Introduction:The role of trimodality therapy for locally advanced non-small cell lung cancer (NSCLC) continues to be defined. We hypothesized that imaging parameters on pre- and postradiation positron emission tomography (PET)-computed tomography (CT) imaging are prognostic for outcome after preoperative chemoradiotherapy (CRT)/resection/consolidation chemotherapy and could help risk-stratify patients in clinical trials. Methods:We enrolled 13 patients on a prospective clinical trial of trimodality therapy for resectable locally advanced NSCLC. PET-CT was acquired for radiation planning and after 45 Gy. Gross tumor volume (GTV) and standardized uptake value were measured at pre- and post-CRT time points and correlated with nodal pathologic complete response, loco-regional and/or distant progression, and overall survival. In addition, we evaluated the performance of automatic deformable image registration (ADIR) software for volumetric response assessment. Results:All patients responded with average total GTV reductions after 45 Gy of 43% (range: 27–64%). Pre- and post-CRT GTVs were highly correlated (R2 = 0.9), and their respective median values divided the patients into the same two groups. ADIR measurements agreed closely with manually segmented post-CRT GTVs. Patients with GTV ≥ median (137 ml pre-CRT and 67 ml post-CRT) had 3-year progression-free survival (PFS) of 14% versus 75% for GTV less than median, a significant difference (p = 0.049). Pre- and post-CRT PET-standardized uptake value did not correlate significantly with pathologic complete response, PFS, or overall survival. Conclusions:Preoperative CRT with carboplatin/docetaxel/45 Gy resulted in excellent response rates. In this exploratory analysis, pre- and post-CRT GTV predicted PFS in trimodality therapy, consistent with our earlier studies in a broader cohort of NSCLC. ADIR seems robust enough for volumetric response assessment in clinical trials.

We quantified the performance of time-domain imaging (TDI) and spectral imaging (SI) for fluorescence imaging of quantum dots (QDs) in three distinct imaging instruments: eXplore Optix (TDI, Advanced Research Technologies Inc.), Maestro (SI, CRi Inc.), and IVIS-Spectrum (SI, Caliper Life Sciences Inc.).

This study evaluates the influence of particle size, PEGylation, and surface coating on the quantitative biodistribution of near-infrared-emitting quantum dots (QDs) in mice. Polymer- or peptide-coated 64Cu-labeled QDs 2 or 12 nm in diameter, with or without polyethylene glycol (PEG) of molecular weight 2000, are studied by serial micropositron emission tomography imaging and region-of-interest analysis, as well as transmission electron microscopy and inductively coupled plasma mass spectrometry. PEGylation and peptide coating slow QD uptake into the organs of the reticuloendothelial system (RES), liver and spleen, by a factor of 6-9 and 2-3, respectively. Small particles are in part renally excreted. Peptide-coated particles are cleared from liver faster than physical decay alone would suggest. Renal excretion of small QDs and slowing of RES clearance by PEGylation or peptide surface coating are encouraging steps toward the use of modified QDs for imaging living subjects.

ReO 4 − has similar kinetics regarding the sodium iodide symporter (NIS) to I− and TcO 4 − in NIS-expressing tissue. We investigated the therapeutic potential of 186ReO 4 − in NIS-transfected neuroendocrine tumour tissue.

PURPOSE:To evaluate in vivo whole-body biodistribution of microbubbles (MBs) targeted to tumor angiogenesis-related vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) by using dynamic micro-positron emission tomography (PET) in living mice. MATERIALS AND METHODS:Animal protocols were approved by the Institutional Administrative Panel on Laboratory Animal Care. Lipid-shell perfluorocarbon-filled MBs, targeted to VEGFR2 via anti-VEGFR2 antibodies, were radiolabeled by conjugating the radiofluorination agent N-succinimidyl-4-[(18)F]fluorobenzoate (SFB) to the anti-VEGFR2 antibodies. These MBs were then injected intravenously into nude mice (n = 4) bearing angiosarcomas, and the whole-body biodistribution of these probes was assessed for 60 minutes by using dynamic micro-PET. Results were compared with ex vivo gamma counting (n = 6) and immunofluorescence staining (n = 6). Control studies in angiosarcoma-bearing mice were performed with injection of the radiolabeled antibodies alone (n = 3) or free SFB (n = 3). A mixed-effects regression of MB accumulation on fixed effects of time and tissue type (tumor or muscle) and random effect of animal was performed. RESULTS:VEGFR2-targeted MBs rapidly cleared from the blood circulation (50% blood clearance after approximately 3.5 minutes) and accumulated in the liver (mean, 33.4% injected dose [ID]/g +/- 13.7 [standard deviation] at 60 minutes) and spleen (mean, 9.3% ID/g +/- 6.5 at 60 minutes) on the basis of micro-PET imaging. These findings were confirmed with ex vivo gamma counting. Uptake of targeted MBs was significantly higher (P < .0001) in tumor than in adjacent skeletal muscle tissue. Immunofluorescence staining demonstrated accumulation of the targeted MBs within hepatic Kupffer cells and splenic macrophages. Biodistribution of the radiolabeled antibodies and free SFB differed from the distribution of the targeted MBs. CONCLUSION:Dynamic micro-PET allows assessment of in vivo biodistribution of VEGFR2-targeted MBs.

Single-walled carbon nanotubes are currently under evaluation in biomedical applications, including in vivo delivery1,2,3 of drugs4, proteins, peptides5,6,7 and nucleic acids8,9 (for gene transfer10 or gene silencing11), in vivo tumour imaging12 and tumour targeting of single-walled carbon nanotubes as an anti-neoplastic treatment5. However, concerns about the potential toxicity of single-walled carbon nanotubes have been raised13,14. Here we examine the acute and chronic toxicity of functionalized single-walled carbon nanotubes when injected into the bloodstream of mice. Survival, clinical and laboratory parameters reveal no evidence of toxicity over 4 months. Upon killing, careful necropsy and tissue histology show age-related changes only. Histology and Raman microscopic mapping demonstrate that functionalized single-walled carbon nanotubes persisted within liver and spleen macrophages for 4 months without apparent toxicity. Although this is a preliminary study with a small group of animals, our results encourage further confirmation studies with larger groups of animals.

Evaluation of selective killing of Herpes Simplex Virus 1 thymidine kinase (HSV1-tk) expressing tumors by radiolabeled 131I-fialuridine (FIAU), and of synergy between 131I-FIAU and Ganciclovir (GCV).

This study evaluates the quantitative biodistribution of commercially available CdSe quantum dots (QD) in mice. Methods: 64Cu-Labeled 800- or 525-nm emission wavelength QD (21- or 12-nm diameter), with or without 2,000 MW (molecular weight) polyethylene glycol (PEG), were injected intravenously into mice (5.55 MBq/25 pmol QD) and studied using well counting or by serial microPET and region-of-interest analysis. Results: Both methods show rapid uptake by the liver (27.4–38.9 %ID/g) (%ID/g is percentage injected dose per gram tissue) and spleen (8.0–12.4 %ID/g). Size has no influence on biodistribution within the range tested here. Pegylated QD have slightly slower uptake into liver and spleen (6 vs. 2 min) and show additional low-level bone uptake (6.5–6.9 %ID/g). No evidence of clearance from these organs was observed. Conclusion: Rapid reticuloendothelial system clearance of QD will require modification of QD for optimal utility in imaging living subjects. Formal quantitative biodistribution/imaging studies will be helpful in studying many types of nanoparticles, including quantum dots.

Purpose There is growing interest in the human sodium/iodide symporter (NIS) gene both as a molecular imaging reporter gene and as a therapeutic gene. Here, we show the feasibility of radioisotope therapy of neuroendocrine tumors. As a separate application of NIS gene transfer, we image NIS-expressing tumors with pinhole SPECT in living subjects. Methods Biodistribution studies and in vivo therapy experiments were performed in nude mice carrying stably NIS-expressing neuroendocrine tumor xenografts following i.v. injection of 131 I and 99m Tc pertechnetate. To show the usefulness of NIS as an imaging reporter gene, 99m Tc pertechnetate uptake was imaged in vivo using a clinical gamma camera in combination with a custom-made single pinhole collimator, followed by SPECT/small animal MRI data coregistration. Results NIS-expressing neuroendocrine tumors strongly accumulated 131 I and 99m Tc pertechnetate, as did thyroid, stomach, and salivary gland. The volume of NIS-expressing neuroendocrine tumors decreased significantly after therapeutic administration of 131 I or 99m Tc pertechnetate, whereas control tumors continued to grow. NIS-mediated uptake of 99m Tc pertechnetate could be imaged in vivo at high resolution with a clinical gamma camera equipped with a custom-made single pinhole collimator. High-resolution functional and morphologic information could be combined in a single three-dimensional data set by coregistration of SPECT and small animal MRI data. Lastly, we demonstrated a therapeutic effect of 99m Tc pertechnetate on NIS-expressing neuroendocrine tumors in cell culture and, for the first time, in vivo, thought to be due to emitted Auger and conversion electrons. Conclusions NIS-expressing neuroendocrine tumors efficiently concentrate radioisotopes, allowing for in vivo high-resolution small animal SPECT imaging as well as rendering possible successful radioisotope therapy of neuroendocrine tumors.

Radiopeptide imaging is a valuable imaging method in the management of patients with neuroendocrine tumours (NET). To determine the clinical performance of gastrin receptor scintigraphy (GRS), it was compared with somatostatin receptor scintigraphy (SRS), computed tomography (CT) and 18F-FDG positron emission tomography (PET) in patients with metastasised/recurrent medullary thyroid carcinoma (MTC).

PURPOSE:This work investigated whether fLuc-catalyzed oxidation of D-luciferin generates sufficient light to induce photodynamic toxicity in cancer cells.PROCEDURES:Light emission was assessed via cooled CCD (charge-coupled device) camera. Parental and fLuc expressing cancer cells were exposed to subtoxic concentrations of photosensitizers (Rose Bengal or hypericin) and D-luciferin, sunlight, or lamplight. Toxicity was assessed by MTT assay.RESULTS:fLuc expressing cells emitted up to 500-fold higher levels of photons than parental cell lines. Although exposure to photosensitizer and sunlight reduced survival of various cell lines, survival of fLuc expressing cells incubated with photosensitizer and D-luciferin, or photosensitizer and lamplight, did not differ significantly from parental or untreated cells.CONCLUSIONS:Contesting recent reports, fLuc bioluminescence does not generate sufficient photons to induce Rose Bengal or hypericin photodynamic toxicity in a range of malignant and nonmalignant cell lines, and is not suitable as a generalizable approach to antineoplastic therapy.

Gastrin receptor scintigraphy (GRS) is a new imaging method primarily developed for the detection of metastases of medullary thyroid carcinoma (MTC). As gastrin-binding CCK 2 receptors are also expressed on a variety of other neuroendocrine tumours (NET), we compared GRS to somatostatin receptor scintigraphy (SRS) in patients with NET. SRS and GRS were performed within 21 days in a series of 60 consecutive patients with NET. GRS was directly compared with SRS. If lesions were visible on GRS but not detectable by SRS, other imaging modalities (MRI, CT) and follow-up were used for verification. Of the 60 evaluable patients, 51 had carcinoid tumours, 3 gastrinomas, 2 glucagonomas, 1 insulinoma and 3 paragangliomas. The overall tumour-detection rate was 73.7% for GRS and 82.1% for SRS. In the 11 patients with negative SRS, GRS was positive in 6 (54.5%). Based on the number of tumour sites detected and the degree of uptake, GRS performed better than SRS in 13 patients (21.7%), equivalent images were obtained in 18 cases (30.0%) and SRS performed better in 24 (40.0%) cases. In six of the SRS positive patients, 18 additional sites of tumour involvement could be detected. Overall, GRS detected additional tumour sites in 20% of the patients. Localisation of the primary tumours or their functional status had no influence on the outcome of imaging. GRS should be performed in selected patients as it may provide additional information in patients with NET with equivocal or absent somatostatin uptake.

There is a considerable discrepancy in the literature concerning the sensitivity of parathyroid scintigraphy (PS) with 99mTc-MIBI. We therefore analyzed our own data and compared them to the literature in a metaanalysis. All patients who received 99mTc -MIBI scintigraphy and subsequent surgery in our department for the detection of enlarged parathyroid glands in primary (pHPT) or secondary (sHPT) hyperparathyroidism between 1991 and 1999 were included in our retrospective analysis. The results of surgery served as the gold standard. For a true positive result, the scintigraphy had to predict the exact location of parathyroid adenoma (PA) or parathyroid hyperplasia (PH). We then compared these data to the results of a nonstatistical systematic metaanalysis of the literature. Patients (178) underwent PS between 1991 and 1999; 139 were operated on and included in this study. Of these, 109 had pHPT and 30 had sHPT. The sensitivity and specificity of the PS were found to be 45% / 94% for pHPT and 39% / 40% for sHPT. Fifty-two studies concerning PS were included in the metaanalysis. Sensitivities reported varied from 39% to > 90%. Consideration of the different possible techniques used for PS could not explain these discrepancies. Our data show that the sensitivity of PS in clinical routine may be lower than expected from the literature. Our data are consistent with other studies and with partially unpublished clinical observations from other university hospitals. We believe that a well-designed and properly conducted prospective study is necessary to evaluate the reasons for the differences observed.

Calculation of iodine-131 activities for radioiodine treatment (RIT) in patients with disseminated thyroid autonomy may be difficult because of uncertainties in the determination of the autonomous volume (volaut). The algorithm established by Emrich is used for calculation of the volaut based on the TcTUs (technetium thyroid uptake under TSH suppression) (volaut= 5×TcTUs+0.6). Clinical experience using this approach has shown that there is a negative correlation between increasing TcTUs and the results of RIT. Our aim was to identify the reasons for this observation as well as to assess the relation between TcTUs and sonographic volaut. Furthermore, we intended to find an alternative algorithm for the TcTUs-based calculation of the volaut. Data from 100 patients with unifocal autonomy who met strict inclusion criteria were used to evaluate the correlation between TcTUs and sonographic volaut. Using Marinelli's algorithm, we calculated the therapeutic activities for a standardised patient at a target dose of 300 Gy. The volaut was determined based on the TcTUs using the four published algorithms [Emrich 1993 (volaut= 5×TcTUs+0.6), Kreisig 1992 (volaut=10×TcTUs−9.3), Joseph 1977 (volaut=8.33×TcTUs−6.67) and 1994 (volaut=2.88×TcTUs+0.09)]. We then compared the results of the calculation of therapeutic activities obtained using Emrich's algorithm (with known success rates) with those obtained by the other algorithms in order to determine which algorithm would lead to better results in RIT. Only a weak correlation was found between the TcTUs and the sonographic volaut (r2=0.39). The calculated therapeutic activities of 131I were similar for all algorithms at a TcTUs of around 2% but Joseph's (1977) and Kreisig's (1992) algorithms resulted in clearly higher activities than Emrich's algorithm at a TcTUs above 2%. The need for target doses to increase with TcTUs in RIT may be overcome by the use of adequate algorithms for determination of the volaut. The algorithm published by Joseph and co-workers in 1977 probably offers the most reliable approach to the TcTUs-based calculation of volaut in RIT. In contrast to the other algorithms, it is based on autoradiographic planimetric data. Thus, it takes into account the polyclonal origin of thyroid nodules as well as the presence of regressive or cystic changes. The well-established algorithm of Emrich underestimates the true volaut, which explains the decreasing success of RIT with increasing TcTUs.

This study evaluates the possibility of treating Bon1 and QGP pancreatic neuroendocrine tumor cells with radioactive iodide ((131)I) after stable transfection with the thyroid sodium iodide symporter (NIS). NIS expression was driven either by the strong viral cytomegalovirus promoter or by the tissue-specific chromogranin A promoter. Using either approach, NIS expression was confirmed by reverse transcription-PCR and Western blotting. Uptake of radioactive iodide was increased approximately 20-fold by chromogranin A promoter-driven NIS expression and approximately 50-fold by cytomegalovirus promoter-driven NIS expression. Maximal uptake was reached within 15 min in QGP cells and 30 min in Bon1 cells. Effective half-life was 5 min in QGP and 30 min in Bon1 cells. No evidence of organification was detected by high-performance liquid chromatography and gel filtration chromatography. (131)I was a highly effective treatment in NIS-expressing QGP and Bon1 cells, reducing clone formation by 99.83 and 98.75%, respectively, in the in vitro clonogenic assay. In contrast, clone formation was not reduced in QGP and Bon1 cells without NIS expression after incubation with the same activity concentration of (131)I as compared with mock treated cells. Absorbed doses to QGP and Bon1 cells are up to 150 and 30 Gy, respectively. In addition, a direct cytotoxic effect of radioiodide was demonstrated in NIS-expressing Bon1 cells after (131)I incubation. In conclusion, radioiodide treatment after NIS gene transfer appears to be a promising novel approach in the therapy of neuroendocrine tumors if its highly encouraging in vitro effectiveness can be transferred to the in vivo situation.

The recent cloning and molecular characterization of the sodium iodide-symporter (NIS) has inspired novel approaches to the diagnosis and treatment of thyroidal and nonthyroidal malignancies. This article briefly reviews the physiologic regulation of NIS expression by cytokines, the expression in benign and malignant thyroidal diseases, and the expression in extrathyroidal tissues. Current concepts for NIS-based cancer therapy in thyroidal and extrathyroidal tumors are presented. The recent discovery of NIS expression in a majority of breast cancers as well as its promising application for prostate cancer imply potential applications in diagnostic imaging and radioiodine anticancer therapy for these highly common and lethal malignancies.