Study On The Accuracy Of CT And MRI In Tumor Size Of Primary Hepatic Carcinoma

Objective:Primary hepatic carcinoma are (PHC) from those cells, including liver cells or intrahepatic bile duct cancer cells. It is the most common primary liver neoplasm, the fifth to sixth most common cancer in the world .And the cancer mortality rate is in the third to fourth place. PHC is responsible for up to 700,000 new cases and 600,000 deaths annually worldwide.The high-risk areas is China, Africa and South Asia[1-4]. According to the ministry of health statistics,the number of HCC in China now accounts for about 55% of the worldwide. It is the first most common cancer in some rural areas,the second in many cities. In China, the cancer mortality rate of PHC is in the second place,lung cancer first.The overall five-year survival rate for the patients underwent operation has remained steady at 60-75%.But middle-late stage patients are majority[5]. Only 15-25% of them may receive operation[6-7].Non-operative treatments are including radiotherapy, biological therapy, traditional Chinese medicine therapy, transcatheter arterial chemoembolization, percutaneous ethanol injection tumor, radiofrequency ablation, high-intensity focus ultrasound, intensitial laser photocoagulation.Radiotherapy,which is one of the most important nonoperative treatments, has been limited by the risk of radiation-induced liver disease(RILD) and the low tolerance of the whole liver to RT [8]. With advances in 3-dimensional planning tools, 3D conformal radio- therapy (3D-CRT) has enabled high dose RT to be directed to the tumor while achieveing good Tumor Control Probability (TCP) and Normal Tissue Complication Probability(NTCP) [9].Its target, including Gross tumor volume(GTV),Clinical target volume (CTV) and Planning target volume(PTV).International Commission on Radiation Units and Measurement Committee(ICRU) Report No. 50 on the target volume in 3DCRT delivered a clear definition of GTV, pointed out: GTV is the clinical examination and imaging study findings of the tumor volume.Purdy, etc. study [10]pointed out: to outline the tumor target, if we compare the actual tumor size may be unnecessary normal tissue radiation injury, and if the outline of the tumor target is less than the actual tumor size, easy for leakage according to tumor , resulting in no control or recurrence. So,in 3D radiotherapy planning system, determination of target irradiation is the key, determines the success or failure of radiation therapy, and the GTV determination is outlined in the key target.Clinicopathologic correlation studies are needed to ensure that imaging before radiotherapy accurately delineates the true extent of disease. The purpose of the present analysis was to compare the size of HCC on gross pathologic exam ination after surgical resection with the size on preoperative computer tomography(CT) or magnetic resonance imaging(MRI).Methods:Between September 2009 and December 2010, 9 patients with primary hepatic carcinoma and cirrhosis were included in this study. The patient did not receive preoperative local therapy. All patients underwent liver transplantation and the tumour size was measured on histology. Tumour size was measured by the two modalities.The maximal measurement in one dimension on sagittal imaging and pathologic examination was extracted for statistical analysis. Results were evaluated by paired Student's t-test and calculating correlation coefficients. And An assessment was made in respect of the accuracy in tumor size( the accordance was defined as≤5mm of error between preoperative imaging findings and resected tumor).Results: There were statistical differences between computer tomography images and pathological samples (P=0.017) and magnetic resonance imaging images and pathological samples (P=0.000).The correlation coefficient between computer tomography and and pathological size (r=0.979) was significantly better than the correlations between magnetic resonance imaging and pathological size (r=0.928).The accuracy of CT and MRI in tumor diameter was 22% and 44% respectively.Conclusions:Magnetic resonance imaging is better than computer tomography to measure size of liver tumor and determine the GTV.