Three-dimensional computed tomography-guided monotherapeutic pararectal brachytherapy of prostate cancer with seminal vesicle invasion.

PURPOSE: To treat patients with prostate cancer and seminal vesicle invasion with monotherapeutic three dimensional computed tomography (3-DCT)-guided posterior pararectal brachytherapy. METHODS AND MATERIALS: Three hundred and sixty two patients with clinical stage T1 a,b or T2 a,b of prostate cancer were referred for 3-DCT-guided brachytherapy. Each underwent ftirther staging with 3-D CT-guided pararectal biopsy of the seminal vesicles under local anesthesia during the pre-treatment CT-planning. Forty-three patients (12%) were upstaged to T3 cNoMo disease. In the set of 43 patients, Eight had Gleason's score< or =6, 24 Gleason's score=7, and 11 patients > or =8. Initial PSA was <10 ng/ml in 14 patients, 10-20 ng/ml in 11 patients, and >20 in 18 patients. Of the 43 patients, 37 patients were treated monotherapeutically with 3-D CT-guided brachytherapy. No patients received hormone therapy after the implant. The prescribed dosage to the seminal vesicles and prostate is 120 Gy with Pd-103 seeds and 144 Gy with 1-125 seeds. RESULTS: The prescribed dosage was achieved in all 37 patient's throughout the seminal vesicles whose range of target radiation extended 5-10 mm outside the target in the adjacent fat as calculated with post-implant CT-dosimetry with Varian Brachy Vision or MMS software. Prostate Specific Antigen (PSA) outcome data were available in 34 patients treated with monotherapy and follow up ranged from 12-56 months (median, 24 months). Decreased PSA levels were stratified into six groups based on the presenting Gleason's score and initial PSA. In the first group (with Gleason's score< or =6 and initial PSA <20 ng/ml), PSA levels decreased to less than 0.5 ng/ml in all seven patients (100%) after brachytherapy. In the second group (with Gleason's=7 and initial PSA<20 ng/ml), PSA levels decreased to less than 1 ng/ml in 11 of 13 patients (85%); additionally PSA levels decreased to less than 0.5 ng/ml in ten patients (77% in this group). In the third group (with Gleason's score=7 and initial PSA> 20 ng/ml), PSA decreased to less than 0.5 ng/ml in four out of eight patients (50%). All of the patients in the fourth group (with Gleason's score> or =8 and initial PSA<20 ng/ml) decreased their PSA levels to less than 0.5 ng/ml in three of three patients. PSA decreased less than 0.5 ng/ml in two out of three patients (67% in the last group with Gleason's score> or =8 and initial PSA> 20 ng/ml). There were no patients with Gleason's score of 1-6 and greater than 20 ng/ml initial PSA. Patients, irrespective of the Gleason's score and PSA, had an overall response of decreased PSA (less than 1 ng/ml) of 79%. CONCLUSION: 3-D CT-guided brachytherapy delivers adequate dosage to the seminal vesicles. Clinical and biochemical results are encouraging in patients with low initial PSA levels regardless of their Gleason's scores, but longer-term data in a greater number of patients is necessary.

High- and low-risk prostate cancer treated with 3D CT-guided brachytherapy: 1-to 5-year follow-up.

PURPOSE: To provide a preliminary report of 301 patients treated for prostate carcinoma with three-dimensional CT-guided transischiorectal stereotactic brachytherapy using either iodine-125 or palladium-103 seeds as monotherapy. PATIENTS AND METHODS: Patients with clinical stage T1, T(2ab), or T(3ab) disease with prostate volumes 23 to 180 cm3 and serum prostate specific antigen (PSA) concentrations of 0.9 to 143 ng/mL had seeds placed 10 mm apart under CT guidance. No androgen blockade was used postoperatively, but 47% of the patients had hormonal therapy preoperatively. RESULTS: At 12 to 63 months (median 26 months) of follow-up, PSA concentrations had decreased to <2 ng/mL in 90% of the patients and to <1 ng/mL in 83%. Four patients underwent transurethral resection or incision at least 12 months after implantation; none became incontinent. Three patients had rectal ulceration that lasted for several months. CONCLUSIONS: Computed tomography-guided transischiorectal brachytherapy allows accurate placement of radionuclide seeds in prostate glands of all sizes. The early results, as judged by serum PSA, are encouraging.

Technical basis for EPA's proposed regulation on the cleanup of sites contaminated with radioactivity.

The U.S. Environmental Protection Agency is proposing a regulation for the protection of the public from radioactive contamination at sites that are to be cleaned up and released for public use. The rule will apply to sites under the control of Federal agencies, and will impose limits on radiation doses to individuals living or working on a site following cleanup; it will thereby provide site owners and managers with uniform, consistent cleanup criteria for planning and carrying out remediation. This paper presents an overview of EPA's approach to assessing some of the beneficial and adverse effects associated with various possible values for the annual dose limit. In particular, it discusses the method developed to determine how the choice of cleanup criterion affects (1) the time-integrated potential numbers of non-fatal and fatal radiogenic cancers averted among future populations, (2) the occurrence of radiogenic cancers among remediation workers and the public caused by the cleanup process itself, and (3) the volumes of contaminated soil that may require remediation. The analytic methods described here were used to provide input data and assumptions for the Regulatory Impact Analysis (RIA) that supports the proposed regulation; the RIA also considered non-radiological benefits and costs (i.e., public health, economic, and ecological) of the standards.

Progressive ureteral dilation for subsequent ureterocystoplasty.

PURPOSE: The complications associated with bladder augmentation using the gastrointestinal tract are well known. A bladder based ureteral flap is a viable alternative for augmentation. However, its use is limited to cases in which a dilated ureter is already present due to associated pathological conditions, such as reflux. We designed a system for performing progressive dilation in a normal ureter, which can subsequently be used for augmentation. MATERIALS AND METHODS: Ten rabbits underwent unilateral ureteral ligation at the ureterovesical junction and ipsilateral nephrectomy. A silicone catheter was threaded into the proximal ipsilateral ureter and connected to an injection port, which was secured subcutaneously. Ten days to 2 weeks after surgery a saline-antibiotic solution was injected subcutaneously daily into the injection port. Cystography and cystometrography were performed with an accurate measurement of bladder capacity. Ureterography was done initially and then weekly by injecting contrast medium into the ureter. After ureteral dilation ureterocystoplasty was performed in each animal. RESULTS: After 1 month of daily saline-antibiotic solution injections the ureteral units were dilated at least 10-fold, as measured by radiography. The dilated ureteral diameter exceeded that of adjacent colon in each instance. Augmentation cystoplasty was performed with the reconfigured dilated ureteral segment. Repeat cystography and cystometrography showed an average 260% increase in bladder capacity (range 190 to 380%). CONCLUSIONS: Ureteral dilation can be accomplished using our system. At least a 10-fold increase in ureteral size is possible. The dilated ureteral segment can be used effectively for bladder augmentation, avoiding the use of bowel segments.