Changes of local tissue of a case who was exposed to '5.7' ¹⁹²Ir source accident in Nanjing

Objective: To observe changes of local tissue injury caused by ¹⁹²Ir external exposure and investigate the diagnosis and treatment of local radiation injury. Methods: Observation was mainly focused on the clinical manifestations of local pathological changes, by using MRI to evaluate local tissue injury, using dual energy X-ray to detect bone mineral density(BMD) and using electrochemiluminescence (ECL) to assay bone metabolic biochemical indicators of β-CTx, PINP and serum testosterone levels. Results: Exposed local skin was diagnosed as Ⅳ degree acute radiation injury to skin, showing erythema, swelling, pain, blisters, ulcers, and necrosis. The wound healed 383 days after exposure, but the right lower limb was dyskinetic. MRI eximanations showed that femoral injury on the right lower extremity involved skin, femur, multiple muscles and bone marrow tissue. BMD examination showed a reduction in bone mass(-1.5 to -1.1), transient increase in bone metabolism index β-CTx(493.50 to 1580.00 pg/ml), and fluctuation in levels of PINP(49.30 to 291.80 ng/ml) and serum testosterone(5.41 to 608.80 ng/dl). Conclusions: Acute external radiation exposure at high dose can lead to severe local tissue injury. MRI examinations are important for local damage assessment. BMD bone metabolism index and serum testosterone are useful in evaluation of bone injury. Both systemic and local therapy should be considered as equally important for local injury treatment. (authors)