Prevention of radiation-induced rectal injuries with perirectal blocks in radiation therapy.

Abstract

e17507 Background: The purpose of this study was to evaluate perirectal blocks in prevention of radiation-induced rectal injuries in patients with cervical cancer. Methods: The study included 18 patients diagnosed with stage III cervical cancer (T3bNxM0) receiving chemoradiotherapy. All patients showed pronounced inflammatory and dystrophic changes in tissue planes and organs of the small pelvis due to comorbidities (diabetes mellitus, hypertension, pelvic varicose veins, proctitis, inflammatory and adhesive processes in the small pelvis reducing chemoradiotherapy effectiveness due to impaired microcirculation and increasing the risk of post-radiation complications). All patients received brachytherapy with additional perirectal administration of drugs relieving pain and inflammation and improving neurotrophic processes and microcirculation in tissues (novocaine 0.25% -20.0; milgamma 2.0; ceftriaxone 1 g; dexamethasone 8 mg). The combined administration causes drug potentiation, positively affects the nervous and neuromuscular systems, restores microcirculation and venous outflow, decreases swelling, improves tissue trophism, reduces blood vessel permeability, and improves reflexes from interoceptors. Radiation therapy was completed on schedule with the introduction of radical doses in all patients, which is challenging in patients with comorbidities leading to impaired trophism and tissue hypoxia. Results: Complete tumor regression confirmed by MRI and ultrasound was observed by the end of the treatment in 90% of patients, apparently due to the radiosensitizing effect on cervical cancer and the radioprotective effect on surrounding tissues. Conclusions: Parametrial blocks during brachytherapy improve the status of tissues of the small pelvis which, in turn, prevents radiation damage, contributes to the timely radiotherapy completion, and improves the treatment effectiveness and the quality of life of patients. This technique is especially relevant in view of the increasing number of diseases that disrupt microcirculation, and hence the oxygenation of tissues, causing tumor radio- and chemoresistance.