Background: Many studies have pointed out the role of 18F-FDG PET/CT in the assessment of metastatic breast cancer patients, compared to conventional imaging. Using the FDG PET metabolic parameters to measure tumor burden shows potentiality to predict their survival. Aim of work: To evaluate the role of PET/CT in assessment of metastatic breast cancer patients, monitoring the treatment response and correlating this with the molecular subtypes.
Patients and methods: A retrospective study was done at Maadi military hospital (from February 2017 to March 2021) involved fifty female patients with metastatic breast cancer (mean ±SD age 53.4±10.8), underwent FDG PET/CT before receiving treatment. PET/CT follow-up protocol was done depending on the type of treatment. Comparison between PET/CT and CT findings were carried out and metabolic PET parameters were calculated and analyzed.
Results: PET/ CT was superior to CT in detecting bone, lymph nodes, liver, and pleural metastases than did CT while CT was more sensitive for lung metastases. HR-/HRE2+ and triple-negative patients showed worse prognosis with more frequent mortality than hormonal positive patients did. Non-survivors showed statistically significantly higher mean WB-MTV and WB-TLG than survivors did (307.7±171.1 VS 97.8±57.4 and 1214.0±962.1 VS 383.0±214.4 respectively, P-Value = <0.001 each) while W-SUV max values showed no statistically significant difference between the two groups. Survival analysis revealed that WB-MTV was the only independent factor affecting mortality rate (HR (95% CI) =13.46 (1.36-132.72); P-Value = 0.026).
Conclusion: 18F-FDG PET/CT could be a non-invasive suitable imaging technique in the assessment of metastatic IDC breast cancer patients with the advantage of being a single modality. WB-MTV is suggestive to be a strong independent parameter in predicting the survival in metastatic breast cancer patients.