Bladder cancer in patients after previous irradiation for treatment of tumors of the organs of the lesser pelvis

Background. This article presents clinical cases of bladder cancer (BC) developed after previous irradiation and diagnosed in flat suspicious area by cross-polarization optical coherence tomography (CP-OCT) based on analysis of characteristics of scattered light, and with histological material confirmed by nonlinear microscopy.Objective: to present clinical cases and features of BC diagnosis in presence of radiation-induced changes.Materials and methods. Intra-vitam examination of the bladder mucosa was performed using the OKT 1300-U system (Institute of Applied Physics of the Russian Academy of Sciences, Nizhniy Novgorod). Areas that appeared malignant per CP-OCT data were biopsied. Apart from traditional examination of histological samples with hematoxylin and eosin staining, tissue samples were analyzed using nonlinear microscopy in the mode of second harmonic generation (collagen state analysis) and emission of two-photon fluorescence excitation (elastin state analysis).Results are presented through 2 cases of BC in patients with side effects of radiation therapy of varying severity. CP-OCT allowed in-life differentiation of areas of post-radiation inflammatory changes and malignant tumors developed as a result. Nonlinear microscopy provided information on the state of connective tissue matrix of the bladder in the context of radiation changes and transition to tumor.Conclusion. Radiation changes of the bladder mucosa, especially severe ones, can conceal development of malignant tumors. Use of optical methods helps in differential diagnosis of cancer and post-radiation changes of the bladder. CP-OCT is an optimal noninvasive method of examination of the bladder mucosa during cystoscopy. Demonstration of clinical material is aimed at practicing urologists to increase their vigilance in relation to possible BC in patients who underwent radiation therapy of the organs of the lesser pelvis