Related Experiment Video
Updated: Aug 18, 2025
Gene Regulation and Targeted Therapy in Gastric Cancer Peritoneal Metastasis: Radiological Findings from Dual Energy CT and PET/CT
Published on: January 22, 2018
[68Ga]Ga-Pentixafor PET/CT imaging for in vivo CXCR4 receptor mapping in different lung cancer histologic sub-types:
Ankit Watts1, Baljinder Singh2, Harmandeep Singh1
1Department of Nuclear Medicine, Postgraduate Institute of Medical Education & Research (PGIMER), Chandigarh, 160012, India.
Purpose:
In vivo CXCR4 receptor quantification in different lung cancer (LC) sub-types using [68Ga]Ga-Pentixafor PET/CT and to study correlation with quantitative CXCR4 receptors' tissue density by immunochemistry analyses.
Methods:
[68Ga]Ga-Pentixafor PET/CT imaging was performed prospectively in 94 (77 M: 17F, mean age 60.1 ± 10.1 years) LC patients. CXCR4 receptors' expression on lung mass in all the patients was estimated by immunohistochemistry (IHC) and fluorescence-activated cell sorting (FACS) analyses. SUVmax on PET, intensity score on IHC, and mean fluorescence index (MFI) on FACS analyses were measured.
Results:
A total of 75/94 (79.8%) cases had non-small cell lung cancer (NSCLC), 14 (14.9%) had small cell lung cancer (SCLC), and 5 (5.3%) had lung neuroendocrine neoplasm (NEN). All LC types showed increased CXCR4 expression on PET (SUVmax) and FACS (MFI). However, both these parameters (mean SUVmax = 10.3 ± 5.0; mean MFI = 349.0 ± 99.0) were significantly (p = 0.005) higher in SCLC as compared to those in NSCLC and lung NEN. The mean SUVmax in adenocarcinoma (n = 16) was 8.0 ± 1.9 which was significantly (p = 0.003) higher than in squamous cell carcinoma (n = 54; 6.2 ± 2.1) and in not-otherwise specified (NOS) sub-types (n = 5; 5.8 ± 1.5) of NSCLC. A significant correlation (r = 0.697; p = 001) was seen between SUVmax and MFI values in squamous cell NSCLC as well as in NSCLC adenocarcinoma (r = 0.538, p = 0.031) which supports the specific in vivo uptake of [68Ga]Ga-Pentixafor by CXCR4 receptors. However, this correlation was not significant in SCLC (r = 0.435, p = 0.121) and NEN (r = 0.747, p = 0.147) which may be due to the small sample size. [68Ga]Ga-Pentixafor PET/CT provided good sensitivity (85.7%) and specificity (78.1%) for differentiating SCLC from NSCLC (ROC cutoff SUVmax = 7.2). This technique presented similar sensitivity (87.5%) and specificity (71.4%) (ROC cutoff SUVmax = 6.7) for differentiating adenocarcinoma and squamous cell variants of NSCLC.
Conclusion:
The high sensitivity and specificity of [68Ga]Ga-Pentixafor PET/CT for in vivo targeting of CXCR4 receptors in lung cancer can thus be used effectively for the response assessment and development of CXCR4-based radioligand therapies in LC.
