A New Method of Forearm Tumor Immobilization in Radiotherapy
Objective To propose a new method of forearm tumor immobilization in radiotherapy.Methods The patient lied prone on the treatment bed,tilted to the healthy side,with a soft pillow under the head.The healthy arm placed on the body side,while the affected arm extended and gripped a beverage which was placed at the original headrest of the body board.Making the ulnar side of the palm was flat against the body board,and the affected arm was slightly bent to ensure the comfort of the patient lying prone and the natural relaxation of the affected palm grip.Moved the fixed bed and positioned the laser lamp to the predetermined scanning center,drew three sets of body surface marking lines on the affected arm,made and pressed a thermoplastic film on the affected arm,attached lead dots,and performed CT scanning.After the plan design,review and verification were approved,the patients were put on the machine.Before treatment,the patients were underwent pre-treatment position verification by using cone beam CT(CBCT),and treatment were carried out after the verification was approved.When the translation error in the three-dimensional direction was less than 5 mm and the rotation error in the six dimensional direction was less than 3°,it was artificially defined as a pass through position.Results The pass rate for 18 CBCT verifications in two patients was 83.3%.The total setup errors in the translation direction were(2.33±0.14),(2.39±0.12),and(1.49±0.12)mm in the patient's left-right,superior-inferior and anterior-posterior,respectively.The total setup errors in the rotation direction are 0.76°±0.42°,1.05°±0.72°,and 2.43°±0.88° in the patient's pitch,yaw and roll directions,respectively.Conclusion The new method of forearm tumor immobilization in radiotherapy meets the requirements of conventional fractionated radiotherapy for treatment positioning.
万方数据
维普
