The relation of oral glutamine supplementation with treatment-related oesaphagus side effects in lung cancer patients undergoing thoracic radiotherapy

The primary aim of thoracic radiotherapy (TRT) in lung carcinoma is to maximize the therapeutic ratio in order to deliver an effective dose to the tumor while maintaining an acceptable dose to the neighboring normal tissues. However, complications such as acute radiation-induced esophagitis (ARIE) may cause significant morbidity and unplanned treatment delays, These issues may reduce tumor control and survival rates, as well as the patients? quality of life (QOL). The use of more effective regimens combining concomitant radiation and chemotherapy has resulted in increased incidence and severity of this toxicity. To lessen this effect, doses to the esophagus have been minimized by the use of three-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy, but toxicity could not be effectively avoided because the proximity of the esophagus target tumor volumes precludes that possibility. Therefore, the primary strategies in controlling ARIE currently revolve around identifying an effective radioprotective agent. In cancer patients, there is a tendency for progressive depletion of glutamine from muscle, which is a key factor in cancer-induced cachexia. ARIE and related complications such as nausea, vomiting, pain, dysphagia, or odynophagiamay furtherworsen the tolerance of normal tissues to radiation. Therefore, it is reasonable to assume that glutamine supplementation may be beneficial in prevention of ARIE and related complications in patients undergoing TRT. This evidence suggests a selective radioprotective role for glutamine, so that, thirty-two patients with lung cancer that thoracic radiotherapy applied alone or concurrent with chemotherapy in Gazi University Medicine School Radiation Oncology Department with curative purposes were fallowed throughout the radiotherapy as regards the side effects of the treatments. The primary objective of the current study was to prospectively evaluate the efficacy of oral glutamine use in the prevention of ARIE and weight loss in lung cancer patients during TRT. Our second objective was to determine the predictive role of clinical (such as; serum immunological parameters and oesophageal transit time) and dosimetric parameters in terms of ARIE incidence and severity. When the toxicity grade, weiğht loss, serum cytokine levels and oesophageal transit time were compared between the group receiving glutamine and group not receiving glutamine, statistically significant improvement was found. Glutamine supress the inflammation related to the disease and treatment and reduce toxicity with statistical significanceIn conclusion, the results of this study suggest a beneficial role for oral glutamine use in prevention and/or delay of ARIE incidence and severity, as well as weight loss in lung cancer patients treated with definitive RT. These findings may potentially contribute positively on treatment results and QOL in patients treated with intensive regimens. Therefore, glutamine can be recommended for patients with lung cancer that receive RT.