AbstractBACKGROUNDThe objective of the current study was to provide descriptive information on a representative national sample of patients with prostate carcinoma who were treated with prostate brachytherapy (PB) in calendar year 1999.METHODSA random survey was conducted by the Patterns of Care Study in radiation oncology of 59 facilities (1 facility had no eligible patients) that treated patients with prostate carcinoma in 1999 in the United States. A weighted sample size of 36,496 patients with prostate cancer was included in the 1999 survey (unweighted sample size, 554 patients). The main measures were the clinical characteristics of men prior to treatment and the technical characteristics of PB. Patients were classified into three prognostic groups according to T stage, pretreatment prostate specific antigen (PSA) level, and Gleason score.RESULTSA weighted sample size of 13,293 patients (36%; unweighted sample size, 162 patients) was treated with PB. Compared with a weighted sample size of 23,203 patients (64%; unweighted sample size, 392 patients) was treated with external beam radiotherapy (EB), patients who received PB were significantly younger (mean age: PB group, 67.7 years; EB group, 70.8 years; P = 0.0006). The mean pretreatment PSA level for the PB group was lower compared with the EB group (9.9 ng/mL vs. 13.33 ng/mL; P = 0.0015). The prognostic groupings were more favorable for patients in the PB group compared with patients in EB group (P = 0.0365). The utilization of androgen deprivation therapy (ADT) in the PB group was similar to the utilization of ADT in the EB group (40.4% vs. 51.3%; P = 0.2282). The vast majority of men who were treated with PB received low‐dose‐rate, permanent sources (89%). Fifty‐four percent of men received PB monotherapy (PBM), and the remaining 46% were treated with EB in addition to PB (EBPB). The prognostic groupings were more favorable for patients in the PBM group compared with patients in the EBPB group (P = 0.0037). Of the men who were treated with low‐dose‐rate PB, 59% were treated with iodine‐125 (I‐125), and 41% were treated with palladium‐103 (Pd‐103). I‐125 was used more frequently in men who were treated with PBM, and Pd‐103 was used more frequently in men who were treated with EBPB. Postimplantation dosimetry was documented in 61.0% of men who were treated with low‐dose‐rate PB. Computed tomography imaging was used for 46.5% of men.CONCLUSIONSPB was used in 36% of men who were treated with radiotherapy nationally. The mean age of men who were treated with PB was younger than the population of men who were treated with EB alone. Nearly 50% of men who received PB also received EB. EB was used more frequently in men with higher‐risk disease. ADT was used in 40% of patients in the PB group. Techniques and prescription doses were consistent with published guidelines. Cancer 2003. © 2003 American Cancer Society.