Functional changes of the gustatory organ caused by local radiation exposure during radiotherapy of the head-and-neck region.
OBJECTIVE
The aim of this prospective study was to investigate how often and at which dose levels gustatory disturbances appear during radiotherapy of the tongue and to which extent permanent gustatory deficiencies occur.


METHODS
The study included 44 patients treated by definitive irradiation for malignant head-and-neck tumors. In 22 patients the posterior two thirds of the tongue (group 1), and in the other 22 patients the entire tongue (group 2) were exposed to radiation. The control group comprised 30 patients with non-small cell lung cancer receiving definitive radiation therapy (group 3). The dose distribution in the tongue area was calculated using CT-based three-dimensional planning. Before, during and after irradiation the gustatory function was determined by means of gustometry and correlated with the corresponding results of enoral inspection and the patients' subjective statements on gustatory function.


RESULTS
The gustatory ability of the control group was not affected, whereas patients in the locally irradiated groups in parallel with enoral mucositis suffered from loss of gustatory function after a total dose of 20 Gy with a maximum between 40 and 60 Gy. Supportive measures had little influence on acute side effects. The gustatory disturbances regressed within 8 weeks after radiotherapy in patients with partial-tongue irradiation and almost completely after 6 months in patients with entire-tongue irradiation.


CONCLUSIONS
The severity of gustatory disturbances and the longer recovery time in patients with entire-tongue irradiation suggest an influence of the volume exposed. Therefore, reduction of the highly exposed tongue volume by intensity-modulated radiotherapy opens up possibilities for a reduction of this undesirable side effect.
Kamprad
Friedrich
F
Department of Radiotherapy and Radiooncology, University Hospital Leipzig AöR, Germany.
Ranft
Dörthe
D
Weber
Anette
A
Hildebrandt
Guido
G
D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000532:radiotherapy; D003627:Data Interpretation, Statistical; D019583:Dose Fractionation, Radiation; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D008175:Lung Neoplasms / Q000532:radiotherapy; D008875:Middle Aged; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D020127:Recovery of Function; D012307:Risk Factors; D013649:Taste / Q000528:radiation effects; D013650:Taste Buds / Q000502:physiology / Q000528:radiation effects*; D013997:Time Factors; D014059:Tongue / Q000528:radiation effects; D014062:Tongue Neoplasms / Q000532:radiotherapy*