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Objective Bladder filling in patients with cervical cancer before and after operation during intensity-modulated radiotherapy (IMRT) was controlled by using bladder volume measurement instrument (BVI 9400).The displacement errors of the target area and the changes of the irradiation dose and the morphology of the filling bladder were compared.The significance of consistency of preoperative and postoperative bladder filling in IMRT for cervical cancer was investigated.Methods Forty-five patients with cervical cancer treated with radiotherapy in our hospital in 2018 were recruited and divided into A,B and C groups (n=15).In group A,patients did not undergo surgery,patients in group B received radical resection of cervical cancer (bladder volume measurement (BVI 9400) was utilized to monitor the bladder urine volume in both A and B groups before treatment).In group C,patients who self-controlled urination without monitoring bladder urine volume before treatment were randomly selected.All patients in three groups underwent KV-CBCT scan before treatment for online registration analysis.The displacement errors in the x-(left and right),y-(head and foot),z-axis directions (ventral and dorsal),PTV coverage volume percentage (V10o) and percentage difference (△ V100) of the prescription dose were calculated.Results The average displacement errors in the x-,y-,z-axis directions were as follows:1.67 mm,1.55 mm and 1.67 mm in group A,1.43 mm,1.58 mm and 1.84 mm in group B,and 2.27 mm,2.30 mm and 2.08 mm in group C,respectively.In group A,the V1oo was calculated as 96.96％ and △ V1oo was 1.17％.In group B,V1oo was 9 5.9 ％ and △ V10o was 1.2 9 ％.In group C,V10o was 9 4.0 2 ％ and △ V100 was 2.1 7 ％.Conclusions Controlling the consistency of bladder filling can reduce the effect of inconsistency of bladder filling upon the displacement errors to certain extent,which can guarantee the accuracy of the target location and the irradiation dose of the target,protect the bladder,small intestine and rectum,and alleviate the radiation-induced response of cervical cancer patients.
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Objective To explore the importance of head fixation in chest wall field combined with supraclavicular field radiotherapy for breast cancer by comparing the displacement error and dosimetric differences caused by multi-functional body board and breast bracket.Methods Thirty patients with breast cancer were randomly divided into groups A and B.In group A,patients were fixed with multi-functional body board and head thermoplastic film.In group B,patients were fixed with traditional breast brackets.Each patient received CBCT scan before and after radiotherapy.Both setup errors and intra-fractional displacements in the x-,y-and z-axis,V100 and V95 were calculated.Statistical analyses were performed using the independent sample t-test.Results The displacement errors in groups A and B before and after radiotherapy were (1.24± 0.42),(1.71± 0.61) and (2.25± 1.04) mm vs.(3.67± 2.05),(3.78± 1.74),(4.65±2.66) mm in the x-,y-and z-axis,respectively (P=0.033,0.027,0.020).The intra-fractional displacements in groups A and B were (1.10±0.66),(1.13±0.59),(1.11 ±0.62) mm vs.(2.48±0.88),(2.21 ±0.98),(3.53±2.01) mm in the x-,y-and z-axis,respectively (P=0.030,0.021,0.013).The V100 in groups A and B were (94.27± 3.20) ％ and (99.08± 0.60) ％ (P =0.065),and (89.48± 4.70) ％ and (96.53± 2.50) ％ for V95 (P =0.002),respectively.Conclusion The risk of displacement error is significantly reduced using multi-functional body board,which enhances the accuracy of radiation dose in chest wall and supraclavicular fields of breast cancer patients.
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Objective To investigate the clinical target volume (CTV)-planned target volume (PTV) setup margins during intensity-modulated radiotherapy (IMRT) for cervical cancer patients with different body mass index (BMI),aiming to provide reference for precise individual therapy.Methods Forty patients diagnosed with cervical cancer undergoing IMRT in Cancer Hospital of Fudan University between March and September 2017 were recruited and assigned into the BMI ≤ 18.4,18.5-23.9,24.0-27.9 and ≥ 28 kg/m2 groups according to the BMI classification criteria proposed by National Health and Family Planning Commission (NHFPC) of the People's Republic of China.Assisted with the bladder volume measurement device,9 cycles of kilo-voltage cone beam computed tomography (CBCT) images were subject to online registration and imaging analysis.CTV-PTV setup margins were calculated based on the formula of MPTV =2.5∑+0.7σamong four groups.Single factor variance analysis was performed.LSD test was utilized for two-group comparison.Results Among four groups,the CTV-PTV setup margins in the x,y and z directions were (6.87 mm,6.06 mm,8.49 mm),(3.13 mm,3.02 mm,3.14 mm),(4.70 mm,4.86 mm,5.31 mm) and (7.63 mm,8.28 mm,8.54 mm),respectively (P=0.038,0.048 and 0.004).Conclusions The setup errors in the BMI ≤ 18.4 and ≥28 kg/m2 groups are significantly larger compared with those in the remaining groups Consequently,CTV-PTV setup margins should be enlarged to certain extent for patients with BMI≤ 18.4 and ≥≥28 kg/m2.
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Background and purpose:Radiotherapy is one of the main treatment methods for brain tumor patients, but neurotoxicity was observed frequently. Because of the confounding factors in clinical data, it’s hard to summarize the characteristic of neurological changes after brain irradiation. This study used the brain irradiation injury model of rats to test whether brain irradiation change the mood and memory.Methods:Whole brain of SD rats (6-8 weeks old) was exposed to 22 Gy radiation. Open ifeld and elevated plus maze was used to assess the anxiety of rats, passive avoidance was used to assess the mood memory, and novel place recognition was used to assess the spatial memory at 1 month or 10 months after brain irradiation.Results:At 1 month post irradiation, rats moved with less distance and entrance to the central zone of open ifeld with less time, explored the open and closed arms with less time and the exploration of open arms also decreased, entered the darkroom more rapidly during the test phase of passive avoidance, and lose the interest to explore the novel place during novel place recognition. At 10 months post irradiation, rats exhibited similarly with control group during open ifeld and elevated plus maze test, but still entered the darkroom more rapidly during the test phase of passive avoidance, and lose the interest to explore the novel place during novel place recognition.Conclusion:Brain irradiation could decrease the locomotor activity, increase the anxiety mood, reduce the mood and spatial memory; mood dysfunction induced by brain irradiation could restore, but memory impairments would be long-standing.