Image-guided IMRT for localized prostate cancer with daily repositioning: Inferring the difference between planned dose and delivered dose distribution

Ultrasound versus Cone-beam CT image-guided radiotherapy for prostate and post-prostatectomy pretreatment localization

“…Hence, patient movements between acquisitions are likely to explain, in part, the observed differences between the 2 modalities. Daily patient repositioning is required to ensure a uniform and homogeneous dose distribution to the target volume [28], but CBCT modality implies additional dose to the patient (about 30 mGy per CBCT) and longer treatment sessions. Therefore, a method for correcting these systematic shifts was proposed in order to replace CBCT by TA-US after a few sessions.…”

Rotation effects on the target-volume margin determination

“…In practice, most setup adjustments are applied to only translational shifts and rotational positioning errors are routinely disregarded throughout the patient's treatment. It is known that clinical target volume (CTV) to planning target volume (PTV) margin is determined by setup errors and possible motion during the treatment [4][5][6][7][8][9][10]. The margin should account for both translation and rotation setup uncertainties.…”