Kumar Rajeev, Sonkawade Rajendra G, Pandey Anil K, Tripathi Madhavi, Damle Nishikant A, Kumar Praveen, Bal Chandra S
aDepartment of Nuclear Medicine and PET Cyclotron Facility, All India Institute of Medical Sciences, New Delhi bDepartment of Physics, Shivaji University, Kolhapur, Maharashtra, India.
Nucl Med Commun. 2017 Jan;38(1):10-14. doi: 10.1097/MNM.0000000000000598.
The aim of this article was to share 10 years of operational experience of medical cyclotron and to provide working knowledge on the same. This experience has helped us gain working knowledge on cyclotron operation with practical points, which may help in improving F yield, minimizing the breakdown time, and help in the prevention of the occurrence of unusual events.
Our facility has a self-shielded radioisotope delivery system eclipse 111 medical cyclotron with an 11 MeV proton beam in use for the past 10 years to produce positron emitters - namely, F, N, and F-2 gas - for PET imaging. During F production, we have followed a set protocol comprising the following: monitoring target pressure, rinsing the target with O water just immediately after bombardment, ion source feedback, radiofrequency (RF) feedback, and recording any unusual events that occurred during the operation. Besides this, enrichment of O water, target volume, target current, energy of the beam, variation in argon pressure on the target, bombardment duration, target status (new or old target or total number of previous bombardments on the same target), status of the delivery lines from target to the radiochemistry module (old or new) were also recorded.
Rinsing with O water immediately after bombardment increases the life of the target and delivery line. The frequent problems encountered were with the ion source, RF, and target foil rupture. These problems were solved by rebuilding the ion source, changing the fuse of RF, and rebuilding the target.
F yield can be increased by rinsing with O water immediately after bombardment. The effect of target leak - that is, rupture of vacuum window - can be avoided by immediate stoppage of bombardment.
本文旨在分享医用回旋加速器10年的运行经验，并提供相关实用知识。这些经验帮助我们掌握了回旋加速器运行的实用要点，有助于提高氟产量、缩短故障时间，并预防异常事件的发生。
我们的设施拥有一台自屏蔽放射性同位素输送系统——日蚀111医用回旋加速器，其11兆电子伏质子束在过去10年一直用于生产正电子发射体，即氟、氮和氟-2气体，用于正电子发射断层显像（PET）成像。在生产氟的过程中，我们遵循了一套既定方案，包括：监测靶压，轰击后立即用重水冲洗靶，离子源反馈，射频（RF）反馈，以及记录运行期间发生的任何异常事件。除此之外，还记录了重水的富集情况、靶体积、靶电流、束流能量、靶上氩气压力变化、轰击持续时间、靶状态（新靶或旧靶或同一靶之前的轰击总次数）、从靶到放射化学模块的输送管道状态（旧的或新的）。
轰击后立即用重水冲洗可延长靶和输送管道的使用寿命。常见问题出在离子源、射频和靶箔破裂上。通过重建离子源、更换射频保险丝和重建靶解决了这些问题。
轰击后立即用重水冲洗可提高氟产量。通过立即停止轰击可避免靶泄漏的影响，即真空窗破裂。
