Nadir prostate specific antigen (PSA) levels and time to nadir PSA (TnPSA) following radiotherapy have been proposed as predictors of outcome in prostate cancer. Ray et al. attempted to determine ...

There are two WCL systems available, an up-pointing lidar (zenith, WCL-I) at a wavelength of 355 nm and a down-pointing lidar (nadir, WCL-II) at 351 nm, which can be deployed separately or together.