Beta-particle dosimetry in radiation synovectomy

Abstract

Beta-particle dosimetry of various radionuclides used in the treatment of rheumatoid arthritis was estimated using Monte Carlo radiation transport simulation coupled with experiments using reactor-produced radionuclides and radiachromic film dosimeters inserted into joint phantoms and the knees of cadavers. Results are presented as absorbed dose factors (cGy-cm2/MBq-s) versus depth in a mathematical model of the rheumatoid joint which includes regions of bone, articular cartilage, joint capsule, and tissue (synovium) found in all synovial joints. The factors can be used to estimate absorbed dose and dose rate distributions in treated joints. In particular, guidance is provided for those interested in (a) a given radionuclide's therapeutic range, (b) the amount of radioactivity to administer on a case-by-case basis, (c) the expected therapeutic dose to synovium, and (d) the radiation dose imparted to other, nontarget components in the joint, including bone and articular cartilage.

Long-term Clinical Outcome of Phase IIb Clinical Trial of Percutaneous Injection with Holmium-166/Chitosan Complex (Milican) for the Treatment of Small Hepatocellular Carcinoma

“…In an evaluation of acute toxicity in mice after the i.v. injection of 166 Ho/CHICO, the major effects of the injection of 1 mCi/kg were limited to the spleen, and the changes in the hematologic variables were reversible by day 14 after the injection (20).…”

Short-term clinico-radiological outcome of chronic knee synovitis among haemophilia A patients post phosphorus-32 radiosynoviorthesis

“…These radioisotopes, which are b emitters, generate free radicals resulting in apoptosis and finally ablation of inflamed synovial membrane. 5 Moreover, these molecules are safe and cause no damage to the articular surface.…”

An investigation of the thermoluminescence of Ge-doped SiO2 optical fibres for application in interface radiation dosimetry

“…Using the 90 kVp energy spectrum, the photon energy at which maximum photon yield is obtained is 31.2 keV, photon energies in the range of $ 40-50 keV contributing most prominently to the dose enhancement (Edward, 1966). For radiation synovectomy applications, 100 Gy is required to be deposited in the synovial membrane based on the estimation of 1 Gy per 1 g of synovial membrane (Johnson et al, 1995); the enhanced TL yields obtained herein indicate that large dose deposition can be made to happen at an interface between synovium and iodine contrast medium. Photoelectron production and concomitant dose distribution on the few micron scale (Johnson et al, 1995) can be obtained through use of stable iodine in association with incident X-ray irradiation for energies above and close to the absorption edge, the K-edge in this case.…”

“…For radiation synovectomy applications, 100 Gy is required to be deposited in the synovial membrane based on the estimation of 1 Gy per 1 g of synovial membrane (Johnson et al, 1995); the enhanced TL yields obtained herein indicate that large dose deposition can be made to happen at an interface between synovium and iodine contrast medium. Photoelectron production and concomitant dose distribution on the few micron scale (Johnson et al, 1995) can be obtained through use of stable iodine in association with incident X-ray irradiation for energies above and close to the absorption edge, the K-edge in this case. This may suggest that radiation synovectomy using a beta emitting radionuclide such as, 125 I, with a risk of skin necrosis and of organ damage due to leakage of activity from the joint capsule, could be replaced by the present so-called combination radiotherapy technique.…”

“…Synovectomy, the surgical removal of the inflammation of the synovium membrane of a synovial joint, is one of the treatment options. Radiation synovectomy is an alternative treatment, use of a beta-particle emitting radionuclide being the general method, treating or destroying inflamed and diseased synovium, the beta particles travelling 1-3 mm in soft tissues (Deutsch et al, 1993;Johnson et al, 1995;Clunie and Ell, 1995). As an alternative, X-ray phototherapy is a technique that offers considerable promise (Bradley et al, 2008), also for tumour treatment (Boudou et al, 2007).…”