放射学：联合PET和CT扫描能够提高精确性

一项研究在21例非小细胞性肺癌患者中进行，制定了2种三维投影放射治疗计划，第一种是以CT为基础的计划，第二种是联合使用PET和CT为基础的计划。

研究人员发现：总体而言，使用PET扫描信息能够减少放射区域的大小，这意味着健康肺组织和食道暴露于放射的减少。这项研究发表在2005年3月1日的《国际肿瘤生物和生理放射学期刊》，该期刊是ASTRO（美国治疗放射学和肿瘤学学会）的官方期刊。

“这项研究突出了联合使用PET扫描资料与放射治疗计划的巨大优点，不仅减少了副作用而且增加了治疗有效比例。”Dirk de Ruysscher医生说。他也是新西兰Maastricht大学医院的放射肿瘤学家，该项研究的共同作者。

de Ruysscher还指出：“因为放射区域的减小，与单独使用CT为基础的计划相比较，理论上放射剂量可以增加而不会增加副作用的发生。这会导致控制肿瘤的机会增加。”

研究显示：两种非创伤性影像检查方法可以联合使用，因为PET扫描在预测淋巴结是否含有肿瘤细胞反面比CT扫描的准确性更高。单独使用PET扫描不能提供足够的解剖学信息来准确定义肿瘤体积。

ASTRO是世界上最大的放射肿瘤学学会，拥有超过8000名专业为放射治疗领域的会员。

Radiation: Combining PET and CT Scans Leads to More Accuracy

The study, conducted on 21 patients with non-small cell lung cancer, created two three-dimensional conformal radiation treatment plans, one with CT-based planning and the second with a combination of PET and CT-based planning.

The researchers found that, in general, the size of the radiation fields could be decreased by using PET scan information, which meant less radiation exposure of the healthy lung tissue and the esophagus.

The report was published in the March 1, 2005, issue of the International Journal of Radiation in Oncology, Biology and Physics, the official journal of ASTRO, the American Society for Therapeutic Radiology and Oncology.

"This study underlines the great potential benefit of incorporating PET scan data into radiotherapy planning, both to decrease side-effects and increase cure rates,” said Dirk de Ruysscher, M.D., Ph.D., a radiation oncologist at University Hospital Maastricht in The Netherlands and co-author of the study.

"Because of the smaller radiation fields, the radiation dose may theoretically be increased without increasing the side-effects compared to CT-based planning alone. This may lead to a higher chance of achieving tumour control,” de Ruysscher adds.

The study showed that the two non-invasive imaging methods were combined because PET scans were shown to have a higher accuracy than CT scans to predict which lymph nodes contain cancer cells and which do not. PET scans alone do not give enough anatomical information to accurately define the tumour volume.

ASTRO is the largest radiation oncology society in the world, with more than 8,000 members who specialise in treating patients with radiation therapies.