一項研究在21例非小細胞性肺癌患者中進行，制定了2種三維投影放射治療計劃，第一種是以CT為基礎的計劃，第二種是聯合使用PET和CT為基礎的計劃。

研究人員發現：總體而言，使用PET掃描信息能夠減少放射區域的大小，這意味著健康肺組織和食道暴露于放射的減少。這項研究發表在2005年3月1日的《國際腫瘤生物和生理放射學期刊》，該期刊是ASTRO（美國治療放射學和腫瘤學學會）的官方期刊。

“這項研究突出了聯合使用PET掃描資料與放射治療計劃的巨大優點，不僅減少了副作用而且增加了治療有效比例。”Dirk de Ruysscher醫生說。他也是新西蘭Maastricht大學醫院的放射腫瘤學家，該項研究的共同作者。

de Ruysscher還指出：“因為放射區域的減小，與單獨使用CT為基礎的計劃相比較，理論上放射劑量可以增加而不會增加副作用的發生。這會導致控制腫瘤的機會增加。”

研究顯示：兩種非創傷性影像檢查方法可以聯合使用，因為PET掃描在預測淋巴結是否含有腫瘤細胞反面比CT掃描的準確性更高。單獨使用PET掃描不能提供足夠的解剖學信息來準確定義腫瘤體積。

ASTRO是世界上最大的放射腫瘤學學會，擁有超過8000名專業為放射治療領域的會員。

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.