IMRT Course 2016

…this was all portal-image based visualization of implanted fiducial markers.

Improvements by daily

Cone-Beam-CT

-based setup?

CONCLUSIONS:

For protocols with CBCT guidance, RL, AP, and SI margins of 2, 4, and 3 mm

Zero Margins in daily online ART/IGRT?

Intrafraction motion: prostate

J. Adamson et al. 2011: Dosimetric effect of intrafraction motion and residual setup error

for hypofractionated prostate intensity-modulated radiotherapy with online cone beam

computed tomography image guidance. IJROBP 80(2)

ESTRO IMRT course 2016

Adaptive Radiotherapy

London April 7th, 2016

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are sufficient to account for translational errors; however, the large variation in

patient-specific margins suggests that adaptive management may be

beneficial.

Note: This is not resulting from geometric considerations (CTV appropriately

covered by PTV), but from dosimetric considerations: coverage by 95% isodose

line.

→

Influence of planning strategy and TPS!