Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology
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Randomized Controlled Trial
A randomized comparison of interfraction and intrafraction prostate motion with and without abdominal compression.
To quantify inter- and intrafraction prostate motion in a standard VacLok (VL) immobilization device or in the BodyFix (BF) system incorporating a compression element which may reduce abdominal movement. ⋯ Intrafraction motion became the major source of error during radiotherapy after online correction of interfraction prostate motion. The addition of 120 mbar abdominal compression to custom pelvic immobilization influenced neither interfraction nor intrafraction prostate motion.
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To compare the dose coverage of planning and clinical target volume (PTV, CTV), and organs-at-risk (OAR) between intensity-modulated (3D-IMRT) and conventional conformal radiotherapy (3D-CRT) before and after internal organ variation in prostate cancer. ⋯ Dose coverage of the PTV and OAR was better with 3D-IMRT for each patient and remained so after internal volume changes.
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Randomized Controlled Trial Comparative Study
Dosimetric effects of the prone and supine positions on image guided localized prostate cancer radiotherapy.
To compare target coverage and doses to rectum and bladder in IMRT of localized prostate cancer in the supine versus prone position, with the inclusion of image guidance. ⋯ Soft-tissue alignment combined with 5mm planning margins is appropriate in minimizing treatment planning and delivery uncertainties in both the supine and prone positions. Alignment based on bony structures showed improved results over the use of skin marks for both supine and prone setups. Under bony alignment, the dose coverage and PTV overlap index for prone setup were statistically better than for supine setup, illustrating a more consistent geometric relationship between the prostate and the pelvic bony structures when patients were treated in the prone position.
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Comparative Study
MRI-based preplanning in low-dose-rate prostate brachytherapy.
To compare the dosimetric results between MRI-based and TRUS-based preplanning in permanent prostate brachytherapy, and to estimate the accuracy of MRI-based preplanning by comparing with CT/MRI fusion-based postimplant dosimetry. ⋯ Prostate volume estimation and DVH-related parameters in MRI-based preplanning were almost identical to TRUS-based preplanning. From the results of CT/MRI fusion-based postimplant dosimetry, MRI-based preplanning was therefore found to be a reliable and useful modality, as well as being helpful for TRUS-based preplanning. MRI-based preplanning can more accurately predict postimplant rectal dose than TRUS-based preplanning.
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To report on the incidence of benign prostate-specific antigen bounce following permanent I(125) prostate brachytherapy, to describe the associations in our population and review the relationship of bounce to subsequent biochemical failure. ⋯ PSA bounce is a common finding in our population and is associated with a lower rate of subsequent biochemical failure. The noted differences in PSA velocity will require verification in a future analysis to reduce the influence of median follow-up on this finding. Patients should be advised of the potential of bounce in PSA follow-up after permanent I(125) prostate brachytherapy and physicians involved in follow-up of prostate brachytherapy patients should be aware of this phenomenon, allowing them to commit to appropriate PSA surveillance, avoiding the premature and inappropriate initiation of salvage therapy during PSA bounce.