The benchmark test for IMRT

Credentialing of institutions for IMRT in clinical trials.

                                                           Int J Radiat Oncol Biol Phys. 2004 Jul 15;59(4):1257-9.

The primary OAR is a central cylinder 2 cm in diameter, that extends at least 5 cm caudad/cephalad. The PTV to be treated is a half annulus 2.5 cm wide that has the same center as the OAR and surrounds the cylinder by 180°. It too shall extend at least 5 cm caudad/cephalad. There shall be a 3-mm separation of the PTV and OAR. Thus the annulus has an inner radius of 1.3 cm and an outer radius of 3.8 cm. For °»step and shoot°… and °»sliding window°… techniques, the treatment plan shall consist of beams from at least four and not more than nine gantry angles. Tomotherapy are treatments shall be delivered in the usual way. All beams shall be coplanar in the plane of the axial slices.

The aim of the plan is to deliver the prescribed dose of 200 cGy per fraction to the PTV while limiting the dose to the OAR to 60% of the prescribed dose. Specifically, at least 95% of the PTV should receive 95% of the prescribed dose. No more than 5% of the OAR may receive greater than 120 cGy (60% of the prescribed dose). The constraint on the OAR has priority over the target volume coverage. That is, the constraint of no more than 60% of the prescribed dose to 95% of the OAR shall be achieved.


A prototype for benchmark test with CFIMRT




5% of OAR receives °ś60% prescribed dose

95% PTV receives °ś95% prescribed dose

6% PTV receives >120% prescribed dose

maximum dose occurs in PTV.

This plan consists of conventional radiation fields ( No subsegments! ). This thing is a very big merit.

Another plan

5 ports plan with wedge filter


 My friend made bellow plan. Of course, by conventional fields!

  last modification date: 2006/04/05