We applied Demons and accelerated Demons elastic registration algorithm in radiotherapy cone beam CT (CBCT) images, We provided software support for real-time understanding of organ changes during radiotherapy. We wrote a 3D CBCT image elastic registration program using Matlab software, and we tested and verified the images of two patients with cervical cancer 3D CBCT images for elastic registration, based on the classic Demons algorithm, minimum mean square error (MSE) decreased 59.7%, correlation coefficient (CC) increased 11.0%. While for the accelerated Demons algorithm, MSE decreased 40.1%, CC increased 7.2%. The experimental verification with two methods of Demons algorithm obtained the desired results, but the small difference appeared to be lack of precision, and the total registration time was a little long. All these problems need to be further improved for accuracy and reducing of time.
Algorithms ; Cone-Beam Computed Tomography ; Humans ; Image Interpretation, Computer-Assisted ; Imaging, Three-Dimensional ; Software

Objective To explore a new method of comparing the references images first to enhance the precision of the central point of the radiation treatment planning(RTP), try to establish a reference standard for this method in the nasopharyngeal cancer(NPC)and carcinoma of utercin cervix in the work of position verification. Methods For 50 RTPs of NPC and 20 RTPs of carcinoma of utercin cervix, the reference-CT-images in set-up and in position verification were compared, and to measure the difference between the two images. Then, in the same way, compare and measure the difference in the central-pointimages. Results For NPC, there was over 90% RTPs in which every difference measured was less than 2 mm;for carcinoma of utercin cervix, over 80% RTPs meet the criterion:the value of △MU1 ' or △MU2' was less than 5 mm and the others are less than 3 mm. Conclusions By comparing the references-CT-images in set-up and in position verification, the precision of the central point of the RTP is enhanced. The marks on the skin become more credible. So, it is feasible to perform the criterions in the work of position verification:for NPC every difference measured is less than 2 mm;for carcinoma of utercin cervix the value of △MU1 ' or △MU2 ' is less than 5 mm and the others are less than 3 mm.

Objective To explore the relationship between the overlap volume of organ at risk (OAR) and target (Voverlap) and the mean dose to OAR (DmOAR) in intensity-modulated radiotherapy (IMRT).Methods Fifty randomly selected patients undergoing IMRT for nasopharyngeal carcinoma (NPC) and an equal number of patients undergoing radical IMRT for cervical cancer in our hospital were enrolled as subjects.The relationship between Voverlap and DmoAR in IMRT was analyzed.The Matlab software was used to generate function to fit the relationship between Voverlap and DmOAR for different OARs.Results The Voverlap varied among patients with NPC or cervical cancer.The ratio of Voverlap to the volume of OAR (VOAR) was positively correlated with the ratio of DmOAR to the prescribed dose (Dp) (all P=0.01).A function was generated to fit the correlation between Voverlap/VOAR ratio and DmOAR/Dp ratio.Conclusions In IMRT,patients have different Voverlap/VoAR ratios due to varicd target volume,disease stages,OAR filling status,and OAR volume.As criteria for plan verification,a specific DmOAR value for each OAR should be calculated before radiotherapy planning based on the corresponding correlation function and the Voverlap/VoAR ratio with a fixed dose prescription.It can be used to reduce the subjective influence on the optimization of radiotherapy planning.

Objective To study the iso-center point coincidence of two accelerators with treatment planning system (TPS) based on γ passing rates of intensity-modulated radiotherapy (IMRT) plan verification.Methods Twenty-one IMRT plans were verified by Varian accelerator and twenty by Elekta accelerator with a gamma criterion of 3 mm/3％.The passing rates were measured when the iso-center point of TPS had-2,-1,0,1,and 2 mm shift in the x or y direction.A binomial curve of γwas fit to figure out the values of the two accelerators on the x and y axes when γ value reached the maximum.The γ pass rate difference was analysed by x2 test.Results The mean values of γ-2,γ-1,γ0,γ1,and γ2 in the x direction were (92.56±3.27) ％,(96.53± 1.82) ％,(96.13± 1.41) ％,(90.14± 2.87) ％,and (82.28± 4.69) ％ for Varian accelerator,and (94.82± 2.04) ％,(97.05± 2.02) ％,(98.38± 1.33) ％,(97.96± 1.44) ％,and (94.49±2.34)％ for Elekta accelerator.There was no significant difference in the mean value of γ0between the two accelerators (P=0.332).When γvalue reached the maximum,the values on the x and y axes were0.65 and-0.30 mm for Varian accelerator and 0.01 and 0.30 mm for Elekta accelerator,respectively.Conclusions In the same TPS,different accelerators have different degrees of coincidence of the actual field center point with the iso-center point of TPS,to which more attention should be paid in clinical practice.

Objective:To introduce a novel surgical technique for dissecting perforator vessels (orderly retrograde four-side dissection) in anterolateral thigh perforator flap (ALTPF) and explore its clinical outcome.Methods:Respective analysis of 94 patients who underwent reconstruction of soft tissue defects with ALTPF which were dissected by orderly retrograde four-side dissection between June, 2013 and December, 2016. After surgery, the survival of flaps, recovery in shape and function of the recipient sites, and the effect on shape and function of the donor sites were observed.Results:The size of ALTPF ranged from 7 cm×5 cm to 32 cm×10 cm. Ninety-four perforators were included in 94 ALTPF, which were 89 perforators of the descending branch of circumflex femoral lateral artery, 4 perforators of the transverse branch of circumflex femoral lateral artery and 1 perforator of femoral medial artery. The time for flap harvesting was 35-95(54.39±16.39) min. Success rate of perforator harvesting was 98.9%, only 1 perforator was injured and another encountered vasospasm during surgery. Three cases had vascular crisis after flap transfer with 2 venous crises and 1 artery crisis. All of the flaps completely survived except 1 that had a partial necrosis. The follow-up time was (12.91±9.17) months. No muscular weakness on donor sites was shown in all cases.Conclusion:Orderly retrograde four-side dissection of perforator vessels in the ALTPF has achieved less donor site morbidity, shorter surgical time and is safer than the traditional techniques. It is a reliable technique to harvest perforator flaps.

A child who suffered a complex and exceptionally large soft tissue defects of both lower extremities and feet was referred in January, 2017. A debulking deep inferior epigastric perforator (DIEPF) was used to cover the defect in right shank. The defects in left shank and foot were reconstructed by latissimus dorsi flap and bilateral debulking anterolateral thigh perforator flap (ALTPF) . Two years after operation, the appearance and texture of both lower limbs were good, and the child could walk and run almost normally. There were slightly noticeable scars left in both thighs and the back.

Objective: To preliminarily evaluate the safety of the coplanar template-assisted ¹⁹²Ir hypofractionated stereotactic ablative brachytherapy (SABT) in patients with locally advanced non-small cell lung cancer (LA-NSCLC), and assess the effect of template-assisted technology upon the accuracy of SABT by comparing the consistency of dosimetric parameters between preoperative and operative plans. Methods: Fifteen patients histologically confirmed with LA-NSCLC (stage Ⅱ_B-Ⅲ_A) were recruited and received the template-assisted SABT delivered in a risk-adapted fractionation (30 Gy/1F). Preoperative planning, template-assisted needle implantation, operative planning and implementation were performed in all patients. Dosimetric results of preoperative and operative plans were statistically compared by assessing the dosimetric parameters of gross tumor volume (HI, CI, D₉₀, V₁₀₀ and V₁₅₀) and organ at risk(V₅, V₂₀ and mean dose of bilateral lung, D_2cc of spinal cord. The incidence of perioperative complications of SABT was recorded. The safety and feasibility of SABT were evaluated. Results: Slight changes were noted in terms of target dose and irradiated dose to the lung between preoperative and operative plans without statistical significance (both P>0.05). No severe adverse events, such as severe pneumothorax, hemothorax and hemoptysis were observed. Conclusions Application of the template-assisted SABT can enhance the accuracy of implantation, maintain the consistency of the dosimetric parameters between the preoperative and operative plans and guarantee the clinical efficacy.

Autoimmune encephalitis (AE) is a novel form of encephalitis associated with antibodies to cell-surface or synaptic proteins. Epileptic seizures act as the predominant manifestation of AE which are triggered by interaction between kinds of antibodies and antigens on cell-surface or intracellular. Patients with AE-related epilepsy are insensitive to antiepileptic drugs but sensitive to immunotherapy. Early initiation of immunotherapy can significantly improve the prognosis. To date, there are few reports on the treatment plan of antiepileptic drug to the patients with AE-related epilepsy. In this review we report the most relevant data about the morbidity, pathogenesis and treatment of AE-related epilepsy with aim of providing better treatment options.

Objective To analyze the effect of needle arrangement on the lung dose in interstitial brachytherapy for lung cancer. Methods For 15 patients undergoing interstitial brachytherapy for lung cancer, a virtual radiotherapy plan in which needle arrangement was not restricted by the ribs was designed and compared with the original plan. For the two plans, V5, V20, V30, and mean lung dose(MLD)of the whole lung were determined when the prescribed doses were 10,30, 60, and 120 Gy, respectively. The data were analyzed by Wilcoxon signed-rank test. Results The lung V5,V20, V30, and MLD were significantly smaller in the virtual plan than in the actual plan(all P<0.05). Conclusions Irregular needle arrangement prevents a further reduction in the lung dose in interstitial brachytherapy for lung cancer. In the implantation surgery, therefore, the needles should be arranged as regularly as possible.

Objective To investigate the clinical efficiency of posterior tibial artery perforator pedicle propeller flaps for soft tissue coverage of the lower leg and foot defects.Methods From May,2008 to May,2016,30 cases with soft tissue defects of the lower leg and foot were cured by using posterior tibial artery perforator pedicle propeller flaps.The size of flaps ranged from 8.0 cm×4.0 cm to 24.0 cm×9.0 cm.Fascia flap was harvested in 5 cases,8 cases with deep fascia,and 6 cases with saphenous vein and saphenous nerve.The degree of flap rotation were from 160° to 180°.The donor sites were closed directly in 27 cases,and covered with skin grafting in 1 case,and with sequential flap in 2 cases.The shape,color,texture and satisfaction of the flaps were recorded during follow-up.Results Twenty-five flaps survived completely.The distal part of skin flap necrosis occurred in 3 cases and the wound healed well after dressing change.The distal part of flap necrosis occurred in 1 case,and free anterolateral thigh perforator flap was used to repair in the second phase.The complete necrosis of the flap occurred in 1 case,healing with scar after 2 months dressing treatment.All cases were followed-up from 4 months to 4.5 yeas (average 1.7 years).All flaps were smooth with a satis fied appearance and high patient satisfaction.Conclusion Posterior tibial artery perforator pedicle propeller flap which has reliable blood supply,less donor-site morbidities,cosmetic shape,simple operation and less postoperative complications,is an ideal method for soft tissue coverage of the lower leg and foot defects.