Thyroid dose-volume thresholds for the risk of radiation-related hypothyroidism in nasopharyngeal carcinoma treated with intensity-modulated radiotherapy-A single-institution study.

BACKGROUND: To identify thyroid dose-volume thresholds for radiotherapy (RT)-related hypothyroidism (HT) in patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated RT (IMRT). In this way, we desired to guide the design of treatment plans and, finally, lower HT prevalence. METHODS: In total, 345 NPC patients treated with IMRT were evaluated retrospectively during a median follow-up of 45.2 (range, 11.3-64.9) months. Serum-based assessments of thyroid function before and after IMRT were monitored periodically. Thyroid dose-volume parameters were analyzed for their association with HT risk. RESULTS: In total, 44.1% of patients (152/345) developed primary HT. Analyses of thyroid dose-volume parameters identified a stringent dose-volume histogram (DVH) threshold defined by V25Gy (the percentage thyroid volume that receives >25 Gy, not the absolute volume) ≤60%, V35Gy  ≤ 55%, and V45Gy  ≤ 45%. Patients whose thyroid DVHs satisfied these constraints had a lower prevalence of 2-year HT compared with the overall prevalence (13.2% vs 25.8%, P < .001). Another DVH was defined by V25Gy  > 95%, V35Gy  > 90%, and V45Gy  > 75%, and patients whose thyroid DVHs satisfied with these constraints had a higher prevalence of 2-year HT than the overall incidence (36.0% vs 25.8%, P < .001). CONCLUSION: We recommend V25Gy  ≤ 60%, V35Gy  ≤ 55%, and V45Gy  ≤ 45% as the "stringent" DVH line, and V25Gy  > 95%, V35Gy  > 90%, and V45Gy  > 75% as the "inhibition" DVH line, under the precondition of not compromising the target coverage. These findings could help in the design of individual treatment plans and, eventually, to lowering of HT prevalence.

Transcatheter closure of medium and large congenital coronary artery fistula using wire-maintaining technique.

BACKGROUND: For medium and large coronary artery fistula (CAF), the initially selected device sometimes has to be exchanged by reconstruction of track wire loop due to the complexity of CAF. OBJECTIVES: We sought to evaluate the feasibility and safety of transcatheter closure of medium and large CAF by using the wire-maintaining technique (WMT). METHODS: A total of 18 patients aged 15-56 years with congenital CAF underwent percutaneous transcatheter closure by WMT between April 2006 and October 2012. The immediate and long-term outcomes were evaluated. RESULTS: Of the 18 patients (11 females), 16 (88%) underwent successful transcatheter closure of fistula using WMT. The CAFs originated from the right coronary artery (67%), the left circumflex coronary artery (28%), and the left anterior descending coronary artery (5%). The drainage sites were the right ventricle (56%), right atrium (22%), left ventricle (11%), and coronary sinus (11%). The mean diameter of fistulas was 9.5±1.71mm and mean size of the devices was 13.6±3.03mm. An angiogram following device deployment showed complete occlusion in 11 patients, mild residual shunt in 2 patients, and trivial residual shunt in 3 patients. One patient had transient ST-T wave changes, and one patient had hemolysis after the procedure. Follow-up ranged from 1 month to 54 months (median 39 months). Echocardiogram showed trivial residual shunt in 3 patients at 6-month follow-up and in 1 patient at 12-month follow-up. Coronary artery thrombosis was observed in 1 patient by multislice computed tomography at 12-month follow-up. CONCLUSION: For those patients with medium and large complex fistula, transcatheter closure of CAF can be performed by using the wire-maintaining technique.

Balloon-expanding stent and delivery system for transcatheter aortic valve implantation: An animal study.

OBJECTIVE: To evaluate the feasibility and satefy of transcatheter aortic valve implantation in animals by using a new balloon-expanding valved stent. METHODS: The balloon-expandable stent is made from cobalt-based alloy material and designed with a tubular, slotted structure. Fresh bovine pericardium was treated, sutured and fixed on the balloon-expandable stent. Ten healthy sheep (five males and five females), weighing an average of (25.16 ± 1.83) kg, were selected to undergo transcatheter implantation of the valve stents. The function of the valve stent was evaluated by angiography, echocardiography, and histology six months after the procedure. RESULTS: Of the ten experimental sheep, two sheep died during the operation because the higher position of the artificial valve affected the opening of the coronary artery. We successfully implanted the aortic valve stent in other eight sheep; however, one sheep died of heart failure two weeks after the operation due to the lower position of the valve stent. The valve stents were implanted in the desired position in seven sheep. Ascending aortic angiographic and autoptic findings immediately after the operation confirmed the satisfactory location and function of the valved stent. Echocardiography, angiography, and histology at six postoperative months confirmed the satisfactory location and function of the valve stent. CONCLUSION: We successfully implanted our new valve stent as a replacement of native aortic valve via the transcatheter route with satisfactory outcome.

[The effects of different occluder selection on cardiac remodeling post transcatheter closure in patients with secundum atrial septal defect].

OBJECTIVE: To evaluate the effects on cardiac remodeling post transcatheter closure by Amplatzer septal occluder selected by oval circumference formula in patients with atrial septal defect (ASD). METHODS: A total of 146 patients with ASD (68 males,mean 33.5 years) treated by transcatheter closure with the Amplatzer occluder were enrolled in this study. The diameter of defects was corrected with the oval circumference formula (group A, 73 cases) or by echocardiography (group B, 73 cases). Cardiac remodeling was assessed by transthoracic echocardiography (TTE) before the procedure, 3 days, 3 months and 6 months after ASD closure. RESULTS: The mean ASD diameter was similar between the two groups [(20.16 +/- 4.98) mm vs. (21.36 +/- 5.69) mm, P > 0.05] and the mean diameter of the selected occluder of group A was significantly smaller than that in group B [(21.95 +/- 6.78) mm vs. (25.85 +/- 6.75) mm, P < 0.05]. Procedural success rate was identical between the two groups (97.3%) and the defects were completely occluded and there was no residual shunt during the 6 months follow up period, there were also no complications during and after the procedure. The lateral diameter of right atrial (RALD), the diastolic diameter of right ventricle (RVDD), RALD/LALD, RVDD/LVDD and pulmonary diameter (PD) were significantly decreased while the lateral diameter of left atrial (LALD) and left ventricle (LVDD) were significantly increased post ASD closure in both groups. At 6 months follow up, RALD decreased by (18.63 +/- 10.59)% in group A versus (10.14 +/- 6.59)% in group B, LALD increased by (13.42 +/- 8.38)% in group A versus (9.28 +/- 4.95)% in group B and RALD/LALD ratio decreased by (26.35 +/- 11.24)% in group A versus (13.98 +/- 8.96)% in groups B (all P < 0.05). CONCLUSION: ASD occluder selection based on the oval circumferen ce formula is superior to that made by echocardiography in terms of more favorable cardiac remodeling post ASD closure.

[Clinical observation on warming needle moxibustion plus exercise for treatment of temporomandibular joint dysfunction syndrome].

OBJECTIVE: To search for a better therapy for temporomandibular joint dysfunction syndrome. METHODS: Two hundred and ten cases of temporomandibular joint dysfunction syndrome were randomly divided into a treatment group, a control group I and a control group II, 70 cases in each group. The treatment group were treated with warming needle moxibustion plus exercise, with Hegu (LI 4), Xiaguan (ST 7), Yifeng (TE 17) and so on selected, in combination with opening and closing the mouth; the control group I were treated with simple filiform needle needling, and the control group II with local blocking therapy. The therapeutic effects of the 3 groups were compared. RESULTS: The total effective rate was 94.3% in the treatment group, 87.1% in the control group I and 85.7% in the control group II with a significant difference among the 3 groups, the treatment group being better than the two control groups (P < 0.05). CONCLUSION: Warming needle moxibustion plus exercise has a good therapeutic effect on temporomandibular joint dysfunction syndrome.