To Detect The Different Spatial Distribution Of Glucose And Hypoxia By In-situ Fusion Acquisition

Background: The accumulation of 18F-FDG can represent spatial distribution of tumor cells with high glucose transport rate, and reflect the invasiveness of tumor tissue. However, it does not clearly illustrate spatial distribution of hypoxic cells. The deposition of 99mTc-HL91 can reflect the distribution of tumor cells with low oxygen pressure, and is lack of aggressive biology information. Thus, in forecasting the prognosis of patients before treatment, we should take into account both subjective factors (invasiveness) and objective factors (hypoxia microenvironment).Objective: This study systematically investigate the"in-situ"fusion images of dual-isotope simultaneously acquisition on:①the change laws of threshold and possible delineating methods;②predicting the prognosis of non-small cell lung cancer (NSCLC) patients before treatment.Method: Based on the different energy peaks of two radionuclides (that of 99mTc and 18F were 140KeV and 511KeV respectively), simultaneously acquiring the corresponding images can avoid the position differences of setup and physical movement. In phantom study, we determine the threshold change laws and possible delineation methods. In clinical study, we evaluate the prognosis of NSCLC patients.Results: On 18F SIDA, 99mTc SIDA and DISA images, regression analysis indicated the relationship as following: Tm= d +c/Vm+e×Bm/Sm. In the point to point analysis of spatial distribution, the correlation coefficient between scatter width and survival time of NSCLC patients was -0.734 (p=0.014). The median survival time was 14.0, 5.0 and 8.3 months for patients with greater, middle and smaller scatter width. In the Cox regression of primary tumor on early images, among factors of scatter width, CT volume, the T/N ratio and treatment, scatter width and Tmax/Nmax-Bone(99mTc) were significantly correlated to survival time with partial correlated coefficients (PCC) of 1.830 and 1.266, respectively. While on the 6 delayed images, only scatter width included in COX model (PCC=2.458).Conclusion: There was apparent law among threshold, VOI and B/S on SIDA and DISA images. The relationship might be useful in the target delineation for clinical purposes. The point-to-point analysis of spatial distribution on in-situ fusion images can effectively assess the prognosis of the NSCLC patients with a higher power than different T/N ratio, CT volume and treatment. This study has important value on assessing the prognosis of NSCLC patients and provides new methods for exploring the differences among metabolic images.