Radiation exposure to comforters and carers during paediatric molecular radiotherapy.

BACKGROUND: To show whether the incidental radiation exposure received by comforters and carers of children undergoing molecular radiotherapy was kept as low as reasonably achievable and was within English national dose constraints. PROCEDURE: The radiation exposure of adult comforters and carers was routinely monitored with a whole body personal dose meter while the child was in hospital. Data were collected on iodine-131 meta-iodobenzylguanidine (131 I-mIBG), lutetium-177 DOTATATE (177 Lu-DOTATATE), and iodine-131 sodium iodide (131 I-NaI) treatments. RESULTS: Data were available for 50 treatments with high-administered activity double-infusion 131 I-mIBG and 12 single administrations; 15 177 Lu-DOTATATE treatments and 28 131 I-NaI administrations. The median age was 7 years (1-18). The median administered activity of: 131 I-mIBG was 16.2 GBq (6.8-59 GBq) for double infusion patients and 8.1 GBq (5.26-16.25 GBq) for single administrations; 177 Lu-DOTATATE was 7.2 GBq (2.5-7.5 GBq); and 131 I-NaI was 3 GBq for thyroid remnant ablation and 5.5 GBq for cancer therapy. The median number of comforters and carers for all administrations was 2 (range 1-9). The median exposure values for comforters and carers for high-administered activity 131 I-mIBG administrations was 302 µSv (0-5282 µSv); for single fraction 131 I-mIBG 163 µSv (3-3104 µSv); 177 Lu-DOTATATE 6 µSv (1-79 µSv); and 131 I-NaI 37 µSv (0-274 µSv). Only one of the comforters and carers exceeded the dose constraint of 5 mSv. CONCLUSIONS: Doses to comforters and carers were in all but one case within the dose constraint nationally recommended by the Health Protection Agency, now part of Public Health England. New evidence is presented which show that comforter and carer radiation exposure levels from paediatric molecular radiotherapy in routine clinical practice are acceptably low. Pediatr Blood Cancer 2015;62:235-239. © 2014 Wiley Periodicals, Inc.

The association between metal ions from hip resurfacing and reduced T-cell counts.

We have studied the relationship between metal ion levels and lymphocyte counts in patients with metal-on-metal hip resurfacings. Peripheral blood samples were analysed for lymphocyte subtypes and whole blood cobalt and chromium ion levels in 68 patients (34 with metal-on-metal hip resurfacings and 34 with standard metal-on-polyethylene total hip replacements). All hip components were radiologically well-fixed and the patients were asymptomatic. Cobalt and chromium levels were significantly elevated in the patients with metal-on-metal hip resurfacings, compared with the patients with standard metal-on-polyethylene designs (p < 0.0001). There was a statistically significant decrease in the level of CD8(+) cells (T-cytotoxic/suppressor) (p = 0.005) in the metal-on-metal hip resurfacing group. A threshold level of blood cobalt and chromium ions was associated with reduced CD8(+) T-cell counts. We have no evidence that our patients suffered as a result of this reduced level of CD8(+) T-cells.