在电子术中放疗加速部分乳腺照射期间，使用金属氧化物半导体场效应晶体管（MOSFET）和放射变色薄膜进行体内剂量测定。

In vivo dosimetry with MOSFETs and GAFCHROMIC films during electron IORT for Accelerated Partial Breast Irradiation.

作者信息

Petoukhova Anna, Rüssel Iris, Nijst-Brouwers Julienne, van Wingerden Ko, van Egmond Jaap, Jacobs Daphne, Marinelli Andreas, van der Sijp Joost, Koper Peter, Struikmans Henk

机构信息

Haaglanden Medical Center, Department of Medical Physics, Leidschendam, The Netherlands.

出版信息

Phys Med. 2017 Dec;44:26-33. doi: 10.1016/j.ejmp.2017.11.004. Epub 2017 Nov 21.

DOI:10.1016/j.ejmp.2017.11.004

PMID:29254588

Abstract

PURPOSE

The purpose of this study was to compare the delivered dose to the expected intraoperative radiation therapy (IORT) dose with in vivo dosimetry. For IORT using electrons in accelerated partial breast irradiation, this is especially relevant since a high dose is delivered in a single fraction.

METHODS

For 47 of breast cancer patients, in vivo dosimetry was performed with MOSFETs and/or GAFCHROMIC EBT2 films. A total dose of 23.33 Gy at d was given directly after completing the lumpectomy procedure with electron beams generated with an IORT dedicated mobile accelerator. A protection disk was used to shield the thoracic wall.

RESULTS

The results of in vivo MOSFET dosimetry for 27 patients and GAFROMIC film dosimetry for 20 patients were analysed. The entry dose for the breast tissue, measured with MOSFETs, (mean value 22.3 Gy, SD 3.4%) agreed within 1.7% with the expected dose (mean value 21.9 Gy). The dose in breast tissue, measured with GAFCHROMIC films (mean value 23.50 Gy) was on average within 0.7% (SD = 3.7%, range -5.5% to 5.6%) of the prescribed dose of 23.33 Gy.

CONCLUSIONS

The dose measured with MOSFETs and GAFROMIC EBT2 films agreed well with the expected dose. For both methods, the dose to the thoracic wall, lungs and heart for left sided patents was lower than 2.5 Gy even when 12 MeV was applied. The positioning time of GAFCHROMIC films is negligible and based on our results we recommend its use as a standard tool for patient quality assurance during breast cancer IORT.

摘要

目的

本研究的目的是通过体内剂量测定法比较实际给予的剂量与预期的术中放射治疗（IORT）剂量。对于在加速局部乳腺照射中使用电子的IORT而言，这一点尤为重要，因为单次分割就会给予高剂量。

方法

对47例乳腺癌患者使用金属氧化物半导体场效应晶体管（MOSFET）和/或放射变色EBT2薄膜进行体内剂量测定。在使用IORT专用移动加速器产生的电子束完成肿块切除术后，直接给予d点23.33 Gy的总剂量。使用保护盘屏蔽胸壁。

结果

分析了27例患者的体内MOSFET剂量测定结果和20例患者的放射变色薄膜剂量测定结果。用MOSFET测量的乳腺组织入射剂量（平均值22.3 Gy，标准差3.4%）与预期剂量（平均值21.9 Gy）的偏差在1.7%以内。用放射变色薄膜测量的乳腺组织剂量（平均值23.50 Gy）平均在规定剂量23.33 Gy的0.7%以内（标准差=3.7%，范围-5.5%至5.6%）。