Accumulated dose to the rectum, measured using dose-volume histograms and dose-surface maps, is different from planned dose in all patients treated with radiotherapy for prostate cancer
Scaife, Jessica E
Thomas, Simon J
Bates, Amy M
British Journal of Radiology
British Institute of Radiology
MetadataShow full item record
Scaife, J. E., Thomas, S. J., Harrison, K., Romanchikova, M., Sutcliffe, M., Forman, J., Bates, A. M., et al. (2015). Accumulated dose to the rectum, measured using dose-volume histograms and dose-surface maps, is different from planned dose in all patients treated with radiotherapy for prostate cancer. British Journal of Radiology, 88 (20150243.)https://doi.org/10.1259/bjr.20150243
Objectives: We sought to calculate accumulated dose (DA) to the rectum in patients treated with radiotherapy for prostate cancer. We were particularly interested in whether dose-surface maps (DSMs) provide additional information to dose-volume histograms (DVHs). Methods: Manual rectal contours were obtained for kilo-voltage (kV) and daily mega-voltage (MV) CT scans for 10 participants from the VoxTox Study (380 scans). Daily delivered dose recalculation was performed using a ray-tracing algorithm. Delivered DVHs were summated to create accumulated DVHs. The rectum was considered as a cylinder, cut and unfolded to produce daily delivered DSMs; these were summated to produce accumulated DSMs. Results: Accumulated dose-volumes were different from planned in all participants. For one participant, all DA levels were higher and all volumes were larger than planned. For four participants, all DA levels were lower and all volumes were smaller than planned. For each of these four participants, ≥1% of pixels on the accumulated DSM received ≥5 Gy more than had been planned. Conclusions: Differences between accumulated and planned dose-volumes were seen in all participants. DSMs were able to identify differences between DA and planned dose that could not be appreciated from the DVHs. Further work is needed to extract the dose data embedded in the DSMs. These will be correlated with toxicity as part of the VoxTox Programme. Advances in knowledge: DSMs are able to identify differences between DA and planned dose that cannot be appreciated from DVHs alone, and should be incorporated into future studies investigating links between DA and toxicity.
JES is supported by Cancer Research UK through the Cambridge Cancer Centre. NGB is supported by the NIHR Cambridge Biomedical Research Centre. KH, MR and AMB are supported by the VoxTox Research Programme, which is funded by Cancer Research UK.
External DOI: https://doi.org/10.1259/bjr.20150243
This record's URL: https://www.repository.cam.ac.uk/handle/1810/249198
Attribution 2.0 UK: England & Wales
Licence URL: http://creativecommons.org/licenses/by/2.0/uk/
Recommended or similar items
The following licence files are associated with this item: