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Objective The purpose of this study was to assess the efficacy of Lu-labeled peptide receptor radionuclide therapy (PRRT) induction treatments for patients with unresectable metastatic neuroendocrine tumors. Methods MEDLINE, EMBASE, and Ovid were systematically searched with keywords "lutetium," "Lu-177," "PRRT," "neuroendocrine," and "prognosis." Studies evaluating treatment with Lu-labeled PRRT were assessed for disease response and/or disease control rate by Response Evaluation Criteria in Solid Tumors (RECIST) 1.0 or 1.1, modified RECIST, Southwest Oncology Group (SWOG), or modified SWOG criteria. Pooled proportions of disease response and control rates were calculated for both fixed- and random-effects models. Results Eighteen studies with 1920 patients were included (11 with 1268 patients using RECIST and 6 with 804 patients using SWOG). By RECIST criteria, the pooled disease response rate by random-effects model was 29.1% (95% confidence interval [CI], 20.2%-38.9%), and disease control rate was 74.1% (95% CI, 67.8%-80.0%). By SWOG criteria, the pooled disease response rate by random-effects model was 30.6% (95% CI, 20.7%-41.5%), and disease control rate was 81.1% (95% CI, 76.4%-85.4%). Conclusions Induction therapy, typically 4 treatments, with Lu PRRT is an effective method of treating unresectable metastatic neuroendocrine tumors with significant disease response and control rates.

This paper presents the irradiation and processing of high-current 100Mo targets at the University of Alberta (UofA) in a GMP compliant setting. For purpose of comparison with a second production facility, additional studies at Centre Hospitalier Universitaire de Sherbrooke (CHUS) are also described. Introduction More than 70% of today's diagnostic radiopharmaceuticals are based on 99mTc, however the conventional supply chain for obtaining 99mTc is fragile. The aim of this work was to demonstrate reliable high yield production and processing of 99mTc with medium-energy, high-current, cyclotrons. Methods We used two cyclotrons (TR-24, Advanced Cyclotron Systems, Inc) for irradiations with 22 MeV or 24 MeV incident energy and 400 μA current up to a maximum of 6 h. The irradiated 100Mo was dissolved using peroxide, basified using ammonium carbonate, and purified using a PEG-based solid phase extraction technique. Results High-yield productions with 22 MeV (400 μA, 6 h) yielded an average isolated [99mTc]TcO4− yield of 878 GBq ± 99 GBq (23.7 Ci ± 2.7 Ci) decay corrected to EOB, n = 8 (isolated saturation yield: 4.36 ± 0.49 GBq/μA). Irradiations with 24 MeV (400 μA, 6 h) resulted in an average isolated [99mTc]TcO4− yield of 993 GBq ± 100 GBq (26.8 Ci ± 2.7 Ci) decay corrected to EOB, n = 7 (isolated saturation yield: 4.97 ± 0.50 GBq/μA). These yields corresponds to 600–700 GBq (16–19 Ci) of [99mTc]TcO4− at release (i.e. 3 hour post-EOB). For all tested batches, the QC results were within the recently published specifications in the European Pharmacopoeia. Conclusion Reliable near-TBq production yields for 99mTc can be obtained using medium-energy cyclotrons. Advances in knowledge and implications for patient care This work presents evidence that medium-energy high-current cyclotrons can provide high yields of [99mTc]TcO4− with radionuclidic impurities levels within the specifications of the existing European Pharmacopoeia monograph, indicating that this technology can have a share in the future 99mTc supply market.

Neuroendocrine tumours (NETs) are heterogeneous, with varying presentations and treatment options. To our knowledge, there are no randomized and few long-term studies of patient outcomes. The role of surgical and medical therapy for local, regional and metastatic disease continues to be evaluated in the literature.We conducted a population-based search of the provincial cancer registry to identify patients with gastrointestinal NETs from the stomach, small intestine, colon and rectum diagnosed between 1990 and 2005 and assessed their outcomes.We examined clinicopathological information on the outcomes of 530 patients with gastrointestinal NETs. The overall incidence of NETs increased from 11 per million to 19 per million during the study period. Advancing stage and patient age were associated with poor overall or disease-specific outcomes. Surgery, both curative and palliative, was associated with decreased risk of overall (hazard ratio [HR] 0.5,There has been a significant increase in incidence of gastrointestinal NETs, and advancing patient age, but not sex, is linked to poor outcomes in terms of overall and disease-specific survival. Surgery, both curative and palliative, was associated with decreased risk of overall and disease-specific death. Compared with patients with residual macroscopic disease, patients with distant disease were nearly twice as likely to survive 5 years if they had R0 resections. The use of radioisotope therapy and long-acting octreotide therapy was also associated with improved outcomes overall.Les tumeurs neuroendocrines (TNE) sont hétérogènes, et les tableaux et options thérapeutiques sont variables. À notre connaissance, il n'existe pas d'études randomisées et il y a peu d'études à long terme sur les résultats chez les patients. Le rôle du traitement chirurgical et médicamenteux de la maladie locale, régionale et métastatique continue d'être évalué dans la littérature.Nous avons procédé à une interrogation démographique du Registre provincial du cancer pour recenser les patients atteints de TNE gastro-intestinales provenant de l'estomac, de l'intestin grêle, du côlon et du rectum, diagnostiqués entre 1990 et 2005 et nous avons évalué les résultats.Nous avons examiné les données clinico-pathologiques des résultats enregistrés chez 530 patients atteints de TNE gastro-intestinales. L'incidence globale des TNE a augmenté de 11 par million à 19 par million pendant la période de l'étude. Le stade de la maladie et l'âge avancés ont été associés à des résultats globaux ou spécifiques à la maladie moins favorables. La chirurgie, curative et palliative, a été associée à un risque moindre de décès global (risque relatif [RR] 0.5,L'incidence des TNE gastro-intestinales a significativement augmenté, et l'âge avancé des patients, mais non le sexe, est lié à des résultats défavorables aux plans de la survie globale et spécifique à la maladie. La chirurgie, curative et palliative, a été associée à un risque moindre de décès global et spécifique à la maladie. Comparativement aux patients ayant une maladie macroscopique résiduelle, ceux qui avaient une maladie distale étaient près de 2 fois plus susceptibles de survivre 5 ans s'ils avaient des résections R0. Les traitements par radio-isotopes et octréotide à longue durée d'action ont aussi été associés à une amélioration globale des résultats.

A single-site prospective open-label clinical study with cyclotron-produced sodium 99mTc-pertechnetate (99mTc-NaTcO4) was performed in patients with indications for a thyroid scan to demonstrate the clinical safety and diagnostic efficacy of the drug and to confirm its equivalence with conventional 99mTc-NaTcO4 eluted from a generator. Methods:99mTc-NaTcO4 was produced from enriched 100Mo (99.815%) with a cyclotron (24 MeV; 2 h of irradiation) or supplied by a commercial manufacturer (bulk vial eluted from a generator). Eleven patients received 325 ± 29 (mean ± SD) MBq of the cyclotron-produced 99mTc-NaTcO4, whereas the age- and sex-matched controls received a comparable amount of the generator-derived tracer. Whole-body and thyroid planar images were obtained for each participant. In addition to the standard-energy window (140.5 keV ± 7.5%), data were acquired in lower-energy (117 keV ± 10%) and higher-energy (170 keV ± 10%) windows. Vital signs and hematologic and biochemical parameters were monitored before and after tracer administration. Results: Cyclotron-produced 99mTc-NaTcO4 showed organ and whole-body distributions identical to those of conventional 99mTc-NaTcO4 and was well tolerated. All images led to a clear final diagnosis. The fact that the number of counts in the higher-energy window was significantly higher for cyclotron-produced 99mTc-NaTcO4 did not influence image quality in the standard-energy window. Image definition in the standard-energy window with cyclotron-produced 99mTc was equivalent to that with generator-eluted 99mTc and had no particular features allowing discrimination between the 99mTc production methods. Conclusion: The systemic distribution, clinical safety, and imaging efficacy of cyclotron-produced 99mTc-NaTcO4 in humans provide supporting evidence for the use of this tracer as an equivalent for generator-eluted 99mTc-NaTcO4 in routine clinical practice.

Purpose: A robust method is required to standardise objective reporting of diagnostic 123I-mIBG images in neuroblastoma. Prerequisites for an appropriate system are low inter- and intra-observer error and reproducibility across a broad disease spectrum. We present a new reporting method, developed and tested for SIOPEN by an international expert panel. Method: Patterns of abnormal skeletal 123I-mIBG uptake were defined and assigned numerical scores [0–6] based on disease extent within 12 body segments. Uptake intensity was excluded from the analysis. Data sets from 82 patients were scored independently by six experienced specialists as unblinded pairs (pre- and post-induction chemotherapy) and in random order as a blinded study. Response was defined as ≥50 % reduction in post induction score compared with baseline. Results: In total, 1968 image sets were reviewed individually. Response rates of 88 % and 82 % were recorded for patients with baseline skeletal scores ≤23 and 24-48 respectively, compared with 44 % response in patients with skeletal scores >48 (p = 0.02). Reducing the number of segments or extension scale had a small but statistically negative impact upon the number of responses detected. Intraclass correlation coefficients [ICCs] calculated for the unblinded and blinded study were 0.95 at diagnosis and 0.98 and 0.99 post-induction chemotherapy, respectively. Conclusions: The SIOPEN mIBG score method is reproducible across the full spectrum of disease in high risk neuroblastoma. Numerical assessment of skeletal disease extent avoids subjective evaluation of uptake intensity. This robust approach provides a reliable means with which to examine the role of 123I mIBG scintigraphy as a prognostic indicator in neuroblastoma.

Hydrophobic adsorbents such as C18 and C30 were coated with PEG and subsequently used for the separation of Mo/Tc. The most effective resin for adsorbing PEG was the C18-U resin, which demonstrated a coating capacity of 97.6±2.8 mg PEG per g of resin. The ability to adsorb pertechnetate was proportional to the amount of PEG coated on the hydrophobic resin. The [ 99m Tc]pertechnetate recovery during the separation of cyclotron produced 99m Tc from 100 Mo was 91.8±0.3% ( n =2). The resultant product met relevant USP monograph specifications.

A 26-year-old woman with a 5-year history of metastatic paraganglioma due to hereditary paraganglioma-pheochromocytoma syndrome with SDHB mutation, who had failed multiple treatment regimens and had transfusion dependent pancytopenia, presented with progressive liver and bone metastases. She was unable to sleep due to painful skull metastases and had severe weakness in her extremities that limited her mobility and daily activities. She was treated with 2 doses of Ra-dichloride (Xofigo, Ra) and had a dramatic improvement in pain control, mobility, and overall quality of life for 8 weeks, before passing away from pulmonary hemorrhage.

There is no consensus on optimal follow-up for completely resected gastroenteropancreatic neuroendocrine tumors. Published guidelines for follow-up are complex and emphasize closer surveillance in the first 3 years after resection. Neuroendocrine tumors have a different pattern and timescale of recurrence, and thus require more practical and tailored follow-up. The Commonwealth Neuroendocrine Tumour Collaboration convened an international multidisciplinary expert panel, in collaboration with the North American Neuroendocrine Tumor Society, to create patient-centered follow-up recommendations for completely resected gastroenteropancreatic neuroendocrine tumors. This panel used the RAND/UCLA (University of California, Los Angeles) Appropriateness Method to generate recommendations. A large international survey was conducted outlining current the surveillance practice of neuroendocrine tumor practitioners and shortcomings of the current guidelines. A systematic review of available data to date was supplemented by recurrence data from 2 large patient series. The resultant guidelines suggest follow-up for at least 10 years for fully resected small-bowel and pancreatic neuroendocrine tumors and also identify clinical situations in which no follow-up is required. These recommendations stratify follow-up strategies based on evidence-based prognostic factors that allow for a more individualized patient-centered approach to this complex and heterogeneous malignant neoplasm.

The objective of this work is to evaluate the potential effect of cardiac stress exercise on the accumulation of [123I]IAZA, a radiopharmaceutical used to image focal tissue hypoxia, in otherwise normal myocardium in healthy volunteers, and to determine the impact of exercise on [123I]IAZA pharmacokinetics. The underlying goal is to establish a rational basis and a baseline for studies of focal myocardial hypoxia in cardiac patients using [123I]IAZA. Three healthy male volunteers ran the ‘Bruce’ treadmill protocol, a clinically-accepted protocol designed to expose myocardial ischemia in patients. The ‘Bruce’ criterion heart rate is 85% of [220 – age]. Approximately one minute before reaching this level, [123I]IAZA (5.0 mCi/0.85 mg) was administered as a slow (1–3 min) single intravenous (i.v.) injection via an indwelling venous catheter. The volunteer continued running for an additional 1 min before being transferred to a gamma camera. Serum samples were collected from the arm contralateral to the administration site at pre-determined intervals from 1 min to 45 h post injection and were analyzed by radio HPLC. Pharmacokinetic (PK) parameters were derived for [123I]IAZA and total radioactivity (total[123I]) using compartmental and noncompartmental analyses. Whole-body planar scintigraphic images were acquired from 0.75 to 24 h after dosing. PK data and scintigraphic images were compared to previously published [123I]IAZA data from healthy volunteers rest. Following exercise stress, both [123I]IAZA and total[123I] exhibited bi-exponential decline profiles, with rapid distribution phases [half-lives (t1/2α) of 1.2 and 1.4 min, respectively], followed by slower elimination phases [t1/2β of 195 and 290 min, respectively]. Total body clearance (CLTB) and the steady state volume of distribution (Vss) were 0.647 L/kg and 185 mL/min, respectively, for [123I]IAZA and 0.785 L/kg and 135 mL/min, respectively, for total[123I]. The t1/2β, CLTB and Vss values were comparable to those reported previously for rested volunteers. The t1/2α was approximately 4-fold shorter for [123I]IAZA and approximately 3-fold shorter for total[123I] under exercise relative to rested subjects. The heart region was visualized in early whole body scintigraphic images, but later images showed no accumulated radioactivity in this region, and no differences from images reported for rested volunteers were apparent. Minimal uptake of radiotracer in myocardium and skeletal muscle was consistent with uptake in non-stressed myocardium. Whole-body scintigrams for [123I]IAZA in exercise-stressed healthy volunteers were indistinguishable from images of non-exercised volunteers. There was no evidence of hypoxia-dependent binding in exercised but otherwise healthy myocardium, supporting the conclusion that exercise stress at Bruce protocol intensity does not induce measurable myocardial hypoxia. Effects of exercise on PK parameters were minimal; specifically, the t1/2α was shortened, reflecting increased cardiac output associated with exercise. It is concluded that because [123I]IAZA was not metabolically bound in exercise-stressed myocardium, a stress test will not create elevated myocardial background that would mask regions of myocardial perfusion deficiency. [123I]IAZA would therefore be suitable for the detection of viable, hypoxic myocardium in patients undergoing stress-test-based diagnosis.

Radiolabeled peptides for tumor imaging with PET that can be produced with kits are currently in the spotlight of radiopharmacy and nuclear medicine. The diagnosis of neuroendocrine tumors in particular has been a prime example for the usefulness of peptides labeled with a variety of different radionuclides. Among those, 68Ga and 18F stand out because of the ease of radionuclide introduction (e.g., 68Ga isotope) or optimal nuclide properties for PET imaging (slightly favoring the 18F isotope). The in vivo properties of good manufacturing practice–compliant, newly developed kitlike-producible 18F-SiFA– and 18F-SiFAlin– (SiFA = silicon-fluoride acceptor) modified TATE derivatives were compared with the current clinical gold standard 68Ga-DOTATATE for high-quality imaging of somatostatin receptor–bearing tumors. Methods: SiFA- and SiFAlin-derivatized somatostatin analogs were synthesized and radiolabeled using cartridge-based dried 18F and purified via a C18 cartridge (radiochemical yield 49.8% ± 5.9% within 20–25 min) without high-performance liquid chromatography purification. Tracer lipophilicity and stability in human serum were tested in vitro. Competitive receptor binding affinity studies were performed using AR42J cells. The most promising tracers were evaluated in vivo in an AR42J xenograft mouse model by ex vivo biodistribution and in vivo PET/CT imaging studies for evaluation of their pharmacokinetic profiles, and the results were compared with those of the current clinical gold standard 68Ga-DOTATATE. Results: Synthetically easily accessible 18F-labeled silicon-fluoride acceptor–modified somatostatin analogs were developed. They exhibited high binding affinities to somatostatin receptor–positive tumor cells (1.88–14.82 nM). The most potent compound demonstrated comparable pharmacokinetics and an even slightly higher absolute tumor accumulation level in ex vivo biodistribution studies as well as higher tumor standardized uptake values in PET/CT imaging than 68Ga-DOTATATE in vivo. The radioactivity uptake in nontumor tissue was higher than for 68Ga-DOTATATE. Conclusion: The introduction of the novel SiFA building block SiFAlin and of hydrophilic auxiliaries enables a favorable in vivo biodistribution profile of the modified TATE peptides, resulting in high tumor-to-background ratios although lower than those observed with 68Ga-DOTATATE. As further advantage, the SiFA methodology enables a kitlike labeling procedure for 18F-labeled peptides advantageous for routine clinical application.

Two patients diagnosed with metastatic medullary thyroid carcinoma (MTC) were referred for peptide receptor radionuclide therapy (PRRT) with Lu-[DOTA,Tyr]octreotate (DOTATATE). Each patient was treated with 4 doses of Lu-DOTATATE given 2 months apart. One patient achieved stable disease for 10 months then chose to pursue surgery, and the other achieved stable disease for 9 months on imaging; however, calcitonin continued to rise. The use of Lu-DOTATATE PRRT therapy in the management of MTC warrants further research.

A 47-year-old man presented with a recurrent thymoma World Health Organization type A of the anterior chest wall with pleural metastases after failing chemotherapy. The tumor was positive on In-octreotide, and he was referred for peptide receptor radionuclide therapy (PRRT) with Lu DOTATATE. He received 4 induction and 2 maintenance Lu DOTATATE treatments (total dose, 1000 mCi) and reported significant improvement in symptoms. Before the seventh treatment, mild progression was diagnosed on CT, and PRRT was terminated. The use of induction and maintenance Lu DOTATATE PRRT therapy in the management of thymoma warrants further research.

A high percentage of paragangliomas express somatostatin receptors that can be utilized for targeted radioisotope therapy. The aim of this study was to describe and discuss the challenges of treating these tumors with (177)Lu-[DOTA(0),Tyr(3)]octreotate (DOTATATE) radioisotope therapy using established protocols.Three paraganglioma patients were treated with 4-5 cycles of (177)Lu-DOTATATE and were evaluated for side effects and response to therapy. Two of the three patients developed severe adverse reactions following their first (177)Lu-DOTATATE treatment. One patient developed a catecholamine crisis and tumor lysis syndrome within hours of treatment, requiring intensive care unit (ICU) support, and another developed a catecholamine crisis 3 days after treatment, requiring hospitalization. The treatment protocols at our institution were subsequently modified by increasing the radioisotope infusion time from 15 to 30 min, as recommended in the literature, to 2-4 h and by reducing the administered dose of (177)Lu-DOTATATE. Subsequent (177)Lu-DOTATATE treatments utilizing the modified protocols were well tolerated, and response to therapy was achieved in all three patients, resulting in significantly improved quality of life.(177)Lu-DOTATATE is an exciting new therapeutic option in the management of paragangliomas; however, current treatment protocols described in the literature may need to be modified by lengthening the infusion time and/or lowering the initial treatment dose to prevent or reduce the severity of adverse reactions.

A 73-year-old man diagnosed with small bowel neuroendocrine tumor (NET) with liver and bone metastases was treated with 4 induction cycles and 2 maintenance cycles of Lu-DOTATATE peptide receptor radionuclide therapy (PRRT). His symptoms and mobility improved significantly following induction as well as maintenance treatments, and posttherapy imaging studies showed significant improvement in metastatic liver and bone disease. Current protocols consisting of 4 induction cycles of Lu-DOTATATE only may not be sufficient to optimally treat neuroendocrine liver and bone metastases, and further research into maintenance Lu-DOTATATE therapy is warranted.

Objective: To determine the pharmacokinetics (PK) and detect changes in cardiac uptake of [123I]IAZA, a radiopharmaceutical used to image focal tissue hypoxia, in healthy volunteers after exercise-based cardiac stress, to establish a rational basis for studies of focal myocardial hypoxia in cardiac patients using [123I]IAZA. Method: Three healthy male volunteers ran the ‘Bruce’ treadmill protocol (criterion heart rate is 85 % of [220 – age]). Approximately one minute before reaching this level, [123I]IAZA (4.0 mCi/0.85 mg) was administered as a slow (1-3 min) single bolus i.v. injection, then the volunteer continued running for an additional 1 min. Serum from venous blood samples, taken at pre-determined intervals from 1 min to 45 h, was analyzed by radioHPLC. PK parameters were derived for [123I]IAZA and total radioactivity (total[123I]) using compartmental and noncompartmental analyses (NCA). Whole-body planar scintigraphic images were acquired from 0.75 to 24 h after dosing. PK data and scintigraphic images were compared to published data from healthy volunteers administered [123I]IAZA at rest. Results: Following strenuous exercise, both [123I]IAZA and total[123I] exhibited bi-exponential decline profiles, with rapid distribution phases [half-lives (t1/2α) of 1.2 and 1.4 min, respectively], followed by slower elimination phases [t1/2β of 195 and 290 min, respectively]. Total body clearance (CLTB) and steady state volume of distribution (Vss) were 0.647 L/kg and 185 mL/min, respectively, for [123I]IAZA and 0.785 L/kg and 135 mL/min, respectively, for total[123I]. The t1/2β, CLTB and Vss values were comparable to those reported previously for rested volunteers. The t1/2α was approximately 4-fold shorter for [123I]IAZA and approximately 3-fold shorter for total[123I] under exercise relative to rested subjects. The heart was visualized in early whole body scintigraphic images, but overall there were no apparent differences from images reported for rested volunteers. Minimal uptake of radiotracer in myocardium and skeletal muscle was consistent with uptake in non-stressed muscle. Conclusion: The PK and whole-body scintigrams for [123I]IAZA in exercise-stressed healthy volunteers showed no clinically relevant differences relative to non-exercised volunteers. [123I]IAZA may therefore be suitable for the detection of viable, hypoxic myocardium in areas of myocardial perfusion deficiency.

To compare efficacy of thyroid remnant ablation using 30 mCi or 50 mCi 131-I in papillary thyroid cancer patients.Five hundred and fifteen consecutive patients with Tumor-Node-Metastasis (TNM) stages T1-T3 N1/N0/NX receiving either 30 mCi or 50 mCi I-131 were analyzed for the effectiveness of remnant ablation using rhTSH-stimulated serum thyroglobulin. One hundred and five consecutive patients receiving 100 mCi I-131 were analyzed for the incidence of radiation thyroiditis and sialadenitis.Doses of 30 mCi and 50 mCi were equally effective for low- and moderate-risk disease but 30 mCi was less effective for T1T2NX disease, and 50 mCi was less effective for T3 compared to T1T2 disease. Low dose radiation hypersensitivity or unknown more extensive disease may have accounted for observed differences. Radiation thyroiditis and sialadenitis were more common in a comparison series of 100 mCi dose compared to 30 mCi, but not more common than in 50 mCi doses.

Systemic radioisotope therapy with I-metaiodobenzylguanidine (I-MIBG) is an effective form of targeted therapy for neuroendocrine tumors. One of the absolute contraindications to administering I-MIBG therapy listed in the 2008 European Association of Nuclear Medicine guidelines is renal insufficiency requiring dialysis, although this contraindication is not evidence based. We describe a 68-year-old woman with a metastatic small bowel neuroendocrine tumor who developed renal insufficiency requiring hemodialysis. Imaging and dosimetry with I-MIBG were performed and showed that the radiation doses to the whole body and lungs were within safe limits. She was treated with 1820 MBq of I-MIBG with no short-term adverse reactions.

The objective of the study is to demonstrate the feasibility of using [11C]-choline positron-emission tomography (PET)/CT to deliver helical tomotherapy (HT) to the prostate with a simultaneous integrated boost to dominant intraprostatic lesions as a biological target volume for dose escalation. Eleven patients with intermediate-risk prostate cancer were included in this virtual planning study. Pretreatment baseline [11C]-choline PET/CT scans were acquired with a PET/CT scanner dynamically in 2-min frames from injection to 40 min post injection. PET data was reconstructed using the RAMLA 3D algorithm and analyzed to identify dominant intraprostatic lesion(s). Dominant lesions were defined as biological target volume(s) (BTV) including all voxels with a standardized uptake value of 75 % or above relative to the maximum standard uptake value (SUV) within the prostate gland. Three target volumes for optimization included the following: PTV78 (BTV + 5 mm margin), PTV68 (prostate + 5 mm posteriorly and 10 mm in all other dimensions), and PTV50 (prostate gland and proximal seminal vesicles + 7 mm margin posteriorly and 10 mm in all other dimensions). Dose constraints on organs at risk were implemented based on a published data using hypofractionated IMRT with long-term follow-up. Helical tomotherapy plans were generated to deliver hypofractionated radiation therapy to these volumes using simultaneous integrated boost in 25 fractions. Eight patients had one identifiable contiguous BTV, and the other three patients had two noncontiguous BTVs. The mean BTV ratio to prostate volume ratio was 6.03 % (minimum 0.80 %, maximum 13.44 %). Target volume and normal tissue constraints were met in seven of the 11 patients enrolled in the study. Targets and structures in the four patients that did not meet constraints were the bladder (3 patients), peritoneal cavity (2 patients), rectum (1 patient), PTV68 (1 patient), and PTV50 (1 patient). It is feasible in selected patients to use [11C]-choline PET/CT to deliver hypofractionated dose-escalated helical tomotherapy to dominant intraprostatic lesions with simultaneous integrated boost using clinically established normal tissue constraints.

Aim: This study assesses if clinically developed quality of life (QoL) tools are as effective in small bowel neuroendocrine tumors (NETs) as NET-specific research questionnaires. Methods: QoL in patients with small bowel NETs treated with Lu-DOTA-TATE was assessed with The European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30, QLQ-GI.NET21 and Edmonton Symptom Assessment System Revised (ESAS-r) at baseline and after four treatments. Repeated measures ANOVA was performed. Results: Both EORTC and ESAS-r demonstrated maintained overall QoL. EORTC demonstrated statistically and clinically significant improvement in insomnia, diarrhea, gastrointestinal, endocrine symptoms and social function. ESAS-r demonstrated statistically and clinically significant improvement in overall total symptom distress score. Conclusion: ESAS-r is quick and easy to interpret. It is not as sensitive to individual symptoms but does track overall function. EORTC assessment is more complex, but better reflects QoL for NET specific symptoms.

A 64-year-old woman with a 30-year history of recurrent sellar masses presented with severe headache and rapidly progressive visual field loss in the left eye. She was diagnosed with an extraventricular neurocytoma, which was octreotide positive, and was referred for PRRT (peptide receptor radionuclide therapy) with 177Lu [DOTA0,Tyr3]octreotate (DOTATATE). After 4 induction and 4 maintenance treatment cycles, her headaches resolved, her vision improved, and her sellar mass stabilized. The use of 177Lu DOTATATE PRRT in the management of extraventricular neurocytoma warrants further research.

The objective of the present study was to analyze, with relatively high sensitivity and specificity, uptake properties of [11C]-choline in prostate cancer patients by means of positron-emission tomography (pet)/computed tomography (ct) imaging using objectively defined pet parameters to test for statistically significant changes before, during, and after external-beam radiation therapy (ebrt) and to identify the time points at which the changes occur. The study enrolled 11 patients with intermediate-risk prostate cancer treated with ebrt, who were followed for up to 12 months after ebrt. The [11C]-choline pet scans were performed before treatment (baseline), at weeks 4 and 8 of ebrt, and at 1, 2, 3, 6, and 12 months after ebrt. Analysis of [11C]-choline uptake in prostate tissue before treatment resulted in a maximum standardized uptake value (suvmax) of 4.0 &plusmn, 0.4 (n = 11) at 40 minutes after injection. During week 8 of ebrt, the suvmax declined to 2.9 &plusmn, 0.1 (n = 10, p < 0.05). At 2 and 12 months after ebrt, suvmax values were 2.3 &plusmn, 0.3 (n = 10, p < 0.01) and 2.2 &plusmn, 0.2 (n = 11, p < 0.001) respectively, indicating that, after ebrt, maximum radiotracer uptake in the prostate was significantly reduced. Similar effects were observed when analyzing the tumour:muscle ratio (tmr). The tmr declined from 7.4 &plusmn, 0.6 (n = 11) before ebrt to 6.1 &plusmn, 0.4 (n = 11, nonsignificant) during week 8 of ebrt, to 5.6 &plusmn, 0.03 (n = 11, p < 0.05) at 2 months after ebrt, and to 4.4 &plusmn, 0.4 (n = 11, p < 0.001) at 12 months after ebrt. Our study demonstrated that intraprostatic [11C]-choline uptake in the 11 analyzed prostate cancer patients significantly declined during and after ebrt. The pet parameters SUVmax and tmr also declined significantly. These effects can be detected during radiation therapy and up to 1 year after therapy. The prognostic value of these early and statistically significant changes in intraprostatic [11C]-choline pet avidity during and after ebrt are not yet established. Future studies are indicated to correlate changes in [11C]-choline uptake parameters with long-term biochemical recurrence to further evaluate [11C]-choline pet changes as a possible, but currently unproven, biomarker of response.

There is growing interest in the large scale cyclotron production of 99m Tc via the 100 Mo(p,2n) 99m Tc reaction. While the use and recycling of cyclotron-irradiated enriched molybdenum targets has been reported previously in the context of 94m Tc production, to the best of our knowledge, previous recycling studies have been limited to the use of oxide targets. To facilitate reuse of high-power enriched 100 Mo targets, this work presents and evaluates a strategy for recycling of enriched metallic molybdenum. For the irradiated 100 Mo targets in this study, an overall metal to metal recovery of 87% is reported. Evaluation of “new” and “recycled” 100 Mo revealed no changes in the molybdenum isotopic composition (as measured via ICP-MS). For similar irradiation conditions of “new” and “recycled” 100 Mo, (i.e. target thicknesses, irradiation time, and energy), comparable levels of 94g Tc, 95g Tc, and 96g Tc contaminants were observed. Comparable QC specifications (i.e. aluminum ion concentration, pH, and radiochemical purity) were also reported. We finally note that [ 99m Tc]–MDP images obtained by comparing MDP labelled with generator-based 99m Tc vs. 99m Tc obtained following the irradiation of recycled 100 Mo demonstrated comparable biodistribution. With the goal of producing large quantities of 99m Tc, the proposed methodology demonstrates that efficient recycling of enriched metallic 100 Mo targets is feasible and effective.

(18)F-3'-Deoxy-3'-fluorothymidine ((18)F-FLT) is a PET tracer that accumulates in proliferating tissues. The current study was undertaken to determine whether equilibrative nucleoside transporter 1 (ENT1) is important for (18)F-FLT uptake in normal tissues and tumors.ENT1-knockout (ENT1(-/-)) mice were generated and compared with wild-type (ENT1(+/+)) mice using small-animal (18)F-FLT PET. In addition, ENT1(+/+) mice were also injected with the ENT1 inhibitor nitrobenzylmercaptopurine ribonucleoside phosphate (NBMPR-P) at 1 h before radiotracer injection, followed by (18)F-FLT small-animal PET. Tissues of interest were analyzed for thymidine kinase 1 and nucleoside transporters by immunoblotting and immunohistochemistry, respectively, and plasma thymidine levels were analyzed by liquid chromatography-mass spectrometry. Human lung carcinoma A549 cells were stably transfected with pSUPER-producing short-hairpin RNA against human ENT1 (hENT1) or a scrambled sequence with no homology to mammalian genes (A549-pSUPER-hENT1 and A549-pSUPER-SC, respectively). Cultured transfected cells were characterized for hENT1 transcript levels and (18)F-FLT uptake using real-time polymerase chain reaction and (3)H-FLT uptake assays, respectively. Transfected A549 cells were grown as xenograft tumors in NIH-III mice, which were analyzed by (18)F-FLT small-animal PET.Compared with noninjected ENT1(+/+) mice, ENT1(+/+) mice injected with NBMPR-P and ENT1(-/-) mice displayed a reduced percentage injected dose per gram (%ID/g) for (18)F-FLT in the blood (84 and 81%, respectively) and an increased %ID/g for (18)F-FLT in the spleen (188 and 469%, respectively) and bone marrow (266 and 453%, respectively). ENT1(-/-) mice displayed 1.65-fold greater plasma thymidine levels than did ENT1(+/+) mice. Spleen tissue from ENT1(+/+) and ENT1(-/-) mice displayed similar thymidine kinase 1 protein levels and significant concentrative nucleoside transporter 1 and 3 staining. Compared with A549-pSUPER-SC cells, A549-pSUPER-hENT1 cells displayed 0.45-fold hENT1 transcript levels and 0.68-fold (3)H-FLT uptake. Compared with A549-pSUPER-SC xenograft tumors, A549-pSUPER-hENT1 xenograft tumors displayed 0.76-fold %ID/g values (ex vivo gamma-counts) and 0.65-fold maximum standardized uptake values (PET image analysis) for (18)F-FLT uptake at 1 h after tracer injection.Loss of ENT1 activity significantly affected (18)F-FLT biodistribution in mice and (18)F-FLT uptake in xenograft tumors, suggesting that nucleoside transporters are important mediators of (18)F-FLT uptake in normal and transformed cells.

The current work evaluates 1-alpha-d-(2-deoxy-2-fluororibofuranosyl)-2-nitroimidazole (FRAZ), a novel azomycin nucleoside that is a potential radiosensitizer of tumor hypoxia. FRAZ is a ribose analogue of 1-alpha-d-(2-deoxy-2-fluoroarabinofuranosyl)-2-nitroimidazole ([(18)F]-FAZA), a clinically used hypoxia marker. Preliminary assessment of the cytotoxicity and hypoxia-specific in vitro binding in HCT-110 colorectal cancer cells indicate that the radiosensitization properties of FRAZ are similar to that of FAZA, with a sensitizer enhancement ratio (SER) of approximately 1.8. An automated radiosynthesis of [(18)F]-FRAZ using a commercial automated synthesis unit (ASU) was established (synthesis time approximately 32 min; radiochemical yield (decay uncorrecetd) approximately 22%) to facilitate its application in PET-based diagnosis of hypoxic tumors.

We applied a learning methodology framework to assist in the threshold-based segmentation of non-small-cell lung cancer (nsclc) tumours in positron-emission tomography&ndash, computed tomography (pet&ndash, ct) imaging for use in radiotherapy planning. Gated and standard free-breathing studies of two patients were independently analysed (four studies in total). Each study had a pet&ndash, ct and a treatment-planning ct image. The reference gross tumour volume (gtv) was identified by two experienced radiation oncologists who also determined reference standardized uptake value (suv) thresholds that most closely approximated the gtv contour on each slice. A set of uptake distribution-related attributes was calculated for each pet slice. A machine learning algorithm was trained on a subset of the pet slices to cope with slice-to-slice variation in the optimal suv threshold: that is, to predict the most appropriate suv threshold from the calculated attributes for each slice. The algorithm&rsquo, s performance was evaluated using the remainder of the pet slices. A high degree of geometric similarity was achieved between the areas outlined by the predicted and the reference suv thresholds (Jaccard index exceeding 0.82). No significant difference was found between the gated and the free-breathing results in the same patient. In this preliminary work, we demonstrated the potential applicability of a machine learning methodology as an auxiliary tool for radiation treatment planning in nsclc.

Tumour hypoxia is thought to play a significant role in the outcome of solid tumour therapy. Positron emission tomography (PET) is the best-validated noninvasive technique able to demonstrate the presence of hypoxia in vivo. The locally developed PET tracer for imaging hypoxia, 1-alpha-D: -(5-deoxy-5-[(18)F]-fluoroarabinofuranosyl)-2-nitroimidazole ((18)F-FAZA), has been shown to accumulate in experimental models of tumour hypoxia and to clear rapidly from the circulation and nonhypoxic tissues. The safety and general biodistribution patterns of this radiopharmaceutical in patients with squamous cell carcinoma of the head and neck (HNSCC), small-cell lung cancer (SCLC) or non-small-cell lung cancer (NSCLC), malignant lymphoma, and high-grade gliomas, were demonstrated in this study.Patients with known primary or suspected metastatic HNSCC, SCLC or NSCLC, malignant lymphoma or high-grade gliomas were dosed with 5.2 MBq/kg of (18)F-FAZA, then scanned 2-3 h after injection using a PET or PET/CT scanner. Images were interpreted by three experienced nuclear medicine physicians. The location and relative uptake scores (graded 0 to 4) of normal and abnormal (18)F-FAZA biodistribution patterns, the calculated tumour-to-background (T/B) ratio, and the maximum standardized uptake value were recorded.Included in the study were 50 patients (32 men, 18 women). All seven patients with high-grade gliomas showed very high uptake of (18)F-FAZA in the primary tumour. In six out of nine patients with HNSCC, clear uptake of (18)F-FAZA was observed in the primary tumour and/or the lymph nodes in the neck. Of the 21 lymphoma patients (15 with non-Hodgkin's lymphoma and 6 with Hodgkin's disease), 3 demonstrated moderate lymphoma-related uptake. Of the 13 lung cancer patients (12 NSCLC, 1 SCLC), 7 had increased (18)F-FAZA uptake in the primary lung tumour. No side effects of the administration of (18)F-FAZA were observed.This study suggests that (18)F-FAZA may be a very useful radiopharmaceutical to image hypoxia in the tumour types selected. Especially the high uptake by gliomas was encouraging. Given the good imaging properties, including acceptable T/B ratios in the tumour categories studied, (18)F-FAZA could be considered as a very promising agent for assessing the hypoxic fraction of these tumour types.

The purpose of this work is to create a rigorous method of segmenting PETimages using an automated iterative technique. To this end a phantom study employing spherical targets was used to determine local (slice specific) threshold levels which produce correct cross-sections based on the contrast between target and background. Numerous target to background activity concentration ratios were investigated but found to have minimal effect in comparison to the influence of target size. Functions were fit to this data and used to construct an iterative threshold segmentation algorithm. In all cases this approach yielded convergence within ten iterations. Iterative threshold segmentation was applied using both an axial and tri-axial approach to the spherical targets and also to two irregularly shaped volumes. Of these two approaches, the tri-axial method proved less susceptible to imagenoise and better at dealing with partial volume effects at the interface between target and background. For comparative purposes, single thresholds of 28% and 40% were also applied to the spherical data sets. The tri-axial iterative method was found capable of delineating cross sections with areas greater than 250 mm 2 to within the maximum resolution possible ( 1 pixel width). Cross sections of less than 250 mm 2 in area were resolved by the tri-axial method to within 2 pixel widths of their true physical extent. Local contrast based iterative threshold segmentation shows promise as a method of rigorously delineating PET target volumes with good accuracy subject to the limitations imposed by the image resolution which currently characterizes this modality.

Incorporation of positron emission tomography (PET) data into radiotherapy planning is currently under investigation for numerous sites including lung, brain, head and neck, breast, and prostate. Accurate tumor‐volume quantification is essential to the proper utilization of the unique information provided by PET. Unfortunately, target delineation within PET currently remains a largely unaddressed problem. We therefore examined the ability of three segmentation methods—thresholding, Sobel edge detection, and the watershed approach—to yield accurate delineation of PET target cross‐sections. A phantom study employing well‐defined cylindrical and spherical volumes and activity distributions provided an opportunity to assess the relative efficacy with which the three approaches could yield accurate target delineation in PET. Results revealed that threshold segmentation can accurately delineate target cross‐sections, but that the Sobel and watershed techniques both consistently fail to correctly identify the size of experimental volumes. The usefulness of threshold‐based segmentation is limited, however, by the dependence of the correct threshold (that which returns the correct area at each image slice) on target size. PACS numbers: 87.58.Fg, 87.57.Nk

BACKGROUND: Lung cancer is the leading cause of cancer morbidity and mortality. In addition, lung cancer has a significant economic impact on society.OBJECTIVE: To present an economic analysis of the actual care costs of lung cancer which will allow comparison with, and verification of, cost estimates that were developed through modelling and opinion.METHODS: A chart review was conducted of incident cases (circa 1998) of primary bronchogenic lung cancer. Cases were censored at two years from the date of diagnosis. Relevant clinical and health utilization data were collected. Health utilization data included hospital and institutional outpatient (ie, ambulatory clinic) costs. Cost estimates were derived for over 200 specific health services. The present analysis was performed from the economic perspective of the health care institution.RESULTS: A total of 13,389 health service events were captured with an estimated total cost of $8.4 million. Laboratory tests, diagnostic imaging and ambulatory visits constituted 86% of the service events while patient admissions and therapy constituted 76% of the costs. The vast majority of overall costs occurred just before, or within, three months of diagnosis. The median nonsmall cell lung cancer and small cell lung cancer case costs were $10,928 (range $9,234 to $11,047) and $15,350 (range $13,033 to $21,436), respectively.CONCLUSION: The results agree with the literature that the majority of lung cancer case costs are realized around the date of diagnosis (ie, early phase). The present study illustrates Canadian health care system lung cancer case costs based on actual care received versus hypothetical care algorithms.

Neuroendocrine tumors have a propensity to metastasize to the orbit, although the reason is unknown. A review of 251 neuroendocrine tumors treated with Lu-DOTATATE or I-MIBG at our institution since 2003 revealed 4 patients with orbital metastases (1.6%), 2 treated with Lu-DOTATATE and 2 with I-MIBG. Of these 4 patients, 1 patient was symptomatic with diplopia and eye pain, and 2 patients had physical signs of orbital involvement. The symptomatic orbital metastasis improved with Lu-DOTATATE therapy, and proptosis improved with I-MIBG therapy in 1 of 2 patients. We present the imaging findings of these 4 patients, as well as their management.

A 57-year-old woman diagnosed with ectopic Cushing syndrome was found to have a 111In-octreotide-avid corticotropin-producing pancreatic neuroendocrine tumor with liver metastases. She was treated with 4 induction and 4 maintenance cycles of 177Lu-DOTATATE, which normalized her serum corticotropin levels and dramatically reduced the size of the pancreatic primary and liver metastases.

A 52-year-old woman diagnosed with invasive ductal carcinoma of both breasts had a chest x-ray for preoperative assessment. A striking artifact was noted by the x-ray technologist, who, as a result, became very concerned about radiation exposure from the patient. The patient had undergone bilateral sentinel lymph node injections in the nuclear medicine department with Tc-antimony trisulfite colloid just 2 hours before the chest x-ray. Radiation exposure to the x-ray technologist was determined to be similar to 8 hours of naturally occurring background radiation (∼2.96 μSv).

A 22-year-old woman with rapidly progressing metastatic paraganglioma due to hereditary paraganglioma-pheochromocytoma syndrome from an SDHB mutation, who recurred after neoadjuvant chemotherapy, was found to be MIBG avid. She was treated with 2 I-MIBG treatments and concurrent sunitinib, achieving a complete response. She was in full remission for 9 months before developing bone metastases.

A 54-year-old woman presented with a history of nausea, vomiting, diarrhea, and recurrent episodes of severe hypokalemia requiring hospitalization. Imaging revealed a pancreatic mass with liver metastases, histologically confirmed to be a neuroendocrine tumor. Elevated active renin and aldosterone levels were identified, and the patient was treated with 4 induction cycles of Lu-DOTATATE, which resolved the diarrhea, nausea, and hypokalemia, and normalized the renin and aldosterone levels. After 3 additional maintenance Lu-DOTATATE treatments, the pancreatic tumor had decreased in size, was deemed operable, and was resected. She remains on maintenance Lu-DOTATATE therapy with progression-free survival of 45 months thus far.

Neuroendocrine tumors have a propensity to metastasize to the heart, although the reason for this remains unknown. A review of 251 neuroendocrine tumor patients treated with Lu DOTATATE peptide receptor radionuclide therapy or I-MIBG therapy at our institution since 2003 revealed 2 patients with cardiac metastases (incidence, 0.8%), one treated with Lu DOTATATE and one with I-MIBG. We present the imaging findings of these 2 patients, as well as their management and responses to therapy.

A 51-year-old man with a recurrent metastatic esthesioneuroblastoma (olfactory neuroblastoma) was referred for peptide receptor radionuclide therapy (PRRT). He received 4 treatments of 111In-octreotide over 8 months and 3 treatments of 177Lu-DOTATATE over 4 months, which helped alleviate his symptoms and improved his quality of life; however, the tumor ultimately progressed and he passed away shortly thereafter. PRRT with 111In-octreotide or 177Lu-DOTATATE could play a role in the management of esthesioneuroblastoma.

A 61-year-old woman diagnosed with a metastatic well-differentiated neuroendocrine tumor of the cecum was referred for radioisotope therapy. Although her metastatic neuroendocrine tumor was positive on both (123)I-MIBG and (111)In-octreotide, there was a left parotid mass that was octreotide avid but MIBG negative. Further investigation also showed discordance on (18)F-FDG PET/CT and excision of the mass revealed an incidental acinic cell carcinoma of the parotid gland. Somatostatin analog imaging and PRRT (peptide receptor radionuclide therapy) may have a role in the management of acinic cell carcinoma.

An 18-year-old girl presented with a 3-year history of a recurrent skull base mass confirmed to be a rhabdoid papillary meningioma. The tumor was octreotide avid and metastatic to the lungs, thoracic lymph nodes, and bones, and she was referred for PRRT (peptide receptor radionuclide therapy) with 177Lu DOTATATE. After 3 induction treatment cycles of 177Lu DOTATATE, she experienced significant improvements in her symptoms; however, just before the fourth treatment, she developed cervical spinal cord compression and passed away shortly thereafter. The use of 177Lu DOTATATE therapy in the management of rhabdoid papillary meningioma warrants further research.

Purpose Preclinical evidence suggests dichloroacetate (DCA) can reverse the Warburg effect and inhibit growth in cancer models. This phase 1 study was undertaken to assess the safety, recommended phase 2 dose (RP2D), and pharmacokinetic (PK) profile of oral DCA in patients with advanced solid tumors. Patients and Methods Twenty-four patients with advanced solid malignancies were enrolled using a standard 3 + 3 protocol at a starting dose of 6.25 mg/kg twice daily (BID). Treatment on 28 days cycles was continued until progression, toxicity, or consent withdrawal. PK samples were collected on days 1 and 15 of cycle 1, and day 1 of subsequent cycles. PET imaging ((18) F-FDG uptake) was investigated as a potential biomarker of response. Results Twenty-three evaluable patients were treated with DCA at two doses: 6.25 mg/kg and 12.5 mg/kg BID (median of 2 cycles each). No DLTs occurred in the 6.25 mg/kg BID cohort so the dose was escalated. Three of seven patients had DLTs (fatigue, vomiting, diarrhea) at 12.5 mg/kg BID. Thirteen additional patients were treated at 6.25 mg/kg BID. Most toxicities were grade 1-2 with the most common being fatigue, neuropathy and nausea. No responses were observed and eight patients had stable disease. The DCA PK profile in cancer patients was consistent with previously published data. There was high variability in PK values and neuropathy among patients. Progressive increase in DCA trough levels and a trend towards decreased (18) F-FDG uptake with length of DCA therapy was observed. Conclusions The RP2D of oral DCA is 6.25 mg/kg BID. Toxicities will require careful monitoring in future trials.

Current radiation therapy techniques, such as intensity modulated radiation therapy and three-dimensional conformal radiotherapy rely on the precise delivery of high doses of radiation to well-defined volumes. CT, the imaging modality that is most commonly used to determine treatment volumes cannot, however, easily distinguish between cancerous and normal tissue. The ability of positron emission tomography (PET) to more readily differentiate between malignant and healthy tissues has generated great interest in using PET images to delineate target volumes for radiation treatment planning. At present the accurate geometric delineation of tumor volumes is a subject open to considerable interpretation. The possibility of using a local contrast based approach to threshold segmentation to accurately delineate PET target cross sections is investigated using well-defined cylindrical and spherical volumes. Contrast levels which yield correct volumetric quantification are found to be a function of the activity concentration ratio between target and background, target size, and slice location. Possibilities for clinical implementation are explored along with the limits posed by this form of segmentation.

Introduction ( E )-5-(2-Iodovinyl)-2′-fluoro-2′-deoxyuridine (IVFRU) is a pyrimidine nucleoside analogue that accumulates selectively in murine cells expressing herpes simplex type-1 thymidine kinase (HSV-1 TK). The uptake of [ 125 I]IVFRU in human 143B osteosarcoma cells transduced with a retroviral vector bearing the HSV-1 TK gene (143B-LTK cells) is now reported. Methods HSV-1 TK gene expression in 143B-LTK cells was confirmed by Western blotting and reverse transcriptase (RT)-PCR. Cell and subcellular uptake of [ 125 I]IVFRU was determined in cell culture, and whole body biodistribution after intravenous injection of [ 125 I]IVFRU was determined using nude mice bearing implanted 143B or 143B-LTK tumors. Results Although IVFRU was less toxic to the human cell line expressing HSV-1 TK (143B-LTK) than ganciclovir, both IVFRU and ganciclovir were not toxic to the cell line not expressing HSV-1 TK (143B). When cells were exposed to [ 125 I]IVFRU in vitro, only the 143B-LTK cells accumulated radioactivity. The acid-soluble fraction from 143B-LTK cell lysates contained 8-fold greater activity than the acid-insoluble fraction after an 8-h exposure to [ 125 I]IVFRU. Biodistribution of [ 125 I]IVFRU in nude mice bearing subcutaneous 143B and 143B-LTK tumors revealed widespread distribution of the nucleoside in vivo but with specific localization in 143B-LTK tumors. Conclusion The underlying biochemical process of metabolic entrapment of IVFRU in human osteosarcoma cells expressing HSV-1 TK is responsible for selective localization in these cells. The differences in subcellular distribution into the nucleic acid fraction, and in cytotoxicity, reflect the importance of cell type and lineage as determinants of the performance of gene imaging radiopharmaceuticals.

The management of metastatic neuroendocrine tumors incorporates multimodal therapy with surgery, biotherapy, and chemotherapy. Tumor-targeted therapies using radiolabeled octreotide and meta-iodobenzylguanidine (mIBG) represent a novel treatment approach. The aim of this study was to evaluate the effectiveness of 131I-mIBG in the treatment of metastatic midgut carcinoid tumors. survival outcomes were assessed for patients treated at two regional cancer centers and then compared. One center used 131I-mIBG routinely in the management of metastatic carcinoid tumors (center A), and the other did not use this modality (center B). Only patients with histologically proven metastatic carcinoid tumor shown, or thought most likely, to be of midgut origin were included in the study. During the period 1980 to 2002, a series of 58 patients from center A with metastatic carcinoid tumor arising from the midgut underwent multimodality therapy with the addition of 131I-mIBG. Their median age was 64 years. The median dose of 131I-mIBG administered was 6751 MBq, and there was an average of 2.8 treatments per patient. During the same period, 58 patients with metastatic carcinoid were treated at center B with similar multimodality therapy without the use of 131I-mIBG therapy. Their median age was 65 years. Survivals at 3 and 5 years were 77% and 63%, respectively (95% CI 47–75), for group A. The 3- and 5-year survivals for group B were 56% and 47% (95% CI 34–59), respectively. The mean follow-up was 6.6 years for group A and 5.0 years for group B. Although retrospective in nature, this study suggests that the addition of 131I-mIBG therapy to the treatment protocol of patients with metastatic midgut carcinoid tumors prolongs survival.

The potential targeting of therapeutic bisphosphonate conjugates to bone metastatic lesions was evaluated in vivo in mice. A bisphosphonate conjugate with 5-fluorouracil was synthesized as a potential chemotherapy agent, and a bisphosphonate conjugate with diethylenetriaminepentaacetic acid (DTPA) was prepared as a potential carrier of cytotoxic radionuclides. The compounds are hypothesized to be able to deliver either high doses of radiation or a high concentration of chemotherapy agents at sites of increased osteoclastic activity in patients with bony metastases while exhibiting minimal toxicity to normal tissues. Tissue distribution studies with the 99mTc-labeled bisphosphonate conjugates with DTPA and 5-fluorouracil showed rapid blood clearance and excretion of unbound activity, clearance from most tissues, and substantial retention of the bisphosphonates in bone. For the DTPA conjugate, activity in the bone represents 13.6% of the total injected dose at 8 hours following injection, representing 54.3% of the total whole-body activity at this time period. Under the same conditions, the 5-fluorouracil conjugate showed a 17.1% bone uptake at 60.2% of the whole-body activity. This normal bone uptake predicts that high concentrations of conjugates are expected to be achieved at sites of bone metastatic disease. Chemotherapy and radiotherapy studies with these compounds in animal models of metastatic bone cancer are underway.

A 70-year-old woman presented with frequent episodes of hypoglycemia. Imaging revealed a 6-cm pancreatic mass with several liver lesions. The pancreatic mass was resected and confirmed to be a well-differentiated insulinoma. Surgery improved but did not resolve her hypoglycemic episodes, and she was referred for peptide receptor radionuclide therapy with 177Lu-DOTATATE to treat her residual disease. A modified protocol with a continuous IV dextrose infusion was used, and the treatments were well tolerated. After 4 induction and 2 maintenance treatments, her hypoglycemic symptoms resolved completely and her disease stabilized. She has been progression free for 24 months.

BACKGROUND: Lung cancer contributes significantly to cancer morbidity and mortality. Although case fatality rates have not changed significantly over the past few decades, there have been advances in the diagnosis, staging and management of lung cancer.OBJECTIVE: To describe the epidemiology of primary lung cancer in an Alberta cohort with an analysis of factors contributing to survival to two years.PATIENTS AND METHODS: Six hundred eleven Albertans diagnosed with primary lung cancer in 1998 were identified through the Alberta Cancer Registry. Through a chart review, demographic and clinical data were collected for a period of up to two years from the date of diagnosis.RESULTS: The mean age at diagnosis was 66.5 years. The majority of cases (92%) were smokers. Adenocarcinoma, followed by squamous cell carcinoma, were the most frequent nonsmall cell lung cancer histologies. Adenocarcinoma was more frequent in women, and squamous cell carcinoma was more frequent in men. The overall two- year survival rates for nonsmall cell, small cell and other lung cancers were 24%, 10% and 13%, respectively. In multivariate analysis, stage, thoracic surgery and chemotherapy were significantly associated with survival to two years in nonsmall cell carcinoma; only stage and chemotherapy were significant in small cell carcinoma.CONCLUSIONS: This study provides a Canadian epidemiological perspective, which generally concurs with the North American literature. Continued monitoring of the epidemiology of lung cancer is essential to evaluate the impact of advances in the diagnosis, staging and management of lung cancer. Further clinical and economic analysis, based on data collected on this cohort, is planned.

A 60-year-old woman diagnosed with a well-differentiated neuroendocrine tumor metastatic to the liver and lymph nodes was treated with 4 induction cycles and 2 maintenance cycles of (177)Lu [DOTA,(0)Tyr(3)]octreotate (DOTATATE) peptide receptor radionuclide therapy. Her posttreatment imaging showed partial response after 4 induction cycles and complete response after 2 additional maintenance cycles. This case highlights the need for further research into maintenance (177)Lu DOTATATE therapy to improve outcomes in neuroendocrine tumor patients.