Prognostic Value Of Functional Imaging In Patien With Recurrent Malignant Gliomas Or Non-Small Cell Lung Cancer-The Clinical Studies

Part I Prognostic value of 3’-Deoxy-3’-18F-Fluorothymidine (18F-FLT PET) in patients with recurrent malignant gliomasIntroduction:Malignant gliomas is the most aggressive and lethal primary brain malignancy. Despite intensive efforts to improve treatment strategies, the prognosis for patients with malignant glioma (WHO grade Ⅲ and Ⅳ glioma) remains extremely poor.3’-Deoxy-3’-18F-Fluorothymidine (18F-FLT) PET has been proven to be of value in diagnosis and assessment of glioma grading, in differentiating tumor recurrence from necrosis, in response assessment and in predicting overall survival (OS) in the primary high grade glioma. In this study, we evaluated the value of 18F-FLT PET-CT in predicting the OS of patients with recurrent malignant glioma.Methods:Fifty-six patients with recurrent malignant glioma were enrolled in this prospective study. The PET-CT and contrast-enhanced Magnetic Resonance Imaging (MRI) scans were performed in all patients. The maximum standardized uptake value (SUVmax) of tumors and mean standardized uptake value (SUVmean) of normal contralateral hemisphere were calculated, and the tumor-to-normal (T/N) ratio was determined. Tumor volume was determined from both PET image (proliferative volume, PV) and MRI image (Vol-MRI). Patients were followed up clinically until death. The overall survival (OS) was the interval from the date of PET/CT scan to the date of death. The likelihood of using PET-derived parameters of SUVmax, tumor-to-normal (T/N) ratio, and PV to predict the OS of patients were assessed in comparison with Vol-MRI and other clinical parameters.Result:The follow up periods for all patients ranged from 1.5 to 35.6 months with median of 9.8 months. Univariate analysis showed that the following parameters were significantly correlated with OS:grade of primary tumor (p=0.042), Karnofsky performance score (KPS) (p=0.041),T/N ratio (p<0.01), Vol-MRI [p=0.041), and PV (p<0.001). However, multivariate Cox regression showed that only the PV (p <0.001) and T/N ratio (p=0.001) were independent predictors. The thresholds to predict OS were 16.88 cm3 for PV and 10.94 for T/N ratio. Kaplan-Meier analyses using these thresholds showed a significant discrimination between short and long OS groups (p<0.001).Conclusion:The PV and T/N ratio of tumor on 18F-FLT PET-CT are independent predictors of survival in patients with recurrent malignant glioma. The PV on 18F-FLT PET seems to be more predictive than tumor volume on T1-weighted MRI for OS. Patients with a T/N ratio≤10.94 or PV≤16.88 cm3 have significantly longer survival.Part Ⅱ 18F-FDG PET predicts pain response and local control in palliative radiotherapy treatment in patients with bone metastasis from non-small cell lung cancer Purpose:Approximately 30-40% of patients with non-small cell lung cancer (NSCLC) develop bone metastases during the clinical course of the disease. Bone lesions caused by lung cancer metastasis are often osteolytic and mixed-type lesions, which are associated with a poorer prognosis than sclerotic metastasis. despite the increasing use of integrated PET-CT in the management of lung cancer, to our knowledge, little has been reported about its role in the evaluation of treatment responses in terms of pain or its prognostic value in local control in NSCLC patients with bone metastasis treated with palliative RT. Thus, the purposes of our study were to evaluate the value of 18F-FDG-PET in predicting pain severity, pain response, and in-field tumor control after palliative radiotherapy (RT) in patients with non-small cell lung cancer (NSCLC) bone metastases.Materials and Methods:This retrospective, IRB-approved study involved 74 NSCLC patients with 185 bone metastatic lesions. All patients had PET-CT scans prior to and after RT. Pain scores using numerical rating scale (NRS) and SUVmax at each location were recorded. Pain scores and responses to RT were compared with Pre-SUVmax and SUVmax changes after RT. Cox regression analyses were performed to identify prognostic factors for in-field progression-free survival (PFS) and in-field event-free survival (EFS). The receiver operating characteristic (ROC) curve analysis was used to determine the prognostic cutoffs of 18F-FDG PET parameters.Results:Median BS was 6.2 months. BS at 3 months,6 months,1 year, and 2 years were 90.5,51.4,-23.0, and 8.1%, respectively, for all patients. Pre-SUVmax was correlated with initial pain scores (r=0.885, p<0.001), and the decrease in SUVmax after RT was associated with the pain response to RT (p=0.001). During follow-up, regardless of disease progression outside the treatment area,47.03% and 38.92% of lesions showed in-field tumor radiographic progression and in-field events, respectively. Cox regression analysis showed that higher pre-SUVmax (≥8.2) was independent prognostic factor of worse in-field PFS and worse in-field EFS (hazard ratio, HR=1.42 and 1.46; p=0.044 and 0.005,respectively) and greater SUVmax decrease (≥28.3%) after RT were independent prognostic factors of better in-field PFS better in-field EFS (HR=0.59 and 0.60, respectively; and both p<0.001). Compared with lesions that didn’t satisfy both cutoff points (a pre-SUVmax<8.2, and a SUVmax decrease≥28.31%), those who did have longer mean PFS (18.41 months vs 8.44 months) and longer mean EFS (22.83 months vs 11.04 months).Colusion:In patients with NSCLC osseous metastasis treated with palliative RT, the pre-SUVmax from FDG PET-CT may be a useful predictor of initial pain severity and outcomes of local tumor control. The change in SUVmax of bone metastases after RT was highly predictive of the pain response and the outcomes of local control. FDG PET-CT provides a strong prognostic indicator for patients with NSCLC bone metastasis and could be an important guide for making treatment decisions in these patients.