ABSTRACT
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.
ABSTRACT
Objective To develop a balloon-type head fixation pillow for interventional neuroradiology operation.Methods Some radiotransparent sponge with high elasticity and strength and some nonopaque cloth with high skin compatibility were employed to make pillow base adaptable to the posterior fossa, neck and shoulder. A inflatable balloon made of anti-tensile airtight nylon was used to fix the underjaw.Results The fixation pillow gained advantages over the common one in imaging times, X-ray exposure dose and abnormal condition.Conclusion The head fixation pillow may decrease operating time, exposure dose and complications during interventional neuroradiology operation, and thus is worth popularizing clinically.
ABSTRACT
Head restraining is an experimental technique that firmly secures the animal's head to a fixation apparatus for the precise control and sensing of behaviors. However, procedural and surgical difficulties and limitations have been obstructing the use of the technique in neurophysiological and behavioral experiments. Here, we propose a novel design of the head-restraining apparatus which is easy to develop and convenient for practical use. Head restraining procedure can be completed by sliding the head mounter, which is molded by dental cement during implantation surgery, into the port, which serves as matching guide rails for the mounter, of the fixation bar. So neither skull-attached plates nor screws for fixation are needed. We performed intracranial self stimulation experiment in rats using the newly designed device. Rats were habituated to acclimatize the head-restraint environment and trained to discriminate two spatially distinguished cues using a customized push-pull lever as an operandum. Direct electrical stimulation into the medial forebrain bundle served as reward. We confirmed that head restraining was stable throughout experiments and rats were able to learn to manipulate the lever after successful habituation. Our experimental framework might help precise control or sensing of behavior under head fixed rats using direct electrical brain stimulation as a reward.