Feasibility study of glass dosimeter postal dosimetry audit of high-energy radiotherapy photon beams.

INTRODUCTION: The characteristics of a glass dosimeter were investigated for its potential use as a tool for postal dose audits. Reproducibility, energy dependence, field size and depth dependence were compared to those of a thermoluminescence dosimeter (TLD), which has been the major tool for postal dose audits worldwide. MATERIALS AND METHODS: A glass dosimeter, GD-302M (Asahi Techno Glass Co.) and a TLD, TLD-100 chip (Harshaw Co.) were irradiated with gamma-rays from a (60)Co unit and X-rays from a medical linear accelerator (4, 6, 10 and 20 MV). RESULTS: The dosimetric characteristics of the glass dosimeter were almost equivalent to those of the TLD, in terms of utility for dosimetry under the reference condition, which is a 10 x 10 cm(2) field and 10 cm depth. Because of its reduced fading, compared to the TLD, and easy quality control with the ID number, the glass dosimeter proved to be a suitable tool for postal dose audits. Then, we conducted postal dose surveys of over 100 facilities and got good agreement, with a standard deviation of about 1.3%. CONCLUSIONS: Based on this study, postal dose audits throughout Japan will be carried out using a glass dosimeter.     

Detection of Homing, Proliferation, and Infiltration Sites of Adult T Cell Leukemia Cells in Severe Combined Immunodeficiency Mice Using Radiometric Techniques

To clarify the mechanism of in vivo proliferation of adult T cell leukemia (ATL) cells, we examined the organ distribution of ATL-43T cell line cells derived from original leukemic cells in severe combined immunodeficiency (SCID) mice using radiometric techniques. First, we injected ¹¹¹In-oxine-labeled ATL-43T cells into SCID and CB17 mice. On day 6, significant accumulation of radioactivity was found in the spleen and thymus of SCID mice (33.3±9.4 and 10.0±3.6 % injected dose/g of tissue [%ID/g], respectively) in comparison with that in CB17 mice (19.1±2.5 and 3.7±0.9 %ID/g, respectively). Next, we injected radiolabeled anti-Tac monoclonal antibody (MoAb) recognizing human interleukin-2 receptor (IL-2R) α chain or isotype-matched control MoAb RPC5 in SCID mice bearing ATL-43T cells 4 weeks after cell inoculation. The amounts of radioactivity found in the spleen and thymus of SCID mice injected with ¹²⁵I-labeled anti-Tac MoAb (22.5±6.9 and 22.8±9.6 %ID/g, respectively) were significantly higher than those in the corresponding organs of SCID mice injected with ¹²⁵I-labeled RPC5 MoAb (12.0±5.1 and 7.5±4.6 %ID/g, respectively). Similar results were obtained with ¹¹¹In-labeled anti-Tac MoAb. These results were consistent with the histological findings of SCID mice bearing ATL-43T cells, indicating that ATL-43T cells infiltrated preferentially into the lymphoid organs, such as the spleen and thymus, and proliferated there. Thus, the radiometric techniques employed in this study were very useful to evaluate the proliferation sites of ATL-43T cells in SCID mice. Furthermore, this murine model could give us an opportunity to test the feasibility of therapeutic application of radiolabeled anti-Tac MoAb.     

Aurora-B/AIM-1 kinase activity is involved in Ras-mediated cell transformation

Aurora-B, previously known as AIM-1, is a conserved eukaryotic mitotic protein kinase. In mammals, this kinase plays an essential role in chromosomal segregation processes, including chromosome condensation, alignment, control of spindle checkpoints, chromosome segregation, and cytokinesis. Aurora-B is overexpressed in various cancer cells, suggesting that the kinase activity perturbs chromosomal segregation processes. Its forced overexpression induces chromosomal number instability and progressive tumorigenicity in rodent cells in vitro and in vivo. Nevertheless, based on focus formation in BALB/c 3T3 A31-1-1 cells, Aurora-B is not oncogenic. Here, we show that Aurora-B kinase activity augments Ras-mediated cell transformation. RNA interference with short hairpin RNA inhibits transformation by Ras and its upstream oncogene Src, but not by the downstream oncogene Raf. In addition, the inner centromere protein, which is a passenger protein associated with Aurora-B, has a similar ability to potentiate the activity of oncogenic Ras. These data indicate that elevated Aurora-B activity promotes transformation by oncogenic Ras by enhancing oncogenic signaling and by converting chromosome number-stable cells to aneuploid cells.     

Cranial subdural hematoma after inadvertent dural puncture at epidural anesthesia

Intracranial subdural haematoma has been reported to be an exceptionally rare complication of accidental dural puncture. An accidental lumbar dural puncture occurred in a 36-yr-old male undergoing orthopedic knee surgery. On the morning after the operation, the patient complained of severe occipital headache, although this was relieved with loxoprofen and rest. This was assumed to be a postdural puncture headache (PDPH) because it had a postural component (it was worse on sitting up). On the third day after the operation, the patient developed a severe diffuse headache together with nausea, which did not subside with analgesia and bed rest. Magnetic resonance imaging of the head showed a small acute subdural hematoma in the bilateral temporooccipital region with no mass effect. The patient was conscious and oriented. There was no focal neurological deficit. The patient was managed conservatively with bed rest and intravenous fluids. His condition improved without surgical decompression and was discharged on the 40 th day after the operation. Severe and prolonged PDPH shoud be considered as a warning sign of an intracranial complication.     

Clinicopathologic study of non-Hodgkin lymphoma in sinonasal and hard palate regions in 15 Japanese cases

Non-Hodgkin lymphomas of the sinonasal region have been the subject of numerous studies. Previous reports have suggested that nasal lymphomas occurring in Orientals are mostly of the natural killer cell (NK)/T-cell phenotype which contrasts with the preponderance of the B-cell type in western populations. Recent studies indicated that NK/T-cell lymphoma constitutes the clinical condition of lethal midline granuloma. These reports led us to question whether all NK/T lymphomas are always lethal midline granuloma. We have investigated a series of 15 cases of non-Hodgkin lymphomas in the nasal and/or paranasal sinuses clinically, immunohistochemically and for the presence of Epstein-Barr virus (EBV). This study showed that the presence of EBV was common in nasal NK/T lymphoma, and this type of lymphoma was clearly highly frequent in other types of nasal lymphoma in our department. Moreover, in 4 cases of NK/T-cell lymphomas, the clinical features of lethal midline granuloma did not appear, indicating that NK/T lymphomas are not always lethal midline granuloma.     

Spatial fragment distribution from a therapeutic pencil-like carbon beam in water

The latest heavy ion therapy tends to require information about the spatial distribution of the quality of radiation in a patient's body in order to make the best use of any potential advantage of swift heavy ions for the therapeutic treatment of a tumour. The deflection of incident particles is described well by Molière's multiple-scattering theory of primary particles; however, the deflection of projectile fragments is not yet thoroughly understood. This paper reports on our investigation of the spatial distribution of fragments produced from a therapeutic carbon beam through nuclear reactions in thick water. A DeltaE-E counter telescope system, composed of a plastic scintillator, a gas-flow proportional counter and a BGO scintillator, was rotated around a water target in order to measure the spatial distribution of the radiation quality. The results revealed that the observed deflection of fragment particles exceeded the multiple scattering effect estimated by Molière's theory. However, the difference can be sufficiently accounted for by considering one term involved in the multiple-scattering formula; this term corresponds to a lateral 'kick' at the point of production of the fragment. This kick is successfully explained as a transfer of the intra-nucleus Fermi momentum of a projectile to the fragment; the extent of the kick obeys the expectation derived from the Goldhaber model.     

Gallbladder carcinoma presenting as exfoliative dermatitis (erythroderma)

Although exfoliative dermatitis (erythroderma) secondary to malignancy is commonly associated with lymphomas or leukemias, coincident gastrointestinal (GI) malignancy and erythroderma is rare. The authors recently encountered a patient with gallbladder carcinoma presenting as erythroderma. A 77-yr-old Japanese man presented with a 3-mo history of erythematous eruptions with pruritus over almost the entire body. After confirming the diagnosis of erythroderma, asymptomatic gallbladder carcinoma was found. Further investigations detected no malignancies in other organs. An extended cholecystectomy was performed. Histologic examination of resected specimens revealed poorly differentiated adenocarcinoma with negative resection margins. The eruptions with pruritus resolved within 1 wk after the operation. This is the first report, to our knowledge, of coincident biliary malignancy and erythroderma. The experience of the current patient suggests that erythroderma secondary to GI malignancy may resolve spontaneously after curative resection of the tumor.     

Metabolic penumbra of acute brain infarction: a correlation with infarct growth

Volume expansion associated with brain infarction occurs in perfusion-diffusion mismatch of magnetic resonance imaging. We aimed at elucidating the metabolic impairment of this phenomenon with (15)O positron emission tomography and perfusion and diffusion magnetic resonance imaging. Eleven patients with acute unilateral embolic occlusion of the internal carotid or middle cerebral artery were studied within 6 hours of onset. Regional cerebral blood flow and cerebral metabolic rate of oxygen (CMRO(2)) were compared with those in the contralateral cerebral hemisphere. The relative apparent diffusion coefficient of water was estimated as a marker of cytotoxic edema. Relative cerebral blood flow and relative CMRO(2) in an evolving infarct (normal diffusion initially, but abnormal on day 3) were significantly (p < 0.05) less than those in the periinfarct area (normal diffusion initially and on day 3). The relative apparent diffusion coefficient between the evolving infarct and periinfarct showed no significant difference. These findings indicated that the initial 3-day volume expansion of an embolic brain infarction was associated with disturbed CMRD(2) but not with cytotoxic edema as early as 6 hours after onset. The "metabolic penumbra" defined as normal water diffusion with depressed CMRO(2) is a target to reduce the volume expansion of brain infarction.