic and functional images can be acquired for each patient in a single scanning session. Currently, over 800 combined PET/CT scanners are installed in medical institutions worldwide, many of them for the diagnosis and staging of malignant disease and increasingly for monitoring of the response to therapy. This review will describe some of the most recent technologic developments in PET/CT instrumentation and the clinical indications for which combined PET/CT has been shown to be more useful than PET and CT performed separately.

Synergistic Value of Single-Photon Emission Computed Tomography/Computed Tomography Fusion to Radioimmunoscintigraphic Imaging of Prostate Cancer

The rationale on which positron emission tomography/computed tomography (PET/CT) imaging is based, combining the functional features of PET with the anatomic detail of CT, provides many advantages that are easily transferable to single-photon emission computed tomography (SPECT)/CT imaging. Our efforts have focused on applying fused SPECT/CT imaging to identify prostate cancer and its metastasis and recurrence through radioimmunoscintigraphy (RIS). This application of RIS to imaging prostate cancer requires 2 key components: (1) a well-defined target associated with the cancer and (2) a "magic bullet" to seek that target. A well-characterized RIS target for prostate cancer is prostate-specific membrane antigen, or PSMA, and finding the bullet to seek this target with high sensitivity and specificity has been the focus of intensive study for nearly two decades. One of the candidate bullets developed is capromab pendetide, which is a monoclonal antibody that seeks PSMA. This antibody is commercially available as ProstaScint, which can be labeled with indium-111 to localize prostate cancer via SPECT imaging. In the course of applying fused SPECT/CT ProstaScint imaging to more than 800 prostate cancer cases, numerous refinements to our protocol have evolved that are aimed at staging the cancer with utmost accuracy. In addition to optimizing the localization of prostate cancer and its metastasis, these refinements also have been extended toward guiding both the implantation of radioactive seeds in brachytherapy and in other types of radiation therapy which is illustrated through 5 case reports. Progress in the therapeutic targeting of PSMA is also being actively explored, which has more universal ramifications because PSMA is found in the neovasculature of other types of cancers.

The evolution of imaging in advanced prostate cancer

Medical advances will be driven by the enhancement of imaging for diagnosis, refinement of treatment, and evaluation of treatment efficacy. The convergence of technology in materials science, biology, and the computer industry has greatly advanced diagnostic imaging. Precision in control of the spatial and temporal properties of light and its heterogeneous scattering properties have extended our capability for imaging. Refinements in radioimmunoscintigraphy for image acquisition, fusion of images, and outcome data now suggest use for image-guided therapy. Novel MRI agents appear to provide significant imaging capabilities to detect malignant lymph nodes. Future applications of optical coherence tomography, electron paramagnetic resonance imaging, nanotechnology, molecular imaging, and hyperspectral spectroscopy promise further refinements to image tissues for diagnosis.

Technology Insight: monoclonal antibody imaging of prostate cancer

Imaging is a critical component of diagnosis, staging and monitoring, all of which factor heavily in treatment decision-making for cancer patients. Agents, such as antibodies, can target molecules that are relatively unique to cancer cells. Prostate-specific membrane antigen (PSMA) is the most well-established, highly restricted prostate-cancer-related cell membrane antigen known. Ten years ago, the FDA approved (111)In-capromab pendetide for use in imaging soft-tissue, but not bone, sites of metastatic prostate cancer for presurgical staging or the evaluation of PSA relapse after local therapy. For presurgical patients with high-risk disease but negative bone, CT and MRI scans, capromab demonstrated the ability to identify some patients with positive nodes, thereby sparing them an unnecessary surgical procedure. But there have been no follow-up studies to indicate that high-risk patients with a negative capromab scan have a lower failure rate after surgery. In the setting of PSA relapse, capromab is compromised by its inability to sensitively image bone metastases; bone is the first site of metastatic prostate cancer in 72% of patients. The problem with imaging bone metastases is that capromab detects an antigenic site on the intracellular portion of PSMA-a site not accessible to circulating antibodies. Early results indicate that second-generation antibodies that target the extracellular domain of PSMA might provide significant benefits in the imaging of prostate cancer.

Cancer control after low-dose-rate prostate brachytherapy performed by a multidisciplinary team with no previous prostate brachytherapy experience

OBJECTIVES

To describe the biochemical disease-free survival observed in the first cohort men treated by a multidisciplinary team of clinicians with no previous experience in low-dose-rate prostate brachytherapy (LDRPB).

METHODS

The information in this report concerns the first 63 men treated with LDRPB alone at our institution between September 1997 and September 1998. All men had histologically confirmed, clinically localized prostate cancer. All men were treated with iodine 125 according to published methods. The prescription dose was 144 Gy according to the Task Group 43 formalism. LDRPB was performed jointly by a radiation oncologist and urologist. Three definitions of biochemical recurrence were used: the American Society for Therapeutic Radiology and Oncology consensus definition; prostate-specific antigen level greater than 0.4 ng/mL at last follow-up; and prostate-specific antigen level greater than 0.2 ng/mL at last follow-up. Biochemical relapse-free survival was estimated using the product-limit method. Putative covariates for biochemical relapse-free survival were examined using the proportional hazards regression model. All P values are two-sided.

RESULTS

The median follow-up for the entire cohort was 62 months. Of the 63 men, 45 (71%) had more than 60 months of follow-up. The median pretreatment prostate-specific antigen level was 6.68 ng/mL (range 1.1 to 23), and most men (44 of 63; 70%) had nonpalpable disease. The institutionally assigned Gleason score was less than 7 in 54 men (86%). Nine men developed evidence of biochemical relapse at a median of 19 months (range 6 to 38). The 5-year estimate of biochemical relapse-free survival was 85% (95% confidence interval 80% to 90%), 80% (95% confidence interval 74% to 86%), and 70% (95% confidence interval 64% to 76%) according to the three definitions given above.

CONCLUSIONS

The biochemical results achieved in the first cohort of men treated with LDRPB by a previously inexperienced multidisciplinary team of clinicians are similar to the results reported from centers with extensive LDRPB experience.

Migration of implanted free radioactive seeds for adenocarcinoma of the prostate using a Mick applicator

PURPOSE

This study investigates the rate of free seed migration and associated seed-related sequelae after using a radioimmunoguided Mick applicator technique to place radioactive seeds within the prostate.

METHODS AND MATERIALS

Between December 1998 and September 2002, 120 patients diagnosed with prostate cancer underwent interstitial transperineal prostate brachytherapy with free (125)I or (103)Pd seeds positioned using a radioimmunoguided Mick applicator technique. Orthogonal pelvic and chest radiographs were obtained postimplant (Day 0) and at a second follow-up visit to determine the rate of radioactive seed embolization.

RESULTS

On the day of implant (Day 0), 7 (6%) of the 120 men demonstrated single pulmonary seed emboli; none of these seeds migrated subsequently. During follow-up, 87 (72.5%) men had a total of 249 (2.0%) out of 12,524 seeds implanted migrate. Sixty-eight (0.55%) of the implanted seeds migrated to the lungs, an incidence common among brachytherapy techniques utilizing free or vicryl-laden radioactive seeds. No clinical symptoms or adverse sequelae from seed emboli have been reported.

CONCLUSIONS

The rate of seed emboli to the pulmonary vessels or to other tissue localities resulting from a radioimmunoguided Mick applicator technique does not appear to be markedly different from the reported rate seen with other free seed techniques.