PURPOSE: : In various types of non–small cell lung cancer (NSCLC) there are possibilities of metabolic differences. To our knowledge Standardized Uptake Values (SUVs) in different subtypes of NSCLC have not been studied in detail. The objective of this study is to investigate the metabolic differences in various histological types of stage I NSCLC and their potential implications on treatment (Tx) and prognosis.
METHODS: This is study was performed at William Beaumont Hospital, Royal Oak, MI. Initial staging 18F-FDG (Fluoro Deoxy Glucose) PET (Positron Emission Tomography) scans of 40 patients (age=73±8; M: F=24:16) with histopathological diagnosis of NSCLC receiving definitive treatment (surgery: 33; chemo radiation: 7) and follow-up (mean: 137 months) were analyzed. PET scans were obtained 1.5 hour after injection of 15 mCi F-18 FDG. The blood glucose level was monitored before injection. The maximal SUVs (tumor activity/dose per lean body mass) were measured over the primary tumor along with tumor size.
RESULTS: There were 24, 13 and 3 patients diagnosed with adenocarcinoma (ACa), squamous cell carcinoma (SCC) and poorly differentiated carcinoma, respectively, with mean CT sizes of (2.8±1.5) × (3.0±1.2) cm and pathological size of 3.4±1.3 cm in surgical cases. The SUV of ACa was significantly lower than that of SCC (8.7±6.7 vs. 15.1±6.8, p=0.009). Apart from type of carcinoma SUV was also correlated with pathological size of tumor. During multivariate analysis SUV had statistically significant correlation with type of carcinoma (p 0.011) and pathological size (p 0.008). Surprisingly there were no differences in recurrence rates between ACa and SCC pts (33% vs. 31% respectively).
CONCLUSION: SUV has multiple clinical implications.1. SCC has higher SUV compared to Aca. 2. High SUV is probably correlated with larger tumor size as measured during pathological sampling after resection. 3. Higher SUV is not correlated with recurrence at least during early stages of NSCLC.
CLINICAL IMPLICATIONS: PET Scans in future can be used for determinig type and size of lung cancer as well as for prognosis purpose also.
DISCLOSURE: Bhavinkumar Dalal, No Financial Disclosure Information; No Product/Research Disclosure Information