Radiation treatment planning

[1] By the 1990s CT scans, more powerful computers, improved dose calculation algorithms and Multileaf collimators (MLCs) lead to 3D conformal planning (3DCRT), categorised as a Level 2 technique by the European Dynarad consortium.

[4] Level 3 techniques such as IMRT and VMAT utilise inverse planning to provide further improved dose distributions (i.e. better coverage of target tumours and sparing of healthy tissue).

Positron emission tomography is less commonly used and reserved for cases where specific uptake studies can enhance planning target volume delineation.

[12][13] Plans are often assessed with the aid of dose-volume histograms, allowing the clinician to evaluate the uniformity of the dose to the diseased tissue (tumor) and sparing of healthy structures.

Different dose calculation models are available, including pencil beam, convolution-superposition and monte carlo simulation, with precision versus computation time being the relevant trade-off.