Assessment of salivary gland dysfunction after radioiodine therapy for thyroid carcinoma using non-contrast-enhanced CT: the significance of changes in volume and attenuation of the glands.

BACKGROUND AND PURPOSE: Although radiation induced damage to the salivary gland is a known complication of radioactive iodine ((131)I) therapy for thyroid carcinoma, prediction of the severity and reversibility of sialoadenitis is difficult. Our aim was to correlate the extent of salivary dysfunction assessed by salivary gland scintigraphy with changes in the volume and attenuation of salivary glands on nonenhanced CT in postoperative patients with thyroid cancer treated with RIT. MATERIALS AND METHODS: Forty patients with thyroid carcinoma, 13 men (age range, 21-80 years) and 27 women (age range, 28-75 years) who underwent a total thyroidectomy and were treated with RIT were assessed retrospectively. On CT, the percentage of volume reduction and the difference in attenuation of the parotid and submandibular glands after RIT were determined and correlated with the extent of radiation-induced salivary dysfunction on scintigraphy. RESULTS: The salivary gland volume significantly decreased with an increase in the dysfunction grade on scintigraphy for both the parotid and submandibular glands (P < .001). The attenuation significantly increased with an increase in the dysfunction grade on scintigraphy for the parotid gland (P < .001), but not for the submandibular gland. The cutoff value of volume reduction to diagnose severe gland dysfunction was 19.5% (sensitivity, 86.0%; specificity, 100%) for the parotid gland and 31.0% (sensitivity, 100%; specificity, 97.0%) for the submandibular gland, and that of the attenuation change was 9.8 HU (sensitivity, 81.0%; specificity, 95%) for the parotid gland. CONCLUSIONS: The reduction in volume of the parotid and submandibular glands and the increase in attenuation of the parotid gland on nonenhanced CT can be indicators of the grade of RIT-induced salivary dysfunction.

Immunoglobulin G4-related sclerosing disease mimicking invasive tumor in the nasal cavity and paranasal sinuses.

IgG4RSD affecting the nasal cavity and paranasal sinuses is extremely rare. A 71-year-old man presented with an invasive mass in the nasal cavity and paranasal sinuses that was confirmed by immunostaining to be IgG4RSD. The occurrence of this disease in the nasal cavity and paranasal sinuses can resemble a malignant tumor on diagnostic imaging.

Diagnosis and treatment of progressive space-occupying radiation necrosis following stereotactic radiosurgery for brain metastasis: value of proton magnetic resonance spectroscopy.

BACKGROUND: There have been some reports that radiation necrosis can be controlled conservatively. There are rare cases showing progressive space-occupying radiation necrosis (PSORN). It is very difficult to control PSORN by conservative treatment. The purpose of this study was to evaluate the early diagnosis of those cases and the timing of surgery for patients with PSORN. METHOD: We have experienced some cases where quality of life was improved by the removal of PSORN after stereotactic radiosurgery (SRS) for brain metastases. Therefore, we evaluated retrospectively the diagnosis and treatment of six cases of symptomatic PSORN at approximately 6-12 months after SRS for metastatic brain tumours. FINDINGS: In all six cases, on Magnetic Resonance Imaging with Gd contrast material (Gd-MRI), PSORN was revealed as a ring-like enhanced mass with large perifocal oedema coupled with the appearance of neurological deficit. Proton Magnetic Resonance Spectroscopy ((1)H-MRS) enabled us to differentiate PSORN from recurrence of metastases in all six cases. Single Photon Emission Computed Tomography with thallium-201 chloride (201TlCl-SPECT) enabled us to do this in four cases of the six. In four cases of the six, lesionectomy of the ring-like enhanced mass (PSORN) was performed, and in two of these cases the removal was performed within 4 weeks from the time when conservative treatment became ineffective, and the neurological deficit and perifocal oedema was improved as was the quality of life. However, in the other two patients who were left for more than 16 weeks, the deficit was gradually progressive. The two patients who did not receive lesionectomy were treated by conservative means with steroids and/or heparin and warfarin and they had progressive neurological symptoms. INTERPRETATION: Although, the number of patients is small in this study, and more data will be needed, it is recommended that lesionectomy is performed at an early stage, if possible, when conservative management has failed.

Estimation of fractional liver uptake and blood retention of 99mTc-DTPA-galactosyl human serum albumin: an application of a simple graphical method to dynamic SPECT.

The objective of this study was to investigate clinical utility of a graphical method for estimating liver uptake and blood retention of 99mTc-DTPA-galactosyl human serum albumin (99mTc-GSA; DTPA is diethylenetriaminepentaacetic acid) using dynamic single photon emission computed tomography (SPECT) data. When considering the kinetics of 99mTc-GSA, if it is assumed that (1) 99mTc-GSA distributes only between blood and liver, and (2) no metabolism of 99mTc-GSA occurs during the observation period, a plot of liver counts versus cardiac blood pool counts should, theoretically, be a straight line. From the slope and y intercept of a regression line, coefficients for converting count based liver and blood pool data to the per cent injected dose (%ID) can be calculated. The applicability of this method was tested on dynamic SPECT data from 30 patients with liver dysfunction. To validate this method, plasma concentrations (%ID/ml plasma) at 6, 15 and 30 min after the injection were estimated by this method and compared with the measured ones. To investigate the clinical significance of the per cent liver uptake, the value obtained by this method was compared with the results of conventional liver function tests, including serum albumin, the hepaplastin test, prothrombin time and indocyanine green clearance. In every data set, a plot of liver counts to cardiac blood pool counts was fitted well by a straight line (P<0.00001). Estimated plasma concentrations by this method showed good correlation with the measured ones at 6, 15 and 30 min after the injection (r=0.748, 0.838, 0.875, respectively; P<0.0001). The liver uptake determined by this method showed good correlation with the results of conventional hepatic function tests (P<0.002). The graphical method could provide an accurate estimate of %ID of 99mTc-GSA in blood without the need for blood sampling. The liver uptake determined by this method could be a simple but useful quantitative indicator of hepatic function.

Comparison of cardiac sympathetic nervous function with left ventricular function and perfusion in cardiomyopathies by (123)I-MIBG SPECT and (99m)Tc-tetrofosmin electrocardiographically gated SPECT.

UNLABELLED: The objective of this study was to clarify the relationship between cardiac sympathetic nervous function (CSNF) and left ventricular (LV) function and perfusion in hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). METHODS: Thirty-eight cases (32 males, 6 females; mean age, 56 +/- 15 y), consisting of 5 healthy control subjects, 15 patients with DCM, and 18 patients with HCM, were studied with (123)I-metaiodobenzylguanidine (MIBG) and (99m)Tc-tetrofosmin SPECT. CSNF was evaluated from cardiac uptake and washout of MIBG, whereas LV perfusion and function were evaluated from tetrofosmin uptake and wall thickening on electrocardiographically gated SPECT. As quantitative parameters of global cardiac MIBG uptake and washout, the heart-to-mediastinum ratio (H/M) and percentage washout were calculated from early and delayed planar images. As quantitative regional parameters, the regional uptake and percentage washout of MIBG were calculated from SPECT images dividing the left ventricle into 12 segments. In the tetrofosmin study, the H/M and LV ejection fraction were calculated as the parameters of global LV perfusion and function. As quantitative regional parameters, the regional uptake and wall thickening were also calculated for the 12 myocardial segments using the quantitative gated SPECT software. Multiple linear regression analysis was performed to investigate the correlations between the parameters from the 2 studies. RESULTS: In DCM and HCM, multiple linear regression analysis of the regional parameters showed significant correlations between LV function and CSNF (P < 0.0001) and between LV perfusion and CSNF (P < 0.0001). According to the partial correlation coefficients, washout and early uptake of MIBG were the most significant factors for predicting LV function and LV perfusion, respectively. CONCLUSION: In cardiomyopathies, CSNF was closely related to LV function. The quantitative parameters of MIBG washout could reflect cardiac functional impairment. Early MIBG uptake might be determined by myocardial perfusion in cardiomyopathies.

Scintigraphic evaluation of pamidronate and corticosteroid therapy in a patient with progressive diaphyseal dysplasia (Camurati-Engelmann disease).

A 27-year-old woman with progressive diaphyseal dysplasia (Camurati-Engelmann disease) received pamidronate and corticosteroid therapy for bone pain. During therapy, disease activity was assessed serially using bone scintigraphy with Tc-99m HMDP. With pamidronate administration, the bone pain became worse and diaphyseal uptake of Tc-99m HMDP increased, whereas corticosteroid administration improved the bone pain and reduced the diaphyseal uptake. In this case, pamidronate and corticosteroid produced different effects. Bone scintigraphy allowed an objective assessment of the response to these treatments, accurately reflecting clinical symptoms.

Intense uptake of technetium-99m tetrofosmin by lactating breasts.

A 38-year-old woman was hospitalized for syncope. Because an electrocardiogram showed intermittent ventricular tachycardia, myocardial perfusion imaging with technetium-99m tetrofosmin was performed to screen for coronary artery disease. Left ventricular myocardial perfusion was within normal limits. However, symmetric bilateral breast uptake was noted. According to her clinical history, she had been breast-feeding her 5-month-old infant until this admission. In these circumstances, the breast uptake of Tc-99m tetrofosmin was thought to be physiologic and related to lactation.

Optimal timing of administration of hyperthermia in combined radioimmunotherapy.

Local hyperthermia (HT) may enhance the efficacy of radioimmunotherapy (RIT). However, the optimal timing of HT relative to administration of antibody is unknown. Human colon cancer xenografts (290 +/- 26 mm3) were treated with 4.63 MBq 131I-A7 monoclonal antibody (MAb) anti-Mr 45,000 glycoprotein antigen on colorectal cancer, and HT at 43 degrees C for 1 h was administered at: (A), 2 days after the 131I-A7 injection at the maximum 131I-A7 tumor accumulation (radiation); (B), soon after the 131I-A7 injection aiming to increase the tumor accumulation of 131I-A7 due to HT vascular effects; or (C), 2 days before the 131I-A7 injection in an attempt at injecting 131I-A7 when increased antigen expression could be expected. Specific growth delay (SGD) of tumors was calculated as (Tqtreat-Tqcontrol)/Tqcontrol where Tq was tumor quadrupling time. The biodistribution and intratumoral distribution of 131I-A7 were investigated to explore the mechanism of tumor response among the different HT regimens. HT alone produced some antitumor effect (SGD 1.90 +/- 0.26), which was less effective than RIT (3.11 +/- 0.50). HT soon after 131I-A7 RIT (B) significantly enhanced RIT efficacy (6.57 +/- 0.51, p < 0.0001) whereas neither HT at 2 days after RIT (A) nor at 2 days before RIT (C) did so. Biodistribution study revealed that HT soon after RIT (B) increased the tumor radiation absorbed dose by a factor of 2.4, while HT after RIT (A) did not increase radiation dose and HT before RIT (C) decreased it. Radioluminograms of tumor sections indicated that HT soon after RIT (B) improved the uniformity of 131I-A7 distribution whereas HT after RIT (A) did not and HT before RIT (C) diminished the uniformity of A7 distribution. In conclusion, the best therapeutic efficacy was obtained when HT was combined soon after the initiation of RIT with 131I-A7. The increased tumor radiation absorbed dose and the uniform intratumoral distribution of 131I-A7 were important factors underlying this improvement, and the additive cytotoxicity of HT is suspected to some extent. HT-induced radiosensitization of tumor was not apparent in this model when HT was given 2 days after 131I-A7 MAb.

[Clinical study of cerebral blood flow in bilateral chronic subdural hematoma measured by 99mTc-HMPAO SPECT].

Cerebral blood flow(CBF) in 34 patients with bilateral chronic subdural hematoma was measured by 99mTc-HMPAO SPECT before operation. The regional CBF was measured in 26 regions of the 10 cortical regions, putamen, thalamus and cerebellar hemisphere on both sides. According to the thickness of subdural hematoma, the thicker hematoma side was measured and examined as the thick hematoma side, and the other side as the thin hematoma side. Thirty four cases with bilateral chronic subdural hematoma were classified into four groups on the basis of clinical symptoms: 13 cases with headache(headache group), 10 cases with hemiparesis(hemiparesis group), 5 cases with tetraparesis(tetraparesis group) and 6 cases with consciousness disturbance or dementia(consciousness disturbance group), and into two groups according to the degree of midline brain shift on MRI: 14 cases of non-shifted group and 20 cases of shifted group. The average CBF of 34 patients in each region indicated a regional CBF reduction in the frontal, parietal and occipital cortices on the thin hematoma side, and in the putamen on the thick hematoma side. In the headache group, the regional CBF reduction on the thin hematoma side was found in the frontal, parietal and occipital cortices compared with the corresponding regions on the thick hematoma side, and in thalamus on the thick hematoma side. In the hemiparesis and tetraparesis groups, there was no statistically significant CBF reduction between the thick and thin hematoma sides. In the consciousness disturbance group, the CBF reduction in whole brain was remarkably significant. By the degree of the midline brain shift, the CBF reductions between the thick and thin hematoma sides were observed. Namely, in the shifted group, the CBF reductions were noted in the frontal, parietal and occipital cortices in the thin hematoma side, and in the putamen in the thick hematoma side. We concluded that the CBF reduction of bilateral chronic subdural hematoma was bilaterally found in the hemiparesis and tetraparesis groups, and which was finally observed in whole brain in the consciousness disturbance group.

Pulmonary vein and left atrial invasion by lung cancer: assessment by breath-hold gadolinium-enhanced three-dimensional MR angiography.

PURPOSE: The purpose of this work was to evaluate the ability of breath-hold gadolinium-enhanced three-dimensional (3D) MR angiography to assess the invasion of the pulmonary vein and the left atrium by lung cancer. METHOD: Gadolinium-enhanced 3D MR angiography was performed in 20 consecutive patients with lung cancer. RESULTS: At two sites with left atrial invasion shown by MR angiography, associated partial resection of the left atrium was performed. At five sites with invasion of the proximal pulmonary vein within 1.5 cm from the left atrium on MR, partial resection of the left atrium was performed at one site, and the pulmonary vein was resected at the intrapericardial portion at three sites. At two sites with invasion of the proximal pulmonary vein 1.5 cm more distal to the left atrium, the pulmonary vein was resected at the extrapericardial portion. CONCLUSION: Breath-hold gadolinium-enhanced 3D MR angiography is suitable for assessing invasion of the pulmonary vein and the left atrium by lung cancer.

[Study on evaluation method of patient dose in diagnostic radiology required for introducing the guidance level: investigation of entrance surface dose of patient using direct measurement by TLD].

Using direct measurement, we investigated entrance surface doses of patients for routine radiographs in attempt to develop evaluation methods of patient dose in order to establish the guidance level in Japan. To date, patient doses have been evaluated by calculations based on radiographic conditions, or model experiments using phantoms. Their patient doses are then evaluated based on several assumptions. Direct measurement of patient dose is difficult to perform in many patients due to its time requirement, level of expertise required and difficulty in providing an explanation of the procedure to the patient. However, such direct measurement is essential since it incorporates all aspects of radiography from the radiographic equipment used, to the actual conditions of each patient without assumption. In this study, we examined the (1) need for introducing the guidance level, (2) controversial points in the calculation method for patient dose evaluation, (3) evaluation accuracy required for introducing the guidance level, and (4) necessity for a standardized method.

Extensively calcified hemangioma of the diaphragm with increased 99mTc-hydroxymethylene diphosphonate uptake.

A 31-year-old woman visited an out-patient clinic, because of low-grade fever and general fatigue. She was referred to our hospital and admitted for examination of an abnormal shadow which had been found on the chest radiograph. She had experienced faint right lateral chest pain several times on the deep inspirations. Chest radiography showed a mass shadow with calcification in the right lower lung field on the mediastinal side. Chest radiographic computed tomography showed a 6x6 cm tumor in the right lung field. There were low-density areas with septae inside the tumor. Bone scintigraphy showed extremely high uptake of (99m)Tc-HMDP in the tumor. After surgical resection and pathological examination, we concluded that the tumor was an extensively calcified benign hemangioma of the diaphragm.

Protein-loss into retroperitoneal lymphangioma: demonstration by lymphoscintigraphy and blood-pool scintigraphy with Tc-99m-human serum albumin.

A rare, benign congenital lymphangioma has been reported to occur frequently in the neck and axilla, but rarely in the retroperitoneal space. We report a case of a retroperitoneal lymphangioma associated with hypoproteinemia caused by protein-loss into the tumor. In this case, lymphoscintigraphy with subcutaneously injected Tc-99m-human serum albumin (HSA) disclosed the communication between the tumor and the lymphatic system, and sequential abdominal scintigraphy with intravenously injected Tc-99m-HSA revealed the protein loss into the tumor. Abdominal scintigraphy with Tc-99m-HSA injected intravenously or subcutaneously is occasionally useful for determining the etiology of hypoproteinemia.

Increased uptake of 99mTc-HL91 in tumor cells exposed to X-ray radiation.

99mTc-HL91, a hypoxic marker, may be a predictor of tumor response to radiotherapy and an indicator of tumor oxygenation in the course of treatment. In this study, serial changes in 99mTc-HL91 uptake were observed in the normoxic condition in a human bladder cancer cell line exposed to a single dose or a fractionated dose of 10 Gy with an x-ray beam. The uptake per cell increased during cell growth retardation induced by the irradiation. This finding indicates that 99mTc-HL91 uptake is affected by injury to cells due to radiation; it may therefore be difficult to correctly assess the tissue oxygenation status during radiotherapy with 99mTc-HL91.