Seed loss through the urinary tract after prostate brachytherapy: examining the role of cystoscopy and urine straining post implant

Fiducial markers implantation for prostate image-guided radiotherapy: a report on the transperineal approach

INTRODUCTION

In the external beam prostate cancer radiation therapy, daily gland displacement could lead to a target missing. The use of intra-prostatic gold fiducial markers for daily prostate position verification and correction before and during treatment delivery (image-guided radiotherapy, IGRT) is widely used in the radiation therapy centers to accurately target the prostate. Usually, the fiducial markers are implanted through the rectum, with complications such as infections and rectal bleeding. We report our experience in prostate fiducial markers implantation through a transperineal approach.

PATIENTS AND METHODS

Between September 2011 and January 2018 at our center, 101 patients underwent gold seed fiducial marker transperineal ultrasound-guided implantation for prostate IGRT. We retrospectively reviewed their features and outcome. Twenty-two (21.8%) patients had previously been subjected to a transurethral prostate resection (TURP) for obstructive urinary symptoms because of benign prostatic hypertrophy. No antibiotic prophylaxis was used.

RESULTS

The procedure was well tolerated. In one patient, a single episode of self-limiting urinary bleeding occurred just after it. No other complication was recorded. All the patients, at the evaluation before discharge, reported no pain or dysuria. No rectal bleeding, hematospermia, urinary obstruction or infection were reported in the next days. No markers lost or migration occurred.

DISCUSSION AND CONCLUSION

According to our experience, prostate fiducial markers implantation through a transperineal approach is safe and should be recommended to limit the use of antibiotic therapy and patients morbidity. A previous TURP was not related to a higher risk of loss of seeds.

Injectable polypeptide micelles that form radiation crosslinked hydrogels in situ for intratumoral radiotherapy

Intratumoral radiation therapy - 'brachytherapy' - is a highly effective treatment for solid tumors, particularly prostate cancer. Current titanium seed implants, however, are permanent and are limited in clinical application to indolent malignancies of low- to intermediate-risk. Attempts to develop polymeric alternatives, however, have been plagued by poor retention and off-target toxicity due to degradation. Herein, we report on a new approach whereby thermally sensitive micelles composed of an elastin-like polypeptide (ELP) are labeled with the radionuclide (131)I to form an in situ hydrogel that is stabilized by two independent mechanisms: first, body heat triggers the radioactive ELP micelles to rapidly phase transition into an insoluble, viscous coacervate in under 2 min; second, the high energy β-emissions of (131)I further stabilize the depot by introducing crosslinks within the ELP depot over 24h. These injectable brachytherapy hydrogels were used to treat two aggressive orthotopic tumor models in athymic nude mice: a human PC-3 M-luc-C6 prostate tumor and a human BxPc3-luc2 pancreatic tumor model. The ELP depots retained greater than 52% and 70% of their radioactivity through 60 days in the prostate and pancreatic tumors with no appreciable radioactive accumulation (≤ 0.1% ID) in off-target tissues after 72h. The (131)I-ELP depots achieved >95% tumor regression in the prostate tumors (n=8); with a median survival of more than 60 days compared to 12 days for control mice. For the pancreatic tumors, ELP brachytherapy (n=6) induced significant growth inhibition (p=0.001, ANOVA) and enhanced median survival to 27 days over controls.

Prostate Brachytherapy seed migration to the Bladder presenting with Gross Hematuria

We present the radiologic findings in a case of prostate brachytherapy seed migration to the bladder presenting as gross hematuria. While prostate brachytherapy seed implantation is considered a relatively safe procedure, migration is not uncommon; however, it is usually clinically silent and the seeds most commonly migrate to the lungs through the venous circulation via the periprostatic venous plexus. Our case illustrates that local erosion is possible, can be symptomatic, and therefore must be considered when evaluating select patients.

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.

A prospective randomized comparison of stranded vs. loose 125I seeds for prostate brachytherapy

PURPOSE

To compare seed loss and dosimetric parameters between stranded and loose 125I seeds (LS) for prostate brachytherapy.

METHODS AND MATERIALS

Sixty-four patients with 1997 American Joint Commission on Cancer (AJCC) clinical stage T1c or T2a prostate carcinoma were prospectively randomized to brachytherapy (144Gy) with RAPID Strand 125I seeds (RS) vs. LS (Oncura, Plymouth Meeting, PA) The treatment plan for each patient was devised before randomization, and was not modified based on the randomization. Each patient underwent magnetic resonance, computed tomography, and plain film radiographs on the day of the implant (Day 0) and 30 days later (Day 30).

RESULTS

Overall, 21 of 62 patients (30%) experienced seed loss. Seed loss occurred in 15 of 32 of LS patients (47%) vs. 6 of 30 RS patients (23%; p=0.053). Mean seed loss was 1.09 in the LS patient vs. 0.43 in RS patients (p=0.062). Eight LS patients (25%) lost multiple seeds, compared to 3 stranded patients (10%). Despite the lesser degree of seed loss in patients who received stranded seeds, they had a paradoxical trend toward lower V100 and D90 values.

CONCLUSION

This prospective randomized trial showed a strong trend toward a decrease in postimplant seed loss with stranded seeds. Improved seed retention may be more advantageous in a setting of less generous periprostatic coverage. The lowered risk seed migration seen with stranded seeds would presumably also decrease the likelihood of lung or cardiac seed embolization.

Prostate brachytherapy seed migration to the right coronary artery associated with an acute myocardial infarction

PURPOSE

We report a case of prostate brachytherapy seed migration to the right coronary artery (RCA) associated with an acute myocardial infarction (AMI).

METHODS AND MATERIALS

A 69-year-old male was diagnosed with Prostate Adenocarcinoma Stage II (T(1c)N0M0) in October 2003. He underwent percutaneous transperineal interstitial permanent prostate brachytherapy with the implantation of 94 loose iodine (125I) seeds under transrectal ultrasound guidance on 15 December, 2003. The implantation was designed to deliver a minimum dose of 144 Gy.

RESULTS

Postimplant pelvic radiography at Day 30 showed five seeds missing. No chest radiography was done until hospital admission on October 10, 2005 for AMI. Cine radiography from cardiac catheterization revealed 86 metallic seeds remaining in the pelvic region, 4 that had migrated to the lungs (2 left and 2 right) and 2 to the heart. Two seeds were unaccounted for. Of the two cardiac seeds, one was lodged in the right ventricle endocardium and the other in the midsegment of the RCA at the site of a severely stenotic lesion that resulted in an AMI.

CONCLUSIONS

To our knowledge, this is the first case of brachytherapy seed migration to the RCA associated with an AMI. Echocardiography before brachytherapy seed implantation might be considered in patients felt to be at high risk for cardiac shunting.

Image guided I125 prostate brachytherapy with Hybrid Interactive Mick technique in the community setting: How does it compare?

The aim of this study is to evaluate the target coverage, procedural techniques, and merits of Hybrid Interactive Mick (HIM) I125 transperineal permanent implantation (TPPI) of the prostate performed with 10 urologists in a community hospital. Detailed day 0 post-implant dosimetric evaluations of TPPI procedures were performed on 333 consecutive monotherapy patients treated between September 2000 and November 2003 at a single institution. All patients underwent TPPI with HIM. Pelvic and CXR films were obtained for a manual seed count at day 0 and again > day 90 on 175 patients. The HIM-prostate brachytherapy performed in a community hospital provided median D(90), V100, and V150 values of 157Gy, 94%, and 42.3%, respectively. 18% of patients had seed migration to the lungs while 2% had seed migration to the bladder. Only 7 patients (4%) had 2 or more seeds migrate to the lungs. Procedure times average 38 minutes and number of needles used averaged 18. The post-implant urinary retention rate was 2.1% Use of HIM-prostate brachytherapy in the community setting with multiple urologists reproducibly maintained excellent and consistent dosimetric coverage. Procedure times and number of needles used were minimized, and with careful attention to image-guided technique, seed migration to bladder and lung was also minimized.

Migration des grains d'iode 125 après curiethérapie prostatique : étude d'une série de 170 patients

PURPOSE

To study the number of migrating seeds, the anatomical site of migration and possible predictive parameters of migration, after prostate cancer brachytherapy using a loose-seed (I125) implantation technique.

PATIENTS AND METHODS

The charts of the 170 patients consecutively treated by the Institut Curie/Hospital Cochin/Hospital Necker Group between September 1, 2001 and August 31, 2002, were analysed. All seeds having migrated to the lungs and seen on the chest X-ray systematically performed at 2 months, have been recorded, as well as the seeds lost by the urines (after sieving) or in the sperm (condom).

RESULTS

Among 12,179 implanted seeds, 44 were found to have migrated (0.36%). Most of the migrating seeds (32/44; 73%), were found in the lungs. Overall, one or several seed migrations were observed in 35 patients (21% of the total number of patients in this series). In the majority of cases (77%), only one seed migrated. A significant relationship (P = 0.04) was found between the number of migrating seeds and the number of implanted ones (or with the prostate volume, but those two parameters were closely linked in our series). More specifically, a significant relationship (P = 0.02) could be demonstrated between the number of seeds implanted at the periphery of the prostate and the number of seeds migrating to the lungs.

CONCLUSION

The percentage of migrating seeds observed in this series is low, actually one of the lowest found in the literature when using the loose-seed technique. There was no clinical consequences and the loss of-usually-only one seed is very unlikely to alter the quality of the dose distribution. However, the predominance of pulmonary migrations in our series led us to slightly modify our implantation technique. We now try to avoid too "peripheral" seed implantations, due to the risk of migration towards the periprostatic veins, and subsequently to the lungs.