Influence of fractionation on acute and late reactions in vocal cord carcinoma.
Four schedules for the treatment of localized vocal cord carcinoma were compared, to establish a relationship between daily and total dose, and acute and late normal tissue reactions. All patients were treated 5 days per week. All of those who received 200 R daily (6,000 R in 30 treatments) developed a confluent mucositis and minimal to moderate subsequent aryepiglottic edema. Patients who received 180 R daily (6,480 R in 36 treatments) developed a patchy mucositis. Those who received 170 R daily (7,140 R or 6,400 rads in 42 treatments) developed only a brisk erythema, with decreasing incidence and severity of edema. At 160 R daily (6,880 R in 43 treatments) only a mild erythema developed, with no visible edema at any time. Local recurrence rates of about 10 percent for T1 lesions, and of about 25 per cent for T2 and T3 lesions, indicate that the decrease in reactions with longer fractionation has been achieved without loss of tumor control. Even minimal improvement in functional status following treatment for this highly curable malignancy well justifies the inconvenience of the increased number of treatments. The present formula of Ellis for normal tissue tolerance is not consistent with these findings, since the NSDs are essentially identical for all 4 schedules, while tolerance is notably improved by increasing fractionation.
D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy*; D003037:Cobalt Radioisotopes; D004307:Dose-Response Relationship, Radiation; D004890:Erythema / Q000209:etiology; D006801:Humans; D007249:Inflammation / Q000209:etiology; D007819:Laryngeal Edema / Q000209:etiology* / Q000517:prevention & control; D007822:Laryngeal Neoplasms / Q000532:radiotherapy*; D009092:Mucous Membrane / Q000528:radiation effects; D009364:Neoplasm Recurrence, Local; D011867:Radioisotope Teletherapy / Q000009:adverse effects; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy / Q000009:adverse effects*; D012008:Recurrence; D014827:Vocal Cords / Q000528:radiation effects
D003037:Cobalt Radioisotopes