The evidence-based role of catecholaminergic PET tracers in Neuroblastoma. A systematic review and a head-to-head comparison with mIBG scintigraphy.

BACKGROUND: Molecular imaging is pivotal in staging and response assessment of children with neuroblastoma (NB). [123I]-metaiodobenzylguanidine (mIBG) is the standard imaging method; however, it is characterised by low spatial resolution, time-consuming acquisition procedures and difficult interpretation. Many PET catecholaminergic radiotracers have been proposed as a replacement for [123I]-mIBG, however they have not yet made it into clinical practice. We aimed to review the available literature comparing head-to-head [123I]-mIBG with the most common PET catecholaminergic radiopharmaceuticals. METHODS: We searched the PubMed database for studies performing a head-to-head comparison between [123I]-mIBG and PET radiopharmaceuticals including meta-hydroxyephedrine ([11C]C-HED), 18F-18F-3,4-dihydroxyphenylalanine ([18F]DOPA) [124I]mIBG and Meta-[18F]fluorobenzylguanidine ([18F]mFBG). Review articles, preclinical studies, small case series (< 5 subjects), case reports, and articles not in English were excluded. From each study, the following characteristics were extracted: bibliographic information, technical parameters, and the sensitivity of the procedure according to a patient-based analysis (PBA) and a lesion-based analysis (LBA). RESULTS: Ten studies were selected: two regarding [11C]C-HED, four [18F]DOPA, one [124I]mIBG, and three [18F]mFBG. These studies included 181 patients (range 5-46). For the PBA, the superiority of the PET method was reported in two out of ten studies (both using [18F]DOPA). For LBA, PET detected significantly more lesions than scintigraphy in seven out of ten studies. CONCLUSIONS: PET/CT using catecholaminergic tracers shows superior diagnostic performance than mIBG scintigraphy. However, it is still unknown if such superiority can influence clinical decision-making. Nonetheless, the PET examination appears promising for clinical practice as it offers faster image acquisition, less need for sedation, and a single-day examination.

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.

[Differentiated thyroid carcinoma in children: study of 80 cases]. / Carcinoma diferenciado de tiroides en niños: estudio de 80 casos.

BACKGROUND AND OBJECTIVE: The objective was to analyze the clinical profile of Differentiated Thyroid Carcinoma in children (DTC) and the predisposing factors to suffering the disease. MATERIAL AND METHOD: Eighty children with DTC were studied retrospectively. They all underwent total/near total thyroidectomy and 75 cases underwent ablative iodine therapy. Patients were controlled periodically with clinical, laboratory and imaging tests follow-up. RESULTS: Twenty eight patients were male and 52 female (mean age: 13.43+/-3.6 y). The 87.5% of patients had an increased cervical perimeter as the first clinical symptom, 65% of them corresponding to a thyroid nodule with a predominance of females. The papillary histological pattern was more frequent than the follicular pattern, and it was associated with the presence of lymph involvement and metastasis. About 56.4% of patients showed advanced disease at the time of diagnosis. 9 patients had previous irradiation. Surgical complications appeared in 32.5% of patients. At the end of follow-up (mean: 10.79+/-5.69 y) 9 patients had persistent disease with a significant relation with stage 4. CONCLUSIONS: DTC presents a higher incidence in females than in males. Cervical node is the most frequent form of initial presentation. The papillary type is more prevalent than the follicular type, and it is frequently associated with lymph node involvement and metastatic spread.

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.

[Differential diagnosis of parkinsonism using dopamine transporters brain SPECT]. / Contribución de la SPECT cerebral de transportadores de dopamina en el diagnóstico diferencial de los parkinsonismos.

BACKGROUND AND OBJECTIVE: Parkinsonism is a group of neurological disorders characterized by extrapiramidal signs. Often, the differential diagnosis between parkinsonism, essential tremor and drug-induced parkinsonism is difficult. The aim of the study was to evaluate the utility of (123I)-FP-CIT SPECT in patients with movement disorders. PATIENTS AND METHOD: 52 patients were referred from the neurology department to characterize those with parkinsonism. Patients were clinically evaluated and those with Parkinson's disease were assessed using the rating scale Hoehn & Yahr and the UPDRS motor score. Subsequently, a (123I)-FP-CIT SPECT was performed with a qualitative analysis. RESULTS: All patients with essential tremor and drug-induced parkinsonism had a normal SPECT. All patients with parkinsonism displayed SPECT defects, except for four who had a normal SPECT result. Two of them were categorized as vascular parkinsonisms, one patient had a Shy-Drager's syndrome and the another one had probably a Parkinson's disease. The sensitivity and specificity were 90.47% (38/42; CI95%, 81.59%-99.35%) and 100% (10/10; CI95%, 69.15%-100%), respectively. CONCLUSIONS: (123I)-FP-CIT SPECT is an effective tool to study the integrity of the dopaminergic nigrostriatal system. Moreover, it permits to characterize the different types of parkinsonism.