Preoperative staging of non-small cell lung cancer: prospective comparison of PET/MR and PET/CT.

OBJECTIVES

To prospectively compare the accuracies of PET/MR and PET/CT in the preoperative staging of non-small cell lung cancer (NSCLC).

METHODS

Institutional review board approval and patients' informed consents were obtained. 45 patients with proven or radiologically suspected lung cancer which appeared to be resectable on CT were enrolled. PET/MR was performed for the preoperative staging of NSCLC followed by PET/CT without contrast enhancement on the same day. Dedicated MR images including diffusion weighted images were obtained. Readers assessed PET/MR and PET/CT with contrast-enhanced CT. Accuracies of PET/MR and PET/CT for NSCLC staging were compared.

RESULTS

Primary tumour stages (n = 40) were correctly diagnosed in 32 patients (80.0 %) on PET/MR and in 32 patients (80.0 %) on PET/CT (P = 1.0). Node stages (n = 42) were correctly determined in 24 patients (57.1 %) on PET/MR and in 22 patients (52.4 %) on PET/CT (P = 0.683). Metastatic lesions in the brain, bone, liver, and pleura were detected in 6 patients (13.3 %). PET/MR missed one patient with pleural metastasis while PET/CT missed one patient with solitary brain metastasis and two patients with pleural metastases (P = 0.480).

CONCLUSIONS

This study demonstrated that PET/MR in combination with contrast-enhanced CT was comparable to PET/CT in the preoperative staging of NSCLC while reducing radiation exposure.

KEY POINTS: • PET/MR can be comparable to PET/CT for preoperative NSCLC staging. • PET/MR and PET/CT show excellent correlation in measuring SUVmax of primary lesions. • Using PET/MR, estimated radiation dose can decrease by 31.1 % compared with PET/CT.