Objective To study the impacts of bladder filling status on the dosimetric parameters of the target volume and organs at risk (OAR) in intensity-modulated radiotherapy (IMRT) for prostate cancer.Methods Ten localized prostate cancer patients without serious complications treated with IMRT were selected for this study.These patients underwent CT scans of the whole pelvic cavity three times in different bladder filling status (empty and injected with 150 ml and 300 ml of normal saline) to obtain three series of pelvic CT images.The three sets of CT images were transferred to the treatment planning system.The target volume and OAR such as the rectum,bladder,and femoral heads were contoured by the same doctor.The treatment planning was performed and optimized by the physicist.The dosimetric parameters of the target volume and OAR in three bladder filling status were subjected to analysis by paired t-test.Results If the bladder filling status was consistent in orientation and radiation,the bladder filling status was not associated with the dosimetric parameters of the target volume and femoral heads (P =0.077-0.998 ; P =0.219-0.969) ;it had significant impacts on the dosimetric parameters of the bladder (P =0.000-0.562) and some dosimetric parameters of the rectum (P =0.000-0.645),and bladder filling was favorable for the protection of the bladder and rectum.If the bladder filling status was not consistent in orientation and actual radiation,the calculated planning target volume,the dosimetric parameters of the bladder,and some dosimetric parameters of the rectum were different from those in actual treatment (P =0.000-0.913).Conclusions For the prostate cancer patients treated with IMRT,it is recommended to keep the bladder well and consistently filled.

ObjectivesTo detect the effects of P-selectin on deep venous thrombosis (DVT) in nephrotic syndrome (NS). and to evaluate the molecular magnetic resonance imaging (MRI) with a P-selectin targeted conlrost agent in diagnosis of thrombosis in the early phase. Methods(1) Forty-one patients with NS hospitalized in our department from 2005 to 2006 were enrolled in this study. They were assigned into DVT group and non-DVT group according to lower limbs radionuclide imaging (RNV) with 99mTc MAA. Blood P-selectin level was measured by ELISA method. (2) P-selectin was detected both in injured vein and blood immediately, 1 h and 3 h after the dog DVT model was established. (3) The P-selectin-targeted contrast agent was developed by conjugating anti-P-selectin lectin-EGF domain monoclonal antibody (PsL-EGFmAb) which was prepared by our lab. The potential of this contrast agent used in vitro molecular imaging experiment as well as in vivo experiment in dog DVT model was investigated. Results (1) Blood P-selectin level was elevated in patients with NS. It was much higher in DVT group than that in non-DVT group. (2) Blood P-selectin level was also elevated in DVT dogs and P-selectin expressed immediately in tunica intima of injured vein and subsequently in thrombus after the model established. (3) Mural thrombus showed higher signal visualization than surrounding muscle in 30 rain after contrast agent injection. These enhanced signals exhibited P-selectin specificity and persisted from the initiation of intima lesions to 3 h after development of thrombosis. There was signficant Differences in contrast-to-noise ratio (CNR) of the experiment group and the control group (11.50±2.32 vs 2.71±0.86, P＜0.01). The same results were derived from 30 rain to 1 hafter contrast agent being injected in distal to heart part of the injured vessel, and the signal decreased 24 h later. Differences in CNR of the experiment group and the control group were also statistically significant (10.40±2.15 vs 1.93±0.57, P＜0.01). Moreover, the contrast agent did not affect the vital signs of the dog. The function of the heart, lung, liver and kidney functions remained normal after contrast administration. Conclusions P-selectin*targeted new MR contrast can be used to early locate thrombus in vivo in an early stage, which does not compromise the function of the important organs. It may become a new method for early diagnosis of thrombosis.