PT  - JOURNAL ARTICLE
AU  - Jain, Vandita
AU  - jaiswal, Abhishek
AU  - chaudhary, vikas
AU  - sahoo, Manas
TI  - <strong>Comparative PSMA expression at early (1hour) vs late (2hour) in primary and secondary sites of involvement in prostate cancer. </strong>
DP  - 2022 Aug 01
TA  - Journal of Nuclear Medicine
PG  - 2704--2704
VI  - 63
IP  - supplement 2
4099  - http://jnm.snmjournals.org/content/63/supplement_2/2704.short
4100  - http://jnm.snmjournals.org/content/63/supplement_2/2704.full
SO  - J Nucl Med2022 Aug 01; 63
AB  - 2704 Introduction: Retrospective evaluation of PSMA expression by using F-18 PSMA -1007 at two different time points early (1hour) and late (2hour) in prostate cancer patients.Methods: 40 patients (Mean Age: 69.8± 9.4 years) who underwent F-18 PSMA -1007 scan were selected for this retrospective study. F-18 PSMA-1007 PET/CT was performed for localization of biochemical relapse, primary staging or therapy follow-up. Patients were divided into two subgroups on the basis of time of acquisition (1 hour and 2 hour). Region of interests were drawn on bone marrow, liver, spleen, kidney, urinary bladder and prostate slices. Quantitative assessment of uptake of F-18PSMA-1007 in malignant lesions (SUVmax) and in normal organs (SUVmean) at both time points was done. Target to Background ratios for primary malignant lesion (lesion: normal prostate) and metastatic sites were assessed by taking into consideration of lymph nodes and skeletal lesions with liver as background for calculation.Results: Mean TBR (Target to background ratio) was 2.3(prostate), 1.3(skeletal lesions), 1.0(lymph nodes) at 1hour whereas mean TBR was 3.5(prostate), 3.2(skeletal lesions), 1.9(lymph nodes) at 2hour. Conclusions: Target to background ratios calculated for primary as well as secondary sites (lymph nodes and skeletal) was higher at 2 hour as compared to 1 hour. It can be concluded that performance of F-18 PSMA-1007 may be better at 2hour post injection but further evaluation with larger sample size needs to be done.