With the development of modern computing technology and medical physics,radiotherapy has made great progress.The theoretical basis of radiobiology seems to lag behind the clinical application of radiotherapy,which hampers the further improvement of treatment efficacy and the optimization of treatment modality.In this paper,some emerging challenges of precision radiotherapy technology to the traditional theory of radiobiology,such as radiosensitivity,dose-response curve and survival curve,linear-quadratic model,4Rs theory,as well as the interaction between cancer and microenvironment,radiation-induced second primary cancers (RISPC),will be discussed.The interplay between precision radiotherapy and traditional radiobiology theories will be addressed with the aim to potentially solve some of the challenging problems.

Objective To evaluate the diagnostic efficacy of Kwak and ACR( 2017 ) thyroid imaging reporting and data systems ( T I‐RADS ) for thyroid nodules . Methods Cases of thyroid nodule who underwent surgery from January 2015 to M arch 2018 in 15 hospitals in Sichuan province were collected and the ultrasonographic features of thyroid nodules were retrospectively analyzed by trained senior ultrasound physicians using Kwak and ACR T I‐RADS classification methods . Totally ,12 712 thyroid nodules were observed ,7 023 thyroid nodules in 7 023 cases with complete ultrasound and surgical and pathological data were eventually enrolled in the study . T hyroid nodules with solid ,hypoechoic or very hypoechoic ,tall/wide ratio ≥ 1 , margin ill‐defined and microcalcification were classified as malignant signs of ultrasound . M alignant percentage was calculated and diagnostic tests were performed . Results ① T here was a statistical difference between the benign and malignant nodules in the two types of T I‐RADS classification ( P＜0 .01) . ② T he area under ROC curve of Kwak and ACR in the diagnosis of malignant nodules were 0 .89 and 0 .84 ,respectively . T he Youden index of Kwak and ACR were 0 .66 and 0 .57 ,respectively . ③Taking Kwak T I4B and ACR T R4 as critical points for malignancy ,the sensitivity ,specificity ,positive predictive value and negative predictive value of Kwak T I 4B were 75 .0% ,90 .9% ,83 .2% ,and 85 .9% , respectively . T he accuracy of Kwak T I4B was 84 .9% ; T he sensitivity ,specificity ,positive predictive value and negative predictive value of ACR T R4 were 88 .2% ,68 .9% ,62 .9% ,and 90 .8% ,respectively . T he accuracy of ACR T R4 was 76 .2% . T he Kappa value of Kwak TI4B and ACR T R4 was 0 .52 . T he χ2 value of Kwak T I4B and ACR T R4 was 2 174 .6 ( P ＜ 0 .01 ) . Conclusions T he diagnostic values of two T I‐RADS classification methods for thyroid malignant nodules are high . T he overall efficiency of Kwak T I‐RADS classification method is better than that of ACR TI‐RADS classification method .

ObjectiveTo discuss the clinical application of the temporary balloon occlusion of the common iliac artery in the control of hemorrhage in the operations of the old pelvic fractures.Methods From January 2006 to June 2009,twelve patients (10 males,2 females; mean age 33.9 years) with old pelvic fractures of Tile C type were treated operatively.Three cases were treated with external fixator.Operative treatments were delayed for the treatment of the life-threatening visceral injuries in six nonunions and three malunions.A balloon catheter was placed through intravascular intervention in the common iliac artery of the affected side.The balloon catheter was infolded when the osteotomy was performed and the operations were undertaken under temporary and total occlusion of the common iliac artery.Osteotomies and internal fixations were performed in 12 cases.Decompressions of lumbosacral trunk were undertaken in 4 cases complicated with injuries of sciatic nerve.ResultsThe mean time of operations was 290 min(range,210-367min).The mean time of occlusions was 65 min (range,45-90 min).The loss of blood ranged from 700 ml to 2800 ml,with an average of 1833 ml.All cases were followed up for 12-48 months,with an average of 35 months.The mean time of bone healing was 20.6 weeks (range,16-24 weeks).No thrombosis of the common iliac artery and deep venous thrombosis of the lower extremity or ischemic necrosis happened.In the four cases complicated with injuries of sciatic nerve,three recovered partly and could walk with a crutch and one recovered completely and could walk normally.Two cases limped and other six cases could walk normally.ConclusionThe effect of temporary balloon catheter occlusion of common iliac artery is reliable.It drastically reduces hemorrhage during the operation and avoid the complications of selective arterial embolism and ligation and makes the operations of the old pelvic fractures more safer.

Objective To explore effects of sequel recanalization PCI therapy(primary coronary intervention,PCI) on cardiac function for the patients with acute ST segment elevation myocardial infarction(STEMI),and related factors.Methods 116 patients with STEMI enrolled were divided randomly into two groups:sequel recanalization PCI group(58 cases) and conventional PCI group(58 cases),and the patients of sequel recanalization PCI group were fully absorbed for thrombus before conventional PCI,then compared estoration of their cardiac function of the patients of two groups at once and 2 weeks after PCI procedure,respectively.Meantime to study the effect related-factors for cardiac function by Logistic regression analysis.Results There were significant differences between two groups in RESVmax(P =0.03) 、RESVmin(P = 0.00) 、REFmax(P = 0.00)、 REDVmax(P = 0.01) and the ratio of E/A(P =0.02)(all P＜0.05);it showed that the restoration of cardiac function of sequel recanalization PCI group was faster than that of conventional PCI group.If sequel recanalization PCI served as a variable for predicting REFmax being 50%,the results of logistic regression showed that OR(odds ratio) value was 3.47,95% CI(confidence interval) 1.39-9.75,P =0.04.Among other variables,as was time-to-recanalization(OR =4.59,P =0.01);infarct size(OR =4.59,P=0.01);Kiliip grades(OR = 3.99,P =0.02)and age(OR=2.75,P=0.04).Conclusion The sequel recanalization PCI could be better than conventional PCI for the patients with STEMI in restoration of heart function,but there should be some other effective factors.

Objective To investigate the effects of propofol on death-associated protein kinase (DAPK) mRNA expression in a rat model of traumatic brain injury (TBI). MethodsSixty male Wistar rats with a mean age of 3-4 months and mean body weight of 250-300 g were randomly divided into 6 groups ( n = 10 each) : Ⅰ normal control;Ⅱ sham operation; Ⅲ TBI; Ⅳ normal saline (NS) +TBI;Ⅴ fat emulsinn+ TBI and Ⅵ propefol + TBI. TBI was produced according to Feeney et al. In group Ⅲ-Ⅵ the animals were killed and their brains were removed at 24 h after brain contusion. NS 2 ml·kg-1 · h-1 , 10% fat emulsion 2 ml · kg-1 · h-1 and propofol 2 ml·kg-1·h-1 were infused iv for 4 h after lead trauma in group Ⅳ, Ⅴ and Ⅵ respectively. DAPK mRNA expression in the brain tissue was determined by RT-PCR and neuronal apeptosis was assessed by TUNEL. Results The expression of DAPK mRNA and neuronal apoptosis were significantly increased in the TBI group as compared with normal control and sham operation groups. Propefol infusion significantly attenuated neuronal apoptosis and reduced DAPK mRNA expression as compared with TBI, NS and FE groups. ConclusionPropofol can protect the brain from traumatic injury by suppression of the expression of DAPK mRNA.

Objective To investigate the effectiveness of femoral troehanter reconstruction and artificial femoral head replacement in treatment of unstable intertrochanterie fractures in the elderly pa- tients. Methods Femoral trochanter reconstruction and artificial femoral head replacement was done on 106 patients with unstable intertrochanterie fractures. There were 45 males and 61 females, at age range of 80-105 years (average 88 years). Most of patients slipt in the room and got fractured. According to the Evans classification, there were 31 patients with type ⅢA fractures, 45 with type ⅢB and 30 with type IV. We used 4 kinds of methods to reconstruct the fracturad imertrochanters : (1) shape of" ∞ " ten- sion band fixation after intertrochanterie fracture reduction;(2) wire loop fixation of the lesser troehanter around proximal femur;(3)defect within the femoral ealear was filled with bone cement and remodeled; (4) for patients with relative intact base of femoral neck, the intertrochanterie fracture was transformed in- to femoral neck fracture and the femoral ealear was fixed with femoral prosthesis stem. Results All the operations continued successfully, with duration of the operation for 45-70 minutes (average 55 minutes). No artificial femoral head dislocation occurred during hospitalization. Of all, 79 patients were followed up for 6-48 months (average 16 months). No Late loosening, dislocation or infections occurred, with total excellence rate of 87.3%. Conclusions For elderly patient with unstable intertrochanterie fractures, reconstruction of femoral intertrochant and artificial femoral head replacement can restore the proximal femoral anatomy, maintain stability of the hip joint and help early functional exeereise, as can reduce ease fatality rate and improve the quality of life.

Objective To explore the mechanism of percutaneous laser disc decompression (PLDD) for treating prolapse of intervertebral disc. Methods 15 rabbits were divided into 3 groups randomly: sham group, model group with PLDD treatment, model group without PLDD treatment. The nerve conduction velocity (NCV) of L6 nerve root and the activity of phospholipase A2 (PLA2) in the intervertebral disc of L5-6 were determined 2 weeks after the initial surgery. Results NCV in the group with PLDD was significantly faster than that in the group without PLDD (P<0.001); NCV in the group without PLDD was significantly lower than that in the sham group (P<0.001). The activity of PLA2 in the group with PLDD was significantly lower than that in the group without PLDD (P<0.001); The activity of PLA2 in the group without PLDD was significantly higher than that in the sham group (P<0.001). Conclusion The activity of PLA2 in the herniated discs is higher than that in normal discs, which result in NCV falls remarkably. The PLDD can reduces chemical factors such as PLA2.

Objective To study the clinical effect and necessity of removing internal fixation after treatment of acromioclavicular dislocation (Tossy Ⅲ ) with AO clavicular hook plate. Methods From October 2001 to October 2004, 31 patients with acromioclavicular dislocation (Tossy Ⅲ ) were treated with AO clavicular hook plate and were followed up. All of their broken acromioclavicular joints were sutured and the clavicular insertions of deltoid and trapezius muscles were repaired. The coracoclavicular ligaments were sutured for only 9 patients. Their shoulder functions before and after taking out of the internal fixation were assessed by Constant and Murley evaluation and compared. Results 24 patients were followed up from 4 to 40 months after operations (averaging 22 months). There were no loosening or breakage of internal fixations. The plates were removed 12 to 27 months postoperatively (averaging 18 months) in only 9 patients. No redislocation occurred after taking out of the plates. The scores of shoulder joint function were 76.5? 8.6 and 99.5? 1.0 (P

Objective To evaluate the preliminary outcome of surgical treatment of unstable distal radius fractures caused by osteoporosis in the elderly patients with open reduction and internal fixation with T-shaped locking compression plates(T-LCP).Methods From June 2003 to may 2005,13 elderly cases of comminu ted unstable distal radius fractures caused by osteoporosis were treated with op en reduction and T-LCP internal fixation.They were four males and nine females,with an average age of 74 years old(ranging from 67 to 81).According to AO classification,two cases belonged to types B2,three to type B3,two to type C1,five to type C2 and one to type C3.All of them were closed fractures.They were fixated with T-LCP through the volar approach and their dorsal soft tissues were not dissected during the operation.Osteoset,the artificial bone substitute,was implanted in one case of large bone defect.The postoperative functional recovery ranged from 6 to 30 weeks with an average of 12.3 weeks.Passive wrist motion,active finger motion and forearm rotation were encouraged immediately after surgery.Active wrist motion was suggested seven days postoperatively.Result s The 13 cases were followed up for 4 to 22 months,with an average time of 13.2 months.The X-ray pictures showed that one-stage union was achieved in all the patients,with a mean healing time of seven weeks.No such complications were found as infection,non-union,loosing of nails,carpal tunnel syndrome or medium neuritis.Their clinical outcomes were evaluated according to the modified Mcbride grading system.Nine were rated as excellent,three as good and one as fair,with their good-excellent rate being 92.3%.Conclusions T-LCP can ensure a good fixation in the treatment of unstable distal radius fractures caused by osteoporosis in elderly patients,allow the patients to do early exercise,and achieve satisfactory clinical outcome.

Objective To report the result of minimally invasive treatment of scaphoid non-union in soldiers. Methods Twenty-two soldiers 19 to 27 years of age were admitted for the treatment of non-union of fracture of scaphoid bone. The duration of non-union ranged from 11 to 54 months (average 16 months).All the non-union was located at the scaphoid waist, with a gap of 2 to 5 mm (average 2.5mm) as shown by radiological examination. Cyst-like changes occurred in 6 cases and displacement of the sclerotic fracture ends was found in 3 cases. Under local anethesia, a needle was inserted into the site of non-union under X-ray monitor, and 5-10 ml red bone marrow harvested from the iliac crest was injected into the site of non-union. The wrist was immobilized in functional position with elastic bandage or plaster of paris cast after the injection. Radiological follow-up was carried out every one month postoperatively. Bone marrow injection could be repeated 1 month later when necessary. Results Bone union was found in 19 cases 3-15 months (average 6 months ) after the operation. Non-union recurred in 3 patients in whom displacement of the sclerotic fracture ends was found. No complications, such as infection or joint stiffness, occurred. Conclusion Minimally invasive treatment of scaphoid non-union in soldiers can relieve pain, reduce the hospitalization days and cost, and the result is satisfactory.