Impact of the new ultra-high sensitivity mode in a long axial field-of-view PET/CT.

OBJECTIVE: Long axial field-of-view (LAFOV) PET/CT showed improved performance resulting from higher sensitivity. The aim was to quantify the impact of using the full acceptance angle (UHS) in image reconstructions with the Biograph Vision Quadra LAFOV PET/CT (Siemens Healthineers) compared to the limited acceptance angle (high sensitivity mode, HS). METHODS: 38 oncological patients examined on a LAFOV Biograph Vision Quadra PET/CT were analysed. 15 patients underwent [18F]FDG-PET/CT, 15 patients underwent [18F]PSMA-1007 PET/CT, and 8 patients underwent [68Ga]Ga-DOTA-TOC PET/CT. Signal-to-noise ratio (SNR) and standardised uptake values (SUVmean/max/peak) were used to compare UHS and HS with different acquisition times. RESULTS: The SNR was significantly higher for UHS compared to HS over all acquisition times (SNR UHS/HS [18F]FDG: 1.35 ± 0.02, p < 0.001; [18F]PSMA-1007: 1.25 ± 0.02, p < 0.001; [68Ga]Ga-DOTA-TOC: 1.29 ± 0.02, p < 0.001). CONCLUSION: UHS showed significantly higher SNR opening the possibility of halving short acquisition times. This is of advantage in further reduction of whole-body PET/CT acquisition.

The Impact of Rapid On-Site Evaluation on the Quality and Diagnostic Value of Thyroid Nodule Fine-Needle Aspirations.

Background: Ultrasound-guided fine-needle aspiration (FNA) is the preferred method to evaluate the dignity of thyroid nodules. Nevertheless, the often-reported high nondiagnostic rate burdens affected patients and the health care system. Rapid on-site evaluation (ROSE) constitutes an addition to the thyroid FNA procedure, with various studies showing its beneficial effect on the Bethesda I nondiagnostic rate. We aimed to assess whether ROSE may reduce the rate of Bethesda categories III and V. Additionally, we examined the influence of ROSE on specimen quality. Methods: We performed a retrospective cohort study, comparing Bethesda categorization and specimen quality in specimens subject to ROSE compared with those not subject to ROSE. We also evaluated aspects of specimen quality that differed according to the use of ROSE. We subcategorized Bethesda I into insufficient cellularity or artifacts, and Bethesda categories III and V into cellular without artifacts, sparsely cellular, or artifacts. Results: We evaluated 5030 thyroid FNAs. ROSE was performed in 1304 (25.9%) cases, and ROSE was not utilized for 3726 (74.1%) specimens. The rate of Bethesda I nondiagnostic and Bethesda III categories was reduced in specimens subject to ROSE (4.3%, 56/1304) compared with non-ROSE (39.9%, 1487/3726, p < 0.001). The rate of both benign Bethesda II and malignant Bethesda VI diagnoses was 91.6% (1194/1270) in ROSE specimens compared with 56.6% (1999/3530) in non-ROSE (p < 0.001). This was reflected by a significant improvement in diagnostic accuracy with ROSE (areas under the curve [AUC]non-ROSE = 0.811, AUCROSE = 0.895, p = 0.004). The overall rate of specimens flawed by sparse cellularity in Bethesda categories III and V was 0.1% (1/1304) in ROSE specimens compared with 1.2% (45/3726) in non-ROSE (p < 0.001). The overall artifact rate was 0.3% (4/1304) for ROSE specimens and 2.5% (92/3726) for non-ROSE (p < 0.001). Conclusions: ROSE significantly increased diagnostic accuracy by improving FNA specimens quantitatively and qualitatively. We suggest considering ROSE as standard of care for thyroid FNAs.

Lenvatinib in Advanced Radioiodine-Refractory Thyroid Cancer - A Retrospective Analysis of the Swiss Lenvatinib Named Patient Program.

Purpose: Differentiated thyroid cancer (DTC) accounts for approximately 95% of thyroid carcinomas. In the metastatic RAI-refractory disease, chemotherapy has very limited efficacy and is associated with substantial toxicity. With increasing knowledge of the molecular pathogenesis of DTC, novel targeted therapies have been developed. Lenvatinib is a tyrosine kinase inhibitor (TKI) with promising clinical activity based on the randomized phase III SELECT trial. In Switzerland, a Named Patient Program (NPP) was installed to bridge the time gap to Swissmedic approval. Here, we report the results from the Swiss Lenvatinib NPP including patients with metastatic RAI-refractory DTC. Methods: Main inclusion criteria for the Swiss NPP were RAI-refractory DTC, documented disease progression, Eastern Cooperative Oncology Group (ECOG) performance status 0-3. The number of previous therapies was not limited. The Swiss Lenvatinib NPP was initiated in June 2014 and was closed in October 2015 with the approval of the drug. Results: Between June 2014 and October 2015, 13 patients with a median age of 72 years have been enrolled. Most patients (69%) had at least one prior systemic therapy, mainly sorafenib. 31% of patients showed a PR and 31% SD. Median progression free survival was 7.2 months and the median overall survival was 22.7 months. Dose reduction due to adverse events was necessary in 7 patients (53%). At the time of analysis 6 patients (47%) were still on treatment with a median time on treatment of 9.98 months. Conclusions: Our results show that lenvatinib has reasonable clinical activity in unselected patients with RAI-refractory thyroid cancer with nearly two-third of patients showing clinical benefit. The toxicity profile of lenvatinib is manageable.

18F-FDG PET/CT of Papillary Carcinoma in a Lateral Thyroglossal Duct Cyst.

A 69-year-old man presented with bulging of the right oropharyngeal wall, which revealed cytopathologically malignant cells. The man underwent MRI and F-FDG PET/CT, which demonstrated a cystic parapharyngeal lesion with an F-FDG-avid soft tissue component and right cervical lymph node. The patient was operated on and showed thyroid cancer in normal thyroid tissue, compatible with a papillary thyroid carcinoma in a lateral thyroglossal duct cyst and 2 ipsilateral lymph node metastases. Despite its rarity, papillary thyroid carcinoma in a thyroglossal duct cyst should be kept as one of the differential diagnoses in patients presenting with parapharyngeal cystic lesion.

Technical Note: Determination of individual thyroid clearance effective half-life with a common handheld electronic dosimeter.

PURPOSE: To determine the thyroid clearance effective half-life T with a common handheld electronic dosimeter (ED) in patients undergoing radioiodine treatment for hyperthyroidism. METHODS: Dose rates from 12 inpatients were measured daily with an ED and with a clinical uptake counter. The ED was attached to the patient with two different setups, one using a cervical collar and another employing a neck strap. Estimation of T was performed by linear regression analysis of the log of both the ED and the uptake counter measurements versus time. The latter provided the reference data. RESULTS: Based on repeated neck strap dose rate measurements, individual Ts were determined with clinically required accuracy. The mean difference from the reference method equaled to -0.09 ± 0.35 days. CONCLUSIONS: Determination of individual T is feasible with a common handheld ED using the simple and easy to instruct neck strap measurement setup. This simple method complements stationary uptake counter measurements and thus may improve the accuracy of radioiodine treatment planning by adding an individual T for dose calculation.

Laryngeal and hypopharyngeal carcinomas after (chemo)radiotherapy: a diagnostic dilemma.

PURPOSE OF REVIEW: During recent years, (chemo)radiotherapy has evolved into a primary treatment modality for both early and advanced laryngeal and hypopharyngeal carcinomas. Head and neck surgeons will be concerned more frequently with patients presenting symptoms and signs suggesting recurrent tumor or complications of (chemo)radiotherapy. RECENT FINDINGS: Analysis of histologic characteristics and tumor spread of recurrent carcinomas on whole-organ slices of salvage laryngectomy specimens showed that recurrent laryngeal carcinomas are often present with multiple tumor foci dispersed in different regions; furthermore, they may develop beneath an intact mucosa. Only a few articles analyze the reliability of laryngoscopy and biopsy in detecting recurrences after (chemo)radiotherapy: the number of false negative biopsies is relatively high. The differentiation between radionecrosis and tumor recurrence is difficult by computed tomography scan and magnetic resonance imaging in many cases. Positron emission tomography-computed tomography and diffusion-weighted magnetic resonance imaging are promising diagnostic modalities to detect or exclude persistent or recurrent disease after (chemo)radiotherapy. SUMMARY: Endoscopy with biopsy, computed tomography scan and conventional magnetic resonance imaging present several deficiencies in diagnosing recurrent disease after (chemo)radiotherapy. New imaging modalities such as positron emission tomography-computed tomography and diffusion-weighted magnetic resonance imaging show promising results, increasing the diagnostic efficacy.