Randomized phase II study of axitinib versus physicians best alternative choice of therapy in patients with recurrent glioblastoma.

We conducted a randomized, non-comparative, multi center, phase II clinical trial in order to investigate the efficacy of axitinib, an oral small molecule tyrosine kinase inhibitor with high affinity and specificity for the vascular endothelial growth factor receptors, in patients with recurrent glioblastoma following prior treatment with radiation and temozolomide. Forty-four patients were randomly assigned to receive treatment with axitinib (5 mg BID starting dose; N = 22) or "physicians best alternative choice of therapy" that consisted of bevacizumab (N = 20) or lomustine (N = 2). Six-month progression-free survival served as the primary endpoint. The estimated 6-month progression-free survival rate was 34 % (95 % CI 14-54) for patients treated with axitinib and 28 % (95 % CI 8-48) with best alternative treatment; median overall survival was 29 and 17 weeks, respectively. Objective responses according to RANO criteria were documented in 28 % of patients treated with axitinib and 23 % of patients treated with best alternative therapy. A decrease in maximal uptake of 18F-fluoro-ethyL-tyrosine (18F-FET) by the glioblastoma on PET imaging was documented in 85 % of patients at the time of response on axitinib. Corticosteroid treatment could be stopped in four and tapered in seven out of the 15 patients who were treated with steroids at baseline in the axitinib cohort. Most frequent axitinib related grade ≥3 adverse events consisted of fatigue (9 %), diarrhea (9 %), and oral hyperesthesia (4.5 %). We conclude that axitinib has single-agent clinical activity and a manageable toxicity profile in patients with recurrent glioblastoma.

Phase II study of helical tomotherapy for oligometastatic colorectal cancer.

BACKGROUND: To evaluate the efficacy and toxicity of helical tomotherapy in the treatment of oligometastatic colorectal cancer (CRC) patients who were not amenable for metastasectomy and/or (further) systemic treatment. PATIENTS AND METHODS: CRC patients with five or less metastases were enrolled. No limitations concerning dimension or localization of the metastases were imposed. Patients were treated with intensity-modulated and image-guided radiotherapy using helical tomotherapy, delivering a total dose of 40 Gy in fractions of 4 Gy. Positron emission tomography-computed tomography (PET-CT) was carried out at baseline and 3 months after the initiation of radiotherapy to evaluate the metabolic response rate according to PET Response Criteria in Solid Tumors (PERCIST) version 1.0. Side-effects were scored using National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTC AE) version 3.0. RESULTS: Twenty-three patients were enrolled. A total of 52 metastases were treated. One patient (4%) experienced grade 3 vomiting; two patients (9%) grade 2 diarrhea and dysphagia, respectively. Twenty-two patients were evaluated by post-treatment PET-CT. Five (23%) and seven patients (32%) achieved a complete and partial metabolic response, respectively, resulting in an overall metabolic response rate of 55%. The actuarial 1-year local control, progression-free survival, and overall survival were 54%, 25% and 86%, respectively. CONCLUSION: The use of helical tomotherapy in oligometastatic CRC patients resulted in a promising metabolic response rate of 55%.

Phase II study of sunitinib malate in patients with recurrent high-grade glioma.

Receptor tyrosine kinase signaling causes profound neo-angiogenesis in high-grade gliomas (HGG). The KIT, PDGFR-α, and VEGFR2 genes are frequently amplified and expressed in HGG and are molecular targets for therapeutic inhibition by the small-molecule kinase inhibitor sunitinib malate. Twenty-one patients with progressive HGG after prior radiotherapy and chemotherapy received a daily dose of 37.5 mg sunitinib until progression or unacceptable toxicity. Magnetic resonance imaging (MRI) and dynamic susceptibility contrast (DSC)-enhanced perfusion measurements were performed before and during therapy. Cerebral blood volume (CBV) and cerebral blood flow (CBF) lesion-to-normal-white matter ratios were measured to evaluate the antiangiogenic effects of sunitinib. The most frequent grade ≥3 adverse events were skin toxicity, neutropenia, thrombocytopenia, and lymphocytopenia. None of the patients achieved an objective response, whereas a decrease in CBV and CBF within the lesion compared with the normal brain was documented in four out of 14 (29%) patients evaluable for DSC-enhanced perfusion measurements. All patients experienced progression of their disease before or after eight weeks of therapy. Median time-to-progression and overall survival were 1.6 (95%CI 0.8-2.5) and 3.8 (95% CI 2.2-5.3) months, respectively. No correlation could be established between VEGFR2, PDGFR-α, and KIT gene copy numbers or protein expression and the effects of sunitinib. Single-agent sunitinib at 37.5 mg/day had insufficient activity to warrant further investigation of this monotherapy regimen in recurrent HGG.

The influence of headspace and dissolved oxygen level on growth and haemolytic BL enterotoxin production of a psychrotolerant Bacillus weihenstephanensis isolate on potato based ready-to-eat food products.

The major objective of this study was to determine the influence of the initial headspace and dissolved O(2) level and vacuum packaging on growth and diarrhoeal enterotoxin production by Bacillus weihenstephanensis on potato based ready-to-eat food products. In general, the lower the initial headspace or dissolved O(2) level the slower the maximum growth rate (µ(max), log(10) CFU g(-1) d(-1)), the longer the lag phase duration (λ, d) and the smaller the maximum population density (N(max), log(10) CFU g(-1)) became. The slowest µ(max), the longest λ and the smallest N(max) were generally found for growth under vacuum packaging. This implies shorter shelf-lives will occur at higher initial headspace or dissolved O(2) levels as the growth of B. weihenstephanensis to the infective dose of 10(5) CFU g(-1) in such atmospheres takes a shorter time. Significant consumption of dissolved O(2) only occurred when growth shifted from the lag to the exponential phase and growth generally transitioned from the exponential to the stationary phase when the dissolved O(2) levels fell below ca. 75 ppb. Diarrhoeal enterotoxin production (determined via detection of the L2 component of haemolytic BL) was similar for growth under initial headspace O(2) levels of 1-20.9%, and was only reduced when growth took place under vacuum packaging. The reduction in L2 production when growth took place under vacuum was most probably related to the low final cell densities observed under this condition. Both growth and L2 production were inhibited over a 32-day incubation period at 7 °C by 40% CO(2) irrespective of the headspace or dissolved O(2) levels. The results illustrate the importance of residual O(2) and CO(2) on the shelf-stability and safety of modified atmosphere packaged potato based ready-to-eat food products with regards to B. weihenstephanensis.

Complete metabolic tumour response, assessed by 18-fluorodeoxyglucose positron emission tomography (18FDG-PET), after induction chemotherapy predicts a favourable outcome in patients with locally advanced non-small cell lung cancer (NSCLC).

BACKGROUND: 18FDG-PET and multislice computerized axial tomography (CT) scan are used for diagnosis, staging and response evaluation in NSCLC patients. The correlation between the response assessment by both imaging techniques and survival was assessed in patients with unresectable stage III NSCLC treated with induction chemotherapy followed by consolidation radiotherapy. METHODS: Thirty-one patients, enrolled in a phase II study evaluating the efficacy and toxicity of a novel triplet induction chemotherapy (paclitaxel, carboplatin and gemcitabine) (PACCAGE) before consolidation radiotherapy, were evaluated by CT and 18FDG-PET at baseline and after three cycles of chemotherapy. The correlation between CT and 18FDG-PET response and time to progression and overall survival was analyzed using the Kaplan-Meier estimates of survival and the log rank test. RESULTS: Ten patients with a complete response (CR) on 18FDG-PET had a significantly longer time to progression and overall survival than patients with a non-CR (median 19.9 months versus 9.8 months, p=0.026, and median >49 months versus 14.4 months, p=0.004, respectively). Twenty patients with a partial CT response (PR) had a significantly longer time to progression (median 15 months versus 9.4 months, p=0.001) than patients with a non-PR but the difference in overall survival only showed a trend (23.3 months versus 14.4 months, p=0.093). CONCLUSIONS: A CR on 18FDG-PET following induction chemotherapy for locally advanced, unresectable NSCLC seems to be a more powerful prognostic marker for survival compared to PR on CT.

The feasibility of prostate-specific membrane antigen positron emission tomography(PSMA PET/CT)-guided radiotherapy in oligometastatic prostate cancer patients.

BACKGROUND: To investigate the efficacy and toxicity of 68Ga-PSMA-HBED-CC (68Ga-PSMA) PET-CT-guided RT in the treatment of oligometastatic prostate cancer retrospectively. METHODS: A total of 23 prostate cancer patients with biochemical relapse, of which 13 were castration sensitive (CS) and 10 castration resistant (CR), were treated with intensity-modulated and image-guided RT (IMRT-IGRT) on ≤3 metastases detected by 68Ga PSMA PET-CT. Androgen deprivation therapy was continued in CR patients. RESULTS: A total of 38 metastases were treated. The involved sites were pelvic bone (n = 16), pelvic lymph nodes (n = 11), paraaortic lymph nodes (n = 6), ribs (n = 3) and vertebral body (n = 2). The median PSA prior to RT was 1.1 ng/mL (range 0.1-29.0 ng/mL). A median dose of 43.5 Gy (range 30-64 Gy) was delivered by IMRT-IGRT in 12-27 fractions. At a median follow-up of 7 months (range 2-17 months), 19 patients (83%) were in remission. Four patients (17%) developed distant recurrences. The actuarial 1-year LC, PFS and OS rates were 100, 51 (95% CI 8-83%) and 100%. Univariate analysis demonstrated a statistically significantly better PFS in CS patients as compared to CR patients (1-year PFS 67 vs. 0%, p < 0.01). One patient experienced grade 2 acute gastrointestinal toxicity. Grade 3 or more toxicity events were not observed. CONCLUSIONS: By providing optimal LC, low toxicity and a promising PFS in CS patients, the current retrospective study illustrated that 68Ga PSMA PET-CT-guided RT may be an attractive treatment strategy in patients with oligometastatic prostate cancer. Validation by randomized trials is eagerly awaited.

Aortoesophageal fistula following endovascular exclusion of a thoracic aneurysm.

The aim of this study was to report a case of aortoesophageal fistula following endovascular exclusion of a thoracic aneurysm, treated conservatively with fatal outcome. Endovascular exclusion of a thoracic aneurysm was performed in a 64-year-old female patient. Three months later the diagnosis of an aortoesophageal fistula was made and minimal surgery (cervicotomy and jejunostomy) was performed, combined with antibiotherapy and catheter flushing of the infected excluded aneurysm thrombus. The patient died in septic shock 9 weeks later. As reported, following conventional thoracic aortic aneurysm surgery, endovascular stenting of the thoracic aorta can be complicated by aortoesophageal fistula. Management should be surgical, since the outcome under conservative management seems invariably fatal. However, it looks as if the poor condition of these patients may not permit open surgical treatment.

Comparison of ventilation-perfusion single-photon emission computed tomography (V/Q SPECT) versus dual-energy CT perfusion and angiography (DECT) after 6 months of pulmonary embolism (PE) treatment.

BACKGROUND: The natural evolution of treated symptomatic pulmonary embolism shows often incomplete resolution of pulmonary thrombi. The prevalence of perfusion defects depend on the image modality used. This study directly compares V/Q SPECT with DECT. METHODS: A single-center prospective observational cohort study of patients with intermediate risk PE, reassessed at the end of treatment with V/Q SPECT. Abnormal V/Q SPECT images were compared with DECT. RESULTS: We compared DECT en V/Q SPECT in 28 consecutive patients with persistent V/Q mismatch on V/Q SPECT, 13 men and 15 woman, mean age 60 (+17), range 23-82 year. One patient was excluded from the final analysis due to inferior quality DECT. In 18/27 (66.7%) the results were concordant between CTPA (persistent embolus visible), DECT (segmentary defects on iodine map) and V/Q SPECT (segmentary ventilation-perfusion mismatch). In 3/18 (11.1% of the total group) the partialy matched V/Q SPECT defect could be explained on DECT lung images by lung infarction. In 6/27 (22.1%) only hypoperfusion was seen on DECT iodine map. In 3/27 (11.1%) results were discordant between V/Q SPECT and DECT images. CONCLUSION: Six months after diagnosis of first or recurrent PE, residual pulmonary perfusion-defects encountered on V/Q-SPECT corresponds in the majority of patients with chronic thromboembolic disease seen on DECT. In 22.1% of patients V/Q SPECT mismatch only corresponds with hypoperfusion on iodine map DECT scan. Some (11.1%) of the chronic thromboembolic lesions seen on V/Q SPECT can not be explained by DECT results.

Visualizing ocular melanoma using iodine-123-N-(2-diethylaminoethyl)4-iodobenzamide SPECT.

UNLABELLED: Radiolabeled benzamides have recently been introduced for the detection of melanoma. We evaluated the potential clinical applicability of 123I-N-(2-diethylaminoethyl) 4-iodobenzamide ([123I]IDAB) for SPECT imaging of ocular melanoma. METHODS: Fourteen patients were studied, 10 with or suspected of malignant ocular melanoma and four with ocular naevi. All patients underwent SPECT imaging of the head and whole-body scintigraphy 4-5 hr after injection of 170 MBq [123I]IDAB. RESULTS: A definite tracer hyperfixation was observed in the pathological eye in 9 of 10 (90%) patients with ocular melanoma. The pathological-to-normal eye ratio averaged 1.46 (range 1.07-2.86). The melanoma nature of the scintigraphic lesions was confirmed after enucleation in eight cases and by clinical evolution in two. A false-negative scan was reported in a patient with a small and hypochromic lesion. In patients with ocular naevi, no false-positive scintigrams were documented. CONCLUSION: Iodine-123-IDAB scintigraphy may contribute significantly to decide about enucleation in cases where some doubt persists with conventional techniques.

Automatic determination of left ventricular ejection fraction from gated blood-pool tomography.

UNLABELLED: The aim of this study was to develop and validate a new algorithm to automatically compute left ventricular ejection fraction (LVEF) from gated blood-pool tomography (GBPT). The results were compared with those of conventional planar radionuclide angiocardiography (PRNA). METHODS: Fifty-three consecutive patients received an injection of 740 MBq (99m)Tc-labeled human serum albumin. PRNA and GBPT were performed consecutively in a random sequence. PRNA served as the reference, and GBPT images were processed using a new edge detection algorithm. The algorithm is fast (<45 s), fully automatic, and works in three-dimensional space. The method includes identification of the valve plane and the septum. The left ventricular cavity at end-diastole is delineated by segmentation using an iterative threshold technique. An optimal threshold is reached when the corresponding isocontour best fits the first derivative of the end-diastolic count distribution in three dimensions. This optimal threshold is then applied to delineate the left ventricular cavity on the other time bins. The data are corrected for the partial-volume effect. Left ventricular volumes are determined using a geometry-based method and are used to calculate the ejection fraction. RESULTS: The success rate of the new algorithm was 94%. LVEFs calculated from GBPT agreed well with those calculated from PRNA (r = 0.78; GBPT = 0.94 PRNA + 6.33). The systematic error was 2.8%, and the random error was 8.8%. Excellent inter- and intraobserver reproducibility was found, with average differences of 1.1% +/- 4.6% and 1.1% +/- 5.0%, respectively, between the two measurements. CONCLUSION: This new algorithm provides a fast, automated, and objective method to calculate LVEF from GBPT.

In vitro characterization of the influx of 3-[125I]iodo-L-alpha-methyltyrosine and 2-[125I]iodo-L-tyrosine into U266 human myeloma cells: evidence for system T transport.

The aim of this study was to investigate the cellular uptake mechanisms responsible for the accumulation of 3-[(125)I]iodo-L-alpha-methyltyrosine ((125)I-3-IMT) and 2-[(125)I]iodo-L-tyrosine ((125)I-2-IT), two radiotracers for metabolic tumor imaging, using single-photon emission tomography, into U266 human myeloma cancer cells. Time course and concentration dependency of (125)I-3-IMT uptake was assessed. Kinetic parameters were calculated using an Eadie Hofstee plot. A set of competitive inhibitors of the main amino acid transport systems was used for the discrimination of the transporters responsible for the uptake of (125)I-3-IMT and (125)I-2-IT. Protein incorporation of both tracers was determined using acid precipitation. The measured maximum velocity for (125)I-3-IMT transport was 4.199 nmol per mg protein 20 s(-1), and the Michaelis constant was 107.9 microM. Addition of 2-aminobicyclo[2,2,1]heptane-2-carboxylic acid (BCH), a competitive inhibitor of System L, reduced the influx by 39.0+/-3.3% for (125)I-3-IMT and 66.3+/-0.9% for (125)I-2-IT. The BCH-insensitive influx was further reduced by Tryptophan (Trp) by 43.8+/-3.5% for (125)I-3-IMT and 15.3+/-1.3% for (125)I-2-IT. This suggests involvement of System T transport. We measured <2% of radioactivity in the acid precipitable fractions of both tracers with no increase in time. We conclude that the influx of (125)I-3-IMT and (125)I-2-IT into U266 human myeloma cells is mediated by both System L and System T amino acid transporters. The kinetic parameters suggest that elevated plasma levels of aromatic amino acids will reduce (123)I-3-IMT uptake in myeloma patients. Both tracers do not enter protein synthesis significantly.

Sigma-receptor imaging by means of I123-IDAB scintigraphy: clinical application in melanoma and non-small cell lung cancer.

Scintigraphy with 1123-N-(2-Diethyl aminoethyl) 4-Iodobenzamide (I123-IDAB), a radiolabeled benzamide, has recently been introduced to visualize sigma receptors in vivo. In this study we evaluated the potential clinical applicability of I123-IDAB scintigraphy in patients with melanoma and in patients with non-small cell lung carcinoma (NSCLC); tumors in which sigma receptors are expressed. Twenty-six patients with a history of malignant melanoma and 8 patients with proven NSCLC were studied. Whole body scintigraphy was performed 4-5 hours after the injection of 170 MBq of I123-IDAB. All patients with ocular lesions and those with NSCLC underwent SPECT imaging of the head or thorax, respectively. For other patients additional spot- and or SPECT scans of suspected regions were acquired if necessary. Three patients with a history of malignant melanoma were considered to be in complete remission. None presented abnormalities on the I123-IDAB scintigraphy. In 20 of the 23 patients (87%) with proven melanoma, lesions were identified on the I123-IDAB scintigraphy. On a lesion site basis the sensitivity averaged 64% (43/67) Lesions located in the liver and those originating from an amelanotic melanoma could not be detected, while a sensitivity of 89% was observed for ocular sites when SPECT was used. In patients with NSCLC all primary lesions showed an increased uptake of tracer, but only 4 out of 18 (22%) mediastinal lymph nodes that were suspected radiologically. I123-IDAB scintigraphy can be used to visualize melanoma and NSCLC lesions in vivo. In malignant melanoma this may be useful to confirm the melanoma nature of lesions that are not easily accessible to biopsy. Differences in sensitivity between the various sites however must be kept in mind when interpreting the I123-IDAB scintigraphy. In patients with NSCLC the value of I123-IDAB SPECT is at least questionable.

Cerebral blood flow related to induction of a depressed mood within and out of the realm of attention in normal volunteers.

The effects of a depressed mood on regional cerebral blood flow (rCBF) were measured after a mood-induction procedure (MIP) in normal volunteers. The MIPs were administered 'within the realm of attention' and 'out of the realm of attention'. A modified Velten procedure, which consisted of tape-recorded self-referent depressive statements, was used for mood induction. For the induction out of the realm of attention, a combination of dichotic listening and subliminal stimulation was used. A neutral induction procedure served as a control condition. CBF was measured with Tc-99m HMPAO single photon emission computed tomography (SPECT) with regard to 14 healthy female students. Scores on mood rating scales showed negative changes after both MIPs. Statistical analyses revealed lateralized changes in rCBF in the thalamus. Decreased thalamic CBF in the right hemisphere was demonstrated after both MIPs compared with the neutral induction condition. Moreover, hippocampal rCBF increased significantly, but only after induction out of the realm of attention. These findings suggest both hippocampal and thalamic involvement in the regulation of mood experience.

Quantitative assessment of regional dysfunction from gated single photon emission tomography myocardial perfusion studies: a non-segmental approach.

We present a modified (non-segmental) method for quantification of regional left ventricular dysfunction using gated myocardial perfusion SPET. Gated SPET is increasingly used to obtain complementary information on local perfusion and to assess the relevance of deficits in segmental count densities (attenuation vs perfusion deficit). The non-segmental approach was motivated by a hypothetical limitation regarding the validity of commonly used methods of quantitative wall thickening (WT) analysis. These methods are all based on segmental analysis, which could cause underestimation of 'true' contractile dysfunction in perfusion defects that do not have a strict segmental distribution. SPET images gated in eight time bins 60 min after the injection of 740 MBq 99Tcm-tetrofosmin or 99Tcm-sestamibi were recorded on a triple-headed camera in 20 normal subjects and in 16 patients within 2 weeks and again 3 months after myocardial infarction. Normal limits of wall thickening, calculated from pooled wall thickening profiles obtained in normal subjects, were used to identify and quantify areas with abnormal wall thickening in patients with coronary artery disease. The method was validated against data obtained from contrast ventriculography (CVG) and tested for reproducibility. The reproducibility of the method was excellent: r = 0.98 (WTsev measure 1 = 1.03WTsev measure 2 - 0.01). The localization of wall thickening abnormalities detected by gated SPET correlated well with the localization of regions with abnormal wall motion (WM) identified by CVG. The severity of the regional myocardial dysfunction assessed by gated SPET was closely correlated with the severity of the regional myocardial dysfunction derived from CVG: r = 0.85 (WMsev = 2.55WTsev + 2.30). Furthermore, a good correlation between the total wall thickening severity score and the global left ventricular ejection fraction (LVEF) was observed early and late after myocardial infarction: r = 0.80 (WTsev = -0.4LVEF + 0.46). We conclude that quantitative analysis of regional wall thickening assessed from gated SPET myocardial perfusion scintigraphy is a reliable parameter for regional ventricular function. Categorizing wall thickening abnormalities quantitatively may be helpful in assessing small changes in regional function that may occur between sequential gated SPET images.

Evaluation of the response to therapy of head and neck squamous cell carcinoma by using 3-[123I]iodo-L-alpha-methyl tyrosine and single photon emission tomography.

Early detection of residual tumour tissue offers the possibility for rapid administration of adjuvant treatment. Single photon emission tomography (SPET) with 3-[123I]iodo-L-alpha-methyl tyrosine (IMT) offers the ability to detect recurrence. The aim of this study was to carry out a prospective evaluation of sequential IMT SPET before and after primary therapy and to determine the best timing for scanning in order to establish the response to treatment. Sixteen consecutive patients with histologically proven head and neck cancer (HNC), who underwent IMT SPET before therapy, within 1 week of therapy, and 1 and 3 months after completion of primary therapy were included. Images were classified, according to clinical evaluation, as indicating a high likelihood (HL), intermediate likelihood (IL) and low likelihood (LL) that residual tumoural tissue was present. The definitive clinicopathological diagnosis and follow-up was considered as the 'gold standard'. Based on the definitive clinicopathological outcome, 10 of 16 patients were diagnosed with evidence of local tumour and six without. Nine of 10 patients with evidence of local tumour presented with an HL IMT SPET image after 3 months, seven of whom were from within the first week. In this group, 1/10 patients was considered clinically HS the first week and eventually 4/10 patients became HL, of which there were three at 3 months. Of the six patients diagnosed without local evidence of tumour, with an average follow-up of 15 months, 6/6 were clinically LL in the first week. Three of six had a consistently LL IMT SPET from within the first week. The three other patients had an HL scan the first week, of which one became IL. It is concluded that IMT SPET assessed the response to primary therapy most accurately 3 months after completion of therapy. An IMT SPET image that indicates a high likelihood of residual tumoural tissue may allow earlier stratification of the patients for secondary treatment. If negative, an IMT SPET can exclude residual tumoural tissue from within the first week after completion of therapy.

99Tcm-DMSA renal scintigraphy for acute pyelonephritis in adults: planar and/or SPET imaging?

A number of authors have indicated a more sensitive detection of renal cortical defects using single photon emission tomography (SPET) compared with planar imaging when performing 99Tcm-dimer-captosuccinic acid (99Tcm-DMSA) renal scintigraphy. The place of SPET in the evaluation of kidneys in adults suspected of acute pyelonephritis (APN) remains controversial, however. The aim of this study was to address the role of SPET in adult patients suspected of having APN. Planar and SPET 99Tcm-DMSA renal imaging was performed in 53 patients. The data sets were separated and presented in random order to three independent observers. The kidneys were divided into three segments, which were classified as normal, definitely abnormal or equivocal. Ir. a second step, the number of lesions (definite or equivocal) on planar and SPET imaging were counted. The overall concordance between the planar and SPET imaging scores was 90.9, 89.9 and 87.7% for the three observers, respectively. Inter-observer discordance was recorded in a small percentage of both planar and SPET images. The number of lesions, based on the average of the three observers, was 22 for planar and 25 for SPET imaging. Obvious differences between observers were noted. The planar images were more often interpreted as equivocal by the least experienced observer. The more experienced observers gained limited additional information using SPET routinely. Most equivocal lesions on the planar scintigrams were observed in the lower segment. For SPET, no such distribution was noted. High-quality 99Tcm-DMSA images allow the detection of the same number of lesions as SPET in adults suspected of APN.

Nuclear cardiology, Part II: Scintigraphic evaluation of cardiac function.

OBJECTIVE: Different methods are currently available to assess cardiac function, especially left ventricular ejection fraction, using either planar or tomographic imaging, first-pass or equilibrium techniques, and blood-pool or myocardial perfusion agents. This is the second article of a four-part series on nuclear cardiology. In this article the authors review the most widely used radiopharmaceuticals and methodologies.

Nuclear cardiology, Part III: Scintigraphic evaluation of cardiac perfusion.

OBJECTIVE: After reading Part III of this series of nuclear cardiology articles, the technologist should be able to: (a) compare and contrast radiopharmaceuticals used for myocardial perfusion imaging; (b) describe imaging protocols used for detecting coronary artery disease; and (c) describe imaging patterns seen following reconstruction of myocardial images.

Nuclear cardiology, Part I: Anatomy and function of the normal heart.

This is the first article of a four-part series on nuclear cardiology. This article introduces and reviews the anatomy and function of the normal heart. Future articles will develop the contribution of nuclear medicine techniques in evaluating myocardial perfusion, function and viability. This article describes the external and internal features of the heart and its vascularization, conducting system and physiological function. After reading this article, the reader should understand the anatomy and the function of the normal heart.

Nuclear cardiology, Part IV: Viability.

After reading Part IV of this series of nuclear cardiology articles, the reader should be able to describe: (a) the differences between SPECT and PET techniques; (b) the various radiopharmaceuticals and imaging protocols used for detecting viability with SPECT; (c) the different radiopharmaceuticals and imaging protocols used for detecting viability with PET; and (d) the imaging patterns observed after reconstructing myocardial images.