Carlos Martínez-Duncker

Combined use of fine-needle aspiration biopsy, MIBI scans and frozen section biopsy offers the best diagnostic accuracy in the assessment of the hypofunctioning solitary thyroid nodule

PurposeThe probability of malignancy is increased in hypofunctioning solitary thyroid nodules (HFNs). Fine-needle aspiration biopsy (FNA), 99mTc-methoxyisobutylisonitrile (MIBI) and frozen section biopsy (FS) have limited independent diagnostic accuracy for the differential diagnosis of HFNs. The goal of this study was to assess the accuracy of the three independent diagnostic methods in distinguishing between benign and malignant disease.MethodsA total of 130 patients with an HFN on the 99mTc-pertechnetate scan were included in this study. FNA, MIBI scans, FS, thyroidectomy and histological analysis of surgical specimens for final diagnosis were performed in all patients.ResultsOf the 130 patients, 80 (61.54%) had benign lesions and 50 (38.46%), malignant lesions. FNA was diagnostic in 78/130 (60%) patients and non-diagnostic in 52/130 (40%) patients. None of the patients with a negative MIBI scan had a final histological diagnosis of malignancy, and MIBI scans were negative in 38.46% of patients with non-diagnostic FNA results. FS was diagnostic in 104/130 (80%) patients and non-diagnostic in 26/130 (20%) patients. Sensitivity, specificity, positive and negative predictive values and positive and negative likelihood ratios were 81.3%, 97.8%, 96%, 88%, 36.95 and 0.19 respectively for FNA; 100%, 61.3%, 61.7%, 100%, 2.58 and 0 respectively for MIBI; and 80.5%, 100%, 100%, 89%, 0 and 0.2 respectively for FS. Use of both MIBI scans and FS in patients with non-diagnostic FNA rendered a specificity and sensitivity of 100%.ConclusionMIBI scans exclude malignancy in a significant proportion of patients with non-diagnostic FNAs (38% in this study). Cystic nodules with a positive MIBI scan should be further investigated even when the FNA result indicates a benign lesion. Combined use of FNA, MIBI and FS offers the best diagnostic accuracy.

Assessment of anthracycline-induced myocardial damage by quantitative indium 111 myosin-specific monoclonal antibody studies

To assess chemotherapeutically induced myocardial damage, myosin-specific antibody scans and ejection fraction measurements were performed in 32 patients with breast cancer and in 9 patients with other tumours. All patients had received chemotherapy including anthracyclines. The ejection fraction decreased by ≥ 10% in 14 of 41 (34%) patients after chemotherapy. Antimyosin uptake in the myocardium was observed in 38 of 41 (92%) patients after chemotherapy. Antimyosin uptake was quantified by means of a heart-to-lung ratio, revealing a correlation between the degree of antimyosin uptake in the myocardium and the cumulative dose of anthracycline. Patients with a decreased ejection fraction showed more intense antimyosin uptake, indicating more severe myocardial damage. A higher degree of antimyosin uptake was found in 17 breast cancer patients treated with doxorubicin compared with 15 patients treated with mitoxantrone. We conclude that antimyosin studies provide a sensitive, non-invasive method to monitor myocardial damage in patients treated with anthracyclines. Antimyosin uptake in the myocardium precedes ejection fraction deterioration. This technique may be helpful in the early identification of patients at risk of congestive heart failure during chemotherapy including anthracyclines.

Transient alterations in cardiac performance after a six-hour race☆

Ten long distance runners were enrolled in a 6-hour competitive race. Immediately after the race technetium-99m-albumin gated blood pool scans were performed and indium-111 antimyosin was injected. Forty-eight hours later antimyosin scans were obtained and control gated blood pool scans were performed. Left ventricular ejection fraction was higher after the race (65 +/- 5 vs 60 +/- 7%, p less than 0.01) due to a decrease in end-systolic counts. Right ventricular ejection fraction was lower after the race (42 +/- 7 vs 54 +/- 12%, p = 0.03) due to an increase in both end-diastolic and end-systolic counts. A longer systolic period was observed after the race (53 +/- 5% of the RR interval vs 39 +/- 3%, p = 0.005). No significant differences were observed in peak filling or peak emptying rates after the race. An increase in pulmonary blood volume (116% of control) was observed after the race. Antimyosin scans were normal in 7 athletes and minimal antimyosin myocardial uptake was seen in 3. Transient alterations in biventricular performance present after the race correspond to function adaptation to strenuous exercise and are not due to irreversible myocyte damage.

Negative MIBI thyroid scans exclude differentiated and medullary thyroid cancer in 100% of patients with hypofunctioning thyroid nodules

Dear Sir, Thyroid nodules are a common clinical problem. There is a need to distinguish effectively between malignant and benign nodules in order to avoid expensive evaluation and treatment of patients with benign thyroid disease as well as to ensure appropriate and timely management of patients with thyroid cancer. Most thyroid cancer patients have differentiated thyroid cancer (DTC) or medullary thyroid cancer. Since clinical examination provides limited information on the benign or malignant nature of the hypofunctioning thyroid nodule (HTN), other methods such as fine-needle aspiration biopsy, intra-operative frozen section biopsy, ultrasound (US) and nuclear medicine scans, alone or in combination (i.e. I or I or Tc scans combined with either Tl or Tc-methoxyisobutylisonitrile or Tc-tetrofosmin), have been used to obtain further diagnostic information relevant to therapeutic management. Fine-needle aspiration biopsy (FNAB) does not give a definitive diagnosis in between 10% and 42% of thyroid nodules (indeterminate results), with reports such as follicular lesion, suspicious Hürthle cell proliferation, suspicious follicular cell proliferation, Hürthle cell tumour, absence of epithelial cells in the case of cystic lesions and adequate sample in terms of quantity and quality with limited cytological characteristics [1–3]. About 25% of patients with HTN studied only with FNAB end up in the operating room in order to obtain a diagnosis [4]. US has also been used to differentiate benign from malignant thyroid disease, looking at size, echogenicity, echo structure, border shape and presence of calcifications in the thyroid nodules, as well as patterns of vascularity with power Doppler and vascular patterns, resistive index and maximal systolic velocity with spectral Doppler US; however, none of these features are pathognomonic of thyroid cancer, even in patients with atypical cell cytology or follicular neoplasm cytology [5–8]. Tc-methoxyisobutylisonitrile (MIBI) scans of the thyroid have been studied by several groups searching for differences between benign and malignant HTNs. Both semiquantitative methods (i.e. index calculation, washout rate calculation, uptake differences between early and late images, etc.) and visual methods have been used to assess the HTN. However, the published information conveys the general idea that MIBI scans for evaluation of the HTN are not sufficient for definitive preoperative differentiation between benign thyroid disease and thyroid cancer [9–21]. We have previously reported [17] that MIBI uptake within the HTN should be visually read as either absent (no uptake, uptake similar to that of Tc-pertechnetate) or present (uptake present, and higher than Tc-pertechnetate uptake). In the first case the MIBI scan should be interpreted as a “negative MIBI study”, while in the second case, when MIBI uptake can be visually detected within the thyroid nodule, the scan should be interpreted as a “positive MIBI study”. A “negative MIBI study” always indicates that the HTN is benign, while a “positive MIBI study” is non-specific, meaning that the HTN may be benign or malignant and further study is mandatory. Eur J Nucl Med Mol Imaging (2007) 34:1701–1703 DOI 10.1007/s00259-007-0490-6

Towards In Vivo Imaging of Cancer Sialylation

In vivo assessment of tumor glucose catabolism by positron emission tomography (PET) has become a highly valued study in the medical management of cancer. Emerging technologies offer the potential to evaluate in vivo another aspect of cancer carbohydrate metabolism related to the increased anabolic use of monosaccharides like sialic acid (Sia). Sia is used for the synthesis of sialylated oligosaccharides in the cell surface that in cancer cells are overexpressed and positively associated to malignancy and worse prognosis because of their role in invasion and metastasis. This paper addresses the key points of the different strategies that have been developed to image Sia expression in vivo and the perspectives to translate it from the bench to the bedside where it would offer the clinician highly valued complementary information on cancer carbohydrate metabolism that is currently unavailable in vivo.