Stage Information for NSCLC
The results from the systematic review are similar to those of a large meta-analysis that reported the median sensitivity and specificity of CT scanning for identifying malignant mediastinal nodes as 61% and 79%, respectively.
An earlier meta-analysis reported average sensitivity and specificity of 64% and 74%, respectively.
The wider availability and use of FDG-PET scanning for staging has modified the approach to staging mediastinal lymph nodes and distant metastases.
Randomized trials evaluating the utility of FDG-PET scanning in potentially resectable NSCLC report conflicting results in terms of the relative reduction in the number of noncurative thoracotomies.
Although the current evidence is conflicting, FDG-PET scanning may improve results of early-stage lung cancer by identifying patients who have evidence of metastatic disease that is beyond the scope of surgical resection and that is not evident by standard preoperative staging procedures.
- A systematic review, an expansion of a health technology assessment conducted in 2001 by the Institute for Clinical and Evaluative Sciences, evaluated the accuracy and utility of FDG-PET scanning in the diagnosis and staging of lung cancer. Through a systematic search of the literature, 12 evidence summary reports and 15 prospective studies of the diagnostic accuracy of FDG-PET scanning were identified. FDG-PET scanning appears to be superior to CT imaging for mediastinal staging in NSCLC. FDG-PET scanning also appears to have high sensitivity and reasonable specificity for differentiating benign from malignant lesions as small as 1 cm.
- A systematic review of the medical literature relating to the accuracy of FDG-PET scanning for noninvasive staging of the mediastinum in patients with lung cancer identified 44 studies published between 1994 and 2006 with 2,865 evaluable patients. The median prevalence of mediastinal metastases was 29% (range, 5%-64%). Pooled estimates of sensitivity and specificity for identifying mediastinal metastasis were 74% (95% CI, 69%-79%) and 85% (95% CI, 82%-88%), respectively. Corresponding positive and negative likelihood ratios for mediastinal staging with FDG-PET scanning were 4.9 and 0.3, respectively. These findings demonstrate that FDG-PET scanning is more accurate than CT scanning for staging of the mediastinum in patients with lung cancer.
Cost effectiveness of FDG-PET scanning
Decision analyses demonstrate that FDG-PET scanning may reduce the overall costs of medical care by identifying patients with falsely negative CT scans in the mediastinum or otherwise undetected sites of metastases.[9,10,11] Studies concluded that the money saved by forgoing mediastinoscopy in FDG-PET-positive mediastinal lesions was not justified because of the unacceptably high number of false-positive results.[9,10,11] A randomized study found that the addition of FDG-PET scanning to conventional staging was associated with significantly fewer thoracotomies. A second randomized trial evaluating the impact of FDG-PET scanning on clinical management found that FDG-PET scanning provided additional information regarding appropriate stage but did not lead to significantly fewer thoracotomies.