PT  - JOURNAL ARTICLE
AU  - Minseok Suh
AU  - Hyung-Jun Im
AU  - Hyun Gee Ryoo
AU  - Keon Wook Kang
AU  - Jae Min Jeong
AU  - Sneha Kumar
AU  - SANJANA S BALLAL
AU  - Madhav P Yadav
AU  - Chandrasekhar Bal
AU  - Chang Wook Jeong
AU  - Cheol Kwak
AU  - Gi Jeong Cheon
TI  - Head to head comparison of <sup>68</sup>Ga-NGUL and <sup>68</sup>Ga-PSMA-11 in patients with metastatic prostate cancer: a prospective study
AID  - 10.2967/jnumed.120.258434
DP  - 2021 Feb 01
TA  - Journal of Nuclear Medicine
PG  - jnumed.120.258434
4099  - http://jnm.snmjournals.org/content/early/2021/02/26/jnumed.120.258434.short
4100  - http://jnm.snmjournals.org/content/early/2021/02/26/jnumed.120.258434.full
AB  - Introduction: 68Ga-NOTA Glu-Urea-Lys (NGUL) is a novel prostate-specific membrane antigen (PSMA) targeting tracer used for positron emission tomography/computed tomography (PET/CT) imaging. This study aims to compare the performance in the detection of primary and metastatic lesions, and to compare biodistribution between 68Ga-NGUL and 68Ga-PSMA-11 in the same patients with metastatic prostate cancer. Methods: Eleven patients with histologically proven, metastatic prostate cancer were prospectively recruited. Each patient underwent 68Ga-NGUL and 68Ga-PSMA-11 PET/CT within 4 days. The PET/CT scans were performed at 60 minutes after tracer injection. The quantitative tracer uptakes were obtained in normal organs including salivary glands, liver, spleen, and kidney and blood pool activity was measured in the inferior vena cava. The normal organ distribution of both tracers was quantified as SUVmean. In addition, three patients underwent dynamic PET/CT scanning (60 min) of the pelvic region to evaluate the urinary clearance. Any focal accumulation of 68Ga-NGUL and 68Ga-PSMA-11 not explained by physiologic uptake were defined as pathologic lesions. Lesion numbers and lesion uptake, as SUVmax, were compared. Results: Quantitative uptakes in the kidneys, salivary glands, spleen, and liver were significantly lower on 68Ga-NGUL compared with 68Ga-PSMA-11. The blood pool activity showed no significant difference between the two tracers. The bladder time activity curve revealed a more rapid urinary clearance of 68Ga-NGUL. The number and sites of detected PSMA positive primary (n = 11) and metastatic lesions (n = 220) were identical between both tracers. Quantitative uptakes of primary tumors, lymph node, and bone metastases were well correlated (R2 = 0.869, 0.845, and 0.624, respectively) without significant difference (P = 0.675, 0.175, and 0.102, respectively) between 68Ga-NGUL and 68Ga-PSMA-11. 68Ga-NGUL showed a relatively lower tumor-to-background (gluteal muscle) ratio than 68Ga-PSMA-11, especially for bone metastasis. Conclusion: In head to head comparison with 68Ga-PSMA-11, 68Ga-NGUL showed lower uptake in normal organs and a trend of relatively low tumor-to-background ratio compared to 68Ga-PSMA-11. However, both tracers showed similar performance to detect PSMA avid primary and metastatic lesions without significant difference in the absolute lesion uptake. 68Ga-NGUL could be a valuable option for PSMA imaging and, furthermore, applied in theranostics.