Acute toxicity of curative radiotherapy for intermediate- and high-risk localised prostate cancer in the EORTC trial 22991

Introduction: This trial randomly assessed short-term adjuvant hormonal therapy added to radiotherapy (RT) for intermediate- and high-risk (UICC 1997 cT2a or cT1b-c with high PSA or Gleason score) localised prostate cancer. We report acute toxicity (CTCAE v2) assessed weekly during RT in relation to radiation parameters. Patients and methods: Centres selected the RT dose (70, 74 or 78 Gy) and RT technique. Statistical significance is at 0.05. Results: Of 791 patients, 652 received 3D-CRT (70 Gy: 195, 74 Gy: 376, 78 Gy: 81) and 139 received IMRT (74 Gy: 28, 78 Gy: 111). During RT, grade 3 gastrointestinal (GI) and genitourinary (GU) toxicities were reported by7 (0.8%) and 50 (6.3%) patients, respectively. No grade 4 was reported. The risk of grade ≥2 GI toxicity increased significantly with increasing D50%-rectum (p = 0.004) and that of grade ≥2 GU toxicity correlated only to Dmax-bladder (p = 0.051). 3D-RT technique, increasing total dose and V95% >400 cc increased D50% and Dmax. One month after RT, only 14 patients (1.8%) reported grade 3 toxicity. AST did not seem to influence the risk of GU or GI acute toxicity. Conclusion: RT up to 78 Gy was well tolerated. Dmax-bladder and D50%-rectum influenced the risk of grade ≥2 GU toxicity and GI toxicity, respectively. Both were lower with IMRT but remained high for an irradiated RT volume > 400 cc for 3D-RT and for a dose of 78 Gy. Hormonal treatment did not influence acute toxicity. © 2009 Elsevier Ltd. All rights reserved.