放射線味覚障害の臨床的検討

Clinical Observation of Taste Disturbance Induced by Radiation Therapy

I．緒言

　頭頸部領域の悪性腫瘍は，進行例は別として，外科的切除を行うと日常生活に重大な支障を来たすことが多い。このような機能障害の問題と，大部分の頭頸部悪性腫瘍が扁平上皮癌であり，放射線に比較的感受性に富むことから，放射線治療が選択されることが多い。

　放射線治療中の患者は，全身倦怠感や食欲不振もさることながら，照射部位の疼痛や口腔および咽頭の乾燥感の他に，「何を食べても砂をかむような」という味覚障害を訴えることが多い。このような状態は，頭頸部悪性腫瘍患者の栄養状態を損い，ひいてはその治療の遂行にも支障をきたす場合が多々ある。

　Qualitative gustometry (filter paper disc method) was performed in six patients who underwent radiation therapy. Following results were obtained.

　1) Subjective taste disturbance appeared when irradiation dosage amounted to 1000-2000 rad. Whereas, it disappeared in 1 to 3 months after the termination of irradiation.

　2) The longer the period of irradiation, the more slowly taste disturbance recovered.

　3) Disgeusia was noticed in 44.3% or 5, 66.7% of N, 70% of T and 36.2% of Q tests.

　4) Taste thresholds in the apical tongue region improved almost parallel to subjective recovery of the taste.

　Occasionally taste disturbance was prolonged over a month. This is possibly due to delayed regeneration of the gustatory buds. Furthermore, conditions of the oral cavity, such as infection, or mechanical stimulation, may well influence degree of taste disturbance and the process of regeneration.