Botchu Rajesh, Retnasingam Ganesh, Raj Vimal, Husainy Mohammad Ali, Jakanani George, Rao Balaji, Entwisle James
Department of Radiology, GlenfIeId Hospitals, Glenfield, Leicester, UK.
World J Oncol. 2012 Apr;3(2):54-58. doi: 10.4021/wjon492w. Epub 2012 Apr 23.
Lung cancer is the most common cancer in the world. Staging of lung cancer involves CT of chest and abdomen. Subsequently these are discussed in MDT and if required PET imaging is arranged. We have performed a study to assess double reporting of the initial staging CT would identify in field metastasis and hence decrease the use of PET.
A refined search from the lung cancer database over 2 years of 980 patients was performed. Metastasis identified on PET (SUV > 2.5) was nominated as the gold standard, 219 patients had both PET and staging CT (chest and abdomen) with 38 patients having metastasis on both PET and CT. CT images were reviewed by two independent radiologist who were blinded to the report. Identified metastases were graded if identified. These were grade as 1- definite, 2- equivocal, 3- normal. Subsequently through a process of arbitration a combined decision about the in field metastasis was achieved.
There were 21 metastasis which were within the field of chest and abdomen (in field metastasis). Only a half of these were identified by blinded observers. Following an arbitration there was no significant improvement in the pick up rate. There were 19 out of field metastasis in 15 patients out of this cohort. Majority of these (72%) were in the bony pelvis which would have been reported if a CT pelvis was performed as a part of staging. We estimate that one would have to perform 10 CT pelvises to save one PET-CT.
Double reading of staging scan would not identify all infield metastasis. The increased contrast in PET images makes it easy to spot metastases. Hence there is no role for double reporting of staging CT in lung cancer management. Inclusion of pelvis in staging of lung cancer may be effective and would improve the detection of out of field metastases hence decreasing the use of PET.
肺癌是全球最常见的癌症。肺癌分期包括胸部和腹部CT检查。随后在多学科团队（MDT）中进行讨论，如有需要则安排PET成像。我们开展了一项研究，以评估对初始分期CT进行双重报告是否能发现区域内转移，从而减少PET的使用。
对肺癌数据库中980例患者进行了为期2年的精确检索。将PET检查中确定的转移（SUV>2.5）作为金标准，219例患者同时进行了PET和分期CT（胸部和腹部）检查，其中38例患者PET和CT检查均发现转移。CT图像由两名独立的放射科医生进行阅片，他们对报告内容不知情。对发现的转移灶进行分级（若有发现）。分级为1级-明确，2级-可疑，3级-正常。随后通过仲裁过程达成关于区域内转移的综合决定。
在胸部和腹部区域内有21处转移（区域内转移）。其中只有一半被不知情的观察者发现。经过仲裁后，检出率没有显著提高。该队列中有15例患者存在19处区域外转移。其中大多数（72%）位于骨盆，如果在分期时进行CT骨盆检查，这些转移本应被报告。我们估计，要节省一次PET-CT检查，需要进行10次CT骨盆检查。
对分期扫描进行双重阅片不能发现所有区域内转移。PET图像中对比度增加使得转移灶易于发现。因此，在肺癌管理中对分期CT进行双重报告没有作用。在肺癌分期中纳入骨盆检查可能有效，并且会提高区域外转移的检出率，从而减少PET的使用。
