High-Dose Brachytherapy in Treating Patients With Prostate Cancer

Inclusion Criteria:

* Documented pathologic confirmation of prostate adenocarcinoma
* Clinical T-classification T1-3
* PSA \< 150 ng/mL
* Gleason score 6-10
* Clinically negative lymph nodes as established by abdomino-pelvic CT. CT only for clinical classification of T3 (with contrast if renal function is acceptable; a non-contrast CT is permitted if the patient is not a candidate for contrast), magnetic resonance imaging (MRI), nodal sampling, or dissection. Patients with lymph nodes equivocal or questionable by imaging are eligible if those nodes are \<1 cm in short axis diameter. \[56\]
* No evidence of bone metastases (M0) on bone scan, only for PSA \>20 ng/mLor Gleason ≥8, (NaF PET/CT is an acceptable substitute). Equivocal bone scan findings are allowed if plain films and/or MRI are negative for definite metastases.
* American Urological Association Symptom Index (AUA SI) =\< 20

Exclusion Criteria:

* Clinical T4 disease
* PSA \>= 150 ng/mL
* AUA SI \> 20
* History of radical prostatectomy, external beam radiotherapy (EBRT), or BT for prostate cancer
* Previous chemotherapy for any malignancy, if given within three years of registration
* History of rectal surgery
* History of rectal fistula
* History of inflammatory bowel disease
* Severe, active co-morbidity, defined as follows:

* Unstable angina and/or congestive heart failure requiring hospitalization within the last six months
* Transmural myocardial infarction within the last six months