Objective To evaluate the feasibility of interstitial implantation of ~(125)I seeds for recurrent or metastatic malignant tumor at the Head and Neck.Methods From January 2003 to July 2007,29 patients received interstitial implantation of ~(125)I seeds in our hospital because of recurrent or metastatic malignant tumors at the head or neck after surgery or chemotherapy.Under local anesthesia and guidance of CT,B-ultrasonography,or endoscopy,~(125)I seeds were implanted into the tumor tissues with intervals of 0.5-1.0 cm.The matched peripheral dose(MPD)was 90-160 Gy,and the radioactive activity was set at 29.6 MBq per seed.Results The operation was completed in all the patients.A median of 23 seeds(12-67)were implanted in each case.No complications,such as hemorrhage,infection,or seed migration,occurred in the patients.The patients were followed up for 3-24 months(mean,16 months).During the period,the rate of local control was 55%(16/29)at 3 months,71%(20/28)at 6 months,45%(10/22)at 12 months,and 36%(5/14)at 2 years.Conclusion Interstitial implantation of ~(125)I seeds is feasible for recurrent or metastatic tumor at the head or neck with a good short-term outcome.

Objective To evaluate the feasibility and efficacy of 125 I radioactive seed implantation in treat-ment of aggressive thymoma pleural metastases after surgical resection.Methods The clinical data of 16 patients with thymoma confirmed underwent surgery were retrospectively analyzed.All post -operative pleural metastasis were trea-ted by radioactive particle planting.Results No patients occurred serious complications.15 patients survived at the end of 12 months following -up,13 patients with complete or partial relieved,2 patients progressed and 1 patient lost to following -up.Conclusion DynaCT -guided 125 I radioactive seed implantation is effective and safe for treating aggressive thymoma pleural carcinomatosis,it offers a new and feasible treatment.

Objective To study the methods and effects by using thrombolytic catheter in interventional treatment for patients with acute lower limb arterial thrombosis or embolism. Methods One hundred and twelve patients suffered acute lower limb arterial thrombosis or embolism. There were 85 cases of acute lower limb arterial embolism induced by atrial fibrillation in coronary or rheumatic heart disease,other 27 cases of arterial thrombosis caused by different reasons. Interventional treatment by inlying thrombolytic catheter was applied and continuous perfusion was received locally in all patients. Results Complete recanalization was got in 77 cases (68.8%) of 112 cases. Partial re canalization was got in 23 cases (20.5%), and ischemia limbs were saved in spite of chronic limb ischemia(chronic spasmodic limb) occurring in the later follow-up. Nine cases (8.0%) were amputated as a result of irreversible limbs necrosis, 3 cases (2.7%) died from acute renal failure resulting from reperfusion injury or recurrent cerebral embolism.Conclusion Interventional treatment by inlying thrombolytic catheter is a safe and effective method with lower amputation rate for acute lower limb arterial thrombosis or embolism in patients.

Objective: To observe the effect of 125I on T24 transitional cell carcinoma of nude mouse. Methods: Totally 40 T24 transplanted tumor nude mice were divided into high, medium, low activity and control groups (each n=10), and 125I seeds with activity of 0.9 mCi (33. 3 MBq), 0.6 mCi (22. 2 MBq), 0.3 mCi (11. 1 MBq) and 0 mCi (nuclide free) were implanted in the tumor center, respectively. The 90% target absorbed dose (D90), tumor inhibition rate (IR), radiation reaction grade (RRG) of HE staining, apoptosis index and B-cell lymphoma-2 (Bcl-2) protein expression were analyzed and compared among groups 10 days and 20 days after implantation. Results: D90 and IR of nude mice with high, medium and low activity groups decreased gradually 10 and 20 days after 125I seed implantation (all P<0.05). The necrosis was obvious within 5 mm around the tumor, and the higher the seed activity, the longer the time, the wider the ranges of necrosis. RRG of high activity group 10 and 20 days after 125I seed implantation were higher than that in low activity group and control group (all P<0.05). Meanwhile, the apoptotic index of high, medium and low activity groups gradually decreased, the expression of Bcl-2 protein gradually increased (all P<0.05). Conclusion: 125I seeds can significantly inhibit the growth of T24 metastatic cell carcinoma in nude mouse. Promoting the apoptosis of tumor cells may be one of the mechanisms.

Objective: To observe the effect of integrated gastrointestinal nutritional tube loaded with double 125I strands applied in esophageal cancer with grade dysphagia. Methods: Interventional catheter technology was used to open the occlusive segment of esophagus in 10 patients with esophageal cancer and grade dysphagia. Then the new integrated tube was fed along the guide wire with 125I segment needs crossing the esophageal occlusion segment for brachytherapy. The technical success rate and clinical success rate were counted. The dosimetry parameters were recorded and compared before and 3 days after operation, while the therapeutic effect were estimated according to Karnofsky score and Neuhaus dysphagia grading 2 months after operation. The patients were followed up for 6 months to observe the prognosis. Results: All 10 patients underwent successful tube insertion. The technical success rate was 100%, and the clinical success rate was 70%. No serious complication occurred. There was no statistically significant difference of 90% of gross tumor volume (GTV) received dose (D90%), GTV minimum peripheral dose (mPD), GTV received 200% and 100% of the prescribed dose volume percentage (V200%, V100%), conformal index (CI) nor external index (EI) before and after operation (all P>0.05). Karnofsky score and Neuhaus grading were significantly improved 2 months after operation (both P<0.01), and the local tumor control rate was 70%. During 6 months' follow-up, dysphagia reoccurred in 1 case, 2 cases died, while no relapse was found in 7 patients. Conclusion: The integrated gastrointestinal nutritional tube loaded with double 125I strands can achieve gastrointestinal nutrition and brachytherapy at the same time,which is effective and safe for treating esophageal cancer and grade dysphagia.

Objective: To explore the feasibility of 3.0T closed MR-guided microwave ablation for liver metastases. Methods: Totally 14 patients with 23 liver metastases were treated with 3.0T closed MR-guided microwave ablation. The technical success rate, ablation parameters, procedures time and complications were recorded, and the local ablation effects were evaluated 1 month later. Results: The technical success rate was 100%. The ablation power was (65.65±4.11)W, the ablation time of single lesion was (13.92±6.36)min, and the total operation time was (68.48±19.50)min. No severe complication such as liver abscess, diaphragmatic perforation nor jaundice occurred, while small amount of pleural effusion was obserevd in 2 cases (2/14, 14.29%). One month later, the complete ablation rate was 91.30% (21/23). Conclusion: 3.0T closed MR-guided microwave ablation is safe and effective for treating liver metastases.

Objective To study the efficacy of double inverted Y-shaped airway covered stent for patients with thoracostomach-right main bronchus fistula.Methods Fifteen cases with thoracostomach-right main bronchus fistula were investigated retrospectively.All patients had accepted esophageal resection and thoracostomach esophagus anastomosis,as well as radiation therapy after surgery due to esophageal cancer. All fistulas located close to the opening of right upper lobe bronchus.According to the normal tracheobronchial diameter and length of patients,two inverted Y-shaped airway covered stents were designed individually.Stenting was performed under X-ray,and the situation of fistula and clinical symptoms improvement were investigated.Results The double inverted Y-shaped airway covered stents were implanted and fistulas were closed successfully.All patients could take normal diet,and the supine cough symptoms disappeared, without complications such as airway bleeding and pneumothorax after stenting.Conclusion The stenting of double inverted Y-shaped airway covered stent may be an effective,feasible and safe treatment for thoracostomach-right main bronchus fistula.

Objective To study the effect of 125Iodine seed on the rabbit ischiadic nerve at different time point after implantation. Methods Thirty healthy New-Zealand rabbits were randomly assigned into 3 groups( 2-week group, 2-month group and 4-month group) using envelope method. During operation, 10 radioactive 125I seeds were implanted randomly near one of the ischiadic nerve, while 10 non-radioactive seeds were implanted into the contralateral ischiadie nerve. According to treatment plan system(TPS),90% of the prescription dose (PD)was centered in the specific place, where the nerves were chosen to be studied. After 2 weeks, 2 months and 4 months respectively, nerve electro-physiolngy experiment was used to evaluate the bilateral ischiadic nerves, at the same time the morphology of the ischiadic nerve was examined by general observation, light microscope and electron microscope. The electron microscope photo with the same ×4000 amplification was divided into 100( 10 × 10) cages and non-specific changes in one cage account for 1%. The t test and sum rank test were used for statistics. Results Potential leaking point of experimental ischiadic nerves near heart in 2-week group ,2-month group and 4-month group were (0.52± 0.26), (0.60±0.19), (0.48±0.17)V, while that of the control sides were (0.59±0.19), (0.60± 0.15), (0.53±0.13 ) V, there was no statistical significance in the same group respectively (t=0.91, 0.03,0.67,P>0.05). Potential leak point of experimental ischiadic nerves far from heart in 2-week group, 2-month group and 4-month group were (0.51±0.15), (0.52 s0. 11 ), (0. 53±0.15) V,the control sides were (0.52±0.10), (0.56±0.12), (0.54±0.10)V, there was no statistical significance in the same group respectively (t= 0.25,0.74,0.17, P > 0.05 ). Action potential amplitude of experimental ischiadic nerves near heart in 2-week group,2-menth group and 4-month group were (13.18±4.09), (12.78± 4.42), (12.09±1.20) mV, while that of the control sides were (10.55± 4.21 ), ( 10.31±4.22), (12.88±3.54) mV, there was no statistical significance in the same group respectively (t=1.57,1.36, 0.50,P>0.05). Action potential amplitude of experimental ischiadic nerves far from heart in 2-week group,2-month group and 4-month group were (11.18±3.38), (11.68±3.21), ( 12.52±3.09) mV, while that of the control sides were (11.56±4.80), (10.71±3.40), (11.67±2.48) mV ,there was no statistical significance in the same group respectively(t=0.29,1.01,0.55, P>0.05 ). Nerve conduction velocity of experimental ischiadic nerves in 2-week group,2-month group and 4-month group were (40.56± 9.46), (38.79±5.78), (39.44±8.64) m/V, the control sides were (42.56±6.59), (44.64±7.53), (43.33±6.05)m/V, there was no statistical significance in the same group respectively( t = 0.57,1.94, 0.01,P>0.05). There were some changes in general observation and light microscope, in electron microscope, many non-specificity changes were observed. All of these changes included delamination, collapse, disaggregation of the myelinated nerve, mitochondria swelling and vacuolization of neurilemma cell and axon. The ratio of degenerative alterations in nerves was 60% --70% in 2-week group, 50% in 2-month group and 30% in 4-month group, and there was statistical significance among three groups (P<0.05). Conclusion 125I permanent plantation in our test dose has little effect on ischiadic nerve, all these non-specificity changes were observed in electron microscope, and it has no evident impacts on physiological functions.

Objective To investigate the feasibility and therapeutic effect of stenting therapy by using modified Y-shaped self-expandable metal stent for the stenosis of gastroenteric stoma. Methods According to the particular anatomic structures and the pathological features of the narrowed gastroenteric stoma,the authors designed a modified Y-shaped self-expandable metal stent. Under the fluoroscopic guidance,implantation of modified Y-shaped self-expandable metal stent was performed in 5 patients with narrowed gastroenteric stoma. The technical safety and the clinical results were evaluated. Results The modified Y-shaped self-expandable metal stent was successfully implanted with one procedure in all five patients. After the implantation the symptoms such as nausea,vomiting,abdominal distension were promptly relieved,and the patients' living quality was markedly improved. Conclusion The stenting therapy with modified Y-shaped self-expandable metal stent can rapidly relieve the stenosis of gastroenteric stoma once for all. The technique is feasible and the short-term effect is reliable,therefore,it is worth popularizing this therapy in clinical practice.

Objective To evaluate the safety and efficacy of 125I seed strands cavity brachytherapy for ureteral carcinoma.Methods To tally 10 patients with ureteral carcinoma underwent Carm CT and DSA guided percutaneous nephrostomy with 125I seed strands cavity brachytherapy.The technical success rate,complications,tumor local control rate,ureteral patency andsurvival time,and compared the Karnofsky scores,Girignon grade,pain score before and after treatment were evaluated.The dose related parameters were compared between pre-and post-treatment.Results 125I seed strands implantation was successfully completed in all patients with technical success rate of 100％.The mean procedure time was (12.3 ±3.8) min.No severe complications such as ureteral perforation,infection,severe bleeding occurred.Local tumor response was CR in 4 cases and PR in 6 cases,showing local control efficiency (CR + PR) 100％ after 2-3 months.Ureteral patency rate was 50％ (5/10).Postprocedure Karnofsky scores,Girignon grades,and pain scores were significantly improved (Z =-2.72,-2.88,-2.83,P＜0.01).The average follow-up time was (14.6 ±6.5) months (5-25 months),tumor progression was observed in 3 cases,stable disease in 7 cases.Nine cases were alive and one died due to multiple organ failure.The differences of D90％,mPD,V100％,V150％,V200％,CI,EI,HI between the preand post-treatment were not statistically significant (P ＞ 0.05).Conclusions 125I seed strands cavity brachytherapy for ureteral carcinoma is an effective and safe procedure without serious complications,and an effective alternative treatment for patients who are unable to undergoor refuse surgery.