4.7 Article

ADAPTIVE-PREDICTIVE ORGAN LOCALIZATION USING CONE-BEAM COMPUTED TOMOGRAPHY FOR IMPROVED ACCURACY IN EXTERNAL BEAM RADIOTHERAPY FOR BLADDER CANCER

Journal

Publisher

ELSEVIER SCIENCE INC
DOI: 10.1016/j.ijrobp.2009.12.003

Keywords

Bladder cancer; Radiotherapy; Adaptive radiotherapy; Cone-beam computed tomography; Image-guided radiotherapy

Funding

  1. NHS
  2. Institute of Cancer Research
  3. Bob Champion Cancer Trust
  4. Cancer Research UK Section of Radiotherapy (CUK) [C46/A2131]
  5. RMH/ICR
  6. Cancer Research UK [10588] Funding Source: researchfish

Ask authors/readers for more resources

Purpose: To examine patterns of bladder wall motion during high-dose hypofractionated bladder radiotherapy and to validate a novel adaptive planning method, A-POLO, to prevent subsequent geographic miss. Methods and Materials: Patterns of individual bladder filling were obtained with repeat computed tomography planning scans at 0, 15, and 30 minutes after voiding. A series of patient-specific plans corresponding to these time-displacement points was created. Pretreatment cone-beam computed tomography was performed before each fraction and assessed retrospectively for adaptive intervention. In fractions that would have required intervention, the most appropriate plan was chosen from the patient's library, and the resulting target coverage was reassessed with repeat cone-beam computed tomography. Results: A large variation in patterns of bladder filling and interfraction displacement was seen. During radiotherapy, predominant translations occurred cranially (maximum 2.5 cm) and anteriorly (maximum 1.75 cm). No apparent explanation was found for this variation using pretreatment patient factors. A need for adaptive planning was demonstrated by 51% of fractions, and 73% of fractions would have been delivered correctly using A-POLO. The adaptive strategy improved target coverage and was able to account for intrafraction motion also. Conclusions: Bladder volume variation will result in geographic miss in a high proportion of delivered bladder radiotherapy treatments. The A-POLO strategy can be used to correct for this and can be implemented from the first fraction of radiotherapy; thus, it is particularly suited to hypofractionated bladder radiotherapy regimens. (C) 2011 Elsevier Inc.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.7
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available