Photoselective vaporization of the prostate: pursuing good indications based on the results of 400 Japanese patients

• Published in: BJU international Vol. 109; no. 6; pp. 874 - 879
• Main Authors: Otsuki, Hideo, Kuwahara, Yoshitaka, Tsukamoto, Takuji, Nakamura, Kenzo, Shiroki, Ryoichi, Hoshinaga, Kiyotaka
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-03-2012; Wiley-Blackwell; Wiley Subscription Services, Inc
• Subjects: Aged; Aging; Androgens; Asian Continental Ancestry Group; Biological and medical sciences; BPH; Gynecology. Andrology. Obstetrics; Humans; Laser Therapy - adverse effects; Laser Therapy - methods; Lasers, Solid-State - therapeutic use; Male; Male genital diseases; Medical sciences; Men; Nephrology. Urinary tract diseases; Organ Size; Postoperative Complications - etiology; potassium titanyl phosphate (KTP) laser; Prostate; Prostate - pathology; Prostate - surgery; prostate vaporization; prostate volume; Prostatic Hyperplasia - surgery; Quality of Life; reduction rate; Retrospective Studies; Severity of Illness Index; Therapy; transrectal ultrasonography; Treatment Outcome; Tumors; Tumors of the urinary system; Urinary tract. Prostate gland; Urination - physiology; Asia; Japan; prostate vaporization; Nephrology; Prostate disease; Indication; reduction rate; Urology; Reduction; potassium titanyl phosphate (KTP) laser; Benign prostatic hyperplasia; Benign neoplasm; transrectal ultrasonography; Urogenital system; Male genital diseases; Sonography; Human; Urinary system disease; Rate; prostate volume; Japanese; Vaporization; Potassium phosphate; Volume; Echography; Laser; Titanyl; BPH; Prostate
• ISSN: 1464-4096; 1464-410X
• DOI: 10.1111/j.1464-410X.2011.10525.x

Study Type – Therapy (individual cohort)
Level of Evidence 2b
What's known on the subject? and What does the study add?
Photoselective vaporization of prostate (PVP) with a KTP laser is safer than TURP and has comparable efficacy to TURP. But long‐term durability and suitable amount of vaporization have been unknown. We investigated 400 Japanese patients after PVP regarding prostate volume. The mean reduction rate of prostate size was 43.2% (21.8 mL), which was achieved with 273.5 kj of KTP energy on average. A larger absolute volume reduction in patients with larger prostates was associated with greater improvements of objective urinary function parameters and symptoms score reduction.
OBJECTIVE
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To investigate good indications of photoselective vaporization of the prostate (PVP) by retrospective evaluation of its efficacy in relation to prostate volume.
PATIENTS AND METHODS
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A cohort of 400 patients had International Prostate Symptoms Score (IPSS), Quality of Life (QoL) score, urinary peak flow (Qmax), and prostate volume (Pvol), assessed before and after surgery.
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Changes of outcome variables were compared among four groups classified according to preoperative prostate volume: <30 mL (group A), ≥30 and <50 mL (group B), ≥50 and <70 mL (group C), and >70 mL (group D).
RESULTS
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Operating times and amounts of energy applied were 44.2 min and 159 kJ, 67.7 min and 268 kJ, 111 min and 409 kJ, and 171 min and 604 kJ in groups A, B, C, and D, respectively.
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All variables improved significantly and immediately, and remained for more than 12 months.
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Investigation of groups classified by prostate size demonstrated that IPSS and QoL score decreased and improvement rate of Qmax rose as prostate volume increased.
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Changes of Pvol were from 24.5 mL to 13.2 mL (−46.1%), from 39.8 mL to 22.9 mL (−42.4%), from 58.4 mL to 32.8 mL (−43.8%), and from 92.1 mL to 53.8 mL (−41.5%) in groups A, B, C, and D, respectively. Overall the Pvol reduction rate was 43.2%, and no significant differences were observed in reduction ratios among the groups.
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Complications were minimal, but bladder neck contracture arose in 16 cases with a smaller prostate.
CONCLUSION
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Whilst the percentage reduction in volume was similar across the groups, the larger absolute volume reduction in patients with larger prostates was associated with greater improvement in objective urinary function variables, and with symptom score reduction.