Sarmento Sandra, Pereira Joana, Sousa Maria José, Cunha Luís, Dias Anabela G, Pereira Miguel F, Oliveira Augusto D, Cardoso João V, Santos Luis M, Gouvêa Margarida, Lencart Joana, Alves João G, Santos João A M
Instituto Português de Oncologia do Porto Francisco Gentil (IPOPFG); IPOPFG E.P.E..
J Appl Clin Med Phys. 2016 Jan 8;17(1):316-327. doi: 10.1120/jacmp.v17i1.5725.
Computed tomography fluoroscopy (CTF) is a useful imaging technique to guide biopsies, particularly lung biopsies, but it also has the potential for very high hand exposures, despite use of quick-check method and needle holders whenever feasible. Therefore, reliable monitoring is crucial to ensure the safe use of CTF. This is a challenge, because ring dosimeters monitor exposure only at the base of one finger, while the fingertips may be exposed to the highly collimated CT beam. In this work we have explored the possibility of using Gafchromic XR-QA2 self-developing film as a complementary dosimeter to quantify hand exposure during CTF-guided biopsies. A glove used in a previous study and designed to contain 11 TLDs was adapted to include Gafchromic strips 7 mm wide, covering the fingers. A total of 22 biopsies were successfully performed wearing this GafTLD glove under sterile gloves, and the IR reported no difficulty or reduction of dexterity while wearing it. Comparison of dose distributions obtained from digitization of the Gafchromic film strips and absolute Hp(0.07) readings from TLDs showed good agreement, despite some positional uncertainty due to relative movement. Per procedure, doses at the base of the ring finger can be as low as 3%-8% of hand dose maximum. Accumulated dose at the base of the ring finger was four times lower than the dose maximum.
计算机断层扫描透视（CTF）是一种用于引导活检（尤其是肺活检）的有用成像技术，但尽管在可行时使用了快速检查方法和持针器，它仍有可能导致手部受到非常高的辐射。因此，可靠的监测对于确保CTF的安全使用至关重要。这是一项挑战，因为指环式剂量计仅在一根手指的根部监测辐射，而指尖可能会暴露于高度准直的CT束中。在这项工作中，我们探讨了使用Gafchromic XR-QA2自显影片作为补充剂量计来量化CTF引导活检期间手部辐射的可能性。对先前一项研究中使用的、设计用于包含11个热释光剂量计（TLD）的手套进行了改装，使其包含覆盖手指的7毫米宽的Gafchromic条带。在无菌手套下戴着这种GafTLD手套成功进行了总共22次活检，并且介入放射科医生（IR）报告称戴着它时没有困难或灵活性降低。对从Gafchromic胶片条带数字化获得的剂量分布与TLD的绝对Hp(0.07)读数进行比较，结果显示尽管由于相对移动存在一些位置不确定性，但两者吻合良好。每次操作时，无名指根部的剂量可低至手部最大剂量的3%-8%。无名指根部的累积剂量比最大剂量低四倍。
