The basic characteristics of cellulose triacetate (CTA) film dosimeter have been investigated with 5, 8, and 15 MeV proton beams. The optical density change per unit absorbed dose for 8 and 15 MeV protons is the same as that given for electron beams, but a little smaller for 5 MeV protons. The CTA dosimeter was found to be useful to obtain dose distributions with high spatial resolution in samples exposed to proton beams.
The availability of an X-ray absorption technique employing a very low power X-ray tube was examined to extend measurable range for photographic film dosimetry. The X-ray tube having titanium target was operated at 8 kV and 0.2 μA to emit Ti KX-rays of moderate intensity. The degree of the Ti KX-ray absorption, defined as similar to photographic density, was measured for the two kinds of badge film, Fuji gamma-ray badge film and Kodak personal monitoring film, type 2 exposed for60Co or137Cs gamma-rays and developed by the respective standard procedures. The experimental results show that the dosimetric range of 0.01-100 R for the Fuji film and 0.03-1000 R for the Kodak film may be easily measured by 1 minute counting with the relative statistical error (σ) of 10%.
Hepatobiliary studies on five patients with Dubin-Johnson syndrome were performed using99mTc-PMT. Time-activity curves of the liver of the patients showed delayed excretion and that plasma elimination in the patients was prolonged compared to that of normal subjects.
To clarify clinical evaluation of highly sensitive thyroid stimulating hormone (TSH) immunoradiometric assay (IRMA) using RIABEAD II kit, we measured serum TSH and its changes after TRH test in normal subjects and patients with hyperor hypo-thyroidism due to Grave's disease, TSHproducing pituitary adenoma and chronic thyroi-ditis or Ref etof's syndrome. In 12 normals, basal TSH (0.23 -1.85μIU/ml) increased in 2.29 -18.85μIU/ml 30 min after TRH test. In patients whose serum TSH and thyroid hormone showed less than 0.10μIU/ml and more than normal level, respectively, no response of TSH to TRH was observed, while in patients whose serum TSH and thyroid hormone showed more than 3.5μIU/ml and less than normal level, respectively, hyperresponse of TSH to TRH was observed. In patients with hyper-or hypo-thyroidism, changes in serum TSH after treatment were normalized a few months later after normalizing of thyroid hormone. In patients with TSH producing pituitary tumor or Ref etof's syndrome, serum TSH increased. These results show that serum TSH using IRMA- (RIABEAD II) kit indicates a precise function of pituitary TSH.