GreenLight HPS laser 120 W vs diode laser 300 W vaporization of the prostate for the treatment of benign prostatic hyperplasia in Japanese patients: A prospective, single-center, randomized clinical trial.

OBJECTIVES: This study aimed to compare the safety and efficacy of laser vaporization with 532 nm GreenLight High Performance System (HPS) laser 120 W (PVP) and 980 nm diode laser 300 W (CVP) for the treatment of benign prostatic hyperplasia (BPH) in a prospective, single-center, randomized clinical trial. METHODS: A total of 153 consecutive patients with symptomatic BPH were included; 79 patients were treated with PVP and 74 with CVP. Patients were assessed preoperatively and at 3, 6, and 12 months postoperatively using the International Prostate Symptom Score, quality of life index, peak urinary flow rate, and postvoid residual urine volume. All perioperative and postoperative complications were noted. RESULTS: There were significant and comparable improvements in each of the outcome variables over a follow-up period of 12 months in both groups. The mean operation/vaporization duration (minutes) was comparable at 74/38 (PVP) and 76/34 (CVP), whereas the mean applied laser energy was significantly higher with CVP than with PVP at 260 vs 195 (kJ), respectively. The mean vaporization rate (mL/min) was not significantly different between the two groups (0.53 PVP vs 0.56 CVP). Immediately after surgery, the rate of recatheterization for urinary retention was significantly higher with CVP than with PVP (17.6% vs 6.8%; P < 0.05). CONCLUSIONS: Both laser systems provided comparable improvement in the subjective and objective parameters with excellent hemostatic properties. Although our results suggest that both procedures are useful treatment choices, further follow-up is needed to draw definitive conclusions regarding the most ideal laser for treating patients with symptomatic BPH.

Plasma and cerebrospinal fluid pharmacokinetics of O6-benzylguanine and analogues in nonhuman primates.

O6-Benzylguanine (BG) is a potent, specific inactivator of the DNA repair protein, O6-alkylguanine-DNA alkyltransferase, that enhances the sensitivity of tumor cell lines and tumor xenografts to chloroethylnitrosoureas. To search for BG analogues with greater penetration into the cerebrospinal fluid (CSF), we evaluated plasma and CSF pharmacokinetics of BG, 8-aza-O6-benzylguanine (8-azaBG), O6-benzyl-8-bromoguanine (8-BrBG), O6-benzyl-8-oxoguanine (8-oxoBG), O6-benzyl-8-trifluoromethylguanine (8-tfmBG), and O6-benzyl-2'-deoxyguanosine (B2dG) after i.v. administration of 200 mg/m2 of drug through an indwelling Ommaya reservoir in a nonhuman primate model. BG and its analogues were quantified in plasma and CSF using reverse-phase high-performance liquid chromatography assays. The plasma clearances of the four 8-substituted BG analogues were similar (0.04-0.06 l/h/kg), but half-lives ranged from <2 to >24 h. BG was converted to 8-oxoBG, an equally potent O6-alkylguanine-DNA alkyltransferase inactivator, and the elimination of 8-oxoBG was much slower than that of BG. As a result, the plasma area under the curve of 8-oxoBG was 3.5-fold greater than that of BG. B2dG was metabolized to BG and 8-oxoBG, but this pathway accounted for only 20% of B2dG elimination. The CSF penetration percentages (based on the ratio of AUC(CSF): AUCplasma) for BG, 8-azaBG, 8-oxoBG, 8-tfmBG, 8-BrBG, and B2dG were 3.2, 0.18, 4.1, 1.4, <0.3, and 2.0%, respectively. The CSF penetration of BG and its active metabolite 8-oxoBG is greater than the penetration of 8-azaBG, 8-BrBG, 8-tfmBG, and B2dG.