ABSTRACT
PURPOSE: To report the biochemical control rate and clinical outcomes with real-time inverse planning (inverse optimization prostate seed implant [IO-PSI]) for favorable-risk (FR) and intermediate-risk (IR) prostate adenocarcinoma in a community practice setting. This analysis is an extended followup of our initial report, with favorable early biochemical control rate (biochemical nonevidence of disease) of 97% at 4 years. METHODS AND MATERIALS: Three hundred fifty-seven evaluable patients with FR and IR prostate cancer underwent real-time IO-PSI (iodine-125/145 Gy or palladium-103/120 Gy) between 2001 and 2013. RESULTS: With a median followup of 54 months (range, 24-110 months), the absolute biochemical failure free survival of disease was 96%. The 8-year actuarial probability of prostate-specific antigen failure-free survival for FR and IR cohorts was 92.4% and 87%, respectively. Late genitourinary and gastrointestinal toxicity remained low. Late Grade 2 and Grade 3 genitourinary toxicity was 19% and 1%, respectively. Late Grade 2 and 3 rectal bleeding rates were 1% and 0%, respectively. No difference in biochemical control was observed with preimplant short course androgen deprivation or between Gleason score 3 + 4 vs. 4 + 3 patients. No dosimetric parameter was predictive of biochemical failure. Patients with FR had a significantly decreased risk of failure (hazard ratio = 0.26; 95% confidence interval = 0.09-0.78; p = 0.02) compared with those with IR. Patients with a prostate-specific antigen nadir >0.4 ng/mL had an increased risk of failure (hazard ratio = 1.37; 95% confidence interval = 1.27-1.47; p < 0.0001). CONCLUSIONS: Our initial biochemical and clinical outcomes using real-time IO-PSI persisted with extended followup and support our original hypothesis for use of a reduced number of sources, needles, and total activity, suggesting that with IO, less is more.
Subject(s)
Adenocarcinoma/therapy , Brachytherapy/methods , Iodine Radioisotopes/therapeutic use , Palladium/therapeutic use , Prostate-Specific Antigen/blood , Prostatic Neoplasms/therapy , Radioisotopes/therapeutic use , Adenocarcinoma/blood , Adenocarcinoma/pathology , Aged , Androgen Antagonists/therapeutic use , Brachytherapy/adverse effects , Disease-Free Survival , Follow-Up Studies , Humans , Intraoperative Care , Male , Middle Aged , Neoplasm Grading , Prostatectomy , Prostatic Neoplasms/blood , Prostatic Neoplasms/pathology , Radiotherapy Dosage , Risk FactorsABSTRACT
The earliest and still most prevalent use of computers in the humanities is the compilation of concordances, rationalized vocabulary lists for literary works. The residue of these efforts has created the potential for extensive databases of natural-language text for a wide range of studies and for instruction. As yet, however, computer-aided instruction has focused on mechanical skills, like spelling and grammar. With rapid advances in storage (like videodisks) and in communications between computers, humanists are finding a challengingly altered environment in which to study and teach.