Improved tumor localization of 111In labeled monoclonal antibody with chelator administration to host nude mice

Administration of calcium disodium edetate (EDTA) substantially increased the tumor:muscle ratios of nude mice injected with ¹¹¹In labeled monoclonal antibody injection of mice bearing the BRO human melanoma, but not earlier. The tumor:muscle ratios decreased during this time for animals not receiving chelator. Contemporaneously, EDTA treated mice lost whole body radioactivity more rapidly than did their untreated counterparts, suggesting that ¹¹¹In which had dissociated from the antibody-DTPA-radiometal complex was chelated and excreted. These results suggest that effective chelator treatment might improve tumor localization of radioactivity after injection of ¹¹¹In labeled antibodies.     

Human breast tumor imaging using 111In labeled monoclonal antibody: Athymic mouse model

The monoclonal antibody (MoAb) 323/A3, an IgG1, was raised against the human breast tumor cell line MCF-7 and recognized a 43 Kd membrane associated glycoprotein. Histochemical studies with the antibody detected 75% of metastatic lymph nodes, 59% of primary breast tumors, and showed some staining in 20% of benign breast lesions. For radionuclide imaging, the MoAb 323/A3 was labeled with both ¹²⁵I and ¹¹¹In, via covalently coupled diethylenetriaminepentaacetic acid (DTPA) by the mixed anhydride method. The antibody activity of the DTPA modified 323/A3 was assessed by an immunoassay using viable and fixed MCF-7 target cells. Male athymic nude mice bearing BT-20 human mammary tumors were injected with dual ¹²⁵I/¹¹¹In labeled DTPA 323/A3 via the tail veins. The animals were imaged with a gamma camera equipped with a pinhole collimator at 1–3 h, 1, 2, 3, 4 and 5 days after the tracer administration. On day 5 or 6, the animals were killed, and the biodistribution of the radiotracers was determined for the blood, thyroid, heart, lungs, liver, spleen, kidneys, gastrointestinal tract and tumor. Target to blood ratio at 6 days for the ¹¹¹In tracer was 24:1 in the group with a mean tumor weight of 0.492 g, and 13:1 in another group with a mean tumor weight of 0.1906 g (day 5). However, the ¹²⁵I activity showed only 3.6:1 and 5.4:1 target to blood ratios in the corresponding groups. The larger tumors localized less ¹¹¹In tracer (27.13%±7.57% injected dose/g, Mean±SD) than the smaller tumors (52.75%±22.25% ID/g). Analysis of the gamma images showed that the maximum tracer concentration occurred in the tumors at about 2 to 3 days after intravenous tracer administration. The excellent tumor resolution observed with BT-20 tumors may be due to increased 43 Kd glycoprotein antigen density in this tumor cell line.     

The preparation and characterisation of 111In-labelled 791T/36 monoclonal antibody for tumour immunoscintigraphy

The anti-human tumour monoclonal antibody 791T/36 was conjugated to the cyclic dianhydride of DTPA and radio-labelled with ¹¹¹In. The labelling method proved to be both simple and reliable and would be suitable for routine clinical use. Subsequent characterisation of this radio-pharmaceutical in vitro and in tumour-bearing hosts gave a strong indication as to its suitability for clinical tumour localisation studies.     

In vivo imaging of rat lymphocytes with an indium 111-labelled anti-T cell monoclonal antibody: a comparison with indium 111-labelled lymphocytes

An indium 111-labelled mouse anti-rat T cell monoclonal antibody, MRC OX-19, was injected intravenously into rats to establish the usefulness of radiolabelled anti-lymphocyte antibodies in imaging lymphoid tissues. Antibody binding in vivo, measured by immunofluorescence analysis of cell suspensions made from lymphoid tissues, was detectable on lymphocytes in blood, spleen and lymph nodes. The extent of binding was time and antibody-dose dependent. Doses of antibody above 80 g/kg body weight resulted in modulation, i.e. loss of CD 5 (T 1) molecules from the cell surface, although the cells remained in the circulation. Modulation was demonstrable within 2 h and for at least 24 h after a single injection of antibody. Intravenous injection of¹¹¹In-MRC OX-19 resulted in levels of in vivo binding comparable with those seen with unlabelled antibody. Scintillation imaging showed early splenic localisation persisting over 48h, a more gradual localisation in the lymph nodes seen clearly at 24 h and a steady background. Comparison of the in vivo distribution of labelled antibody and¹¹¹In-tropolone-labelled lymphocytes showed that both could be used for external imaging of lymphocytes by scintillation camera.     

Imaging platelet deposition on Dacron bifurcation grafts in man: Quantification by a dual-tracer method using 111In-labeled platelets and 99mTc-labeled human serum albumin

A dual tracer technique using ¹¹¹In-labeled platelets and ^99mTc-labeled human serum albumin was applied to evaluate the thrombogenicity of Dacron bifurcation arterial grafts. The level of platelet accumulation over the whole of the graft was estimated from the ratio of ¹¹¹In-platelet radioactivity deposited on the vascular wall to these radioactivity circulating in the blood pool, i.e., the platelet-accumulation index (PAI). Furthermore, the PAI value was calculated for each pixel in digitized images and the PAI distribution image (PAI image) was reconstructed. Eighteen patients with DeBakey knitted Dacron bifurcation grafts and 11 normal volunteers were studied. Of the 18 patients, 11 had no graft occlusion (group I) and the remaining 7 (group II) had occlusion. The mean PAI value (±SD) over the whole of the graft in group I was 32.6%±33.7% as compared to -8.8%±4.5% in the control group (P<0.01). In group I, the PAI value over the entire graft decreased with the age of the fraft (r=-0.763; P<0.01). In contrast, in group II, platelet accumulation did not diminish with time and persisted beyond the time of which platelet accumulation was no longer found in group I. Moreover, analysis of the PAI images revealed enhanced platelet accumulation on the proximal part of the graft to be more frequent in group II than in group I (6/7 vs 0/11; _c ² = 10.55; P<0.005). The method used for platelet imaging in the present study may be useful in the study of platelet reactions on Dacron arterial prostheses.     

Pretargeting CWR22 prostate tumor in mice with MORF-B72.3 antibody and radiolabeled cMORF

Purpose We have now applied our MORF/cMORF pretargeting technology to the targeting of CWR22 prostate tumor in nude mice. Methods The antiTAG-72 antibody B72.3 was conjugated with an 18 mer MORF while the cMORF was radiolabeled with ^99mTc. The specific binding of the antibody to the CWR22 cells was first confirmed in an assay placing the radiolabeled B72.3 antibody in competition with increasing concentrations of native B72.3. Thereafter, a group of four CWR22 tumored mice intravenously received the MORF-B72.3 and, 3 days later, the ^99mTc-cMORF, and were killed at 3 h postradioactivity injection. The dosage of the labeled cMORF was selected on the basis of previous experience in LS174T tumored mice. As controls, four animals received only the radiolabeled cMORF and another four received only the ¹¹¹In-B72.3. The maximum percent tumor accumulation (MPTA) of the labeled cMORF was subsequently determined by a dosage study of labeled cMORF. Both a multipinhole SPECT image and a planar gamma camera image were obtained of a representative mouse. Results The CWR22 tumor was confirmed to be TAG-72-positive. The MPTA of the labeled cMORF in the CWR22 tumor was 2.22%ID/g compared to only 0.12%ID/g in control mice without pretargeting. Both the planar and tomographic images confirmed the success of the CWR22 pretargeting. Conclusions The MORF/cMORF pretargeting approach has been successfully applied to tumor targeting of the prostate xenograft CWR22. However, the MPTA in this tumor model is lower than that in the LS174T tumor model investigated earlier, possibly due to a lower tumor blood supply. Financial support: CA107360 and CA94994.     

Nesidioblastosis as a cause of focal pancreatic 111In-pentetreotide uptake in a patient with putative VIPoma: another differential diagnosis

In adults, nesidioblastosis is a very infrequent condition and a rare cause of symptomatic presentations. The diagnosis of nesidioblastosis may be difficult with functional and anatomical imaging modalities. “Slight focal” pancreatic abnormalities using ¹¹¹In-pentetreotide imaging has been reported in patients with hyperinsulinaemic hypoglycaemia, confirmed histologically as nesidioblastosis. We describe a 60-year-old man who presented with a 1-year history of intermittent faecal urgency and refractory diarrhoea, non-specific laboratory results, negative imaging results (CT, MRI and EUS), a FNA biopsy that was inconclusive, but suggested an endocrine cell neoplasm, and a ¹¹¹In-pentetreotide scan that showed a moderately intense focal uptake clearly localised to the pancreatic head on a low-dose fusion CT. The histopathology of the specimen confirmed the diagnosis of nesidioblastosis.     

Clinical experience with intra lymphatic administration of111In-labelled monoclonal antibody PAY 276 for the detection of pelvic nodal metastases in prostatic carcinoma

The ability of¹¹¹In-PAY 276 (anti prostatic acid phosphatase antibody) in detecting pelvic lymph node metastasis following bipedal intra lymphatic administration was studied in five patients with carcinoma of the prostate. The labeled antibody was injected directly into the lymphatics of each foot. Planar and tomographic images radioactivity content of lymph nodes resected during staging pelvic lymphadenectomy were compared to the histologic and immunoperoxidase findings. Radioactivity in pelvic lymph nodes was prominently seen within 20 min of injection and was present 16 days later. Persistent accumulation of tracer in the lymphatics of the lower extremities was also observed in all patients 16 days post injection. Radioactivity counts in tumor-free lymph nodes were higher than in tumored lymph nodes resected. Our results demonstrate that intra lymphatic administration of¹¹¹In-labeled PAY 276 monoclonal antibody has major technical limitations, and that further research directed at the causes of tracer accumulation in the lymphatics and tumor-free lymph nodes is required.     

计算点阵网格大小对125I粒子植入剂量计算精度的影响

目的 观察 ¹²⁵I 粒子植入时,计算机治疗计划系统（TPS）软件中计算点阵网格大小对剂量计算精度的影响。方法 采用随机数字表法抽取10例粒子植入患者的验证计划,将点阵网格调整为128×128、96×96、64×64、32×32共4组,在粒子数目、位置、活度及靶区大小相同的条件下,应用TPS计算每个计划的剂量,分别得出4组D₉₀、V₉₀、V₁₀₀及V₁₅₀,并计算D₉₀的误差。结果 128×128、96×96、64×64、32×32 4组点阵网格D₉₀平均数分别为（7 178.8±2 237.7）、（7 072.7±2 240.8）、（6 889.1±2 305.5）、（6 351.0±2 515.7）cGy;D₉₀误差百分比分别为（0.74±0.6）%、（-0.89±2.2）%、（-3.85±4.7）%、（-10.46±4.8）%,组间差异有统计学意义（F=8.95,P<0.05）。4组点阵网格V₉₀分别为（93.12±0.32）%、（92.75±0.29）%、（91.87±1.28）%、（88.06±5.06）%,组间差异有统计学意义（F=7.85,P<0.05）;V₁₀₀分别为（90.21±0.14）%、（89.67±0.64）%、（88.68±1.80）%、（84.10±6.56）%,组间差异有统计学意义（F=6.64,P<0.05）;V₁₅₀分别为（73.48±3.49）%、（72.66±3.96）%、（71.33±4.83）%、（65.41±9.49）%,组间差异有统计学意义（F=3.90,P<0.05）。结论 计算点阵网格大小明显影响TPS计算剂量的准确性,在保证运算速度同时应尽量应用128×128的计算点阵网格。     

Comparison of high-dose rate prostate brachytherapy dose distributions with iridium-192, ytterbium-169, and thulium-170 sources

Purpose

Recent studies have identified that among different available radionuclides, the dose characteristics and shielding properties of ytterbium-169 (¹⁶⁹Yb) and thulium-170 (¹⁷⁰Tm) may suit high-dose rate (HDR) brachytherapy needs. The purpose of this work was to compare clinically optimized dose distributions using proposed ¹⁶⁹Yb and ¹⁷⁰Tm HDR sources with the clinical dose distribution from a standard microSelectron V2 HDR iridium-192 (¹⁹²Ir) brachytherapy source (Nucletron B.V., Veenendaal, The Netherlands).

Methods and materials

CT-based treatment plans of 10 patients having prostate volumes ranging from 17 to 92 cm³ were studied retrospectively. Clinical treatment of these patients involved 16 catheters and a microSelectron V2 HDR ¹⁹²Ir source. All dose plans were generated with inverse planning simulated annealing optimization algorithm. Dose objectives used for the ¹⁹²Ir radionuclide source were used for the other two radionuclides. The dose objective parameters were adjusted to obtain the same clinical target (prostate) volume coverage as the original ¹⁹²Ir radionuclide plan. A complete set of dosimetric indices was used to compare the plans from different radionuclides. A pairwise statistical analysis was also performed.

Results and conclusions

All the dose distributions optimized with specific ¹⁹²Ir, ¹⁶⁹Yb, and ¹⁷⁰Tm sources satisfied the standard clinical criteria for HDR prostate implants, such as those for the Radiation Therapy Oncology Group clinical trial 0321, for combined HDR and external beam treatment for prostate adenocarcinoma. For equivalent clinical target volume dose coverage, the specific ¹⁶⁹Yb and ¹⁷⁰Tm sources resulted in a statistically significant dose reduction to organs at risk compared with microSelectron V2 HDR ¹⁹²Ir source. This study indicates that a ¹⁷⁰Tm or ¹⁶⁹Yb radionuclide source may be an alternative to the ¹⁹²Ir radionuclide sources in HDR brachytherapy.     

Yttrium-90 and indium-111 labelling, receptor binding and biodistribution of [DOTA0,d-Phe1,Tyr3]octreotide, a promising somatostatin analogue for radionuclide therapy

In vitro octreotide receptor binding of [¹¹¹In-DOTA⁰,d-Phe¹,Tyr³]octreotide (¹¹¹In-DOTATOC) and the in vivo metabolism of⁹⁰Y or¹¹¹In-labelled DOTATOC were investigated in rats in comparison with [¹¹¹In-DTPA⁰]octreotide [¹¹¹In-DTPAOC).¹¹¹In-DOTATOC was found to have an affinity similar to octreotide itself for the octreotide receptor in rat cerebral cortex microsomes. Twenty-four hours after injection of⁹⁰Y or¹¹¹In-labelled DOTATOC, uptake of radioactivity in the octreotide receptor-expressing tissues pancreas, pituitary, adrenals and tumour was a factor of 2–6 that after injection of¹¹¹In-DTPAOC. Uptake of labelled DOTATOC in pituitary, pancreas, adrenals and tumour was almost completely blocked by pretreatment with 0.5 mg unlabelled octreotide, indicating specific binding to the octreotide receptors. These findings strongly indicate that⁹⁰Y-DOTATOC is a promising radiopharmaceutical for radiotherapy and that¹¹¹In-DOTATOC is of potential value for diagnosis of patients with octreotide receptor-positive lesions, such as most neuroendocrine tumours.     

Diverse characteristics of111In labelled anti-CEA monoclonal antibodies for tumour immunoscintigraphy: Radiolabelling,biodistribution and imaging studies in mice with human tumour xenografts

Three monoclonal anti-CEA antibodies, designated 161, 198 (both IgG1) and 228 (IgG2a) have been labelled with¹¹¹In via DTPA chelation and assessed for localization in human gastro-intestinal carcinomas as xenografts in athymic nude mice. Following reaction of the antibodies with DTPA anhydride, efficiency of chelation of¹¹¹In varied between the antibodies with mean values of 30%, 52% and 62% with 161, 198 and 228 respectively. Gel filtration chromatography with all three labelled antibodies showed radiolabel predominantly coincident with IgG with little radioactivity in either high molecular weight form or as free¹¹¹In. However, the efficiency of binding of radiolabelled antibodies to CEA producing tumour cells varied, with maxima of 42%, 65% and 20% for 161, 198 and 228. In vivo, in mice,¹¹¹In was excreted at virtually identical rates (half times approx. 12 days) with all three prepartions and this was similar to the clearance of indium injected as¹¹¹In-indium chloride, but¹¹¹In-DTPA was rapidly eliminated (half time approximately 5 h). After injection inton mice with CEA producing xenografts of colon carcinoma HT29 and LS174T and gastric carcinoma MKN 45, circulating radiolabel was still predominantly in the form of labelled antibody with little or no detectable immune complexes or¹¹¹In labelled transferrin. Tumour localization of all three antibodies was visualized by gamma camera imaging with target: non target ratios of up to 5:1. Dissection of mice with MKN45 gastric carcinoma xenograft showed 16%, 19.5% and 13% of the injected dose of¹¹¹In from 161, 198 and 228 antibodies in each g of tumour tissue. Tumour to liver ratios were 3.8:1, 3.4:1 and 3.3:1. Similar studies in mice with xenografts of a human osteosarcoma, virtually devoid of CEA, showed no tumour localization with any of the antibodies (tumour: liver ratios <0.8:1).These studies illustrate the diverse nature of anti-CEA antibodies as bases for radiopharmaceutical preparations, and emphasise that in vitro criteria alone may not reflect in vivo tumour localization capacity.     

Standardized uptake values of uterine leiomyoma with <Superscript>18</Superscript>F-FDG PET/CT: variation with age,size, degeneration,and contrast enhancement on MRI

OBJECTIVE: To assess the effect of age, size, the degree of degeneration, and contrast enhancement on magnetic resonance imaging (MRI) on 18F-fluoro-2-deoxyglucose (18F-FDG) uptake in uterine leiomyomas using quantitative standardized uptake values (SUVs). METHODS: A total of 61 leiomyomas of 41 patients, who underwent combined positron emission tomography/computed tomography (PET/CT) using 18F-FDG and contrast-enhanced MRI were included in this study. Sixty-one leiomyomas were divided into two groups: "non-degenerated" leiomyomas showing distinct low signal intensity on T2-weighted images and intermediate signal intensity on T1-weighted images, and "degenerated" leiomyomas showing other types of signal intensity. Sixty-one leiomyomas were also divided into two groups of "strongly enhancing" leiomyomas and "weakly enhancing" leiomyomas in terms of their degree of contrast enhancement on MRI. RESULTS: The mean values of the maximum and average SUVs for the total of 61 leiomyomas were 2.34 +/- 0.75 (range 1.59-5.15) and 1.74 +/- 0.50 (0.66-3.95), respectively. There was a moderate negative correlation between the maximum and average SUVs and age (r = -0.43 and P = 0.00016, r = -0.31 and P = 0.029, respectively). Although there was a mild positive correlation between maximum SUV and size (r = 0.35 and P = 0.011), there was no significant difference between average SUV and size. Although there was no significant difference in average SUV between "degenerated" and "non-degenerated" leiomyomas, the maximum SUV of "degenerated" leiomyomas was significantly higher than that of "non-degenerated" leiomyomas (P = 0.0012). The degree of contrast enhancement on MRI was not significantly correlated with 18F-FDG uptake. CONCLUSIONS: Mild or moderate uptake of 18F-FDG is often observed in uterine leiomyoma and declines with age, and should not be confused with malignant accumulation.     

Effect of the EGFR density of breast cancer cells on nuclear importation, in vitro cytotoxicity, and tumor and normal-tissue uptake of [111In]DTPA-hEGF

INTRODUCTION: Our objective was to evaluate the effect of epidermal growth factor receptor(s) (EGFR) density on the importation and nuclear localization of 111In-labeled diethylenetriaminepentaacetic acid human epidermal growth factor ([111In]DTPA-hEGF) in breast cancer (BC) cells in vitro and in tumor xenografts and normal tissues in vivo in athymic mice, as well as on its cytotoxicity and tumor and normal-tissue distribution. METHODS: The internalization and nuclear importation of [111In]DTPA-hEGF were measured in MCF-7, MDA-MB-231, BT-474 and MDA-MB-468 BC cells (10(4), 2 x 10(5), 6 x 10(5) and 10(6) EGFR/cell, respectively). The molecular size (Mr) distribution and immunoreactivity of nuclear radioactivity were characterized. Tumor and normal-tissue uptake of [111In]DTPA-hEGF in athymic mice implanted subcutaneously with BC xenografts were compared. Nuclear radioactivity in the tumor, lungs, liver, kidneys, spleen and colon was measured. RESULTS: There was a direct association between EGFR density and the nuclear localization of [111In]DTPA-hEGF in BC cells; nuclear importation approached saturation at 6 x 10(5) EGFR/cell. Almost all nuclear radioactivities exhibited an Mr of >100 kDa; immunoreactivity with anti-hEGF, anti-EGFR and anti-importin beta 1 antibodies was detected. The efflux of nuclear radioactivity was slowest for MDA-MB-468 cells. Cytotoxicity was correlated with EGFR expression. Uptake was greater in MDA-MB-468 than in MCF-7 xenografts and improved with preinjection of a 100-fold excess of unlabeled DTPA-hEGF. Nuclear importation was higher in liver, kidney and spleen cells than in tumor cells. CONCLUSION: [111In]DTPA-hEGF is translocated to the nucleus of BC cells complexed with EGFR and importin beta1. Nuclear importation and cytotoxicity are effected by EGFR density. The absence of hepatic and renal toxicities in [111In]DTPA-hEGF cannot be explained by a low efficiency of nuclear importation.     

Effect of oxygen pressure during incubation with a 10B-carrier on 10B uptake capacity of cultured p53 wild-type and mutated tumor cells: dependency on p53 status of tumor cells and types of 10B-carriers

Purpose To evaluate the effect of oxygen pressure during incubation with a ¹⁰B-carrier on ¹⁰B uptake capacity of cultured p53 wild-type and mutated tumor cells.

Materials and methods Cultured human head and neck squamous cell carcinoma cell line transfected with mutant TP53 (SAS/mp53), or with a neo vector as a control (SAS/neo) was incubated with L-para-boronophenylalanine-¹⁰B (BPA) or sodium mercaptoundecahydrododecaborate-¹⁰B (BSH) as a ¹⁰B-carrier at the ¹⁰B concentration of 60 ppm for 24?h under aerobic (20.7% of oxygen) or hypoxic (0.28% of oxygen) conditions. Immediately after incubation, cultured tumor cells received reactor thermal neutron beams, and a cell survival assay was performed. ¹⁰B concentration of cultured SAS/neo or SAS/mp53 cells incubated under aerobic or hypoxic conditions was determined with a thermal neutron guide tube.

Results Hypoxic incubation significantly decreased ¹⁰B concentration of cultured cells with a clearer tendency observed following BPA than BSH treatment in both SAS/neo and SAS/mp53 cells. Following neutron beam irradiation, SAS/mp53 cells showed significantly higher relative biological effectiveness values than SAS/neo cells because of the significantly lower radiosensitivity of SAS/mp53 to γ-rays than SAS/neo cells.

Conclusion Oxygen pressure during incubation with a ¹⁰B-carrier had a critical impact on ¹⁰B uptake of cultured tumor cells.     

Correlation between 99mTc-(V)-DMSA uptake and constitutive level of phosphorylated focal adhesion kinase in an in vitro model of cancer cell lines

Purpose Although a number of prognostic indicators have been developed, it is still difficult to predict the biological behaviour of all cancer types. ^99mTc-(V)-DMSA (V DMSA) uptake and focal adhesion kinase (FAK) expression and activation level could be potential agents for this purpose. We hypothesised the existence of a correlation between V DMSA, whose uptake is linked to phosphate ions, essential compounds for tumour growth and cell proliferation, and the adhesion protein FAK, whose elevated expression and level of constitutive activation are implicated in cancer progression. The aim of this study was to assess the relationship between V DMSA incorporation rate and FAK expression and activation by phosphorylation on tyrosine 397 residue.Methods We determined V DMSA uptake in six different cancer cell lines and we measured FAK expression and activation by using Western Blotting analysis. Correlations with factors known to be associated with poor prognosis, such as invasive potential, resistance to chemotherapy and proliferation rate, were also investigated. Results The cell lines exhibited different V DMSA incorporation rates. In addition, these cells showed the same FAK expression, but various degrees of activation. A correlation was observed between V DMSA uptake and level of FAK phosphorylation and between V DMSA or constitutive FAK activation and proliferation rate. However, no correlation was shown between these parameters and the other factors tested, i.e. invasive potential and anticancer drug resistance.Conclusion The results of this in vitro study clearly demonstrate that phosphorylation of FAK, proliferation rate and V DMSA uptake are closely related. Because proliferation and a high level of constitutive FAK activation are linked to cancer progression, it can be assumed that in vivo V DMSA uptake reflects tumour aggressiveness.     

Cerebral and cerebellar uptake of 99mTc-(d,1)-hexamethyl-propyleneamine oxime (HM-PAO) in patients with brain tumor studied by single photon emission computerized tomography

The cerebral and cerebellar distribution of ^99mTc-(d,1)-hexamethylpropyleneamine oxime (HM-PAO) was investigated by means of a rotating gamma camera in 12 patients with cerebral glioma. Using the corresponding contralateral region as control, reduced uptake of HM-PAO in the tumor region was demonstrated in 10 of the 12 patients. Reduced blood flow in a brain area remote from a circumscribed lesion reflects reduced activation following the interruption of afferent nervous pathways. Reduced HM-PAO uptake indicative of such diaschisis was demonstrated in the visual cortex contralateral to homonymous hemianopia in the two patients with this deficit. In the three patients with the most marked hemiparesis, the cerebellar hemisphere contralateral to the tumor showed significantly reduced HM-PAO uptake indicative of crossed cerebellar diaschisis. SPECT using commonly available gamma cameras and ^99mTc-HM-PAO seems capable of depicting reduced flow in functionally inactivated brain areas, and may be clinically interesting as an alternative to more specialized techniques for the investigation of local cerebral blood flow.     

Quantification of the whole-body distribution of PET radiopharmaceuticals,applied to 3-N-([18F]fluoroethyl)spiperone

Using a multi slice whole body PET scanner PC4096-15WB, diagnostic measurements of the cerebral distribution of the D₂ receptor ligand 3-N-([¹⁸F]fluoroethyl)spiperone were extended to quantify the biodistribution of this PET radiopharmaceutical. As a rotating line source was used for measured attenuation correction, transmission scans could be combined with emission scans even after injection of the tracer. Only 1 of the total administered dose (TAD) was found in the whole brain at 180 min, but the striatum and pituitary were still excellently delineated. Urinary bladder, gall bladder, and liver were the organs with the highest TAD ranging from 6% to 25%. The gall bladder is the critical organ with an absorbed dose of about 200 mGy/kBq followed by the urinary bladder and liver with 83 and 66 mGy/kBq, respectively. In the rest of the body radioactivity was evenly distributed. The total body dose was found to be 11.9 mGy/kBq.     

Effect of cobalt-60 gamma radiation on total hemocyte content and biochemical parameters in Macrobrachium rosenbergii (De Man, 1879)

Abstract

Purpose: The effect of low level cobalt-60 (⁶⁰Co) gamma radiation on the freshwater prawn Macrobrachium rosenbergii was evaluated by observing their hemocyte counts and biochemical parameters.

Materials and methods: Prawns were exposed to 3, 30, 300 and 3000 milligray (mGy) dose levels and their tissues of gills, hepatopancreas and muscle were analyzed.

Results: The results showed that the number of hemocytes in the hemolymph and concentrations of protein and carbohydrate were significantly reduced in irradiated groups than compared to the control prawn. Increased aspartate transaminase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), Acetyl choline esterase (AChE) in the irradiated groups reflects tissue damage.

Conclusions: Hence, this study concludes that even low level of ionizing radiation (⁶⁰Co gamma) can cause acute damages in gills, hepatopancreas and muscles in irradiated groups.

• Highlights

• ⁶⁰Co exposures effect the THC and biochemical of prawn M. rosenbergii.

• Different dose levels such as 3, 30, 300 and 3000?mGy.

• Biochemical parameters serve as reliable indicators of physical status of organism.

• Self-regulating mechanisms might be the reason for preventing from the lethality.

• Suggested that nuclear industries should manage below 3?mGy.

     

125I粒子植入治疗晚期肺癌的损伤效应与临床处置

目的分析、研究和处理^125I粒子植入治疗晚期非小细胞肺癌的损伤效应。方法对121例确诊的晚期非小细胞肺癌，由放射治疗计划系统（TPS）通过CT影像和纤维支气管镜（FFB）引导植入放射性核素^125I粒子，进行验证和病灶周围重要组织器官（如心脏及脊髓）的受量推算，定期进行复查。结果CT引导组和FFB组的总有效率分别为96．6％和77．3％；损伤效应发生率分别为56．2％和7．5％，其中CT引导组患者心肺及脊髓的照射剂量为31．0和7．5Gy，明显低于正常组织的耐受剂量，该组患者的早期和放射损伤反应发生率分别为14．6％和1．1％，而FFB组未观察到放射损伤反应发生。结论粒子植入治疗具有肯定的疗效，但不可避免地存在轻度的、易于处理的和可逆的损伤效应，本研究未观察到严重的放射忭肺炎和不可逆的肺纤维化。