Bladder calcifications after photodynamic therapy: analysis of a rare complication.
Overview
abstract
OBJECTIVES: We analyzed bladder calcifications occurring after photodynamic therapy administered for the treatment of superficial bladder cancer, a finding not previously reported after this treatment. METHODS: Bladder biopsies from 20 patients undergoing photodynamic therapy were evaluated. Bladder calcifications were identified in 2 patients and analyzed for composition. RESULTS: One patient had diffuse microcrystalline deposition in two biopsies composed of calcium oxalate monohydrate A. A second patient had a focal stone at a healing biopsy site composed of monoclinic calcium hydrogen phosphate dihydrate (brushite) (66%), calcium oxalate (25%), hydroxyapatite (6%), and protein (3%). CONCLUSIONS: Rare calcium oxalate and brushite calcifications were identified after photodynamic therapy and presumed to occur because of tissue injury associated with treatment.