Tumor to liver maximum standardized uptake value ratio of FDG-PET/CT parameters predicts tumor treatment response and survival of stage III non-small cell lung cancer

The prognostic value of lymph node to primary tumor standardized uptake value ratio in cancer patients: a meta-analysis

OBJECTIVE

The lymph node to primary tumor standardized uptake value ratio (NTR) is an innovative parameter derived from positron emission tomography/computed tomography (PET/CT) scans that captures the intricate relationship between primary tumors and associated lymph nodes. This meta-analysis aimed to investigate the prognostic value of NTR in cancer patients.

METHODS

A systematic search of PubMed, Cochrane, and Embase databases was conducted to identify studies investigating the association between NTR and survival outcomes in cancer patients. The pooled adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) were calculated using a random-effects model.

RESULTS

Twelve studies comprising a total of 2037 patients were included in the meta-analysis. Elevated NTR was significantly associated with worse overall survival aHR (2.21, 95% CI 1.63 to 2.99), disease-free survival aHR (3.27, 95% CI 2.12 to 5.05), and distant metastasis-free survival aHR (2.07, 95% CI 1.55 to 2.78) in cancer patients. Subgroup analyses by cancer type showed consistent results across various malignancies, including head and neck squamous cell carcinoma, endometrial carcinoma, lung cancer, breast cancer, and nasopharyngeal carcinoma.

CONCLUSIONS

This meta-analysis provides evidence for a significant association between elevated NTR and worse survival outcomes in cancer patients. Elevated NTR may serve as a useful prognostic biomarker for cancer patients and could potentially be used to guide treatment decisions and monitor disease progression. Future studies should aim to validate these findings in larger and more diverse patient populations and investigate the underlying mechanisms for the observed association between NTR and survival outcomes.

Meta-analysis of [18F]FDG-PET/CT in pulmonary sarcoidosis

BACKGROUND

18F-Fluorodeoxyglucose (FDG) PET/CT is emerging as a tool in the diagnosis and evaluation of pulmonary sarcoidosis, however, there is limited consensus regarding its diagnostic performance and prognostic value.

METHOD

A meta-analysis was conducted with PubMed, Science Direct, MEDLINE, Scopus, and CENTRAL databases searched up to and including September 2023. 1355 studies were screened, with seventeen (n = 708 patients) suitable based on their assessment of the diagnostic performance or prognostic value of FDG-PET/CT. Study quality was assessed using the QUADAS-2 tool. Forest plots of pooled sensitivity and specificity were generated to assess diagnostic performance. Pooled changes in SUVmax were correlated with changes in pulmonary function tests (PFT).

RESULTS

FDG-PET/CT in diagnosing suspected pulmonary sarcoidosis (six studies, n = 400) had a pooled sensitivity of 0.971 (95%CI 0.909-1.000, p = < 0.001) and specificity of 0.873 (95%CI 0.845-0.920)(one study, n = 169). Eleven studies for prognostic analysis (n = 308) indicated a pooled reduction in pulmonary SUVmax of 4.538 (95%CI 5.653-3.453, p = < 0.001) post-treatment. PFTs displayed improvement post-treatment with a percentage increase in predicted forced vital capacity (FVC) and diffusion capacity of the lung for carbon monoxide (DLCO) of 7.346% (95%CI 2.257-12.436, p = 0.005) and 3.464% (95%CI -0.205-7.132, p = 0.064), respectively. Reduction in SUVmax correlated significantly with FVC (r = 0.644, p < 0.001) and DLCO (r = 0.582, p < 0.001) improvement.

CONCLUSION

In cases of suspected pulmonary sarcoidosis, FDG-PET/CT demonstrated good diagnostic performance and correlated with functional health scores. FDG-PET/CT may help to guide immunosuppression in cases of complex sarcoidosis or where treatment rationalisation is needed.

CLINICAL RELEVANCE STATEMENT

FDG-PET/CT has demonstrated a high diagnostic performance in the evaluation of suspected pulmonary sarcoidosis with radiologically assessed disease activity correlating strongly with clinically derived pulmonary function tests.

KEY POINTS

In diagnosing pulmonary sarcoidosis, FDG-PET/CT had a sensitivity and specificity of 0.971 and 0.873, respectively. Disease activity, as determined by SUVmax, reduced following treatment in all the included studies. Reduction in SUVmax correlated with an improvement in functional vital capacity, Diffusion Capacity of the Lungs for Carbon Monoxide, and subjective health scoring systems.

Potential role of pre-treatment bone marrow SUVmean to liver SUVmean ratio (BM/L) and comparison of primary tumour FDG uptake with brain FDG uptake in predicting survival in limited-stage lung cancers

INTRODUCTION

The survival rates of patients with limited-stage small-cell lung cancer are low despite curative treatment. Accordingly, we investigated the disease prognosis by comparing the pre-treatment bone marrow mean standardised uptake values (SUVmean) / liver SUVmean ratio (BM/L) and primary tumour FDG uptake and brain FDG uptake to prognosis.

MATERIALS AND METHODS

This was an observational, retrospective, single-centre study of patients with limited-stage small-cell lung cancer. Maximum standardised uptake values before treatment SUVmax, mean SUV (SUVmean), metabolic tumor volume (MTV), total lesion glycolysis (TLG), liver (KC) SUVmean, bone marrow SUVmean, BM/L ratio (grouped as BM/L <1 and BM/L<1), FDG uptake level of the primary tumour are higher than brain FDG uptake. The association of low prevalence with overall survival (OS) and progression-free survival (PFS) was evaluated.

DISCUSSION

A total of 125 patients were included in the study. The risk of death was found to be two times higher in patients with primary tumour FDG uptake higher than brain FDG uptake compared to those with less brain involvement. The risk of death in patients with BM/L>1 was found to be 1.6 times higher than in patients with BM/L<1.

CONCLUSION

Comparison of BM/L, FDG uptake of the primary tumour and brain FDG uptake as new prognostic parameters can be guiding in the classification of patients with LD-SCLC with a higher risk of death or progression and in planning new treatment strategies.