| Background: Positron emission computed tomography (PET/CT) has been regarded as a milestone during the development of imaging study, which not only yields whole body imaging at a time, but also integrates anatomical structure imaging into functional metabolism imaging. Currently, PET/CT has been applied in multiple aspects of cancer clinics including cancer diagnosis, staging, guide treatment (i.e., outline of radiotherapy target, positioning of craniocerebral surgery), efficacy evaluation, prognosis estimate and follow-up. It's difficult to popularize the application of PET/CT due to its high cost and expensive examination fee. Malignant tumors have been considered as a chronic disease, thus the patients have to bear certain degree of financial burden. In 2004, Japanese scholar Takahara et al first optimized diffusion-weighted imaging (DWI) and proposed a novel technique called diffusion weighted whole body imaging with background body signal suppression (DWIBS), which produced similar imaging with PET/CT. Since DWIBS should be operated on magnetic resonance machine, its examination cost was lower compared with that of PET/CT. Therefore, DWIBS draws wide attention since its initial application in clinics. This study focus upon three aspects of DWIBS: (1) The feasibility of performing DWIBS by using SIMEMS 1.5T magnetic resonance machine and evaluating the overall characteristics of DWIBS imaging; (2) The ability of identifying tumor focus and conducted prospective comparison between DWIBS and hPET/CT; (3) Attempt to utilize DWIBS to locate primary focus of metastatic carcinoma; (4) Preliminarily apply DWIBS to evaluate the efficacy of tumors towards chemotherapy. Purpose: (1) To analyze the feasibility for cancer patients to receive DWIBS and preliminarily understand the general characteristics of DWIBS imaging. (2) To compare the ability of identifying tumor lesions between DWIBS and hybrid PET/CT. (3) attempt to use DWIBS to locate primary focus of metastatic carcinoma. (4) Preliminarily apply DWIBS to evaluate the efficacy of chemotherapy.Materials and methods: A total of 43 cancer patients who received treatment in our hospital from October, 2008 to April, 2010 were enrolled in this clinical trial. All patients were subject to DWIBS and hPET/CT subsequently within 14 days (did not receive cancer treatment during this period), and then combined with cytology, pathology, other imaging data and follow-up info. The detection rates of cancer lesions distributed in brain, lung, liver, bone, lymph lode, and other sites was statistically calculated and compared between DWIBS and hPET/CT examinations.Results: (1) Totally 43 cancer patients successfully completed DWIBS examination, approximately 28 to 36 min for each patient. Scanning Parameter b=0,800 made the the quality of DWIBS imaging well. (2) The overall detection rates for DWIBS and hPET/CT were 90.3% (261/289) and 86.6% (251/289), with a concordant ratio of 88.2 (255/289). No statistical significance was noted between two techniques by McNemaer test (P>0.05), and consistency was found between DWIBS and hPET/CT by Kappa test (P=0.000). Analysis outcomes based upon anatomical structure tomography as follows: the detection rates of brain and bone focus were 93.9% and 91.5% by using DWIBS, and 66.7% and 82.7% by hPET/CT, suggesting that DWIBS was better than hPET/CT in terms of identifying the lesions in brain and bone, with statistical significance (all P<0.05); However, the detection rate of lung lesions by DWIBS was lower compared with that by hPET/CT (P<0.05). No significant difference was noted between two methods regarding the detection rates of identifying lesions in liver, lymph lode and other sites (all P>0.05). (3) Among 43 patients, 32 cases did not receive resection of primary focus / had recurrent focus after resection. DWIBS indicated that 27 cases had primary focus, whereas hPET/CT revealed 28 cases with primary focus. Four cases with primary lesions were missed by both DWIBS and hPET/CT. No significant difference was noted between DWIBS and hPET/CT regarding the detection primary focus (P>0.05). (4) when evaluating efficacy of cancer patients after receiving chemotherapy, DWIBS and hPET/CT shared consistent outcomes in 3 cases.Conclusion: (1) DWIBS is a safe and convenient method for whole body imaging examination. (2) Certain degree of consistency existed between DWIBS and hPET/CT regarding lesions identification. The two methods had relative merits when identifying lesions occurring in different sites. (3) DWIBS has certain value in terms of identifying primary focus of metastatic carcinoma. (4) DWIBS maybe apply in assessing the efficacy of chemotherapy. To sum up, DWIBS is a safe, reliable, and economical whole body imaging, which has broad and promising prospects in clinics. |
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