Editing Biochemical Recurrence (section)

=== Imaging ===
* '''Primary'''
** Imaging of the prostate after definitive radiotherapy remains challenging with traditional modalities because of fibrosis and shrinkage of the prostate.
** '''MRI'''
*** '''The most promising technique for identifying recurrent tumors of the prostate in biochemical recurrence following radiotherapy.'''
** '''PET/CT'''
*** '''Use in the setting of BCR after RT, while promising, has not been entirely defined and is under active study.'''
**** 11C-choline PET can assist with differentiating local recurrence from metastatic disease at a PSA value when salvage treatment can be considered. However, PET has poorer spatial resolution than MRI, limiting its ability to assist in biopsy guidance.
**** PSMA based imaging is a relatively new modality with potential use in the evaluation of BCR after RT.
* '''Distant'''
** Bone scan
*** The lowest PSA value at which bone scans are reliably positive is not known, but PSADT is a reasonable indicator of bone scan reliability.
**** In patients with PSA <10 ng/ml the chance of detecting a lesion on bone scan is <1% in those with PSADT >6 months and 10% in those with PSADT <6 months.
** Computerized tomography
*** Patients most likely to benefit from salvage therapy have a PSA <10 ng/ml
*** The probability that CT in asymptomatic men with PSA <10 ng/ml will yield actionable information (ie detection of metastatic disease) is low.
**** CT is reasonable if advanced imaging modalities are unavailable, although newer modalities (PSMA PET) are more sensitive for nodal disease detection.