Lozares-Cordero Sergio, Bermejo-Barbanoj Carlos, Badías-Herbera Alberto, Ibáñez-Carreras Reyes, Ligorred-Padilla Luis, Ponce-Ortega José Miguel, González-Pérez Víctor, Gandía-Martínez Almudena, Font-Gómez José Antonio, Blas-Borroy Olga, González-Ibáñez David
Physics and Radiation Protection Department, Miguel Servet University Hospital, Zaragoza, Spain.
Aragon Institute of Engineering Research, University of Zaragoza, Spain.
Phys Med. 2023 Aug;112:102622. doi: 10.1016/j.ejmp.2023.102622. Epub 2023 Jun 16.
This study presents a treatment planning system for intraoperative low-energy photon radiotherapy based on photogrammetry from real images of the surgical site taken in the operating room.
The study population comprised 15 patients with soft-tissue sarcoma. The system obtains the images of the area to be irradiated with a smartphone or tablet, so that the absorbed doses in the tissue can be calculated from the reconstruction without the need for computed tomography. The system was commissioned using 3D printing of the reconstructions of the tumor beds. The absorbed doses at various points were verified using radiochromic films that were suitably calibrated for the corresponding energy and beam quality.
The average reconstruction time of the 3D model from the video sequence in the 15 patients was 229,6±7,0 s. The entire procedure, including video capture, reconstruction, planning, and dose calculation was 520,6±39,9 s. Absorbed doses were measured on the 3D printed model with radiochromic film, the differences between these measurements and those calculated by the treatment planning system were 1.4% at the applicator surface, 2.6% at 1 cm, 3.9% at 2 cm and 6.2% at 3 cm.
The study shows a photogrammetry-based low-energy photon IORT planning system, capable of obtaining real-time images inside the operating room, immediately after removal of the tumor and immediately before irradiation. The system was commissioned with radiochromic films measurements in 3D-printed model.
本研究提出了一种基于摄影测量法的术中低能光子放射治疗计划系统，该系统利用在手术室拍摄的手术部位真实图像。
研究对象为15例软组织肉瘤患者。该系统通过智能手机或平板电脑获取待照射区域的图像，从而无需计算机断层扫描即可根据重建结果计算组织中的吸收剂量。该系统通过对肿瘤床重建模型进行3D打印来进行调试。使用针对相应能量和射束质量进行适当校准的放射变色胶片验证不同点的吸收剂量。
15例患者从视频序列重建3D模型的平均时间为229.6±7.0秒。包括视频采集、重建、计划制定和剂量计算在内的整个过程为520.6±39.9秒。在3D打印模型上用放射变色胶片测量吸收剂量，这些测量值与治疗计划系统计算值之间的差异在施源器表面为1.4%，在1厘米处为2.6%，在2厘米处为3.9%，在3厘米处为6.2%。
本研究展示了一种基于摄影测量法的低能光子术中放射治疗计划系统，该系统能够在切除肿瘤后、照射前立即在手术室内获取实时图像。该系统通过在3D打印模型中使用放射变色胶片测量进行调试。
