“…For the RS, different radioisotopes can be used. The selection of the radioisotope should take into account two parameters [4,11]: 1) physical properties: half-life, soft tissue penetration, size of the radiocolloid, 2) and clinical features: joint size, amount of joint fluid, synovial thickness. The material should also be a pure beta emitter, thereby minimizing the whole body exposure to gamma radiation [4,8,12,13].…”