Effect of CT-based treatment planning on portal field size and outcome in radiation treatment of localized prostate cancer

The portal field sizes of 361 consecutive patients treated with curative radiotherapy for localized prostate cancer were measured. The introduction of CT-based information resulted in a significant increase of field sizes, leading to an almost doubling of the treated volume, some increase in late rectal toxicity, but also in local control. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.