Value of rigid respiratory control in PET/CT imaging for lung cancer patients: A meta-analysis

Objectives To overcome respiratory motion artifacts in PET/CT, PET respiratory techniques have been proposed. We undertook a meta-analysis to evaluate whether rigid control of respiratory in quantitative analysis of pulmonary lesions in patients with lung cancer is beneficial.

Methods We examined 2 strategies for reducing respiration-induced pulmonary lesions motion in PET: deep inspiration breath-hold (DIBH) and respiratory gating (RG). We selected twelve studies of 623 pulmonary lesions (404 DIBH, 219 RG) to assess the effect of 2 PET respiratory techniques compared with Free Breathing (FB) technique. The maximal standardized uptake value (SUVmax) of DIBG, RG and FB technique was recorded, respectively. We calculated the SUVmax percentage difference between rigid respiratory techniques and FB technique. Statistical heterogeneity across studies was assessed with the χ2 and I2 statistics.

Results The SUVmax of the lesions using DIBH and RG techniques were significantly higher than these in FB technique (DIBH: 2.40±0.86 vs. 2.20±0.85; RG: 4.84±2.16 vs. 3.75±2.11) . There was no statistically significant difference in the average of SUVmax between DIBH and RG in all lesions. However, RG technique benefited sick or uncooperative patients in some studies because RG technique offered reduced respiratory motion with less patient effort than DIBH technique. There was heterogeneity among studies and no evidence of publication bias.

Conclusions The DIBH and RG techniques enabled more precise measurement of SUVmax which may be affected by respiratory motion. We recommend the rigid control of respiratory for quantitative analysis and PET-based radiotherapy planning of pulmonary lesions