Cosset J M, Henry-Amar M, Girinski T, Malaise E, Dupouy N, Dutreix J
Department of Radiotherapy, Institut Gustave Roussy, Villejuif, France.
Acta Oncol. 1988;27(2):123-9. doi: 10.3109/02841868809090332.
From 1972 to 1976 patients at the Gustave Roussy Institute were irradiated for Hodgkin's disease using a modified fractionation schedule (3 fractions of 3.3 Gy per week) for operational reasons. From 1964 to 1971 and from 1977 to 1981, a more conventional regimen (4 fractions of 2.5 Gy per week) was used. The rates of the late complications in these two subsets of patients treated with different fractionation schedules at the same total dose of 40 Gy during the same overall time were compared. Mediastinitis was observed in 19% of the '4 X 2.5 Gy/week' group versus 56% in the '3 X 3.3 Gy/week' group. Pericarditis in 0% versus 9%, gastroduodenal ulceration and severe gastritis in 10 versus 21% and small bowel obstruction in 5 versus 8%. When using the linear quadratic model with an alpha/beta of 2.5 Gy to evaluate the equivalent dose of 40 Gy given in 12 fractions of 3.3 Gy when delivered by fractions of 2.5 Gy, a value of 46.6 Gy is found. This difference of 6.6 Gy in the equivalent doses (for late toxicity) is likely to account for the significant increase of late radiation injuries, such as mediastinitis and pericarditis, in the present study. The local relapse rate was found to be slightly lower in the 3 X 3.3 Gy group. However, this possible benefit cannot offset the considerable increase of late complications.
1972年至1976年期间，出于操作原因，古斯塔夫·鲁西研究所的患者针对霍奇金淋巴瘤采用了改良的分割方案（每周3次，每次3.3 Gy）进行放疗。1964年至1971年以及1977年至1981年，则采用了更为传统的方案（每周4次，每次2.5 Gy）。对在相同总时间内接受相同总剂量40 Gy、不同分割方案治疗的这两组患者的晚期并发症发生率进行了比较。“每周4×2.5 Gy”组中纵隔炎的发生率为19%，而“每周3×3.3 Gy”组为56%。心包炎发生率分别为0%和9%，胃十二指肠溃疡和重度胃炎发生率分别为10%和21%，小肠梗阻发生率分别为5%和8%。当使用α/β为2.5 Gy的线性二次模型来评估以2.5 Gy分割给予的40 Gy（12次分割）等效于以3.3 Gy分割给予时的值时，得出的值为46.6 Gy。等效剂量（针对晚期毒性）的这6.6 Gy差异可能是本研究中纵隔炎和心包炎等晚期放射损伤显著增加的原因。结果发现，“每周3×3.3 Gy”组的局部复发率略低。然而，这种可能的益处无法抵消晚期并发症的大幅增加。
