EndoNUclease Heteroduplex Cleavage typing (ENUHCT) : une technique universelle de typage avec concept de preuve sur la détection des variants de spike du SARS-CoV-2

Introduction

Le rôle épidémiologique et clinique des variants SARS-CoV-2 a démontré la nécessité de techniques d’identification rapide à partir des prélèvements cliniques. Nous avons développé une technique de typage par clivage endonucléasique des hétéroduplexes (ENUHCT). Elle repose sur le mélange de deux produits PCR (une référence et un échantillon à étudier). Après dénaturation et réhybridation, on obtient des homoduplex (Ref/Ref, Var/Var) et potentiellement des hétéroduplex (Ref/Var). La nucléase clive les heteroduplex créant des fragments de taille différente selon le nombre et la position des mutations. Par électrophorèse capillaire, il est facile de détecter la présence de mutation(s) selon le nombre et à la taille des fragments.

Matériels et méthodes

La preuve de concept a été réalisée avec des souches virales (https://www.european-virus-archive.com/) cultivées en cellules Vero-E6 dans un laboratoire NSB3. Les extraits d’acides nucléiques correspondant à 500 prélèvements cliniques identifiés par séquençage ont été étudiés après codage aveugle.

Amplification PCR : les primers sens (TTACCAGATGATTTTACAGGC) et reverse (AGACTTTAGGTCCACAAAC) [400 nm] amplifient un fragment de 303 pb sous 25-μL avec 12,5 μL de 2X Reaction Mix, 0,5 μL de Superscript II RT/Platinum Taq Mix et 5 μL d’ARN de culture ou 3 μL d’ARN provenant d’échantillons biologiques (30 min/50 °C–2 min/94 °C, puis 40 fois 15 s/94 °C–20 s/55 °C–20 s/68 °C, puis 2 min/72 °C).

Mismatch detection : les 2 produits de PCR sont mélangés vol/vol. Après dénaturation/hybridation, les réactifs du Kit SURVEYOR (IDT) sont ajoutés suivant le protocole et incubés pendant 1 heure à 42 °C.

Capillary electrophoresis : l’analyse des fragments est faite par électrophorèse capillaire (Caliper GXII) sur puce ADNerkinElmer avec LabChip GX Reviewer.

Sanger sequencing : les produits de PCR ont été séquencés par Genewiz.

Résultats

Les résultats obtenus sont en parfaite correspondance avec les résultats théoriques. En associant une souche européenne avec variant UK on obtient 2 fragments (231/72 pb [mismatch en 501]) ; en associant variant UK et variant SA (180/123 pb [mismatch en 484]) ; en associant souche européenne et variant SA on obtient 4 fragments (180/123/72/51 [mismatch en 484 et 501]). De même, les résultats obtenus avec les prélèvements cliniques nous ont permis d’identifier correctement les variants connus et d’identifier de nouveaux variants. Ces derniers ont été confirmés par séquençage.

Conclusion

ENUHCT :

– est simple, sensible, peu coûteuse ;

– permet de détecter les variants reconnus et de découvrir des variants encore non répertoriés ;

– peut être appliquée à d’autres microorganismes ;

– permet de typer plus de 1000 échantillons par jour.

Molecular investigation of tick-borne pathogens in ixodid ticks infesting domestic animals (cattle and sheep) and small rodents (black rats) of Corsica, France

Although livestock farming (sheep, goats, pigs, and cattle) is an important economic activity in Corsica, a French Mediterranean island, knowledge about the tick fauna and microorganisms carried by them remains scarce. This study aimed to investigate the presence and perform molecular characterization of Anaplasmataceae, Rickettsia spp., and Borrelia burgdorferi sensu lato (sl) in tick species collected in Corsica. Ticks from cattle (Bos taurus), sheep (Ovis aries), and rodents (Rattus rattus) were collected from May to September 2016. DNA was purified from ticks, submitted to quantitative real-time polymerase chain reaction (qPCR) and sequenced for phylogenetic analysis. In total, 660 ticks were collected from 111 animals during the study. The most abundant collected tick species from cattle was Rhipicephalus bursa (n = 495; 84.5%), followed by Hyalomma marginatum (n = 91; 15.5%). Rhipicephalus bursa and Ixodes ricinus were the only tick species collected from sheep and rodents, respectively. Overall, Rickettsia was the most common pathogen group (n = 48; 24%) detected in ticks. Sequence analysis of partial gltA and ompA genes revealed the presence of Ri. aeschlimannii and Candidatus Ri. barbariae. Anaplasmataceae DNA was detected in eight (6%) of the 127 cattle pools and in one (2%) of the 61 R. bursa specimens collected from sheep. Sequence analysis of the rpoB gene revealed the presence of one Anaplasma species, A. marginale. Borrelia burgdorferi sl DNA was detected in one pool of H. marginatum collected from cattle and in two (15%) of the 13 I. ricinus pools collected from nine black rats. To our knowledge, this is the first report of the occurrence and molecular characterization of Candidatus Ri. barbariae, an emerging member of the Rickettsia group causing spotted fever, in Corsica. The detection of B. burgdorferi sl DNA, which was previously believed to be rare in Corsica, confirms the presence of this agent on the island.

Baseline characteristics and clinical symptoms related to respiratory viruses identified among patients presenting with influenza-like illness in primary care

Objectives

We aimed to identify patients' clinical characteristics associated with respiratory viruses identified among patients presenting with influenza-like illness (ILI).

Methods

A sample of patients of all ages presenting with ILI was included by physicians of the French Sentinelles network during two seasons (2015/16 and 2016/17). Nasopharyngeal samples were tested for the presence of influenza virus (IV), respiratory syncytial virus (RSV), human rhinovirus (HRV) and human metapneumovirus (HMPV). Patients' characteristics associated with each of the four virus classes were studied using multivariate logistic regressions.

Results

A total of 5859 individuals were included in the study: 48.0% tested positive for IV, 7.9% for HRV, 7.5% for RSV and 4.1% for HMPV. Cough was associated with IV (OR 2.14, 95% CI 1.81–2.52) RSV (OR 2.52, 95% CI 1.75–3.74) and HMPV detection (OR 2.15, 95% CI 1.40–3.45). Rhinorrhoea was associated mainly with HRV detection (OR 1.75, 95% CI 1.34–2.32). Headache was associated with IV detection (OR 1.75, 95% CI 1.34–2.32), whereas absence of headache was associated with RSV and HMPV detection. Dyspnoea was associated with RSV detection (OR 2.33, 95% CI 1.73–3.12) and absence of dyspnoea with IV detection. Conjunctivitis was associated with IV detection (OR 1.27, 95% CI 1.08–1.50). Some associations were observed only in children: dyspnoea and cough with RSV detection (age <5 years), conjunctivitis with IV detection (age <15 years). Period of onset of symptoms differed among aetiological diagnoses. Seasonal influenza vaccination decreased the risk of IV detection (OR, 0.67, 95% CI 0.51–0.86).

Conclusions

This study allowed the identification of symptoms associated with several viral aetiologies in patients with ILI. A proper knowledge and understanding of these clinical signs may improve the medical management of patients.

Non-functioning gastroenteropancreatic (GEP) tumors: a 111In-Pentetreotide SPECT/CT diagnostic study

In a retrospective study performed in non-functioning GEP tumor patients we further investigated ¹¹¹In-Pentetreotide SPECT/CT usefulness in diagnosis, staging and follow-up also evaluating whether the procedure may give more information than conventional imaging procedures (CIP), such as CT, MRI, US. We enrolled 104 consecutive patients with non-functioning GEP tumors, 30 in initial diagnosis and staging phases (IDS) and 74 in follow-up (FU). All patients underwent somatostatin receptor scintigraphy (SRS) whole body scan at 4, 24 and, if necessary, 48 hours followed by abdominal and chest SPECT/CT after ¹¹¹In-Pentetreotide 148-222 MBq i.v. injection. The patients previously underwent 2 to 3 CIP. At both CIP and SPECT/CT, 34/104 patients were classified as no evidence of disease (NED); in 70/104 patients, neoplastic lesions were ascertained and 12 IDS and 17 FU were classified as not operable and treated with octeotride or chemotherapy. SPECT/CT and CIP were concordantly positive in 44 patients, while only CIP was positive in 6 cases and only SPECT/CT in 20. Both per-patient sensitivity and accuracy of SPECT/CT (91.4 and 94.2%, respectively) were higher than CIP (71.4 and 80.8%, respectively), but not significantly. Globally, 292 lesions were ascertained: 141 hepatic, 78 abdominal extra-hepatic and 73 extra-abdominal. CIP detected 191/292 (65.4%) lesions in 50 patients, while SPECT/CT 244/292 (83.6%) in 64, the difference being significant (p<0.0001). No false positive results were found at both SPECT/CT and CIP. Both SPECT/CT sensitivity and accuracy were higher than CIP in G1, G2, neuroendocrine carcinoma (NEC) and mixed adeno-neuroendocrine carcinoma (MANEC) patients, but significantly only for G1. Globally, SPECT/CT incremental value than CIP was 35.6%. SPECT/CT correctly modified CIP classification and patient management in 27.9% of cases, while it down-staged the disease than CIP in 9.6% of cases. However, the two procedures combined use could achieve the highest accuracy value. ¹¹¹In-Pentetreotide SRS, acquired as SPECT/CT, showing high sensitivity and accuracy values, more elevated than CIP in the present study, can still have a wide employment in the routine diagnostic protocol of non-functioning GEP tumors with significant impact on patient management and therapy planning. The procedure is simple to perform, has limited cost and wide availability in all Nuclear Medicine Centers.

Influenza-like illness outbreaks in nursing homes in Corsica, France, 2014-2015: epidemiological and molecular characterization

Background

To study the molecular epidemiology of the influenza outbreaks in nursing homes (NHs) to determine whether multiple influenza strains were involved.

Methods

From September to December 2014, NHs in Corsica were invited to participate in an ongoing daily epidemiological and microbiological surveillance for influenza-like illness (ILI) among residents and health care workers (HCWs).

Results

The study involved 12 NHs. Respiratory illness meeting the ILI case definition was observed among 44 residents from whom 22 specimens were collected. Of the 22 residents with a nasopharyngeal sample, 13 (59 %) were positive for at least one of the 11 pathogens analysed. Among these 13 patients, 11 (92 %) presented a confirmed influenza (A/H3N2) and two had another respiratory virus: one human metapneumovirus and one human coronavirus. Of patients with a confirmed influenza A(H3N2), 10 (91 %) were vaccinated against influenza during the 2014–2015 season. Two influenza outbreaks were reported in two NHs, caused by influenza A(H3N2) strains belonging to cluster 3C.3 and 3C.2a. Although antivirals were available, prophylaxis was not used.

Conclusions

Phylogenetic analysis seems to suggest no multiple introduction into the two NHs reporting the two influenza A(H3N2) outbreaks. A number of factors could have contributed to transmitting influenza in NHs including, the absence of administration of antiviral treatment for prophylaxis of all residents/staff regardless of immunization status because of the poor vaccine match during each outbreak, the intensive contacts with incompletely protected residents and HCWs, and the low adherence of NHs to notification of ILI outbreaks to the health authorities.

Electronic supplementary material

The online version of this article (doi:10.1186/s40064-016-2957-z) contains supplementary material, which is available to authorized users.

111In-Pentetreotide SPECT/CT in Pulmonary Carcinoid

AIM

We evaluated somatostatin receptor scintigraphy (SRS) with (111)In-pentetreotide incremental value in pulmonary carcinoid (PC) diagnosis compared to contrast enhanced Computed Tomography (ceCT).

PATIENTS AND METHODS

We enrolled 81 patients with ascertained PC, 39 at initial staging and 42 in follow-up; the primary tumor had already been excised in 68 cases. Single Photon emission Computed Tomography (SPECT) images were reconstructed with the iterative method and fused with non-enhanced Computed tomography (CT) images.

RESULTS

Primary PC or metastatic lesions were ascertained in 55/81 patients and SPECT/CT was positive in 50/55 cases, while ceCT was positive in 44/55. Comparing SPECT/CT with ceCT results, we found a sensitivity of 96 vs. 87.5%, and specificity of 92% vs. 97% for the detection of primary lesion or recurrent disease. A total of 198 lesions were ascertained at SPECT/CT, while 161 at ceCT, with values of sensitivity and specificity of 85.5% and 84.6% for SRS and 75.2% and 90.5% respectively.

CONCLUSION

(111)In-Pentetreotide SPECT/CT proved to be more sensitive and accurate than ceCT, thus enhancing its role in evaluating patients with PC.

Serum leptin and bone metabolism in HIV patients treated with highly active antiretroviral therapy

AIM

The role of leptin in bone metabolism has not yet been fully elucidated and results remain controversial. We investigated whether changes in serum leptin correlated to bone mineral density (BMD) occur in human immunodeficiency virus (HIV) patients on highly active antiretroviral therapy (HAART).

METHODS

The study population was 117 HIV patients (67 men, 50 women) on HAART and 50 healthy controls, all with normal body mass index (BMI). Based on whole body BMD as measured by dual energy x-ray absorptiometry (DEXA), patients were classified as having a low (< -1) T-score (L) or a normal (> -1) T-score (N); DEXA scans were also used to determine total body fat (TFM) and percent fat (F%); radioimmunologic assays were used to measure leptin, osteocalcin (OC), bone alkaline phosphatase (BAP), 1,25 (OH)2 D in serum, and pyridinium cross-links (PYD & DPD) in urine.

RESULTS

Of the 117 HIV patients, 54 (46.1%) were classified as L and 63 (53.9%) as N; BMD in both sexes was lower (P <0.01) among the L patients than among either the N patients or the controls; 25/32 L men and 19/22 women were osteopenic, the remaining were osteoporotic. The mean TFM, F%, OC, BAP and PYD & DPD values were higher and the mean 1,25 (OH)2 D values were lower in the L than in the N patients; leptin was higher among the L men (P <0.002) and the L women (P <0.03) than in the N patients. In both sexes. leptin positively correlated with TFM, F%, BAP and PYD & DPD; however, leptin, TFM and F% correlated negatively with BMD. A negative correlation was found between 1,25 (OH)2 D and PYD & DPD in women. At follow-up assessment of 56 HIV patients continuing HAART, leptin and BAP increased and 1,25 (OH)2 D decreased, but not significantly; BMD significantly decreased in women and PYD & DPD increased in men (P <0.02).

CONCLUSIONS

An inverse relationship was found between leptin and BMD in HIV patients with osteopenia/osteoporosis treated with HAART. While the role of leptin in bone metabolism in a setting of HIV is still unclear, an inhibitory effect of leptin associated with a negative action by HAART may be hypothesized.

Cholesteryl ester transfer protein gene polymorphisms are associated with coronary artery disease in Corsican population (France)

The aim of the present study was to investigate the association between coronary artery disease (CAD) and Cholesterol Ester Transfer Protein (CETP) (gaaa)n polymorphisms of the CETP gene in Central Corsica island (France). The study group was composed by 300 unrelated Corsican patients with angiographically documented CAD and 300 unrelated healthy blood donors. Significant differences were observed in the distribution of CETP (gaaa)n alleles between the groups under study (p=0.03; chi(2): 16.8, df: 8). The occurrence of a long allele (408 bp) was higher in cases (12%) than in control group (2%), showing a 6.75-fold increased risk for CAD in Corsica patients (p=0.0055; OR=6.750; 95% CIs=1.47-31.00). The correlation of this polymorphism with the lipid profile (cholesterol, low density lipoprotein-cholesterol, high density lipoprotein-cholesterol and triglycerides) in the patients group was determined. There was a significant association of the long alleles of CETP (gaaa)n with HDL-C levels. In the patient and in the control groups the LL genotypes had lower HDL-C compared with the SS and SL genotypes (p<0.0001). In summary our results suggest that the genetic variation at the CETP gene may play an important role in determining CAD in Corsican population.

Thyroid function in human immunodeficiency virus patients treated with highly active antiretroviral therapy (HAART): a longitudinal study

OBJECTIVE

Given that few and controversial data have been reported on thyroid function in human immunodeficiency virus (HIV) patients on highly active antiretroviral therapy (HAART), we further investigated whether HAART affects thyroid hormones.

DESIGN AND PATIENTS

Two hundred two consecutive adult HIV patients in stable clinical condition were enrolled, 182 on HAART and 20 naïve; 128 were rechecked during follow-up. Body mass index (BMI), CD4 cell count, HIV RNA, hepatitis C and B virus status and infection duration were determined in all HIV patients and HAART duration in treated patients. In all patients and in 60 controls, the following were measured: FT4 and FT3 by radioimmunoassay; TSH, antithyroid peroxidase (TPO) and antithyroglobulin (TG) antibodies by immunoradiometric assay.

RESULTS

Abnormalities in thyroid function tests were found in 23/182 (12.6%) HAART patients, but not in naïve patients. Most abnormalities were subclinical hypothyroidism, with mean FT4 and TSH levels lower and higher, respectively, in HAART patients compared to naïve patients and controls, FT4 levels being significantly lower than controls. TSH negatively correlated with CD4 count nadir and positively with HAART duration. During follow-up, FT4 and FT3 significantly decreased and TSH increased in patients continuing HAART, whereas CD4 counts were unmodified; subclinical hypothyroid conditions persisted and further cases occurred, whereas the only hypothyroid patient who interrupted HAART shows a normalization of thyroid tests. Patients on stavudine, included in most hypothyroid patient protocols, had significantly lower FT4 levels with prolonged treatment.

CONCLUSIONS

HAART, particularly stavudine, is associated with a high prevalence of subclinical hypothyroidism. Hypotheses are made regarding responsible mechanisms and risk factors. Thyroid function should be tested and sequentially rechecked in HAART patients.

Prevalence of genetic risk factors for coronary artery disease in Corsica island (France)

We have investigated the frequencies of seven markers among 100 unrelated individuals with angiographically documented CAD (Coronary Artery Disease) and among 100 unrelated healthy blood donors in the central region of Corsica island (France). The seven polymorphisms analyzed were chosen from six candidate genes involved in (1) Renin-Angiotensin system: Angiotensin converting enzyme (ACE I/D), (2) Lipid metabolism: Cholesterol Ester Transfer Protein gene (CETP TAQ1B), (3) Platelet aggregation: alpha and beta subunits of the platelet GpIIb/GpIIIa integrin complex (GpIIb HPA3 and GpIIIa Pl(A1/A2)), (4) Coagulation fibrinolysis: Plasminogen Activator Tissue (PLAT TPA25 I/D) and Methylenetetrahydrofolate Reductase (MTHFR C677T and A1298C). The samples were genotyped using the polymerase chain reaction followed by restriction enzyme analysis for the RFLPs. No significant difference in allele frequencies between patient and control groups was observed. The occurrence of the MTHFR T677T genotype and of the T677T/A1298A compound genotype is higher in cases (20%) than in the controls (4%). Odds ratio seems to indicate that individuals with the MTHFR T677T genotype and the T677T/A1298A compound genotype had a 6-fold increased risk for developing CAD (ORs = 6; 95% CIs = 1.96-18.28) suggesting a possible association of MTHFR C677T with the risk of CAD in Corsican population.

Genetic Characterization of the Historical Albanian Ethnic Minority of Calabria (Southern Italy)

Three historical ethnic minorities are present in Calabria: Albanians, Greeks, and Occitans. The Albanian ethnic minority is the more populous, having settled in Calabria between the 15th and 17th centuries, and these populations are now located in the provinces of Cosenza and Catanzaro. In the present study the Albanian population structure is analyzed based on the allele frequencies of six classic genetic markers: ACP, GC, PGM1, AK, ADA, and 6PGD. The results show a significant heterogeneity between the Albanian population in Calabria and the population in Molise. Therefore the cultural and reproductive isolation of the Albanian ethnic minority of Calabria is related to a great genetic peculiarity. Moreover, the frequencies of some alleles, particularly those of the PGM*1W31 variant, and the analysis of the R matrix still show the actual peculiar genetic structure of the Albanians of Calabria, although the genetic flow is evident in the decrease of endogamy and in the increase in the degree of mixing.

β-globin cluster haplotypes in normal individuals and β039-thalassemia carriers from Sardinia, Italy

Seven polymorphic sites in the beta-globin cluster in association with specific thalassemia mutations were analyzed in a sample from Sardinia, Italy. In order to verify previous works carried out on normal samples (beta(A)/beta(A)) and family studies on beta-thalassemia homozygotes individuals, the haplotype frequencies in both normal individuals (beta(A)/beta(A)) and beta(0)39-thalassemia carriers (beta(A)/beta0) were studied. In our work chromosomes carrying beta(0)39 mutation are characterized by a prevalence of haplotype II (- + + - + + +) (52%) relative to haplotype I (+- - - - + +) (29%), in contrast, among chromosomes with beta(A) the frequency of haplotype I is much greater than that of haplotype II. These data confirm what was found by other authors. Nevertheless, our results disagree with those of previous studies of Sardinians, both in frequencies values and in the numbers of haplotypes identified. Population analysis performed with samples carrying the beta-thalassemic mutation highlighted the peculiarity of Sardinians with respect to other Mediterranean populations. The Corsican population is most similar to the Sardinian population, confirming previous analyses performed with both classical markers and mitochondrial and genomic DNA.

Somatostatin receptor scintigraphy with 111In-pentetreotide in non-functioning gastroenteropancreatic neuroendocrine tumors

To investigate somatostatin receptor scintigraphy (SRS) usefulness compared to conventional imaging procedures (CIP) in non-functioning gastroenteropatic (GEP) neuroendocrine tumors, we studied 40 patients, 30 in follow-up (FU) after previous operation for primary tumor (27 cases) or non-operable for disseminated metastases (3 cases), and 10 in the phase of initial diagnosis and staging (IDS). All patients were asymptomatic for hormone overexpression, with slightly high serum chromogranine A in 6 FU. The definitive diagnosis was obtained by surgery, laparotomy or percutaneous CT/US guided biopsy. Within 1 month before scintigraphy, all patients had undergone at least 2 of 3 CIP (CT, MRI and US); 4 and 24 h after 250 MBq 111In-pentetreotide i.v. injection, whole body scanning, planar and SPECT over the abdomen or other suspect regions were performed. Globally, 135 neoplastic lesions (84 hepatic, 34 abdominal extra-hepatic and 17 extra-abdominal) were ascertained in 32/40 patients; SPECT was positive in 29 cases, CIP in 28 and planar in 20, while all 3 procedures were true negative in the remaining 8 cases. Per patient sensitivity and accuracy were significantly higher at SPECT and CIP than planar. SPECT showed a significantly higher per lesion sensitivity (89.6%) than CIP (72.6%) and planar (53.3%) while CIP sensitivity was significantly higher than planar. SPECT correctly modified CIP patient classification and thus management in 18.7% of patients, while it downstaged the disease in 9.4% in respect of CIP; planar was incorrect in 51.3% of cases. SPECT and CIP combined use achieved 100% accuracy and correctly classified all patients. 111In-pentetreotide SRS, particularly SPECT, is a useful diagnostic tool in the detection of non-functioning GEP tumors, contributing to correct patient classification and appropriate therapeutic strategy. SPECT proved more sensitive than CIP, but their combined use achieved the highest accuracy values and gave the most accurate disease staging.

Bone mass loss and vitamin D metabolism impairment in HIV patients receiving highly active antiretroviral therapy

AIM

Given the few controversial data about the effect of highly active antiretroviral therapy (HAART) on bone mass in HIV patients, we investigated whether a relationship between osteopenia/osteoporosis risk and HAART exists.

METHODS

In 172 HIV patients, 152 on HAART, 92 including and 60 not including protease inhibitors (PI), 20 naïve and 64 controls, we measured spine/femur bone mineral density (BMD) by DEXA, and assayed serum osteocalcin (O), bone alkaline phosphatase (BAP), 1,25(OH)2 D, parathormone (PTH), calcium (Ca) and urinary pyridinium cross-links (PYD & DPD).

RESULTS

Following WHO BMD t-score criteria, osteopenia was ascertained in >35% of all HAART groups and in 30% of naive. Only HAART patients had osteoporosis, PI patients more frequently, significantly (p<0.03) in spine (21.7% vs 8.3%). Males, intravenous drug users and B-C stage patients have a higher risk for low bone mass. Mean t-score was significantly lower in both spine and femur and O and PYD & DPD higher in PI than non PI patients and controls; 1,25(OH)2 D was significantly lower in all HIV groups than controls, PI patients having the lowest values positively correlating with BMD and negatively with OC and PYD & DPD, and it decreased further in 27 non selected monitored patients continuing on HAART. PTH was higher and Ca lower in HAART patients than controls but not significantly, PTH negatively correlating with BMD.

CONCLUSION

HAART could be associated with osteopenia, even osteoporosis, and it could aggravate the loss in bone mass due to HIV infection itself. We hypothesize that HAART may directly affect bone remodelling and/or may indirectly affect vitamin D metabolism.

The usefulness of neck pinhole SPECT as a complementary tool to planar scintigraphy in primary and secondary hyperparathyroidism

Pinhole SPECT (P-SPECT) has proven to be a high-resolution and sensitive method in both experimental and clinical studies. In this study, we investigated whether P-SPECT combined with conventional planar scintigraphy can give additional information in hyperfunctioning parathyroid gland detection in both primary hyperparathyroidism (pHPT) and secondary hyperparathyroidism (sHPT) since planar imaging has proved partially limited, especially in sHPT.

METHODS

We studied 110 consecutive patients with HPT, selecting 67 patients who underwent neck surgery and had definitive histology: 48 with pHPT and 19 with sHPT. All patients underwent planar scintigraphy, (99m)Tc-methoxyisobutylisonitrile ((99m)Tc-MIBI) double-phase scintigraphy (n = 22) or (99m)Tc-tetrofosmin subtraction scintigraphy (n = 45), using a gamma-camera with a parallel-hole collimator. P-SPECT was then performed (180 degrees; matrix size, 128 x 128; zoom factor, 2; time per frame, 40 s) using a tilted detector equipped with a pinhole collimator (insert, 4.45 mm).

RESULTS

In the 48 pHPT patients, 49 lesions (43 adenomas, 1 carcinoma, and 5 hyperplastic glands, including 1 intrathyroidal) were found at surgery; in the 19 sHPT patients, 51 lesions (49 hyperplastic glands, including 1 in persistens thymus, and 2 adenomas) were found. P-SPECT proved to be a highly sensitive method, identifying more lesions than planar imaging in both pHPT (97.9% vs. 87.7%) and sHPT (92.1% vs. 78.4%), significantly (P < 0.05) in the latter. P-SPECT, positive in all adenomas, increased planar sensitivity especially in small and light-weight ones, 30.8% of which missed on planar imaging, and also identified a significantly higher number of hyperplastic glands, irrespective of their size. P-SPECT improved image quality and resolution, offering a more correct lesion localization in eutopic and ectopic sites. Neither P-SPECT nor planar imaging had false-positive findings. Moreover, P-SPECT correctly predicted the status found at surgery in 97.9% of pHPT patients and in 82.3% of sHPT patients with multigland disease, whereas planar imaging correctly predicted the status in 89.6% and 58.8%, respectively. P-SPECT was the only positive procedure in 8.9% of all patients, also revealing more lesions in 6% of sHPT patients when both methods were positive.

CONCLUSION

P-SPECT appears a highly sensitive, high-resolution method. We suggest its use as a preoperative complementary tool to neck planar scintigraphy, selectively in pHPT patients but extensively in sHPT patients.

[The usefulness of 99mTc-tetrofosmin SPECT in the detection of lung metastases from extrapulmonary primary tumors]

PURPOSE

The appearance of pulmonary metastases in neoplastic patients previously submitted to radical operation of an extrapulmonary primary tumor and with no recurrences and/or secondary distant localizations can markedly worsen disease prognosis if the lesions are in advanced stages and no longer removable by surgical procedures. In this study, we evaluated the usefulness of 99mTc-tetrofosmin scintigraphy, both planar and SPECT, in the detection of pulmonary metastases from previously treated extrapulmonary primary tumors, comparing the results with those obtained with CT.

MATERIALS AND METHODS

We studied 73 patients, 33 M and 40 F, aged 24 to 79 yrs, had who undergone previously surgical resection extrapulmonary primary tumors; 31 patients had mammary, 13 gastrointestinal, 13 genitourinary, 13 thyroid and 3 laryngeal carcinomas. In all patients CT ascertained single (42 cases) or multiple (31 cases) pulmonary lesions. 99mTc-tetrofosmin scintigraphy, always performed within a week of CT, was acquired 10 min after 740 MBq i.v. tracer injection, using a rectangular, large field of view, dual head gamma camera, equipped with low energy, parallel-hole and high resolution collimators. Conventional planar acquisition, with the patient in the supine position, was followed by SPECT over 360 degrees with body contouring system, using a zoom factor of 1-1.3, a 64x64 matrix size, a 3 degrees angular step and an acquisition time of 30 sec/frame; image reconstruction was performed with the Back Projection Filtered Method using a Metz filter. In the coronal slices of SPECT images a semiquantitative analysis of the lesion was also made and the tumor-to-background (T/B) ratio was calculated; the calculation of the latter, considered indicative for tumor when >1.4, was performed in the lesion with the highest radiotracer uptake in patients with multiple lung lesions. The results of SPECT qualitative images were compared with those of planar scintigraphy and both of these with the data obtained with CT, and statistical difference was calculated with McNemar's test. The definitive diagnosis was achieved after scintigraphy by the analysis of cytologic or histologic specimens obtained by thoracotomy, percutaneous thoracic needle biopsy or bronchoscopic biopsy, and in some cases by the confirmation of instrumental exams at 6-8 month follow up. Pulmonary metastases were ascertained in 65/73 cases, while benign lesions were present in the remaining 8 patients.

RESULTS

CT was true positive in 60/65 (92.3%) patients with metastases and false negative in the remaining five, four with a single lesion and one with two lesions in the same lung. SPECT detected metastases in 62/65 (95.4%) patients, including the five CT false negative cases, while it was false negative in three cases with single lesions, all positive at CT, with a size of 1.0, 1.0, 2.0 cm, respectively. Planar scintigraphy was only positive in 23/65 (35.4%) patients, with a sensitivity value significantly (p<0.0005) lower than both SPECT and CT. In the patients with multiple metastases, SPECT, positive in all cases and capable of correctly differentiating the patients with metastases only in one lung from those with bilateral involvement, underestimated the number of micronodular lesions in respect of CT in six patients with >6 lesions < or =0.5 cm in size, while it was more sensitive in three other cases; CT and SPECT were concordant in macronodular metastases detection, except in one case in which SPECT depicted more lesions. Planar scintigraphy had 42 false negative results and, when positive, underestimated the number of multiple lesions in respect of both SPECT and CT; it was positive but CT negative in only one case with two lesions. Specificity was higher for both SPECT and planar scan (87.5%) than CT (62.5%) but not significantly; accuracy was higher for SPECT (94.5%) than both planar scan (42%) and CT (89%), but the difference was significant only in respect of planar. The combined use of SPECT and CT achieved 100% sensitivity and accuracy values. The T/B ratio was >1.ratio was >1.4 in all SPECT positive cases (range: 1.6-5.3), indicating a suspected tumor, while it was 1.2 in the only benign case which turned out to be false positive at qualitative SPECT imaging.

CONCLUSIONS

99mTc-tetrofosmin SPECT seems to be a reliable diagnostic tool in the detection of pulmonary metastases from extrapulmonary primary tumors, in particular in the cases in which CT is indeterminate or false positive, and therefore contributes to a more correct patient classification. Moreover, SPECT image semiquantitative analysis can give additional information for a differential diagnosis between malignant and benign lesions as well as offering a more accurate selection of the lesions to be subjected to biopsy in patients with multiple metastases. However, only the combined use of CT and 99mTc-tetrofosmin SPECT can achieve the highest sensitivity and accuracy values and obtain the correct staging in most patients, thus suggesting that these two procedures must be employed together.

Somatostatin receptor scintigraphy with 111In-pentetreotide in non-functioning gastroenteropancreatic neuroendocrine tumors

To investigate somatostatin receptor scintigraphy (SRS) usefulness compared to conventional imaging procedures (CIP) in non-functioning gastroenteropatic (GEP) neuroendocrine tumors, we studied 40 patients, 30 in follow-up (FU) after previous operation for primary tumor (27 cases) or non-operable for disseminated metastases (3 cases), and 10 in the phase of initial diagnosis and staging (IDS). All patients were asymptomatic for hormone overexpression, with slightly high serum chromogranine A in 6 FU. The definitive diagnosis was obtained by surgery, laparotomy or percutaneous CT/US guided biopsy. Within 1 month before scintigraphy, all patients had undergone at least 2 of 3 CIP (CT, MRI and US); 4 and 24 h after 250 MBq 111In-pentetreotide i.v. injection, whole body scanning, planar and SPECT over the abdomen or other suspect regions were performed. Globally, 135 neoplastic lesions (84 hepatic, 34 abdominal extra-hepatic and 17 extra-abdominal) were ascertained in 32/40 patients; SPECT was positive in 29 cases, CIP in 28 and planar in 20, while all 3 procedures were true negative in the remaining 8 cases. Per patient sensitivity and accuracy were significantly higher at SPECT and CIP than planar. SPECT showed a significantly higher per lesion sensitivity (89.6%) than CIP (72.6%) and planar (53.3%) while CIP sensitivity was significantly higher than planar. SPECT correctly modified CIP patient classification and thus management in 18.7% of patients, while it downstaged the disease in 9.4% in respect of CIP; planar was incorrect in 51.3% of cases. SPECT and CIP combined use achieved 100% accuracy and correctly classified all patients. 111In-pentetreotide SRS, particularly SPECT, is a useful diagnostic tool in the detection of non-functioning GEP tumors, contributing to correct patient classification and appropriate therapeutic strategy. SPECT proved more sensitive than CIP, but their combined use achieved the highest accuracy values and gave the most accurate disease staging.

The usefulness of 99mTc-tetrofosmin SPECT in monitoring the response to chemotherapy in lung cancer patients

We evaluated the usefulness of 99mTc-tetrofosmin (TF) scintigraphy in monitoring chemotherapy response in 31 inoperable lung cancer (LC) patients, 24 NSCLC and 7 SCLC. In all cases after 740 MBq 99mTc-TF i.v. injection both planar and SPECT images were acquired, before and after 3 cycles of chemotherapy; SPECT was analysed both qualitatively and semiquantitatively by calculating tumor/background ratio (T/B). Scintigraphic data were always related to CT findings, according to which patients were classified into 2 groups after therapy: responders (with >or=50% reduction in tumor size) and non-responders (with an increase or no change/no significant reduction in tumor size). Four patients were rechecked for the third time, during long-term follow-up. SPECT images, positive before therapy in all cases, were concordant with CT in assessing treatment response in 13/13 responders and in 18/18 non-responder patients, showing tumor reduction in the former and an increase or no change/no significant reduction in the latter. Planar imaging failed to give additional information but also led to disease down-staging in some cases. T/B ratio significantly decreased after therapy (1.67+/-0.39 vs. 3.02+/-0.87, p<0.005) in responders <or=1.9 in each patient except one with local disease progression at the third observation. No significant difference in T/B ratio was found in non-responders after treatment (2.11+/-0.65 vs. 2.13+/-0.60), with variable results in single patients, including a T/B ratio reduction in some cases, one of which with local disease remission at third observation. Moreover, pre-therapy T/B ratio was significantly higher (p<0.01) in responders than in non-responders. 99mTc-TF SPECT, but not planar, may be useful in monitoring the chemotherapy response in inoperable LC patients; the additional use of T/B ratio seems to give more accurate information and may be useful for treatment response prediction and for better evaluating disease progression or regression after therapy.

The usefulness of single photon emission computerized tomography with pinhole collimator (P-SPECT) in preoperative localization of hyperfunctioning parathyroid glands in patients with secondary hyperparathyroidism

PURPOSE

In this study the usefulness of parathyroid scintigraphy was evaluated in a group of patients affected by secondary hyperparathyroidism, combining the conventional double-tracer subtraction planar scintigraphy with pinhole-SPECT (P-SPECT) acquisition and comparing the scintigraphic data with those obtained by ultrasonography.

MATERIALS AND METHODS

Twenty-four patients with secondary hyperparathyroidism were enrolled, 19 with chronic renal failure on haemodialysis and 5 with renal transplant. All patients underwent parathyroidectomy because of their unresponsiveness to medical therapy and/or severe osteodystrophy. Histology ascertained a single adenoma each in 3 patients and 61 hyperplastic glands in the remaining 21 cases. Before surgery, all patients were submitted to high resolution ultrasonography and afterwards to double-tracer subtraction planar parathyroid scintigraphy ((99m)Tc-pertechnetate/(99m)Tc-tetrofosmin) followed by neck P-SPECT acquisition.

RESULTS

P-SPECT was true positive in all 24 patients, while both planar and ultrasonography were false negative in one case. Globally, P-SPECT identified 60/64 hyperfunctioning parathyroid glands, planar 47/64 and ultrasonography 45/64. P-SPECT sensitivity (93.7%) was significantly higher than both planar (73.4%; p<0.001) and ultrasonography (70.3%; p< 0.0005). The difference was also significant (p<0.05) when P-SPECT sensitivity was compared with that obtained combining planar scintigraphy and ultrasonography (84.4%). Moreover, P-SPECT defined the exact number of hyperplastic glands in 85.7% of positive patients, while planar in 60% and ultrasonography in 45%. Only 4 hyperplastic glands were false negative at P-SPECT showing a maximum diameter of 10 mm and a weight ranging from 480 to 500 mg. These glands were also false negative at both planar scintigraphy and ultrasonography which missed further 13 and 15 hyperfunctioning glands, respectively, all detected by P-SPECT. Globally, the latter procedure gave the correct preoperative localization of hyperfunctioning parathyroid glands in 87.5%, planar in 62.5% and ultrasonography in 50%. None of the three procedures had false positive

RESULTS

CONCLUSIONS

The data of the present study seem to indicate that P-SPECT is a reliable diagnostic method in preoperative localization of hyperfunctioning parathyroid glands in patients with secondary hyperparathyroidism. This procedure identified a significantly higher number of hyperplastic glands than both double-tracer subtraction planar parathyroid scintigraphy and ultrasonography in our cases, thus proving a more useful guide for the surgeon. Given its low false negative rate, a wider use of P-SPECT is suggested in the preoperative management of patients with secondary hyperparathyroidism undergoing either a first operation of parathyroidectomy or a second operation for recurrence.

The role of (99m)Tc-tetrofosmin pinhole-SPECT in breast cancer non palpable axillary lymph node metastases detection

AIM

We evaluated the usefulness of (99m)Tc-tetrofosmin axillary pinhole (P)-SPECT in breast cancer (BC) non palpable axillary lymph node metastasis detection compared with conventional planar and SPECT scintimammography.

METHODS

We studied prospectively 188 consecutive patients with suspected primary BC, negative at axillary clinical examination. Ten minutes after 740 MBq (99m)Tc-tetrofosmin injection, planar and SPECT scintimammography were acquired, followed by axillary P-SPECT imaging.

RESULTS

At histology, 12 patients had benign mammary lesions and 176 had BC. Axillary lymph node dissection (ALND) was performed in all BC patients, bilaterally in 3 cases: 74/179 axillae had metastases. P-SPECT showed a significantly higher overall sensitivity than SPECT and planar (93.2% vs 85.1% and 36.5%, respectively; p<0.05 and p<0.0005, respectively) and was false negative in 5 patients with 1 metastatic node each, micrometastatic in 4/5 cases; SPECT and planar were also false negative in these 5 cases and in 6 and in 42 further cases, respectively. P-SPECT added important prognostic information by distinguishing single from multiple and pound 3 from >3 nodes; only P-SPECT defined the exact number of nodes in 15/25 patients with 2-4 nodes. P-SPECT showed the highest accuracy and NPV: 92.7% and 95%, respectively (SPECT 90.5% and 90%, respectively; planar 73.2% and 68.9%, respectively).

CONCLUSION

(99m)Tc-tetrofosmin axillary P-SPECT appears highly accurate in BC non palpable axillary lymph node metastasis detection and significantly more sensitive than both planar and SPECT, its few false negative results predominantly concerning micrometastases; moreover, only P-SPECT gave additional important prognostic information. Given its very high NPV, P-SPECT could also be used to better select patients who might avoid ALND.

The usefulness of 99mTc-tetrofosmin SPECT in the detection of intrathoracic malignant lesions

To evaluate the usefulness of 99mTc-tetrofosmin (TF) SPECT in the detection of intrathoracic malignant lesions, we studied 304 patients, 261 with malignant and 43 with benign lesions; 196 of the former had non-treated primary tumors, 193 lung cancer (LC) and 3 mesotheliomas, 11 had LC recurrences and 54 had metastases from different kinds of tumors. Twenty-nine patients with primary tumors were re-checked after chemotherapy or surgery. In all patients, after 740 MBq TF injection, both planar and SPECT images were acquired and analysed qualitatively, SPECT images also semiquantitatively. Scintigraphy was always compared to CT. SPECT showed higher sensitivity, specificity and accuracy values than CT (98.1, 90.7 and 97 vs. 96.2, 81.4, and 93.9%, respectively), their combined use achieving 100% sensitivity and 98.8% accuracy. Planar did not give more information than SPECT, showing a significantly lower sensitivity (63.2%) and accuracy (67.4%). SPECT showed higher accuracy values than CT and planar (86.9 vs. 78.3 and 69.6%) in NSCLC mediastinal lymph node staging. Moreover, SPECT was concordant with CT in correctly evaluating the response to chemotherapy or surgery in all monitorized primary tumors cases, except in one in whom only SPECT detected residual tumor. The semiquantitative analysis added useful information in differentiating malignant from benign lesions and in monitoring the response to chemo-therapy. TF SPECT appears a highly accurate diagnostic method in the detection of intrathoracic malignant lesions, in lungs and pleura, as well as in NSCLC mediastinal lymph node staging and in monitoring treatment effectiveness, playing a complementary role to CT in selected cases.

Somatostatin receptor scintigraphy in liver metastasis detection from gastroenteropancreatic neuroendocrine tumors

In patients with gastroenteropancreatic (GEP) neuroendocrine tumors, we investigated the usefulness of somatostatin receptor scintigraphy (SRS) in the detection of liver metastasis, which represents the most important prognostic factor in these tumors, and in the management of affected patients.

METHODS

We enrolled 149 patients with GEP tumors, 69 during initial staging and 80 in follow-up. All patients underwent whole-body scanning at 4 and 24 h, followed by abdominal planar and SPECT imaging after intravenous injection of 250 MBq (111)In-pentetreotide. The patients had previously been submitted to 2 of 3 conventional imaging procedures (CIP), such as CT, MRI, and ultrasound of the abdomen within 1 mo before SRS; on the basis of liver CIP data, the patients had been classified into 3 groups as follows: no evidence of liver metastases, the presence of resectable metastases, or the presence of nonresectable metastases.

RESULTS

Liver metastases were histologically proven in 65 cases. SPECT identified malignant lesions in 60 of 65 patients with metastases (sensitivity, 92.3%), planar imaging identified malignant lesions in 38 of 65 patients (sensitivity, 58.5%), and CIP identified malignant lesions in 52 of 65 patients (sensitivity, 80%). Only SPECT demonstrated liver involvement in 13 patients, whereas CIP showed liver involvement in 5 other cases. Moreover, SPECT was significantly more sensitive than planar imaging and CIP in identifying patients with single lesions. Neither SPECT nor planar imaging showed false-positive results in patients with no evidence of liver metastases, including 21 patients with hemangiomas (specificity, 100%), 12 of which were false-positive on CIP (specificity, 85.7%). SPECT per-lesion sensitivity (92.4%) was significantly higher than that of planar imaging (52.4%) and CIP (79.4%). Moreover, SPECT correctly changed patient classification and, thus, management in 28 of 149 patients (18.8%), whereas planar imaging changed classification in 13 patients (8.7%), identifying new or additional metastases not evident on CIP or excluding metastases on CIP of patients with false-positive findings, thus avoiding unnecessary surgery; however, SPECT classification was incorrect in 3.3% of patients, and planar imaging was incorrect in 17.4%.

CONCLUSION

(111)In-Pentetreotide SRS is a useful diagnostic tool in the detection of liver metastases in GEP tumor patients. In particular, SPECT proved to be significantly more sensitive and accurate than both planar imaging and CIP. Moreover, SPECT was also the most reliable procedure to obtain correct patient classification, thus guiding the most appropriate therapeutic strategy.

The usefulness of 99mTc tetrofosmin scintigraphy in patients with breast cancer recurrences

To verify the usefulness of 99mTc tetrofosmin scintigraphy in the follow-up of breast cancer patients, we studied 72 surgically treated breast cancer patients with suspected local recurrences (20 cases) or distant metastases (52 cases) at clinical examination and/or at conventional imaging procedures (CIPs). In all patients, a whole-body scan followed by planar and single photon emission tomography (SPET) images of selected sites were acquired 10 min after the intravenous injection of 740 MBq of 99mTc tetrofosmin, using a rectangular dual-head gamma camera equipped with high-resolution parallel-hole collimators. Loco-regional recurrences were diagnosed in 19 patients and distant metastases in 44 cases, while benign lesions were ascertained in nine cases. 99mTc tetrofosmin SPET showed higher sensitivity, specificity and accuracy per patient than did CIP (96.8% vs 85%, 77.7% vs 55.5% and 94.4% vs 81.1%, respectively) with statistical significance for accuracy (P <0.05). The combined use of SPET and CIP achieved 100% sensitivity and 98.6% accuracy. Planar imaging did not give additional information in respect of either SPET or CIP, showing significantly lower sensitivity and accuracy values (47.6% and 52.8%, respectively). Our data seem to suggest that 99mTc tetrofosmin SPET, but not planar, may be useful in the follow-up for the detection of loco-regional and distant recurrences in patients with breast cancer. The technique can play a complementary role to conventional diagnostic imaging procedures in selected patients.

Usefulness of ^99mTc-Tetrofosmin Scintigraphy in Different Variants of Kaposi’s Sarcoma

We investigated ^99mTc-tetrofosmin scintigraphy in 27 patients with Kaposi’s sarcoma: 20 had classic (CK), 5 AIDS-associated (AK) and 2 transplantation-associated (TK) variants. Twenty-three patients had clinically evident cutaneous and/or mucosal lesions, 9 of them with associated sarcomatous lymphadenopathy; 2 TK patients had only lymph nodes or other extracutaneous Kaposi sites. Both planar and SPECT ^99mTc-tetrofosmin scintigraphies were performed in all cases and neck pinhole (P)-SPECT in selected patients. ^99mTc-tetrofosmin uptake was observed in 88% of patients with clinically evident cutaneous and/or extracutaneous Kaposi lesions. Scintigraphy gave additional information on cutaneous lesion extent, particularly SPECT regarding deep invasion and subclinical sites in some cases. However, scintigraphy was less sensitive in the detection of small, isolated and scattered lesions. SPECT/P-SPECT were positive in 8/8 patients with sarcomatous lymph nodes, planar imaging in 5/8, ultrasonography in 7/8, while all procedures were negative in 6 other patients with reactive or HIV infection lymph nodes. SPECT demonstrated lymphadenopathy remission in 1 TK patient after immunosuppressive therapy modification and, like planar imaging, ascertained an associated lymphoma with ⁶⁷Ga-citrate combined. ^99mTc-tetrofosmin scintigraphy, especially SPECT, can be useful both in the detection and staging of Kaposi sarcoma lesions as a complementary tool to clinical and other conventional diagnostic methods.

The usefulness of 99mTc-tetrofosmin SPECT scintimammography in the detection of small size primary breast carcinomas

The aim of this study was to evaluate the usefulness of supine 99mTc-tetrofosmin SPECT in the detection of small size breast carcinomas (BC), for which planar scintimammography has showed a low sensitivity. We studied 93 patients with breast lesions </=10 mm, 69 with BC (14 T1a and 55 T1b, 39 palpable and 30 non-palpable) and 24 with benign lesions (16 palpable and 8 non-palpable). All patients had previously undergone clinical examination and mammography. Ten min after 740 MBq 99mTc-tetrofosmin i.v. injection, both planar and SPECT (360 degrees; angular step: 3 degrees; acquisition time/frame: 30 sec) scintimammography were performed in all patients using a rectangular dual head gamma camera equipped with HR parallel-hole collimators. In all patients the scintigraphic data were related to histology. In the 69 BC patients, SPECT showed a significantly higher overall sensitivity than planar (89.8% vs. 46.4%; p<0.0005). SPECT gave a higher sensitivity than planar in both T1a (71.4% vs. 35.7%) and T1b (94.5% vs. 49.1%) carcinomas, and in the latter the difference was statistically significant (p<0.0005). SPECT sensitivity was also significantly higher in palpable (94.9% vs. 48.7%; p<0.0005) and non-palpable (83.3% vs. 43.3%; p<0.005) carcinomas. SPECT and planar imaging showed the same specificity (95.8%). SPECT showed a significantly higher overall negative predictive value and accuracy than planar (76.7% vs. 38.3% and 91.4% vs. 59.1%, respectively; p<0.0005). In our series mammography sensitivity, specificity and accuracy were 94, 36.8 and 81.4%, respectively. 99mTc-tetrofosmin SPECT is a widely available diagnostic method and appears highly accurate in the detection of small size BC, improving the low sensitivity of planar scintimammography. In particular, SPECT seems indicated for T1b carcinoma detection, although its usefulness in T1a carcinomas should not be ignored. A larger clinical application of SPECT as complementary tool to mammography is suggested in small size primary BC diagnosis.

99mTc-Tetrofosmin pinhole-SPECT (P-SPECT) and radioguided sentinel node (SN) biopsy and in breast cancer axillary lymph node staging

We compared 99mTc-Tetrofosmin P-SPECT with radioguided SN biopsy in 101 T1/T2 BC pts to predict axillary lymph node status. The day before surgery all pts underwent lymphoscintigraphy (LS) to mark the SN, following subdermal injection of 99mTc-colloidal sulphur surrounding the breast lesion. LS was combined with pre and intraoperative gamma probe. Previously, all pts had also undergone P-SPECT. ALND was performed in all cases. The SN(s) was detected in 97/101 cases (96%) by LS and gamma probe; in the 4 missed cases P-SPECT predicted lymph node status. In the 97 comparable cases, radioguided SN biopsy showed a slightly higher accuracy than P-SPECT (94.8% vs 93.8%), but a higher false-negative rate (14.3% vs 8.6%); P-SPECT had a higher NPV (95.2% vs 92.5%). The two procedures when combined achieved 100% accuracy. Radioguided SN biopsy alone had 100% accuracy only in pts with BC < 15 mm. P-SPECT had 3 false negative cases, 2 of which were micrometastatic SNs, and 3 false positives. P-SPECT identified 81.2% of cases with a single node, determined the exact number of nodes in 82.6% of cases with 1 to 3 node and correctly classified 93.7% of pts as having < or = 3 or > 3 metastatic nodes. Radioguided SN biopsy seems indicated in selected, early stage, small BC pts, while P-SPECT shows a high sensitivity independent of primary tumor size, giving additional important preoperative prognostic information. The two procedures combined provided a better axillary lymph node status prediction in T1/T2 carcinomas, and could thus improve ALND pt selection.

(99)mTc-tetrofosmin SPET in the detection of both primary breast cancer and axillary lymph node metastasis

The aim of this study was to evaluate the usefulness of (99m)Tc-tetrofosmin single-photon emission tomography (SPET) in the detection of both primary breast cancer and axillary lymph node metastasis. We studied 192 consecutive patients in whom primary breast cancer was suspected on the basis of mammography and/or physical examination. After intravenous injection of 740 MBq (99m)Tc-tetrofosmin, both planar and SPET scintimammography was performed in all patients using a rectangular dual-head gamma camera equipped with low-energy, high-resolution, parallel-hole collimators. In 175 patients with breast cancer at histology, the per-lesion overall sensitivity of SPET and planar imaging for the detection of breast cancer was 95.8% and 75.9% (P<0.0005), respectively. The sensitivity of SPET and planar imaging was, respectively, 96.5% and 79.5% in palpable (P<0.0005) and 90% and 45% in non-palpable lesions (P<0.01). With regard to lesion size, the sensitivity of SPET and planar imaging was, respectively, 90.5% and 45.2% in lesions < or =10 mm ( P<0.0005), 95.3% and 81.4% in lesions of 11-20 mm (P<0.005), 100% and 84.6% in lesions of 21-30 mm (P<0.05) and 100% and 95.8% in lesions >30 mm (P>0.05). In the remaining 17 patients with benign mammary lesions at histology, per-lesion overall specificity of SPET and planar imaging was 76.2% and 85.7% (P>0.05), respectively. Neither SPET nor planar imaging showed false-positive results in non-palpable lesions or in those < or =10 mm. In 173 breast cancer patients submitted to axillary lymph node dissection (ALND), per-axilla overall sensitivity of SPET and planar imaging in the detection of axillary lymph node metastasis was 93% and 52.3% ( P<0.0005), respectively. The sensitivity of SPET and planar imaging was, respectively, 100% and 82.6% in palpable nodes (P>0.05), 90.5% and 41.3% in non-palpable nodes (P<0.0005), 92.8% and 35.7% in the presence of < or =3 nodes ( P<0.0005) and 93.2% and 68.2% in the presence of >3 nodes (P<0.005). The specificity of SPET and planar imaging was 91% and 100% (P<0.05), respectively. (99m)Tc-tetrofosmin SPET appears to be a reliable method for the detection of both primary BC and axillary lymph node metastasis, and its diagnostic accuracy exceeds that of (99m)Tc-tetrofosmin planar scintimammography. The use of SPET is particularly important in the identification of small non-palpable primary carcinomas and metastatic axillae with < or =3 non-palpable lymph nodes. More extensive use of SPET appears warranted in the management of breast cancer patients.

The role of 99mTc-tetrofosmin Pinhole-SPECT in breast cancer axillary lymph node staging

The number of metastatic axillary nodes represents one of the most important prognostic factors in preoperative breast cancer patients. 99mTc-Tetrofosmin high resolution Pinhole (P)-SPECT was employed in 112 patients, 100 with breast cancer and 12 with benign mammary lesions, to ascertain axillary lymph node involvement. Axillary P-SPECT images were acquired utilizing specific software connected to a circular high resolution, single-head gamma camera equipped with a pinhole collimator with aperture size of 4.45 mm, rotating 180 degrees around the involved axilla. At the same time, patients also underwent conventional SPECT and planar acquisitions. Per-patient sensitivity and specificity were 100% and 93.6% for P-SPECT, 96.2% and 93.6% for SPECT and 56.6% and 100% for planar imaging, respectively. Moreover, P-SPECT detected more than 51% of lesions ascertained by histology, whereas SPECT and planar detected 32.6% and 20.3%, respectively. Only P-SPECT succeeded in identifying the exact number of metastatic axillary lesions in patients with multiple nodes; this procedure was able to correctly differentiate 88.67% of patients with 3 or less nodes from those with more than 3, thus giving important prognostic information. These data suggest 99mTc-Tetrofosmin P-SPECT is a reliable imaging method both for staging and prognostic purposes in breast cancer, and its routine use is recommended.

Clinical and laboratory assessment of subclinical thyroid disease

The availability of highly sensitive in vitro tests for the determination of the free fractions of thyroid hormones (FT3 and FT4) and TSH have allowed the identification of latent thyroid disorders (subclinical hyper- and hypothyroidism) where the clinical signs are minor or absent. The TSH determination is the most sensitive in vitro test to define the thyroid function. FT3 is the most suitable for the correct diagnosis of subclinical hyperthyroidism, while FT4 is diagnostic for subclinical hypothyroidism. In patients with acute or chronic non thyroid disease or in case of assumption of drugs which interfere with in vitro diagnostic tests, the interpretation may be difficult.

[Liver resection with the water dissector; preliminary experience of 8 cases]

New methods for the resection of liver parenchyma was developed in order to simplify liver surgery. The object of our study was to test a method using the water dissector, a rather new equipment. Eight patients, four men end four women, have been operated, from March to September 1997, using the water dissector. Age of the patients ranged from 42 to 83 years (mean age 67 years). Indication for surgery was liver metastasis from colon cancer (6 patients), and gallbladder cancer (2 patients). 1 right lobectomy, 1 left side segmentectomy, 2 V and IV segments resection, 1 unitectomy of the VII segment and 2 III and IV segment resections was performed. In the first four patients we used the Pringle manoeuvre (clamping of the liver stalk), while we did not do it in the last four so we could compare both the operation time and the loss of blood with or without this manoeuvre. One patient died of ARDS in the seventh post-operative day, another patient, who underwent a right lobectomy, developed a biliary fistula which healed in the 10 degrees postoperative day. All the seven surviving patients was in good health, with normal liver ultrasonography when checked on the 31/12/1997. Our results show that the water dissector offers the possibility to isolate vascular stalks very easily, both with a posterior ilar approach and with an intraparenchymal approach, making possible a very accurate haemostasis, in such minimizing blood and biliary losses. This method allows the performing of oncologically correct dissections and in the meanwhile the saving of as much healthy parenchyma as possible.

[Preoperative radiotherapy in cancer of the rectum. Our 5-year experience]

Since 1990, 41 patients with rectal carcinoma have been submitted to preoperative radiotherapy, which induced a shrinkage of the tumor, favouring its surgical resection. Besides, in 3 cases the operative specimens were tumor free, and a higher incidence of A and B 1 categories was found. Surgical results have been compared with an analogous group of 20 patients, where surgery was performed as a first procedure, then followed by radiotherapy in 9. No increase of postoperative complications was observed. While analysis of follow-up results demonstrates a decrease of tumour recurrence in patients with preoperative radiotherapy, no difference in survival was registered, because of the development of extra-pelvic metastases.

[Association of cervico-uterine carcinoma and other extra-uterine primary neoplasms. Observations on 31 cases]

Out of 874 patients undergoing radiotherapy for carcinoma of the uterine cervix, 31 cases (3.5%) of second primary malignant tumour in another site were encountered. Half the cases preceded and half followed uterine cancer. The data are analysed and discussed.