Development of dose verification methods for boron neutron capture therapy / 中华放射医学与防护杂志

To summarize the progress in BNCT dose verification method in the world and discusses their development prospects. Boron neutron capture therapy (BNCT) utilizes the specific capture reaction between the neutrons and boron drugs enriched in tumor cells to selectively kill tumor cells. In order to verify the accuracy of the radiotherapy plan and ensure the therapeutic effect on patients, it is necessary to measure the dose before treatment and compare the experimental radiation dose with the planned dose. The current BNCT dose measurement method mainly include point dose measurement method based on ionization chambers, thermoluminescence dosimeters and activation foils, two-dimensional dose measurement method based on films, and three-dimensional dose measurement method based on gel dosimeters.

Application of three different kinds of local boost techniques in radiotherapy for locally advanced cervical cancer / 中华放射医学与防护杂志

Objective:To investigate the dosimetry differences in the treatment of locally advanced cervical cancer with intracavitary/interstitial brachytherapy (IC/IS BT), intracavity brachytherapy combined with intensity modulated radiotherapy (ICBT+ IMRT) and simple IMRT.Methods:Totally 16 patients with local advanced cervical cancer were retrospectively selected, which were treated by three-dimensional brachytherapy. On the basis of the original three-dimensional intracavitary/interstitial brachytherapy plan, ICBT+ IMRT and IMRT plans were designed respectively to study the dosimetry differences of target and different organs at risk for the three kinds of plans.Results:A total of 75 brachytherapy treatment plans were designed, including 25 IC/IS BT, 25 ICBT+ IMRT and 25 IMRT. There was not statistically significant difference of target dose parameters between ICBT+ IMRT and IC/IS BT plan ( P>0.05). ICBT+ IMRT plans had better OAR sparing than IC/IS BT. The doses of OARs in the IMRT plans were relatively large and the volume irradiated to more than 60 Gy ( V60) was significantly higher( t=6.77, 10.37, 4.61, 2.83, P<0.05). Conclusions:The ICBT+ IMRT technique not only provides better target coverage, but also maintains low doses to the OARS, which can be used as an alternative treatment to IC/IS BT. Although the target coverage of IMRT is better, the protection of OARs is not satisfied, so it is not suitable for local boost therapy of advanced cervical cancer.