A Quantitative Prospective Study for Whole Body- Diffusion MRI and PET-CT in Detection of Primary and Metastatic Malignant Lesions

Abstract

The idea of an integrated nuclear medicine unit consisting of a PET-CT scanner with a practical source of radioisotopes such as a cyclotron to operate efficiently in Palestinian health system is almost impossible due to several reasons, mainly political and financial issues. The goal of this study is to find a safe, valid, and widely available modality as an alternative to help oncologists and patients; we proposed a whole-body diffusion MRI protocol (WB-DWI MRI) A 33 oncological patients, 60% male (n = 20) and 40% female (n = 13), age 18-74 years with a mean age of 48 years old participated in our study for a PET-CT and WB-DWI MRI scan. Participants already diagnosed to have primary tumors including non-Hodgkin's lymphoma (NHL), Hodgkin's lymphoma, endometrial cancer, prostate cancer, pancreatic cancer, gastric cancer, thyroid cancer, idiopathic pathological fractures and skin lesions suspected to be melanoma. Our results shows that PET-CT demonstrated 181 hypermetabolic lesion distributed in the four zones ( head-neck, chest, abdomen-pelvis and musculoskeletal), was detected by WB-DWI MRI which shows most of the same lesions restricted in diffusion with extra small sub centimeter lesions totally 251 lesions in count with a comparison between standard uptake volume (SUV) and apparent diffusion coefficient ADC) which shows most high SUV( SUV>2.5) have ADC < 1.1 x10-3 mm2/S. Statistical quantitative analysis shows a significant positive correlation between number of detected lesions in the same zone for each patient at p value < 0.05 (p=0.00004) and R-value = 0.5335, a comparative correlation between ADC and SUV shows a significant negative correlation between SUV and ADC at p value < 0.05 and R-value= -0.3073. WB-DWI MRI can replace PET-CT scan in lymphoma cases and tumors follow up to monitor the response for treatment after chemotherapy or radiotherapy either post-surgical resection.