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The Japanese Society of Nuclear Medicine has recently published the consensus guidelines for pediatric nuclear medicine. This article is the English version of the guidelines. Part 1 proposes the dose optimization in pediatric nuclear medicine studies. Part 2 comprehensively discusses imaging techniques for the appropriate conduct of pediatric nuclear medicine procedures, considering the characteristics of imaging in children.

Objective: As metastasis of prostate carcinoma occurs in approximately 80 % of terminal prostate carcinoma patients, the prognostic value of the prediction of prostate carcinoma by bone scintigraphy is important. We compared the automated and semi-automated bone scan index (BSI) system with extent of disease (EOD) grade if there is a possibility to substitute for EOD grading., Materials and Methods: We evaluated the bone scintigraphic images of 158 prostate carcinoma patients (mean age, 69.2 years old; range 50-97). Bone scans were obtained approximately 3 h after the intravenous injection of 740 MBq technetium-99 m-methylene diphosphonate. EOD grade was evaluated by 2 experienced radiologists using bone scintigraphy, magnetic resonance imaging, and computed tomography. We calculated the BSI using the Bonenavi(®) system (Fujifilm RI Pharma Co., Ltd.), utilizing data from a Japanese database. The semi-automated BSI of the patients was obtained by modifying the automated BSI independently by 3 radiologists (referred to as "observers" in this study) with 25, 10, and 4 years of experience. We then compared the EOD with the corresponding 4 independent BSIs for each patient. We used the Steel-Dwass test for multiple comparisons of the BSI among different EOD groups of patients. We analyzed the receiver-operating characteristics (ROC) curve to determine the cutoff values of sensitivity and specificity, which were both set at 95 %., Results: There were significant correlations observed among the mean EOD and BSI scores as determined using the Bonenavi(®) system for every patient group for all observers and the automated method. There was also a statistically significant difference in the mean BSI among all EOD groups (grades 0, 1, or 2-4) for all observers and the automated method. Each ROC curve showed an ideal shape and was within the optimal cutoff range., Conclusion: On the basis of the present results, BSI as calculated using the Bonenavi(®) system significantly correlated with EOD. Sensitivity and specificity as measured by the fully automated method were lower than those of semi-automated BSI with modification by radiologists. Therefore, semi-automated BSI is considered to have the possibility to substitute for EOD grading to predict the survival of prostate carcinoma patients with bone metastases, with only slight interobserver variation.

Objectives: This study was undertaken to measure the radiation exposure level of caregivers following outpatient NaI (I-131) 1,110 MBq therapy for remnant thyroid ablation after total thyroidectomy in patients with differentiated thyroid cancer, and to evaluate the influence of activities of daily living on radiation exposure level, with the goal of proposing an optimum method of I-131 therapy., Methods: The study included 37 patients with differentiated thyroid cancer, who had undergone total thyroidectomy and received outpatient based remnant thyroid ablation using NaI (I-131) 1,110 MBq, who were satisfying the following requirements: (1) patients who have no evidence of distant metastases, (2) whose living environments were appropriate for outpatient I-131 (1,110 MBq) therapy, and (3) patients who gave written informed consent. The dose rate at a distance of 1 m from the body surface of the patient at the moment of release was measured using survey meters of the GM type or ionization chamber type. The dose level for the caregiver was measured with a personal dosimeter in all cases., Results: The dose rate at a distance of 1 m from the patient's body surface 1 h after I-131 administration was in the range of 29-115 μSv/h (mean 63.8 μSv/h). The 7-day cumulative effective dose of caregivers was 0.11 ± 0.08 mSv, on an average, in 34 dosimeters. In 31 of 34 dosimeters, cumulative effective dose of caregivers was below 0.2 mSv. Dose levels exceeding 0.2 mSv were recorded in 3 cases (0.21, 0.35 and 0.43 mSv in one case each). These results suggest that the exposure level of family members (caregiver and others) was minimal and is lower than the radiation levels affecting human environments., Conclusion: Outpatient-based remnant thyroid ablation with I-131 (1,110 MBq) performed after total thyroidectomy in patients with differentiated thyroid cancer is safe if applied in accordance with the appropriate supervision and guidance by experts with certain qualifications.

Background: To determine the usefulness of positron emission tomography (PET) with (11)C-acetate (AC) for imaging lung adenocarcinoma and evaluating its tumor aggressiveness, AC- and (18)F-fluorodeoxyglucose (FDG)-PET were compared., Methods: One hundred and sixty-nine adenocarcinomas with clinical stage IA and 53 benign nodules were examined by both AC- and FDG-PET before surgery. The sensitivity and specificity for discriminating benign/adenocarcinoma were compared between AC- and FDG-PET. The AC and FDG uptakes were examined to determine the relationship with tumor aggressiveness, i.e., pathological tumor stage, lymphatic, vascular, or pleural involvement, and proliferative activity determined by Ki-67 staining score., Results: While the sensitivity of AC-PET was significantly higher than FDG-PET for bronchioloalveolar carcinoma (BAC) and well-differentiated (W/D) adenocarcinoma (p < 0.001 and 0.006, respectively), there was no significant difference for moderately or poorly differentiated adenocarcinoma. The specificity was not different between them. While FDG uptakes were significantly higher in tumors with pathological advanced stages or those with lymphatic, vascular and/or pleural involvements than in tumors with pathological stage IA or those without these tumor involvements (p = 0.04 to p < 0.001), AC uptake did not show significant differences between the respective sub-groups except according to the tumor stage. While both AC and FDG uptakes showed a significant correlation with Ki-67 staining scores (p = 0.03 and p < 0.001, respectively), the correlation coefficient of former was lower than that of latter (p = 0.07)., Conclusions: While AC-PET can image BAC and W/D adenocarcinoma with a higher sensitivity than FDG-PET, it cannot evaluate tumor aggressiveness of clinical stage IA lung adenocarcinoma as well as FDG-PET.

Objective: The Subcommittee on the Survey of Nuclear Medicine Practice in Japan has performed a nationwide survey of nuclear medicine practice every 5 years since 1982 to provide detailed information on its present status., Methods: Questionnaires were sent to all institutions known to the Japan Radioisotope Association to conduct nuclear medicine examinations. The questionnaires addressed the number and kind of nuclear medicine examinations performed as well as the kind and dose of the radiopharmaceuticals used during the month of June 2007. The annual number of total or specific examinations was then estimated., Results: Of the institutions sent questionnaires, 1219 were for in vivo study, 49 for in vitro study, and 212 for positron emission tomography (PET) study. Of these, 92.2% provided answers. A total of 1569 gamma cameras were installed in 1119 institutions, of which 70% were dual-head cameras. The estimated total annual number of in vivo examinations expressed by the number of administered radiopharmaceuticals was 1.41 million, representing a decrease of 11.5% when compared with that of the previous survey (2002). The frequency of study with respect to single-photon emission computed tomography (SPECT) slightly increased to 42.3% from 39.9% in the previous survey. The most frequently performed scintigraphy was bone (38.3%), followed by myocardium (26.2%) and brain perfusion (14.1%). Brain perfusion scintigraphy slightly increased, whereas tumor scintigraphy decreased by one-half when compared with the previous survey. The most commonly used radiopharmaceutical for each scintigraphy was (99m)Tc-HMDP for bone, thallium-201 ((201)Tl)-chloride for myocardium, gallium-67 ((67)Ga)-citrate for tumor, and technetium-99m-ethylcysteinate dimmer ((99m)Tc-ECD) for brain. The number of PET institutes increased from 36 to 212. (18)F-fluorodeoxyglucose ((18)F-FDG)-PET dramatically increased 14.8-fold during the past 5 years. Radionuclide therapy also increased. (131)I therapy for thyroid cancer and hyperthyroidism was conducted yearly in 2373 and 4146 patients, respectively. A total of 13.1 million in vitro radioassays were carried out yearly, the number of which has been decreasing continuously since 1992., Conclusions: It was proved that the content of nuclear medicine practice in Japan has changed considerably in the past 5 years. Namely, (18)F-FDG-PET and radionuclide therapy increased. This report might be useful for understanding the present trends of nuclear medicine practice in Japan.

Objective: Dementia with Lewy bodies (DLB) is generally characterized by a decrease in regional cerebral blood flow (rCBF) in the occipital lobe. However, not all patients with DLB have this feature. We explored characteristics of rCBF pattern changes to improve the identification of DLB, in addition to occipital hypoperfusion., Methods: The study population comprised 30 patients with probable DLB and 49 patients with probable Alzheimer's disease (AD) who underwent single-photon emission computed tomography. The data were analyzed using Neurological Statistical Image Analysis Software (NEUROSTAT). We established a template of the region of interest (ROI) presenting the parietal lobe, posterior cingulate, striatum, thalamus, and occipital lobe on the standard brain atlas. We then compared the mean Z scores in each ROI between DLB and AD. Moreover, we investigated the value of analyzing relative rCBF changes in both the deep gray matter and occipital lobe in differentiating DLB from AD., Results: The DLB group showed a significant relative rCBF increase in the bilateral striatum and thalamus, and a significant relative rCBF decrease in the bilateral occipital lobe when compared with the AD group. Receiver-operating characteristic analysis revealed that determining the hyperperfusion in the thalamus together with the hypoperfusion in the occipital lobe enabled a more accurate differentiation between DLB and AD than studying individual areas., Conclusions: Studying the relative increase of rCBF in the deep gray matter, and the relative decrease of that in the occipital lobe achieved a high differentiation between DLB and AD. This suggests that determining both an increase and a decrease in rCBF pattern may be important in differentiating between the two diseases.

Objective: We studied the behaviors of cost functions in the registration of thallium-201 (201Tl) brain tumor single-photon emission computed tomography (SPECT) and magnetic resonance (MR) images, as the similarity index of image positioning., Methods: A marker for image registration [technetium-99m (99mTc) point source] was attached at three sites on the heads of 13 patients with brain tumor, from whom 42 sets of 99mTc-201Tl SPECT (the dual-isotope acquisition) and MR images were obtained. The 201Tl SPECT and MR images were manually registered according to the markers. From the positions where the two images were registered, the position of the 201Tl SPECT was moved to examine the behaviors of the three cost functions, i.e., ratio image uniformity (RIU), mutual information (MI), and normalized MI (NMI)., Results: The cost functions MI and NMI reached the maximum at positions adjacent to those where the SPECT and MR images were manually registered. As for the accuracy of image registration in terms of the cost functions MI and NMI, on average, the images were accurately registered within 3 degrees of rotation around the X-, Y-, and Z-axes, and within 1.5 mm (within 2 pixels), 3 mm (within 3 pixels), and 4 mm (within 1 slice) of translation to the X-, Y-, and Z-axes, respectively. In terms of rotation around the Z-axis, the cost function RIU reached the minimum at positions where the manual registration of the two images was substantially inadequate., Conclusions: The MI and NMI were suitable cost functions in the registration of 201Tl SPECT and MR images. The behavior of the RIU, in contrast, was unstable, being unsuitable as an index of image registration.

Unlabelled: We evaluated a new semiquantitative procedure to more easily and objectively estimate the striatal uptake of 123I-FP-CIT in patients with Parkinsonian syndrome (PS) and essential tremor (ET), using an anatomical standardization method, the Neurostat., Methods: Eleven patients with PS and 8 with ET were examined by clinical assessment and 123I-FP-CIT SPECT imaging. The modified Hoehn and Yahr Staging Scale and Unified Parkinson's Disease Rating Scale (UPDRS) were used to assess the stage and severity of the disease. The co-registered MR and SPECT images were created with fusion software included in Neurostat. On the cross section, which shows the largest area of striate, irregular shaped regions of interest corresponding to the striate and occipital cortex were drawn. Then the ratio of specific striatal uptake to non-specific occipital cortex, V3"(F), was calculated. Another calculation was done by VOIClassic, which is a software included in Neurostat to estimate the counts per voxel of anatomically defined regions such as caudate nucleus, putamen, occipital cortex, and total cortex. Using these count data, the ratio of specific striatal uptake to non-specific occipital cortex, V3"(OC), and total cortex, V3"(TC), was calculated., Results: A fair linear correlation was observed between V3"(OC) and V3"(F) (y = 1.53x + 1.40; r = 0.756; p < 0.01), as well as between V3"(TC) and V3"(F) (y = 1.24x + 1.43; r = 0.713; p < 0.01). Both V3"(OC) and V3"(TC) yielded similar tendencies. Concerning discrimination between ET and PS, there was a significant difference between the mean V3" of PS and ET (p < 0.01). Concerning the correlation between V3" value and the severity of PS, the UPDRS motor score significantly correlated with the V3"(F) value (rs = -0.816). However, V3"(OC) and V3"(TC) correlated less with UPDRS (rs = -0.667 and -0.645, respectively)., Conclusions: Semiquantitative parameters, V3"(OC) and V3"(TC), calculated by VOIClassic including the Neurostat system are useful and easily calculable parameters as well as V3"(F) for the differential diagnosis of PS from ET.

Unlabelled: The Subcommittee on Survey of Nuclear Medicine Practice in Japan has performed a nationwide survey of nuclear medicine practice every five years since 1982 to provide detailed information on its current status., Methods: Questionnaires were sent to every institution known to the Japan Radioisotope Association to provide nuclear medicine examinations. The questionnaires address the number and kind of nuclear medicine examinations performed as well as the kind and dose of the radiopharmaceuticals used during the month of June 2002. The annual number of total or specific examinations was then estimated., Results: Of the institutions sent questionnaires, 1,204 were for in vivo study, 124 were for in vitro study, and 36 were for positron emission tomography (PET) study. Out of these, 95.8% answered them. A total of 1,697 gamma cameras were installed in 1,160 facilities, of which 50% were dual-head cameras. The estimated total annual number of examinations expressed by the number of administered radiopharmaceuticals was 1.60 million, similar to that of the previous survey (1997). The frequency of study with single photon emission computed tomography (SPECT) increased to 40%, from 30% in the previous survey. The scintigraphy most frequently performed was bone (35%), followed by myocardium (24%) and brain perfusion (12%). All showed a continuous increase over the past 20 years. Tumor imaging, however, fell from third to fourth place. The most commonly used radiopharmaceutical for each scintigraphy was 99mTc-HMDP for bone, 201Tl-chloride for myocardium, 67Ga-citrate for tumor, and 123I-IMP for brain. A total of 29,376 PET studies were performed yearly. Among them, 18F-FDG rapidly increased 3.7-fold. 131I therapy for thyroid cancer and hyperthyroidism was conducted yearly in 1,647 and 3,347 patients, respectively. A total of 31.35 million in vitro radioassays were carried out yearly, the number of which has been decreasing continuously since 1992., Conclusions: It was proved that the content of nuclear medicine practice in Japan has changed in the past five years. This report might be useful for understanding the current trends of nuclear medicine practice in Japan.

Unlabelled: The purpose of this study was to evaluate the usefulness in a clinical setting of iodine-123-metaiodobenzylguanidine (123I-MIBG) scintigraphy, planar and single photon emission computed tomography (SPECT) images, in patients with neuroblastoma as detected by a mass screening survey., Methods: 123I-MIBG planar whole body images, and regional SPECT images of patients with neuroblastoma in 51 studies were reviewed. They were all detected by a mass screening survey performed in the 6th month after birth using vanil mandelic acid (VMA), and homovanillic acid (HVA) and the neuroblastoma had been confirmed by surgery. Scintigraphy was performed 24 hours after injection of 111 MBq of 123I-MIBG. We assessed the accuracy of the planar whole body images in order to demonstrate the extent of the lesion and the correlation between the degree and extent of the lesions of 123I-MIBG accumulation and clinical staging with tumor markers, such as urinary VMA, urinary HVA, serum neuron specific enolase (NSE) and serum lactate dehydrogenase (LDH). Additionally, we evaluated SPECT how useful supplemental SPECT might be in a clinical setting as compared with planar whole body images., Results: 123I-MIBG planar whole body images revealed all 33 (100%) primary lesions, 4 of the 5 cases (80%) with liver metastasis, 3 of the 13 (23%) with lymph nodes metastasis and 1 of 3 (33%) with bone marrow infiltration. The extent and degree of accumulation correlated with the values of urinary VMA, urinary HVA and serum NSE. SPECT images helped to understand the positional relation in all cases and provided useful additional information for clinical staging in 7 cases., Conclusion: 123I-MIBG scintigraphy with planar and SPECT images is useful for evaluating patients with neuroblastoma, following detection by a mass screening survey.

Tc-99m-DTPA renal scintigraphy was performed before and after transcatheter coil embolization in a patient with renal arteriovenous fistula (AVF). Before embolization, scintigraphy showed a characteristic accumulation pattern compatible with the hemodynamics of an aneurysmal type of AVF in the vascular phase. After embolization, the effects of treatment, such as a change in the split renal function on the treated-side and the disappearance of the shunt flow through the fistula were evident. It was concluded that dynamic renal scintigraphy was very useful for patients with an aneurysmal type of renal AVF scheduled for transcatheter embolization.

Quantitative crossed cerebellar diaschisis (CCD) and the correlation with a reduction in supratentorial regional cerebral blood flow (rCBF) and cerebrovascular reserve capacity (CVR) were investigated in clinically stable patients with major cerebral artery occlusion by the iodine-123-N-isopropyl-p-iodoamphetamine (I-123 IMP) single photon emission computed tomography (SPECT) method. Thirty patients with major cerebral artery occlusion underwent SPECT by the I-123 IMP autoradiographic method. Regional CBF was measured in the cerebral hemisphere, frontal and parietal lobes, temporo-parietal lobe, and cerebellum both at rest and after administration of acetazolamide. Eighteen of 30 patients (60%) had CCD. CCD was significantly related to magnetic resonance imaging evidence of infarction. Quantitative CCD was 17% and the CVR in the cerebellum was preserved in patients with CCD. There was a significant difference in CBF and CVR between the affected and normal sides in all regions of interest in the patients without CCD [CBF (ml/100 g/min): hemisphere (H), normal side (N): 31.4 +/- 6.8, affected side (A): 27.5 +/- 7.4; p < 0.05. CVR: H, N: 0.56 +/- 0.38, A: 0.42 +/- 0.18; p < 0.01]. CCD is common in patients with major cerebral artery occlusion, and quantitative I-123 IMP SPECT is helpful in detecting CCD in clinically stable patients with occlusion of major cerebral arteries.

A pediatric patient with enteritis, which showed dramatically diffuse uptake of 99mTc pertechnetate in the intestine, is reported. Repeated study after medical treatment exhibited complete disappearance of the intestinal uptake. 99mTc pertechnetate scintigraphy has the potentiality for diagnosing and monitoring active enteritis.

We proposed a simple parameter, the kidney-to-aorta ratio (KAR), for evaluation of renal transplant perfusion. KAR was calculated from the peak counts of the kidney and the aorta. The calculated values were compared with the visual interpretation of the radionuclide first-pass flow study, percent renal uptake (%RU), and tubular extraction rate (TER) by Bubeck's one point sampling method in 37 studies. KAR correlated well with the visual interpretation of the flow study and the other quantitative parameters. Representative cases, which showed the usefulness of KAR for the objective assessment of the perfusion status of renal transplants, were presented. In conclusion, KAR is a simple and practically useful parameter for objective evaluation and follow-up of renal transplant perfusion.

We report here a patient with mucosa associated lymphoid tissue (MALT)-lymphoma of the breast complicated with Sjögren syndrome. It is speculated that Ga-67 could accumulate not only in lymphoma lesions but also in benign lymphoproliferative locations of Sjögren syndrome. Gallium-67 scintigraphy might be useful for the diagnosis and therapeutic monitoring of MALT-lymphoma complicated with Sjögren syndrome.

A 79-year-old man with melena was suspected of having small bowel bleeding because upper and lower endoscopic findings were negative. Technetium-99m-labeled red blood cell (Tc-99m-RBC) scintigraphy was performed by arterial injection of a radiotracer from the superior mesenteric artery (SMA) after angiography. Extravasation was seen in the ileum by scintigraphy although angiography was negative. Scintigram 2 minutes after arterial injection was consistent with the late capillary phase of balloon occluded angiography. This comparison provided a better anatomical distinction. Tc-99m-RBC scintigraphy by arterial injection through the SMA identified the bleeding site in the small bowel more accurately than conventional intravenous Tc-99m-RBC scintigraphy.

Possible involvement of cell membrane ion transport systems in the uptake and extrusion of Tc-99m-MIBI was investigated by using various buffers with or without Na+ and Ca++, and ion transport inhibitors in a tumor cell line. The ion transport modulators dimethyl amiloride (DMA), verapamil, flunarizine and monensin were used. The uptake of Tc-99m-MIBI was significantly increased in all buffers containing either Na+ or Ca++ alone or none of them. There was significantly increased uptake of Tc-99m-MIBI especially in buffers without Na+. Verapamil, a L-type Ca++ channel blocker, increased Tc-99m-MIBI uptake in all buffers. Flunarizine, which inhibits Na+/ Ca++ channels, caused significantly increased accumulation of Tc-99m-MIBI only in buffer containing both Na+ and Ca++. Monensin, a sodium ionophore, significantly increased uptake of Tc-99m-MIBI. DMA, a potent Na+/H+ antiport inhibitor, significantly inhibited the uptake of Tc-99m-MIBI in all buffers. In conclusion, Tc-99m-MIBI behaves like Na+ during its uptake and extrusion. Extrusion of Tc-99m-MIBI may involve both verapamil- and flunarizine-sensitive pathways.

To evaluate the effect of technetium-99m-labeled DTPA-galactosyl human serum albumin (Tc-99m-GSA) SPECT imaging for qualitative diagnosis of hepatic lesions. The subjects were 29 patients with pathologically confirmed hepatic lesions (21 malignant and 8 benign lesions). SPECT data were obtained at about 30 minutes after injecting 185 MBq (5 mCi) of Tc-99m-GSA. The GSA SPECT findings were compared with those of pathological evaluation and T2-weighted MR images (T2WI). Of 29 lesions, 17 showed decreased accumulation, and three exhibited increased accumulation. The other nine lesions were undetectable. The malignant lesions which showed increased accumulation were all well differentiated hepatocellular carcinomas (HCCs). One of the eight benign lesions exhibited increased accumulation. The three lesions which showed increased accumulation of GSA exhibited hypointensity on T2WI, whereas the malignant lesions which showed decreased accumulation of GSA exhibited hyperintensity on T2WI. The GSA SPECT findings correlate well with those of T2WI. GSA SPECT may be useful for qualitative diagnosis of focal liver lesions. If a lesion is suspected of being HCC, increased accumulation may indicate well differentiated HCC.

A 31-year-old male having familial amyloid polyneuropathy underwent a Tc-99m(V)-DMSA study to evaluate the myocardial involvement. The patient also underwent T1-201, I-123-BMIPP and I-123-MIBG myocardial SPECT studies to evaluate blood perfusion, fatty acid metabolism and sympathetic function of the heart, respectively. Tc-99m(V)-DMSA SPECT showed uptake to the myocardium indicating myocardial involvement of amyloidosis. Both T1-201 and I-123-BMIPP studies showed normal uptake indicating normal blood perfusion and fatty acid metabolism but I-123-MIBG SPECT showed no uptake to the heart, indicating severe impairment of sympathetic function.

We performed scintigraphy with technetium-99m-methoxyisobutylisonitrile (MIBI) in 10 patients with parathyroid adenoma (7 lesions) or hyperplasia (9 lesions). Correlation between an amount of accumulation of MIBI and histological types of the lesions were evaluated with special reference to an amount of oxyphilic cell in the lesions. Selected lesions were also evaluated for mitochondrial density by electromicroscopy and showed increased mitochondrial density in the oxyphilic cells. All lesions equal to or above 220 mg showed positive scintigraphic results despite differences in cell types. Undetected lesions were all equal to or below 100 mg. The scintigraphic results for 2 lesions with abundant oxyphilic cells were both positive although those for 11 lesions with abundant chief cells only 6 were positive, probably because these lesions were smaller in the hyperplasia group. In conclusion, MIBI uptake in parathyroid lesions was not dependent on the cell type but either on the size or functional state of the lesions.

We report scan findings of Tl-201 in a case of histologically proved Warthin's tumor. Dual isotopes acquisition was performed in a case of left parotid Warthin's tumor. Both early and delayed Tc-99m-pertechnetate (Tc-99m) images showed increased uptake at the tumor. Tl-201 scan also showed an increase of uptake on the early image and retention on the delayed image. The uptake ratios of Tl-201 were 3.0 (early) and 2.3 (delayed). Scan findings of Tl-201 in a case of Warthin's tumor were similar to those of Tc-99m, and the interpretation of Tl-201 images should be accompanied with Tc-99m images.

We investigated the uptake and washout of I-123-metaiodobenzylguanidine (MIBG) in neuronal (both intra- and extravesicular) and non-neuronal sites in the heart and its relationship to renal clearance. Acute renal failure was induced in rats by ligating the renal vessels, and the findings were compared with those of sham-operated rats. Each group consisted of control, reserpine-treated and 6-hydroxydopamine (6-OHDA)-treated subgroups. Rats were sacrificed at 10 minutes and 4 hours after injection of MIBG. MIBG activity was calculated in specimens of heart, spleen, lung and blood. At 10 minutes, no significant difference in MIBG uptake in the heart was observed among the subgroups or between sham-operated and renal failure rats despite a significantly higher blood MIBG activity in the latter. At 4 hours, however, the hearts of both reserpine-treated and 6-OHDA-treated rats showed significantly lower MIBG uptake than control rats. Furthermore, the hearts of renal failure rats showed higher MIBG uptake in the control and reserpine-treated rats than in the corresponding subgroups in sham-operated rats. Intra and extravesicular neuronal uptake of MIBG in the heart were estimated using control, reserpine-treated and 6-OHDA-treated rats. Vesicular uptake values were similar in both the sham-operated group (0.51% ID/g) and the renal failure group (0.44% ID/g). But extravesicular neuronal uptake values were quite different in the renal failure group (0.86% ID/g) and the sham-operated group (0.19% ID/g). In conclusion, uptake to and washout from extravesicular neuronal sites may depend on the concentration of MIBG in the blood or the state of renal clearance, but vesicular uptake may be independent of these factors.

Tc-99m-tetrofosmin SPECT was performed on 6 occasions in 4 patients with hypopharyngeal carcinoma, lung carcinoma, esophageal carcinoma and maxillary plasmocytoma and compared with Tl-201 SPECT. All lesions accumulated both Tc-99m-tetrofosmin and Tl-201. Early uptake ratios of Tc-99m-tetrofosmin were about 2 but those of Tl-201 were much higher (more than 3). Washout rates of Tc-99m-tetrofosmin were higher than those of Tl-201. There was a good positive correlation between the early uptake ratio of Tc-99m-tetrofosmin and that of Tl-201. The delayed uptake ratio and washout rate showed poor correlation. In conclusion, early uptakes of both the agents were similar but their retention patterns were different. Tc-99m-tetrofosmin may be used for tumor imaging though more studies are required to evaluate diagnostic accuracy and the significance of delayed images.

A case of left breast cancer which was detected incidentally by T1-201 SPECT performed to evaluate the status of myocardial perfusion, is reported. Both stress and redistribution T1-201 SPECT clearly delineated the tumor. It was confirmed later as scirrhous carcinoma of the breast.

Bone scintigraphy is often performed to assess the response to systemic therapy of bone metastasis from prostate cancer. We examined the changes in bone scintigraphic findings and the agreement with AIP, AcP, or other tumor markers measured in the follow-up of patients with known bone metastasis after hormonal therapy. Out of 32 patients, 22 (69%) showed improved scintigraphic findings on the first follow-up bone scintigraphy after hormonal therapy. However, 7 out of 22 patients who showed improvement on the first follow-up scintigraphy, deteriorated thereafter. Changes in the scintigraphic findings were closely correlated with those in the measured tumor markers except for patients with small bone metastasis. Though there were no significant differences in the agreement ratios of the 6 tumor markers evaluated, AIP might be a practical and acceptable indicator. Bone X-ray findings did not change at all in almost half of the cases though the scintigraphic findings showed improvement or deterioration.

A total of 7 (4 males and 3 females) patients were included in this retrospective study to determine the sensitivity of radioimmunoscintigraphy with I-131 labeled anti CEA/CA 19-9 monoclonal antibodies. Out of 7 patients 2 had ascending colon cancer, one had sigmoid colon cancer, one had rectal cancer and one had adenocarcinoma in the CBD and the remaining two had metastatic tumor (one in the lungs and the other in the liver). Whole body as well as spot images showed a 72% (5/7) positive scan. But post operative specimen counts and imaging showed a high tumor to non-tumor ratio and a good tumor to non-tumor contrast of activity of I-131 labeled monoclonal antibody. We did not find any relation between CEA/CA 19-9 levels and scan findings. A case of liver metastasis was also detected by this radioimmunoscintigraphy.

Several parameters calculated with a new functional imaging agent for the liver, Tc-99m DTPA-galactosyl human serum albumin, were evaluated in 9 patients with liver cirrhosis, one with hepatocellular carcinoma, and five with both liver cirrhosis and hepatocellular carcinoma. LU3, which represents the cumulative uptake of the tracer from 3 to 4 minutes after injection, showed a strong correlation (r = 0.858, p = 0.0001) with LHL15, which represents the count ratio for the liver to sum for the liver and heart 15 minutes after injection of the tracer. It also showed a strong correlation (r = -0.896, p = 0.0001) with the indocyanine green retention rate (ICGR15). Regional ICGR15 is therefore calculable from the regional LU3. GSAR15, which represents the radioactivity of the tracer retained in the blood 15 minutes after injection, showed a strong correlation (r = 0.878, p = 0.0001) with HH15, which represents the count ratio for the heart 15 minutes after injection of the tracer divided by the count for the heart 3 minutes after injection. In conclusion, LU3 and GSAR15 are interesting and promising parameters for assessing liver function.

Patients whose Ga-67 whole-body images showed increased uptake by the bone/bone marrow of the lower extremities were selected and classified into three types according to the extent and the grade of the visualization. These types were then compared with their serum iron levels, iron-binding capacities, and the results of several other serum biochemical tests. Of 374 consecutive whole body 72-hr images reviewed, 59 (15.8%) showed increased uptake of the tracer by the bone/bone marrow of the lower extremities. The three classified types were as follows: type T--visualization of both tibiae and femurs; type S--strong visualization of the femurs; and type W--weak visualization of the femurs. The serum iron concentration was significantly high in type T and low in type S. In conclusion, the pattern of Ga-67 uptake by the bone/bone marrow of the lower extremities fairly closely reflects the status of iron metabolism.

We developed monoclonal antibodies against human thyroid cancer-associated antigen by fusing mouse myeloma cells with mouse spleen cells immunized by insoluble fraction of homogenized thyroid papillary carcinoma cells. One monoclonal antibody (KTC-3, IgM) was selected to evaluate basic usefulness for radioimmunoscintigraphy in xenografted human thyroid carcinoma. KTC-3 was labeled with 131I by Iodogen method of 20 to 1 Iodogen to IgM molar ratio. It was also labeled with 111In by cyclic DTPA anhydride method of 20 to 1 DTPA to IgM molar ratio. The labeling efficiency and specific activity for 131I labeling were 16.5% and 0.66 mCi/mg IgM respectively, and those for 111In labeling were 12.7% and 1.6 mCi/mg IgM. Imaging and biodistribution of labeled KTC-3 were evaluated in nude mice bearing thyroid anaplastic carcinoma (THC-5-JCK). The tumors were well visualized 3 and 5 days after injection of 131I KTC-3. Tumor uptake of 131I KTC-3 on day 7 was 0.52 +/- 0.27% ID/g and tumor to blood ratio was 1.98 +/- 0.76 (n = 6). Those of 111In KTC-3 were 0.88 +/- 0.09% ID/g and 5.51 +/- 3.36 (n = 6). In conclusion, KTC-3 is promising for radioimmunoscintigraphy of thyroid cancer.