18F-FDG PET/CT anatomic and metabolic guidance in CT-guided lung biopsies

Abstract

Purpose: To evaluate the role of Fluorine-18 fluorodeoxyglucose (18F-FDG) PET/CT as a metabolic guide in increasing the accuracy, diagnostic yield and safety of CT-guided percutaneous needle lung biopsy (PNB).

Methods and materials: Retrospective analysis of 340 consecutive patients with suspicious lung nodules, masses or extensive disease that underwent lung biopsy over a 3-year period. Patients were divided into three groups; those that had PET/CT prior to the biopsy, those that had PET-CT following the biopsy and those who did not undergo PET-CT. Correlation was made with the histopathological result.

Results: 353 PNBs were performed (median lesion size 30 mm, 7-120 mm) with overall diagnostic rate of 83.9 % (95.8 % malignant). Biopsy success rate was 88.8 % with PET-CT pre-PNB, versus 78.9 % of 175 PNB without PET-CT upfront (p < 0.01 Fisher exact test). Correct targeting to PET-CT-maximum activity area (MAA) was present in 87.1 %. Biopsy success rate was 88.8 % for PNBs targeting the PET-CT-MAA region and only 52.8 % for PNBs not targeting the PET-CT-MAA (p < 0.0001). PET-CT pre-PNB had higher rates of PET-CT-MAA targeting compared to PET-CT post PNB (91.0 % v 80.0 %, p = 0.01). The availability of PET-CT before the PNB lead to significantly increased biopsy success rates in patients with a mass (OR:7.01p = 0.004), compared to a nodule (p = 0.498) or multiple nodules (p = 0.163). Patients with a PET-CT pre-PNB underwent fewer PNB passes (mean 2.6 v 3.1, p < 0.0001 Mann Whitney U). Serious complications were less common in PET-CT pre-PNB group (4.5 % v 10.9 %, p < 0.05). Pre-PNB PET-CT performance improvement applied to all 3 radiologists and was greatest for masses and infiltrative abnormalities.

Conclusion: Metabolic information provided by 18F-FDG PET/CT and PNB localisation to the PET-CT maximum activity region is associated with higher diagnostic biopsy rates especially in masses and appears to account for improved performance, less needle passes and complications when available pre-biopsy.

Keywords: Lung biopsy; Metabolic guide; PET-CT.