前立腺癌に対する三次元原体照射(3D-CRT)の経験

Abstract

1999年10月～2005年4月に照射線量を70Gyから2Gyずつ74Gyまで段階的に増加させながら三次元原体照射(3D-CRT)を行った局所前立腺癌53例(平均年齢70.6歳)を対象に, 70～72Gy照射群(33例, 年齢58～80)と74Gy照射群(20例, 年齢62～76歳)に分けて急性期副作用の検討を行った。74Gy群は経過観察期間が不十分なため晩期副作用と短期治療成績は70～72Gy群のみで行った。70～72Gy群にはhigh risk groupに属する患者が有意に多く, 74Gy群にはgrade1の高分化腺癌が有意に多かった。急性期副作用においては両群ともgrade3以上の重篤な副作用は認められず, G1, 2の比較的軽度な副作用発生率において有意差はなく, 全例目標線量を照射可能であった。晩期副作用では70Gy群にgrade3の直腸出血を認めたのみで, 短期治療成績に関して1年生化学的非再発率は88.1%, 2年生では75%であった。

We retrospectively evaluated acute and late radiation morbidity and short-term PSA relapse-free survival of 53 patients with localized prostate cancer who received three dimensional radiation therapy (3D-CRT) that targeted prostate and seminal vesicles in Hamamatsu Medical Center from 1999.10 to 2005.4. The total dose was increased from 70 to 74 Gy in increments of 2.0 Gy. We divided these patients into two groups who received 70-72 Gy or 74 Gy. Then we analyzed whether there were differences between those two groups in acute radiation morbidity. We also analyzed late radiation morbidity in the 70(-)-72 Gy group. Acute radiation morbidity and late morbidity were described according to the RTOG acute radiation morbidity scoring criteria 1995 and RTOG/EORTC late radiation morbidity scoring scheme 1995, respectively. No acute grade 3 or 4 toxicity and no late grade 4 toxicity was observed. Late grade 3 rectal bleeding was observed in only one patient who received 70 Gy. Acute toxicity was well tolerated and did not correlate with total dose.