[177Lu]Lu-DOTA-TATE plus long-acting octreotide versus high­dose long-acting octreotide for the treatment of newly diagnosed, advanced grade 2-3, well-differentiated, gastroenteropancreatic neuroendocrine tumours (NETTER-2): an open-label, randomised, phase 3 study.

BACKGROUND: There are currently no standard first-line treatment options for patients with higher grade 2-3, well-differentiated, advanced, gastroenteropancreatic neuroendocrine tumours. We aimed to investigate the efficacy and safety of first-line [177Lu]Lu-DOTA-TATE (177Lu-Dotatate) treatment. METHODS: NETTER-2 was an open-label, randomised, parallel-group, superiority, phase 3 trial. We enrolled patients (aged ≥15 years) with newly diagnosed higher grade 2 (Ki67 ≥10% and ≤20%) and grade 3 (Ki67 >20% and ≤55%), somatostatin receptor-positive (in all target lesions), advanced gastroenteropancreatic neuroendocrine tumours from 45 centres across nine countries in North America, Europe, and Asia. We used interactive response technologies to randomly assign (2:1) patients to receive four cycles (cycle interval was 8 weeks ± 1 week) of intravenous 177Lu-Dotatate plus intramuscular octreotide 30 mg long-acting repeatable (LAR) then octreotide 30 mg LAR every 4 weeks (177Lu-Dotatate group) or high-dose octreotide 60 mg LAR every 4 weeks (control group), stratified by neuroendocrine tumour grade (2 vs 3) and origin (pancreas vs other). Tumour assessments were done at baseline, week 16, and week 24, and then every 12 weeks until disease progression or death. The primary endpoint was progression-free survival by blinded, independent, central radiology assessment. We did the primary analysis at 101 progression-free survival events as the final progression-free survival analysis. NETTER-2 is registered with ClinicalTrials.gov, NCT03972488, and is active and not recruiting. FINDINGS: Between Jan 22, 2020, and Oct 13, 2022, we screened 261 patients, 35 (13%) of whom were excluded. We randomly assigned 226 (87%) patients (121 [54%] male and 105 [46%] female) to the 177Lu-Dotatate group (n=151 [67%]) and control group (n=75 [33%]). Median progression-free survival was 8·5 months (95% CI 7·7-13·8) in the control group and 22·8 months (19·4-not estimated) in the 177Lu-Dotatate group (stratified hazard ratio 0·276 [0·182-0·418]; p<0·0001). During the treatment period, adverse events (of any grade) occurred in 136 (93%) of 147 treated patients in the 177Lu-Dotatate group and 69 (95%) of 73 treated patients in the control group. There were no study drug-related deaths during the treatment period. INTERPRETATION: First-line 177Lu-Dotatate plus octreotide LAR significantly extended median progression-free survival (by 14 months) in patients with grade 2 or 3 advanced gastroenteropancreatic neuroendocrine tumours. 177Lu-Dotatate should be considered a new standard of care in first-line therapy in this population. FUNDING: Advanced Accelerator Applications, a Novartis Company.

Efficacy of [177Lu]Lu-DOTATATE in metastatic neuroendocrine neoplasms of different locations: data from the SEPTRALU study.

BACKGROUND: Peptide receptor radionuclide therapy (PRRT) is one of the most promising therapeutic strategies in neuroendocrine neoplasms (NENs). Nevertheless, its role in certain tumor sites remains unclear. This study sought to elucidate the efficacy and safety of [177Lu]Lu-DOTATATE in NENs with different locations and evaluate the effect of the tumor origin, bearing in mind other prognostic variables. Advanced NENs overexpressing somatostatin receptors (SSTRs) on functional imaging, of any grade or location, treated at 24 centers were enrolled. The protocol consisted of four cycles of 177Lu-DOTATATE 7.4 GBq iv every 8 weeks (NCT04949282). RESULTS: The sample comprised 522 subjects with pancreatic (35%), midgut (28%), bronchopulmonary (11%), pheochromocytoma/ paraganglioma (PPGL) (6%), other gastroenteropancreatic (GEP) (11%), and other non-gastroenteropancreatic (NGEP) (9%) NENs. The best RECIST 1.1 responses were complete response, 0.7%; partial response, 33.2%; stable disease, 52.1%; and tumor progression, 14%, with activity conditioned by the tumor subtype, but with benefit in all strata. Median progression-free survival (PFS) was 31.3 months (95% CI, 25.7-not reached [NR]) in midgut, 30.6 months (14.4-NR) in PPGL, 24.3 months (18.0-NR) in other GEP, 20.5 months (11.8-NR) in other NGEP, 19.8 months (16.8-28.1) in pancreatic, and 17.6 months (14.4-33.1) in bronchopulmonary NENs. [177Lu]Lu-DOTATATE exhibited scant severe toxicity. CONCLUSION: This study confirms the efficacy and safety of [177Lu]Lu-DOTATATE in a wide range of SSTR-expressing NENs, regardless of location, with clinical benefit and superimposable survival outcomes between pNENs and other GEP and NGEP tumor subtypes different from midgut NENs.

Nodal metastatic load in papillary thyroid carcinoma. Morphological and molecular analysis with one-step nucleic acid amplification on more than 550 lymph nodes.

BACKGROUND AND OBJECTIVE: The risk of recurrence in papillary thyroid carcinoma (PTC) is likely related to the amount of tumour in the metastatic lymph node (LN). Therefore, the current TNM classification (N0/N1) make it necessary to find a method to quantify the LN metastasis (LNM). We propose that the quantitative molecular assay One-Step Nucleic-Acid Amplification (OSNA), which measures the number of cytokeratin-19 (CK-19) mRNA copies as a marker of LNM, could play this role. Our objective was to describe the characteristics of the LNs from PTC, and to compare the morphological characteristics that have been claimed as criteria for metastatic burden with OSNA. PATIENTS AND METHOD: Prospective study of LNs from 42 patients. All of the LNs were measured, weighed and analysed by OSNA and also by imprint cytology. RESULTS: A total of 573 LNs were included, 187 (32.6%) of them were OSNA-positives. The global consistency between cytology and OSNA was 87.4%. Significant differences were observed in the CK-19 copy number between the LNMs<0.2cm and those >3cm, as well as between those from 0.2 to 3cm with respect to those >3cm, but not between those <0.2cm and those between 0.2 and 3cm. The total tumour load per neck dissection showed no differences based on whether there were ≤5 or >5 LNMs. CONCLUSIONS: In our series the LNMs >3cm show an increased tumour load, but it is unclear if it is necessary to sub-classify the smaller ones as well as the relevance of the number of metastatic nodes according to the cut-off of 5 nodes. We consider that the OSNA analysis avoids the bias of nodal histology and allows for a greater understanding of its real oncological potential.

Acquired hepatocerebral degeneration in a metastatic neuroendocrine tumor long-term survivor - an update on neuroendocrine neoplasm's treatment: A case report.

BACKGROUND: Metastatic small bowel low-grade neuroendocrine tumors (NETs) have a good prognosis. Surgery is the only curative treatment; however, this may induce advanced liver disease, particularly in long-term survivor patients. Acquired hepatocerebral degeneration or Parkinsonism in cirrhosis is characterized by rapidly progressive extrapyramidal symptoms in patients with advanced liver disease. CASE SUMMARY: A 70-year-old man presented to the emergency department with diminished consciousness and disorientation, and was diagnosed with hepatic encephalopathy. The patient was diagnosed in 1993 with a metastatic small bowel NET, for which he twice underwent hepatic surgery, with metastatic resection in 1993 and a right hepatectomy in 2002 to remove two hepatic metastases. In 2003, the patient started first-line chemotherapy and in 2004 started the first of three consecutive biological treatments, followed by radio-molecular therapy, achieving stable disease for 14 years. Disease progression was identified and he underwent an endoscopic retrograde cholangiopancreatography. However, in 2019 advanced liver disease was identified. We diagnosed the development of acquired hepatocerebral degeneration, an unusual long-term side effect after multiple hepatic procedures. CONCLUSION: The importance of regular and ongoing surveillance in long-term NET survivors who undergo hepatic procedures should be integrated into the therapeutic management plan, as some of these negative outcomes could be prevented.

Follicular Thyroid Carcinoma Metastases on Round Ligament of Liver.

ABSTRACT: We describe a case of a 69-year-old woman with follicular thyroid cancer of long evolution, with thyroidectomy 20 years before, who had remained clinically stable until now, when she started to present abnormal levels of serum thyroglobulin. An 123I whole-body scan showed a high uptake in the upper right half of her abdomen, and an 18F-FDG PET/CT located this focus at the liver's round ligament. Pathology findings after surgery showed the focus to be a differentiated thyroid cancer metastasis. This is an unusual presentation of differentiated thyroid cancer metastasis.

Nodal metastatic load in papillary thyroid carcinoma. Morphological and molecular analysis with one-step nucleic acid amplification on more than 550 lymph nodes.

BACKGROUND AND OBJECTIVE: The risk of recurrence in papillary thyroid carcinoma (PTC) is likely related to the amount of tumour in the metastatic lymph node (LN). Therefore, the current TNM classification (N0/N1) make it necessary to find a method to quantify the LN metastasis (LNM). We propose that the quantitative molecular assay One-Step Nucleic-Acid Amplification (OSNA), which measures the number of cytokeratin-19 (CK-19) mRNA copies as a marker of LNM, could play this role. Our objective was to describe the characteristics of the LNs from PTC, and to compare the morphological characteristics that have been claimed as criteria for metastatic burden with OSNA. PATIENTS AND METHOD: Prospective study of LNs from 42 patients. All of the LNs were measured, weighed and analysed by OSNA and also by imprint cytology. RESULTS: A total of 573 LNs were included, 187 (32.6%) of them were OSNA-positives. The global consistency between cytology and OSNA was 87.4%. Significant differences were observed in the CK-19 copy number between the LNMs<0.2cm and those >3cm, as well as between those from 0.2 to 3cm with respect to those >3cm, but not between those <0.2cm and those between 0.2 and 3cm. The total tumour load per neck dissection showed no differences based on whether there were ≤5 or >5 LNMs. CONCLUSIONS: In our series the LNMs >3cm show an increased tumour load, but it is unclear if it is necessary to sub-classify the smaller ones as well as the relevance of the number of metastatic nodes according to the cut-off of 5 nodes. We consider that the OSNA analysis avoids the bias of nodal histology and allows for a greater understanding of its real oncological potential.

Long-term follow-up of differentiated thyroid carcinoma in children and adolescents.

Objectives The aims were to analyze the clinical features, response to treatment, prognostic factors and long-term follow-up of children and adolescents with differentiated thyroid carcinoma (DTC). Methods Eighty patients with DTC were studied retrospectively. All underwent total or near-total thyroidectomy, and in 75 cases, ablative iodine therapy was recommended. Patients were assessed periodically by tests for serum thyroglobulin levels and whole-body iodine scans. Age, gender, initial clinical presentation, histology, tumor stage, postoperative complications, radioiodine treatment protocol, treatment response, thyroglobulin (Tg), recurrence and long-term disease progression were evaluated. Results Seventy patients completed >2 years of follow-up (23 males, 47 females; median age: 14 years; range: 3-18 years). Sixty-two patients showed papillary DTC and eight, follicular DTC. Sixty-five percent presented nodal metastasis and 16%, pulmonary metastasis at diagnosis. Six months after first radioiodine treatment, 36.2% of patients were free of disease. Seven recurrences were documented. At the end of follow-up, overall survival was 100%, and 87.2% of patients were in complete remission. Nine patients had persistent disease. We found a significant association between stage 4 and persistent disease. Hundred percent of patients with negative Tg values at 6 months posttreatment were documented free of disease at the end of the follow-up. The analysis of disease-free survival based on radioiodine treatment protocols used showed no statistically significant differences. Conclusions DTC in children and adolescents is frequently associated with presence of advanced disease at diagnosis. Despite this, complete remission was documented after treatment in most cases, with a good prognosis in the long-term follow-up. Negative posttreatment thyroglobulin and stage 4 at diagnosis were significant prognostic variables.

One-step nucleic acid amplification for intraoperative analysis of sentinel lymph node in papillary thyroid carcinoma.

Objective Lymphadenectomy in papillary thyroid carcinoma (PTC) is controversial. It is indicated whenever metastases have been proven before or during surgery and as a prophylactic treatment in high-risk patients. However, 30-50% of cN0 patients become pN1 postoperatively. In PTC, selective-sentinel-lymph-node-biopsy (SLNB) with conventional intraoperative analysis is 8% false negative. One-step nucleic acid amplification (OSNA) is a molecular technique which allows real-time detection of mRNA encoding for cytokeratin 19. OSNA has been introduced in intraoperative analysis of several tumors to reduce false-negative rates and distinguish micrometastasis from macrometastasis. Our objective was to evaluate the impact of the introduction of OSNA in the intraoperative evaluation of the sentinel node (SN) in PTC. Design We analyzed a series of 35 patients subjected to SLNB. Methods All the dissected nodes, SN and non-SN, were evaluated with OSNA and cytology. Results We obtained a total of 110 SN. SLNB proved positive in 14 patients (40%) with cytology and in 23 (65.7%) with OSNA (P < 0.001). In the 29 patients with subsequent lymphadenectomy we obtained 360 lymph nodes ((52 positive in cytology (14.4%) and 107 in OSNA (29.7%)). Lymphadenectomy proved positive in 16 patients according to cytology (55%) and in 24 according to OSNA (83%) (P = 0002). The majority of patients with micrometastasis in SN showed only micrometastasis in lymphadenectomy. Conclusions The present study shows selective-sentinel-lymph-node-biopsy with one-step nucleic acid amplification technique to be feasible in papillary thyroid carcinoma. The quantitative nature of one-step nucleic acid amplification paves the way toward a more personalized surgical approach, limiting lymphadenectomy to patients with intraoperative evidence of macrometastasis in the sentinel node.

Biopsia selectiva del ganglio centinela en el carcinoma papilar de tiroides en pacientes sin evidencia preoperatoria de metástasis ganglionar / Selective sentinel lymph node biopsy in papillary thyroid carcinoma in patients with no preoperative evidence of lymph node metastasis

Introducción: La linfadenectomía en la cirugía del carcinoma papilar de tiroides se aconseja cuando hay evidencia de metástasis ganglionar cervical (terapéutica) o en pacientes de alto riesgo (profiláctica), como en los tumores T3 y T4 de la clasificación TNM. La técnica de la biopsia selectiva del ganglio centinela puede mejorar el diagnóstico prequirúrgico de las metástasis ganglionares. Objetivo: Analizar el resultado de la biopsia selectiva del ganglio centinela en un grupo de pacientes con carcinoma papilar de tiroides T sin evidencia de afectación ganglionar antes de la cirugía. Pacientes y método: Estudio retrospectivo, unicéntrico en el que se incluyeron los pacientes intervenidos entre los años 2011-2013 que fueran clínicamente N0. La identificación del ganglio centinela se realizó mediante técnica isotópica. En todos los casos, se practicó linfadenectomía del compartimento afecto si el ganglio centinela era positivo, y del compartimento central en caso de ganglio centinela negativo. Resultados: Se incluyeron 43 pacientes, 34 mujeres, con una edad media de 52,3 (±17) años. De los 170 ganglios centinela resecados, 46 (27%) fueron positivos para metástasis, que correspondían a 24 (55,8%) pacientes. En las linfadenectomías se resecaron 612 ganglios. De ellos, 96 (15,6%) fueron positivos para metástasis. Doce de los treinta (40%) pacientes cT1N0 y cT2N0 pasaron a pN1 tras la biopsia selectiva del ganglio centinela, mientras que 12 de los 13 (92%) pacientes cT3N0 y cT4N0, acabaron siendo pN1. Conclusiones: La biopsia selectiva del ganglio centinela recalifica más del 50% de pacientes de cN0 a pN1. Se confirma la necesidad de vaciamiento ganglionar en los tumores T3 y T4, pero pone al descubierto la presencia de metástasis linfáticas en el 40% de los T1-T2 (AU)

Introduction: Lymphadenectomy is recommended during surgery for papillary thyroid carcinoma when there is evidence of cervical lymph node metastasis (therapeutic) or in high-risk patients (prophylactic) such as those with T3 and T4 tumors of the TNM classification. Selective sentinel lymph node biopsy may improve preoperative diagnosis of nodal metastases. Objective: To analyze the results of selective sentinel lymph node biopsy in a group of patients with papillary thyroid carcinoma and no evidence of nodal involvement before surgery. Patients and method: A retrospective, single-center study in patients with papillary thyroid carcinoma and no clinical evidence of lymph node involvement who underwent surgery between 2011 and 2013. The sentinel node was identified by scintigraphy. When the sentinel node was positive, the affected compartment was removed, and when sentinel node was negative, central lymph node dissection was performed. Results: Forty-three patients, 34 females, with a mean age of 52.3 (±17) years, were enrolled. Forty-six (27%) of the 170 SNs resected from 24 (55.8%) patients were positive for metastasis. In addition, 94 (15.6%) out of the 612 lymph nodes removed in the lymphadenectomies were positive for metastases. Twelve of the 30 (40%) low risk patients (cT1N0 and cT2N0) changed their stage to pN1, whereas 12 of 13 (92%) high risk patients (cT3N0 and cT4N0) changed to pN1 stage. Conclusions: Selective sentinel lymph node biopsy changes the stage of more than 50% of patients from cN0 to pN1. This confirms the need for lymph node resection in T3 and T4 tumors, but reveals the presence of lymph node metastases in 40% of T1-T2 tumors (AU)

Selective sentinel lymph node biopsy in papillary thyroid carcinoma in patients with no preoperative evidence of lymph node metastasis. / Biopsia selectiva del ganglio centinela en el carcinoma papilar de tiroides en pacientes sin evidencia preoperatoria de metástasis ganglionar.

INTRODUCTION: Lymphadenectomy is recommended during surgery for papillary thyroid carcinoma when there is evidence of cervical lymph node metastasis (therapeutic) or in high-risk patients (prophylactic) such as those with T3 and T4 tumors of the TNM classification. Selective sentinel lymph node biopsy may improve preoperative diagnosis of nodal metastases. OBJECTIVE: To analyze the results of selective sentinel lymph node biopsy in a group of patients with papillary thyroid carcinoma and no evidence of nodal involvement before surgery. PATIENTS AND METHOD: A retrospective, single-center study in patients with papillary thyroid carcinoma and no clinical evidence of lymph node involvement who underwent surgery between 2011 and 2013. The sentinel node was identified by scintigraphy. When the sentinel node was positive, the affected compartment was removed, and when sentinel node was negative, central lymph node dissection was performed. RESULTS: Forty-three patients, 34 females, with a mean age of 52.3 (±17) years, were enrolled. Forty-six (27%) of the 170 SNs resected from 24 (55.8%) patients were positive for metastasis. In addition, 94 (15.6%) out of the 612 lymph nodes removed in the lymphadenectomies were positive for metastases. Twelve of the 30 (40%) low risk patients (cT1N0 and cT2N0) changed their stage to pN1, whereas 12 of 13 (92%) high risk patients (cT3N0 and cT4N0) changed to pN1 stage. CONCLUSIONS: Selective sentinel lymph node biopsy changes the stage of more than 50% of patients from cN0 to pN1. This confirms the need for lymph node resection in T3 and T4 tumors, but reveals the presence of lymph node metastases in 40% of T1-T2 tumors.

Detection of Thyroid Papillary Carcinoma Lymph Node Metastases Using One Step Nucleic Acid Amplification (OSNA): Preliminary Results.

UNLABELLED: Purpouse: One Step Nucleic Acid Amplification (OSNA) has been previously proposed for the diagnosis of lymph node metastases (LNMs) from several malignant conditions by quantifying the number of copies of cytokeratin 19 mRNA. Our aim was to evaluate the results obtained by OSNA in the lymph nodes of patients with papillary thyroid carcinoma (PTC) by comparing our results with the findings observed using standard pathological examination. MATERIALS AND METHODS: Fifty human lymph nodes (from five patients with diagnosed PTC) were studied. Each node was divided into two: one half was used for molecular study ("OSNA-node"), and the other half was used for conventional staining with hematoxylin and eosin ("HE-non-OSNA node"). Three cytological imprints using Papanicolaou and May-Grunwald-Giemsa strains were obtained from both node halves. The results from each technique were compared, and ROC analysis was performed. RESULTS: The OSNA study showed 22 positive samples for LNM (44%), which demonstrate a high concordance rate with the results observed using conventional pathological examination (cytology of "OSNA-node" and HE of "Non-OSNA node") with specificity and sensitivity values greater than 86% and 89%, respectively. However, both comparisons differed in the number of copies of mRNA as the best cut-off (260 copies in the first case and 93 in the second case). CONCLUSIONS: The OSNA results for the detection of LNM in patients with PTC are comparable with those observed using conventional techniques. However, its quantitative nature could be useful to more accurately detect lymph node involvement.

Giant urinary bladder stone: incidental finding in (99m)Tc-DTPA renography.

A 27-year-old woman presented with a history of recurrent urinary tract infections in infancy and urinary incontinence secondary to lipomyelomeningocele. At the age of 7, she underwent bladder augmentation enterocystoplasty, requiring intermittent catheterization without urinary tract infections until present. A Tc-DTPA renography was performed to evaluate renal function, in which an abnormal tracer distribution was seen in urinary bladder, and furthermore, a retrograde cystography shows a giant bladder stone.

SPECT/CT sentinel lymph node identification in papillary thyroid cancer: lymphatic staging and surgical management improvement.

PURPOSE: Lymphadenectomy in papillary thyroid carcinoma (PTC) continues to be controversial. A better staging method is needed to provide adequate individual surgical treatment. SPECT/CT lymphoscintigraphy and sentinel lymph node (SLN) biopsy may improve lymphatic staging and surgical treatment. Our main objectives were to describe the lymphatic drainage of PTC using lymphoscintigraphy, to evaluate the lymphatic spread (comparing SLN and lymphadenectomy results) and to analyse the impact of SLN identification in surgery. METHODS: We prospectively studied 24 consecutive patients with PTC (19 women; mean age 52.7 years, range 22-81 years). The day before surgery, lymphoscintigraphy with ultrasound-guided intratumoral injection ((99m)Tc-nanocolloid, 148 MBq) was performed, obtaining planar and SPECT/CT images. All patients underwent total thyroidectomy, SLN biopsy (hand-held gamma probe) with perioperative analysis, central compartment node dissection, or laterocervical lymphadenectomy if perioperative stage N1b or positive SLNs in this lymphatic basin. RESULTS: Lymphoscintigraphy revealed at least one SLN in 19 of 24 patients (79 %) on planar and SPECT/CT images, and in 23 of 24 patients (96 %) during surgery using a hand-held gamma probe. Lymph node metastases were detected with classical perioperative techniques (ultrasound guidance and surgical inspection) in 3 of 24 patients, by perioperative SLN analysis in 10 of 23, and by definitive histology in 13 of 24. The false-negative (FN) ratio for SLN was 7.7 % (one patient with bulky lymph nodes). The FN ratio for perioperative frozen sections was 15.4 % (two patients, one with micrometastases, the other with bilateral SLN). Lymphatic drainage was only to the central compartment in 6 of 24 patients (3 of the 6 with positive SLNs for metastases), only to the laterocervical basin in 5 of 24 patients (all unilateral, 2 of 5 positive SLNs) and to the central and laterocervical compartments in 12 of 24 patients (6 of 12 and 3 of 12 positive SLNs, respectively). CONCLUSION: Lymphoscintigraphy reveals the lymph node drainage in a high proportion of patients. It detects laterocervical drainage in a significant percentage of patients, allowing the detection of occult lymph node metastases and improving the surgical management in PTC.

ECT in a patient with Parkinson's disease and schizophrenia, with dopamine transporter visualisation using 123I-ioflupane SPET.

A 58-year old woman with chronic schizophrenia developed worsening parkinsonian symptoms over the previous 6 years, and was eventually diagnosed as having Parkinson's disease. Antipsychotics were stopped because they worsened these symptoms. Antiparkinsonian treatment led to a significant increase in delusions and behavioural disorganisation. The patient underwent electroconvulsive-therapy which improved both her psychiatric and motor symptoms. After treatment, 123I-Ioflupane uptake was mildly increased in the left caudate nucleus, but uptake in right caudate nucleus was lower than in a pretreatment scan.

[Reproducibility of measurements of left ventricular function with gated myocardial perfusion SPECT and comparison with blood pool radionuclide ventriculography]. / Reproducibilidad de la gated-SPECT de perfusión miocárdica en la valoración de la función ventricular y su comparación con la ventriculografía isotópica.

INTRODUCTION AND OBJECTIVE: This study was designed to evaluate the reproducibility of ejection fraction (EF) and ventricular volume measurements obtained with single photon emission computed tomography (gated-SPECT), and to assess the correlation between EF values obtained with this method and blood pool planar radionuclide ventriculography. PATIENTS AND METHOD: A total of 55 patients were included (37 men, mean age 61.3 years) upon referral to two nuclear cardiology units for diagnosis (50%) or follow-up of known coronary artery disease. In a standard 2-day protocol, patients received a dose of [99mTc]tetrofosmin (800 MBq) at stress and at rest. Two resting gated-SPECT studies were performed. QGS software was used to obtain left ventricular EF, end-diastolic volume (EDV) and end-systolic volume (ESV). Forty-nine patients agreed to undergo blood pool ventriculography on the third day. RESULTS: Interobserver variability was 0.5 (2.6)% (r=0.99) for EF, 1.9 (10.7) mL for EDV (r=0.98) and 0.5 (5.4) mL for ESV (r=0.99). Interassay variability was 2 (5.1)% (r=0.94) for EF, 4.5 (8.6) mL for EDV (r=0.99) and 3.4 (6.6) mL for ESV (r=0.99). The correlation between gated-SPECT EF and blood pool EF was suboptimal (r=0.75, 95%CI, 0.59-0.85). CONCLUSIONS: There was excellent interobserver and interassay reproducibility for left ventricular functional parameters measured with gated-SPECT and QGS software, and this method can be used for serial evaluations of ventricular function. Although the correlation between values obtained with gated-SPECT and blood pool ventriculography was acceptable, the differences show that the two techniques cannot be considered equivalent.