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.

The ultrastructural effect of distension on the neuromuscular apparatus of the urinary bladder.

The recent clinical success of distension therapy in the treatment of idiopathic detrusor hyperreflexia has prompted this ultrastructural study. The neuromuscular pathways of conduction in the rat and rabbit urinary bladder wall were examined using perfusion fixation techniques. The effects of short-term and prolonged distension were studied at frequent intervals for 4 months in treated and control animals. Prolonged distension did not alter either smooth muscle architecture or intercellular contact points. A transient phase of nerve degeneration in bladder muscle consisting of axonal swelling and lysis of organelles was observed. A quantitative estimate of nerve injury and regeneration was compiled using pooled histograms. Possible physiologic mechanisms of injury and clinical conclusions are discussed.

Anatomic effect of distention therapy in unstable bladder: new approach.

The recent clinical success of distention therapy in the treatment of the unstable bladder is reviewed. Bladder stability and increased capacity as measured by cystometry following distention therapy as well as relief of symptoms have prompted this anatomic study. The neuromuscular pathways of conduction in rat and rabbit bladder wall were examined following short-term (two-hour) and prolonged (six-hour) distention. Treated and control animals were studied at fixed intervals for four months. Prolonged distention did not alter either smooth muscle cell architecture or intercellular junctions. It did produce a transient phase of degeneration among the unmyelinated nerve fibers in the bladder wall consisting of axonal swelling and lysis of organelles. A quantitative estimate of nerve injury was compiled using pooled histograms. These results suggest that bladder stability following distention therapy may be related to nerve degeneration in the bladder wall.