Comparison between ⁶⁸Ga-labelled PSMA and ¹⁸F-FDG PET/CT in the diagnostic value of clear cell renal cell carcinoma

View Poster

INTRODUCTION

Since the prostate-specific membrane antigen (PSMA) is highly expressed in the cell surface of the solid tumor microvasculature including renal cell carcinoma (RCC), PSMA PET/CT imaging has been a promising method for RCC diagnosis, especially for clear cell RCC (ccRCC) patients. ¹⁸F-FDG PET/CT of whole body imaging is widely used as a valuable method for evaluating metastatic or recurrent lesions in patients with RCC. The aim of this study was to compare the diagnostic value of ccRCC between 68Ga-labelled PSMA PET/CT and traditional ¹⁸F-FDG PET/CT.

METHODS

Twelve patients with ccRCC were involved in the study in which 8 patients suffered from metastasis. All patients underwent both ⁶⁸Ga-PSMA PET/CT and ¹⁸F-FDG PET/CT. SUV_max was calculated for both primary RCCs and PET-positive metastatic lesions. We compared the SUV_max of same lesions between ⁶⁸Ga-PSMA PET/CT and ¹⁸F-FDG PET/CT images. Metastatic bone, lymph node and lung lesions as well as the primary tumor were evaluated respectively.

RESULTS

Primary ccRCC lesions were found in 7 patients. The SUV_max value of primary lesions in ⁶⁸Ga-PSMA and ¹⁸F-FDG PET/CT were 15.34±3.82 and 8.62±3.11, respectively (P=0.012). ⁶⁸Ga-PSMA was much more sensitive than ¹⁸F-FDG in bone (SUV_max: 35.64±5.78 vs. 3.52±1.63 )and lymph node(SUV_max: 43.26±8.53 vs. 16.79±4.68) lesions. However, PSMA based PET/CT was not sensitive for lung metastatic lesions compared to ¹⁸F-FDG PET/CT.

CONCLUSION

PSMA based PET/CT imaging provided great diagnostic value on RCC. Compared to traditional ¹⁸F-FDG PET/CT, PSMA was more sensitive in primary lesions, bone and lymph node metastasis. But PSMA PET/CT was not as good as ¹⁸FDG PET/CT for lung metastatic lesions.

Funding: None