Background: Non small cell lung cancers (NSCLC) mainly provide osteolytic bone metastases which present a high risk of complications such as severe bone pain, fractures and medullary compression leading to deep functional impairment. Thus, an exhaustive detection of bone metastases is warranted to prevent skeletal complications. Current guidelines of the French Cancer Agency (INCa) do not recommend FDG-PET/CT performance in advanced lung cancers at diagnosis but there are no data comparing bone scintigraphy and FDG-PET/CT to detect bone metastases.
Methods: POUMOS is a non-intervention prospective cohort of patients suffering from adenocarcinoma lung cancers with a first bone metastatic lesion (stage IV). The cohort has been approved by local ethic comity. We included patients from the cohort who had both at diagnosis bone scintigraphy and FDG-PET/CT. We compared the number of bone metastases identified by both methods and also analysed long bone localisations (femur, humerus and tibia).
Results: Among the 63 patients of the cohort, 39 were included in this analysis. Nearly half of them suffered from bone pain and 13% experimented pathological fractures. Spine was involved in 85% of patients and 38% had lower limbs localisation. We observed a significant correlation between bone scintigraphy and FDG-PET/CT for the total number of metastases (r=0.73; p<0.001) and the number of spine metastases (r=0.63; p<0.001). FDG-PET/CT identified significantly more lesions than bone scintigraphy for both spine metastases and total number of metastases (p<0.001). In addition, FDG-PET/CT identified significantly more long bone lesions than bone scintigraphy (34 vs 24; p<0.001) corresponding to 14 lesions ignored by bone scintigraphy.
Conclusion: FDG-PET/CT performed in patients with newly diagnosed lung cancer is more powerful to identify bone metastases than bone scintigraphy. Furthermore FDG-PET/CT identified more bone localisations with a high risk of fracture that could benefit from a specific preventive strategy.
Disclosure: The authors declared no competing interests. Young Investigator Award of the Hospices Civils de Lyon (to CC) and grants from the Groupement Interrégional à la Recherche Clinique et à lInnovation (GIRCI) Rhône-Alpes Auvergne (to NG) and from the Société Française de Pathologie (to MB).