What benefit could be derived from on-line adaptive prostate radiotherapy using rectal diameter as a predictor of motion?

Richard Oates, Suki Gill, Farshad Foroudi, Michael Lim Joon, Michal E Schneider, Mathias Bressel, Tomas Kron

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6 Citations (Scopus)


This study investigated a relationship between rectum diameter and prostate motion during treatment with a view to reducing planning target volume (PTV) margins for an adaptive protocol. One hundred and ninety-four cone-beam computed tomography (CBCT) images of 10 patients were used to relate rectum diameter on CBCT to prostate intrafraction displacement. A threshold rectum diameter was used to model the impact of an adaptive PTV margin on rectum and bladder dose. Potential dose escalation with a 6 mm uniform margin adaptive protocol was compared to a PTV margin of 10 mm expansion of the clinical target volume (CTV) except 6 mm posterior. Of 194 fractions, 104 had a maximum rectal diameter of
Original languageEnglish
Pages (from-to)18 - 23
Number of pages6
JournalJournal of Medical Physics
Issue number1
Publication statusPublished - 2015

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