Mattia Squarcia

Update in thyroid imaging. The expanding world of thyroid imaging and its translation to clinical practice

Servicio de Endocrinologίa, Hospital Clίnico Universitario de Valladolid, Centro de Investigaciόn en Endocrinologίa y Nutriciόn Clίnica (IEN), Valladolid, Servei d’Endocrinologia, Servei Radiodiagnostic, Centre diagnostic per la imatge (CDI), Servei de Medicina Nuclear, Centre diagnostic per la imatge (CDI) Hospital Clίnic, Universitat de Barcelona, Barcelona, Spain Review HORMONES 2010, 9(4):287-298

The Truncated Isoform of Somatostatin Receptor5 (sst5TMD4) Is Associated with Poorly Differentiated Thyroid Cancer

Somatostatin receptors (ssts) are expressed in thyroid cancer cells, but their biological significance is not well understood. The aim of this study was to assess ssts in well differentiated (WDTC) and poorly differentiated thyroid cancer (PDTC) by means of imaging and molecular tools and its relationship with the efficacy of somatostatin analog treatment. Thirty-nine cases of thyroid carcinoma were evaluated (20 PDTC and 19 WDTC). Depreotide scintigraphy and mRNA levels of sst-subtypes, including the truncated variant sst5TMD4, were carried out. Depreotide scans were positive in the recurrent tumor in the neck in 6 of 11 (54%) PDTC, and in those with lung metastases in 5/11 cases (45.4%); sst5TMD4 was present in 18/20 (90%) of PDTC, being the most densely expressed sst-subtype, with a 20-fold increase in relation to sst2. In WDTC, sst2 was the most represented, while sst5TMD4 was not found; sst2 was significantly increased in PDTC in comparison to WDTC. Five depreotide positive PDTC received octreotide for 3–6 months in a pilot study with no changes in the size of the lesions in 3 of them, and a significant increase in the pulmonary and cervical lesions in the other 2. All PDTC patients treated with octreotide showed high expression of sst5TMD4. ROC curve analysis demonstrated that only sst5TMD4 discriminates between PDTC and WDTC. We conclude that sst5TMD4 is overexpressed in PDTC and may be involved in the lack of response to somatostatin analogue treatment.

Broadband time-resolved diffuse optical spectrometer for clinical diagnostics: characterization and in-vivo measurements in the 600-1350 nm spectral range

We report on the design, performance assessment, and first in vivo measurement of a Time-Resolved Diffuse Optical system for broadband (600-1350 nm) nm measurement of absorption and scattering spectra of biological tissues for non-invasive clinical diagnostics. Two strategies to reduce drift and enhance responsivity are adopted. The system was enrolled in a first in vivo test phase on healthy volunteers, carrying out non-invasive, in vivo quantification of key tissue constituents (oxy- and deoxy-hemoglobin, water, lipids, collagen) and tissue micro-structure (scatterer size and density).

Diffuse Optical Characterization of the Healthy Human Thyroid Tissue and Two Pathological Case Studies

The in vivo optical and hemodynamic properties of the healthy (n = 22) and pathological (n = 2) human thyroid tissue were measured non-invasively using a custom time-resolved spectroscopy (TRS) and diffuse correlation spectroscopy (DCS) system. Medical ultrasound was used to guide the placement of the hand-held hybrid optical probe. TRS measured the absorption and reduced scattering coefficients (μa, μs′) at three wavelengths (690, 785 and 830 nm) to derive total hemoglobin concentration (THC) and oxygen saturation (StO2). DCS measured the microvascular blood flow index (BFI). Their dependencies on physiological and clinical parameters and positions along the thyroid were investigated and compared to the surrounding sternocleidomastoid muscle. The THC in the thyroid ranged from 131.9 μM to 144.8 μM, showing a 25–44% increase compared to the surrounding sternocleidomastoid muscle tissue. The blood flow was significantly higher in the thyroid (BFIthyroid = 16.0 × 10-9 cm2/s) compared to the muscle (BFImuscle = 7.8 × 10-9 cm2/s), while StO2 showed a small (StO2, muscle = 63.8% to StO2, thyroid = 68.4%), yet significant difference. Two case studies with thyroid nodules underwent the same measurement protocol prior to thyroidectomy. Their THC and BFI reached values around 226.5 μM and 62.8 × 10-9 cm2/s respectively showing a clear contrast to the nodule-free thyroid tissue as well as the general population. The initial characterization of the healthy and pathologic human thyroid tissue lays the ground work for the future investigation on the use of diffuse optics in thyroid cancer screening.

Thyroid tissue constituents characterization and application to in vivo studies by broadband (600-1200 nm) diffuse optical spectroscopy

We present the first broadband (600-1100 nm) diffuse optical characterization of thyroglobulin and tyrosine, which are thyroid-specific tissue constituents. In-vivo measurements at the thyroid region enabled their quantification for functional and diagnostic applications.

Primary adrenal insufficiency due to hereditary apolipoprotein AI amyloidosis: endocrine involvement beyond hypogonadism

Abstract Several mutations in the gene encoding apolipoprotein AI (apoAI) have been described as a cause of familial amyloidosis. Individuals with apoAI-derived (AApoAI) amyloidosis frequently manifest with liver, kidney, laryngeal, skin and myocardial involvement. Although primary hypogonadism (PH) is considered almost pathognomonic of this disease, until now, primary adrenal insufficiency (PAI) has not been described as a common clinical feature. Here, we report the first kindred with AApoAI amyloidosis in which PAI is well-documented. All family members with the Leu60_Phe71delins60Val_61Thr heterozygous mutation who were regularly followed-up at our centre were considered. Nineteen individuals had the confirmed APOA1 deletion/insertion mutation, with detailed medical records available in 11 cases. Of these, 6 had PAI and 3 (all males) had PH. Among them, one 47-year-old man, not previously diagnosed with PAI, developed adrenal crisis after liver transplantation, precipitated by an opportunistic infection. Transplantation due to organ failure, which necessitates use of immunosuppressive medication such as corticosteroids, is frequently required during the course of hereditary amyloidosis. Consequently, PAI can remain masked, being discovered only when an adrenal crisis develops. Therefore, according to the present evidence, patients with AApoAI amyloidosis should be submitted to regular testing of corticotrophin and cortisol levels in order to avoid delaying corticosteroid replacement.