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Purpose: We have incorporated a positron emission tomography (PET) functionality in T cells expressing a CD19-specific chimeric antigen receptor (CAR) to non-invasively monitor the adoptively transferred cells., Procedures: We engineered T cells to express CD19-specific CAR, firefly luciferase (ffLuc), and herpes simplex virus type-1 thymidine kinase (TK) using the non-viral-based Sleeping Beauty (SB) transposon/transposase system adapted for human application. Electroporated primary T cells were propagated on CD19 + artificial antigen-presenting cells., Results: After 4 weeks, 90 % of cultured cells exhibited specific killing of CD19 + targets in vitro, could be ablated by ganciclovir, and were detected in vivo by bioluminescent imaging and PET following injection of 2'-deoxy-2'-[ 18 F]fluoro-5-ethyl-1-β-D-arabinofuranosyl-uracil ([ 18 F]FEAU)., Conclusion: This is the first report demonstrating the use of SB transposition to generate T cells which may be detected using PET laying the foundation for imaging the distribution and trafficking of T cells in patients treated for B cell malignancies., Competing Interests: The technology described in this publication was advanced through research conducted at the University of Texas MD Anderson Cancer Center (MD Anderson) by Laurence Cooper. In January 2015, the technology was licensed by MD Anderson for commercial application to ZIOPHARM Oncology, Inc., and Intrexon Corporation, in exchange for equity interests in each of these companies. Laurence Cooper, Amer M. Najjar, Pallavi R. Manuri, Simon Olivares, Tiejuan Mi, Helen Huls, Richard E. Champlin, Brian Rabinovich, and Dean A. Lee are eligible in accordance with the Rules of Board of Regents of The University of Texas System to share in the proceeds of the disposition of the equity received by MD Anderson as a result of the licensing of this technology. On May 7, 2015, Dr. Cooper was appointed as the Chief Executive Officer at ZIOPHARM. Dr. Cooper is now a Visiting Scientist at MD Anderson where he continues to help supervise the development of this technology. The research being reported in this publication is research in which The University of Texas MD Anderson Cancer Center has an institutional financial conflict of interest. Because MD Anderson is committed to the protection of human subjects and the effective management of its financial conflicts of interest in relation to its research activities, MD Anderson has implemented an Institutional Conflict of Interest Management and Monitoring Plan to manage and monitor the conflict of interest with respect to MD Anderson’ s conduct of this research.

Unlabelled: Many solid tumors overexpress EphB4 receptor, a member of the ephrin receptor tyrosine kinase family. Noninvasive imaging of EphB4 could potentially increase early detection rates, monitor response to therapy directed against EphB4, and improve patient outcomes. The purpose of this study was to evaluate a novel (64)Cu-labeled peptide with high receptor binding affinity for PET of EphB4 receptors., Methods: The EphB4-binding peptide TNYLFSPNGPIARAW (TNYL-RAW) was conjugated with fluorescein isothiocyanate (FITC) and DOTA. DOTA-TNYL-RAW was labeled with (64)Cu with high labeling efficiency. The binding affinity of TNYL-RAW and its derivatives to purified recombinant EphB4 was determined using surface plasmon resonance technology. In vitro binding of both FITC-TNYL-RAW and (64)Cu-DOTA-TNYL-RAW to cancer cells was assessed by fluorescent microscopy and a radioactivity count method. In vivo biodistribution and small-animal PET/CT were performed in mice bearing EphB4-expressing CT26 and PC-3M tumors as well as EphB4-negative A549 tumors., Results: TNYL-RAW and its derivatives displayed high binding affinity to EphB4, with equilibrium dissociation constant of 1.98-23 nM. In vitro, both FITC-TNYL-RAW and (64)Cu-DOTA-TNYL-RAW were selectively taken up by CT26 and PC-3M cells but not by A549 cells. Binding of FITC-TNYL-RAW and (64)Cu-DOTA-TNYL-RAW to CT26 and PC-3M cells could be blocked by an excess amount of TNYL-RAW. In vivo, (64)Cu-DOTA-TNYL-RAW showed significantly higher uptake in PC-3M tumors than in A549 tumors, with percentages of injected dose per gram of tumor of 0.84 ± 0.09 and 0.44 ± 0.09 at 24 h after radiotracer injection, respectively. Small-animal PET/CT clearly revealed deposition of (64)Cu-DOTA-TNYL-RAW in CT26 and PC-3M tumors but not in A549 tumors. Furthermore, uptake of (64)Cu-DOTA-TNYL-RAW in both CT26 and PC-3M tumors could be blocked by cold TNYL-RAW., Conclusion: The expression of EphB4 receptors can be noninvasively interrogated by small-animal PET/CT using (64)Cu-DOTA-TNYL-RAW.

The importance of the EGF receptor (EGFR) signaling pathway in the development and progression of nonsmall cell lung carcinomas (NSCLC) is widely recognized. Gene sequencing studies revealed that a majority of tumors responding to EGFR kinase inhibitors harbor activating mutations in the EGFR kinase domain. This underscores the need for novel biomarkers and diagnostic imaging approaches to identify patients who may benefit from particular therapeutic agents and approaches with improved efficacy and safety profiles. To this goal, we developed 4-[(3-iodophenyl)amino]-7-{2-[2-{2-(2-[2-{2-([(18)F]fluoroethoxy)-ethoxy}-ethoxy]-ethoxy)-ethoxy}-ethoxy]-quinazoline-6-yl-acrylamide ([(18)F]F-PEG6-IPQA), a radiotracer with increased selectivity and irreversible binding to the active mutant L858R EGFR kinase. We show that PET with [(18)F]F-PEG6-IPQA in tumor-bearing mice discriminates H3255 NSCLC xenografts expressing L858R mutant EGFR from H441 and PC14 xenografts expressing EGFR or H1975 xenografts with L858R/T790M dual mutation in EGFR kinase domain, which confers resistance to EGFR inhibitors (i.e., gefitinib). The T790M mutation precludes the [(18)F]F-PEG6-IPQA from irreversible binding to EGFR. These results suggest that PET with [(18)F]F-PEG6-IPQA could be used for the selection of NSCLC patients for individualized therapy with small molecular inhibitors of EGFR kinase that are currently used in the clinic and have a similar structure (i.e., iressa, gefitinib, and erlotinib).

The aim of this study was to develop a new artificial amino acid radiopharmaceutical labelled with radioiodine for detection of malignant melanoma, based on melanin formation. By considering the affinity for tyrosinase, a starting enzyme on the branching point to melanin biosynthesis, 3-[125I]iodo-4-hydroxyphenyl-L-cysteine (125I-L-PC) was synthesized and evaluated biologically. Labelling of 125I-L-PC using the chloramine-T method was carried out conveniently and efficiently in a short period of time, with high specific activity. In a biodistribution study, 125I-L-PC showed a low accumulation in normal tissue and relative retention in B16 melanoma. A high contrast image of peripheral tumour was obtained during autoradiography. During an in vitro accumulation study, inhibition of 125I-L-PC with a tyrosinase inhibitor suggested interaction of this tracer with tyrosinase. It indicates that the uptake mechanism of 125I-L-PC to melanoma tissue was dependent on high tyrosinase activity in melanoma cells. Thus, 125I-L-PC appears to be a promising radioiodinated amino acid radiopharmaceutical for imaging malignant melanoma in relation to melanin formation, namely specific metabolism with high tyrosinase activity.

Technetium-99m methoxy-isobutylisonitrile (MIBI), like thallium-201 (201Tl), is a highly efficient agent for the diagnosis and monitoring of glioma tumors. Although 201Tl uptake is known to be partly associated with proliferative activity, little is known about the correlation between MIBI uptake and proliferation activity in gliomas. The current study was performed to assess the correlation between MIBI uptake and proliferative activities in gliomas, estimated by the monoclonal antibody to Ki-67 antigen (MIB-1) staining method. By comparing the results with those of 201Tl, we determined which tracer would be suitable for estimating proliferative activities. Twenty-four presurgical glioma patients (six with low-grade gliomas, five with anaplastic astrocytomas, and 13 with glioblastomas) were given MIBI and 201Tl SPECT. Early (10 min after injection) and delayed images (3 h after injection) were obtained for both MIBI and 201Tl scintigraphy. SPECT parameters, early ratio (ER), delayed ratio (DR), and retention index (RI) were obtained in both radiopharmaceuticals. All patients underwent subsequent surgical excision, and the specimens were immunostained for MIB-1. The proliferative activity was measured as a percentage positive nuclear area for MIB-1 (MI; MIB-1 index). To evaluate the relationship between the proliferative activity and SPECT parameters, we performed a correlation analysis. MI correlated with the MIBI uptake ratio (r = 0.75 for ER, and r = 0.7 for DR). Both DR and RI of 201Tl also correlated with MI, but weakly (r = 0.6 for DR, and. r = 0.59 for RI). There was no significant correlation between the MIB-1 index and the other parameters. MIBI-uptake parameters demonstrated a stronger positive correlation with the MIB-1 index than that of 201Tl. With the use of MIBI SPECT, we can estimate the proliferative activity of glioma noninvasively.

PURPOSE: This study was undertaken to determine the usefulness of Tc-99m methoxyisobutylisonitrile (MIBI) in brain tumors compared with TI-201 imaging. The authors evaluated the correlation between MIBI uptake and the presence of P-glycoprotein, and also the relation between MIBI uptake in response to combined radiotherapy and chemotherapy in glioblastoma. MATERIALS AND METHODS: Thirty-four brain tumors composed of 15 glioblastoma multiforme (GBM), 5 anaplastic astrocytomas, 5 low-grade astrocytomas, and 9 metastases were evaluated. Early and delayed images were obtained for MIBI and Tl-201 scintigraphy. P-glycoprotein status in all GBM, 2 anaplastic astrocytomas, 2 low-grade astrocytomas, and 2 metastases were evaluated immunohistochemically. Patients with GBM were divided into an effective and a noneffective group according to the change in tumor size. MIBI uptake indices were compared for these two groups. RESULTS: Both radiopharmaceuticals accumulated in all GBM and anaplastic astrocytomas. In low-grade astrocytomas, only one case showed tracer uptake. In metastasis, two cases showed high uptake on early images and marked washout on delayed images. Uptake ratio values (early uptake ratio and delayed uptake ratio) in all tumors were significantly higher in MIBI than in Tl-201. Immunohistochemical studies showed that the metastases were positive for P-glycoprotein but the GBM were not. In low-grade astrocytomas, a few cells were positively stained. In relation to the therapeutic outcome of GBM, both the early and delayed uptake ratios of MIBI were significantly greater in the noneffective group. CONCLUSIONS: Although diagnostic ability was comparable in MIBI and Tl-201, the imaging quality was better in MIBI. Both radiopharmaceuticals are useful in differentiating low-grade glioma from high-grade glioma. MIBI delayed imaging could also reflect the presence of P-glycoprotein. Intense MIBI uptake was also predictive of a poor clinical outcome in GBM.

The purpose of this study is validation of calibrating a standard input function in autoradiography (ARG) method by one point venous blood sampling as a substitute for that by one point arterial blood sampling. Ten and 20 minutes after intravenous constant infusion of 123I-IMP, arterialized venous blood sampling from a dorsal vein were performed on 15 patients having ischemic cerebrovascular disease. And arterial blood sampling from radial artery was performed 10 min after 123I-IMP infusion. The mean difference rates of integrated input function between calibrated standard input function by arterial blood sampling at 10 min and that by venous blood sampling were 4.1 +/- 3% and 9.3 +/- 5.4% at 10 and 20 min after 123I-IMP infusion, respectively. The ratio of venous blood radioactivity to arterial blood radioactivity at 10 min after 123I-IMP infusion was 0.96 +/- 0.02. There was an excellent correlation between ARG method CBF values obtained by arterial blood sampling at 10 min and those obtained by arterialized venous blood sampling at 10 min. In conclusion, a substitution by arterialized venous blood sampling from dorsal hand vein for artery can be possible. The optimized time for arterialized venous blood sampling was 10 min after 123I-IMP infusion.

We report a three-year-old boy with Reye syndrome evaluated by 99mTc-ECD SPECT. On acute stage, 99mTc-ECD brain SPECT disclosed diffuse high uptake in the cerebral cortex in spite of normal findings on brain X-ray CT. These lesions changed to general low uptake on the chronic state and multiple high intensity areas were shown on T2 weighted MRI image. Such a change of cerebral tracer uptake was considered to reflect the neuropathological change of Reye syndrome. 99mTc-ECD SPECT was a useful modality to diagnose Reye syndrome complementary.

Purpose: To investigate cerebral vasodilatory capacity by acetazolamide challenge in healthy subjects and in patients with chronic occlusive cerebrovascular disease by using susceptibility-weighted gradient-echo MR imaging., Methods: Eight patients with chronic occlusive cerebrovascular disease and four healthy volunteers were studied with susceptibility-weighted MR imaging before and after intravenous administration of 1000 mg of acetazolamide. Signal intensities were measured as a function of time in several regions of interest defined on anatomic images. In all patients with chronic occlusive cerebrovascular disease, acetazolamide challenge and resting regional cerebral blood flow were also evaluated with single-photon emission CT (SPECT)., Results: In healthy volunteers, signal intensities began to increase 3 to 4 minutes after acetazolamide administration, with a continuous increase during the subsequent 10 minutes. The effect lasted for approximately 45 minutes after administration. In patients with chronic occlusive cerebrovascular disease, signal changes on susceptibility-weighted MR images of occluded areas with normal vasodilatory capacity on SPECT images did not differ from signal changes of nonocclusive areas. In those patients with changes that reflected diminished vasodilatory capacity, the MR images showed a lower percentage of signal changes after acetazolamide administration than those in normally perfused areas., Conclusion: Susceptibility-weighted MR imaging offers an alternative method for estimating vasodilatory capacity.