Declining free thyroxine levels over time in irradiated childhood brain tumor survivors

Objective: The incidence of cranial radiotherapy (cRT)–induced central hypothyroidism (TSHD) in childhood brain tumor survivors (CBTS) is reported to be low. However, TSHD may be more frequent than currently suspected, as its diagnosis is challenging due to broad reference ranges for free thyroxine (FT4) concentrations. TSHD is more likely to be present when FT4 levels progressively decline over time. Therefore, we determined the incidence and latency time of TSHD and changes of FT4 levels over time in irradiated CBTS. Design: Nationwide, 10-year retrospective study of irradiated CBTS. Methods: TSHD was defined as ‘diagnosed’ when FT4 concentrations were below the reference range with low, normal or mildly elevated thyrotropin levels, and as ‘presumed’ when FT4 declined ≥ 20% within the reference range. Longitudinal FT4 concentrations over time were determined in growth hormone deficient (GHD) CBTS with and without diagnosed TSHD from cRT to last follow-up (paired t-test). Results: Of 207 included CBTS, the 5-year cumulative incidence of diagnosed TSHD was 20.3%, which occurred in 50% (25/50) of CBTS with GHD by 3.4 years (range, 0.9–9.7) after cRT. Presumed TSHD was present in 20 additional CBTS. The median FT4 decline in GH-deficient CBTS was 41.3% (P < 0.01) to diagnosis of TSHD and 12.4% (P = 0.02) in GH-deficient CBTS without diagnosed TSHD. Conclusions: FT4 concentrations in CBTS significantly decline over time after cRT, also in those not diagnosed with TSHD, suggesting that TSHD occurs more frequently and earlier than currently reported. The clinical relevance of cRT-induced FT4 decline over time should be investigated in future studies

Planning for the Transition to Long-Term Stewardship at Three U.S. Department of Energy-Chicago Operations Office Facilities

This paper describes a pilot study that resulted in the generation of draft planning documents for the upcoming transition from remediation construction to long-term stewardship at three national laboratories managed by the U.S. Department of Energy (DOE)-Chicago Operations Office (CH). The remediation construction work at these facilities is being completed under the DOE's Office of Environmental Management (EM) Program. Once the remediation is complete, the responsibility for long-term stewardship (LTS) of the closed waste sites is expected to be transferred to the DOE organization responsible for managing each of the three facilities (i.e., the site landlord). To prepare for this transfer, an extensive planning effort is required. This pilot study utilized the DOE guidance in effect at the time to (1) develop a series of documents identifying applicable requirements that the LTS Programs will need to satisfy, issues that need to be resolved before the transfer can proceed, and criteria to be used to determine when active remediation is complete and a given site is ready for transfer to the LTS Program; (2) examine alternate structures for possible LTS Programs; and (3) develop draft LTS Implementation Plans. This advanced planning effort yielded a number of observations and lessons learned that are applicable to any facility approaching the end of its remediation construction phase