Analysis of CNR and SNR in cases of breast cancer NAC therapy 18F-Fluorothymidine PET: Result From ACRIN 6688
Yeni Pertiwi1,3, Vepy Asyana1, Freddy Haryanto1 , Deni Hardiansyah2 , Idam Arif1

1 The Department of Physics at the Bandung Institute of Technology
2 The Department of Physics at the University of Indonesia
3 Alinsyirah Institute of Health and Technology

Abstract

Spatial resolution greatly affects the value of the partial volume effect (PVE). PVE contributes considerable uncertainty in measuring Volume of interest (VOI), significantly affecting dose calculations, diagnostics, and treatment therapy in nuclear medicine. This study aims to analyze the CNR and SNR values &#8203-&#8203-of 18F-FLT PET scan results on the response to breast cancer NAC therapy as a quantitative analysis to improve spatial resolution quality. The image data analyzed results from the protocol from scanning the 18F-FLT PET device: ACRIN 6688. Each patient underwent three scans- 18flt-1 was done before therapy (baseline), and 18FLT-2 was done 5-10 days after completing one cycle of NAC therapy, or called a scan. On initial treatment, 18FLT-3 was performed after the second cycle of NAC therapy and three weeks after surgical resection. CNR and SNR values were analyzed in 5 patients. The results of CNR and SNR measurements were analyzed using the correlation matrix of the effect on the stage of therapy. Research results show the correlation matrix analysis of the mean SNR with the stages of the therapy process. The research shows a strong positive linear relationship between SNR at Baseline and Early Therapy. In contrast, the relationship between SNR at Baseline and Post Therapy is weak, and there is almost no significant correlation. As well as the mean value of CNR shows a strong positive linear relationship between CNR at Baseline and Early Therapy and a fairly strong linear relationship between CNR at Baseline and Post Therapy. Based on the research results, there is a strong positive linear relationship between SNR and CNR at the initial stage of therapy (Baseline and Early Therapy), so this quantitative analysis is considered capable of supporting changes in tumor volume in further studies of increasing spatial resolution.

Keywords: Breast Cancer, CNR, SNR, PET/CT

Topic: Biophysics and Medical Physics