Radiation therapy for early glottic carcinoma (T1N0M0). The final results of prospective randomized study concerning radiation field.
OBJECTIVE
To investigate the effect of radiation field on the local control of early glottic carcinoma by prospective randomized study.


METHODS
From May 1982 through February 1992, a total of 273 patients with early glottic carcinoma (T1N0M0) was treated at our department with a wedge filter technique using a shell to improve the dose distribution and immobilization during radiotherapy with 4 MV X-ray. Patients were randomly allocated to either treatment group A (radiation field size: 5 x 5 cm) or B (6 x 6 cm) using bilateral parallel opposed portals. Total radiation dose administered was 60 Gy in 30 fractions over a 6-week period.


RESULTS
The 5-year recurrence-free survival rates were 88% in groups A and B (no significant difference). Minor chronic complication such as persistent arytenoid edema lasting more than 6 months or benign polypoid lesion of vocal cord was more frequently observed in group B (23%) than in group A (17%) (p = 0.038) while acute mucosal reaction and skin reaction showed no significant differences.


CONCLUSIONS
A small field (5 x 5 cm) with an appropriate angle of wedge filter and shell fixing device is recommended to avoid adverse effect with keeping local control of early glottic carcinoma.
Chatani
M
M
Department of Radiation Therapy, Center for Adult Diseases, Osaka.
Matayoski
Y
Y
Masaki
N
N
Teshima
T
T
Inoue
T o
To
D000206:Actuarial Analysis; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D002423:Cause of Death; D016009:Chi-Square Distribution; D018572:Disease-Free Survival; D005260:Female; D005931:Glottis; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007822:Laryngeal Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D013997:Time Factors