Value of transrectal power Doppler sonography in the detection of low-risk prostate cancers.

PURPOSE: To evaluate the risk of low-risk prostate cancer or prostate cancer that may benefit from surveillance in patients with a PSA level less than 10 ng/ml, a normal digital rectal examination (DRE) and a transrectal power Doppler sonography (PDS) without anomaly. PATIENTS AND METHODS: Two hundred and forty-three consecutive patients with a PSA level less than 10 ng/ml and a DRE without anomaly had PDS-guided biopsies: 12 to 15 samples were systematically taken and echo-guided in the suspect areas. The PDS results were rated from 1 to 4: 1: normal, 2: slightly hypoechogenic avascular area in which the hypo-echogenicity disappears after compression by probe, 3: hypoechogenic avascular area, 4: hypoechogenic vascularised area with power Doppler sonography. Patients rated 3 or 4 were considered to be pathological. D'Amico's criteria were used to assess the risk of a biological recurrence after treatment and those of Dall'Era were used to select the patients that could benefit from active surveillance (AS). The PDS was considered to be a true positive if at least one biopsy was positive in the same sextant as the suspect image. RESULTS: In a prospective manner, 106 cancers were diagnosed that could be qualified as low-risk in 84% of the cases (89% with a normal PDS and 79% with an abnormal PDS). Sixty-nine percent of the cases could be subject to AS (86% of the normal PDS cases and 47% of the abnormal PDS cases; P<0.001). The PDS was normal in 159 of the 243 patients (65%). With a normal PDS, there was a 96% probability of not having a high-risk cancer. With an abnormal PDS, at least one biopsy was positive in 57% of the cases and the probability of having a significant cancer was 30% according to the Dall'Era criteria. A significant reduction was noted with a normal PDS, to 36% and 5%, respectively (VPN=95%) (P=0.015). CONCLUSION: A normal PDS in patients presenting a PSA level less than 10 ng/ml and a DRE without anomaly may be used to put off the indication for a biopsy in order to reduce their number as well as the risks of overtreatment for a latent cancer.

Multiphoton micrometer-scale photoetching in silicate-based glasses.

Silicate-based glasses containing approximately 10% by weight boron or more have been observed to exhibit selective etching in hydrofluoric acid solution after direct exposure to intense visible laser light at 532 nm. The observation of a ring-shaped etch pattern in samples exposed to solid Gaussian beams suggests that selective etching is related to a charge-diffusion process rather than to local light-induced defect generation. The technique has so far resulted in the maskless production of micrometer-scale features with submicrometer depths.