Localization

For individual TBI treatment planning, information about the relevant physical and topographical parameters of a patient's anatomy are needed under treatment conditions.

In order to plan a TBI treatment, the organs at risk, the specification point and other representative points for parts of the body must be located. At these points, the width and thickness contours are essential for calculating the dose delivered.

Tissue inhomogeneities affect dose distribution through the body. A better accuracy is achieved if position, density and shape of these tissues are taken into account.

Physical treatment planning

Algorithms.

Some centres have developed their own algorithms to calculate the dose. They are normally based on a series of empirical data collected from the radiation unit. In certain more specialized centres the Monte Carlo method of simulation is used.

Planning of dose distribution.

Dose planning systems should calculate the dose at the reference points. With these calculations, distributions of dose along and across the body could be achieved. Alternatively, look-up tables can be used.

It would be very valuable to know the dose along the midline of the following areas: head, neck, mediastinum, upper and lower lung, abdomen, pelvis, genital organs, thigh, knee and ankle. The maximum and minimum dose on the transverse planes defined by those points would be of great value.

The planning system should give the dose delivered to the lung. This dose will be considered at a point representative of the lung, as defined above.