Longitudinal analysis of chest Q-SPECT/CT in patients with severe COVID-19.

INTRODUCTION: Patients with COVID-19 have an increased risk for microvascular lung thrombosis. In order to evaluate the type and prevalence of perfusion defects, we performed a longitudinal analysis of combined perfusion single-photon emission and low-dose computed tomography (Q-SPECT/CT scan) in patients with COVID-19 pneumonia. METHODS: Consecutive patients with severe COVID-19 (B.1.1.7 variant SARS-CoV-2) and respiratory insufficiency underwent chest Q-SPECT/CT during hospitalization, and 3 months after discharge. At follow-up (FU), Q-SPECT/CT were analyzed and compared with pulmonary function tests (PFT), blood analysis (CRP, D-dimers, ferritin), modified Medical Research Council (mMRC) dyspnea scale, and high-resolution CT scans (HRCT). Patients with one or more segmental perfusion defects outside the area of inflammation (PDOI) were treated with anticoagulation until FU. RESULTS: At baseline, PDOI were found in 50 of 105 patients (47.6 %). At FU, Q-SPECT/CT scans had improved significantly (p < 0.001) and PDOI were recorded in 14 of 77 (18.2 %) patients. There was a significant correlation between mMRC score and the number of segmental perfusion defects (r = 0.511, p < 0.001), and a weaker correlation with DLCO (r = -0.333, p = 0.002) and KCO (r = -0.373, p = 0.001) at FU. Neither corticosteroid therapy nor HRCT results showed an influence on Q-SPECT/CT changes (p = 0.94, p = 0.74). CRP, D-Dimers and ferritin improved but did not show any association with the FU Q-SPECT/CT results (p = 0.08). CONCLUSION: Segmental mismatched perfusion defects are common in severe COVID-19 and are correlated with the degree of dyspnea. Longitudinal analyses of Q-SPECT/CT scans in severe COVID-19 may help understand possible mechanisms of long COVID and prolonged dyspnea.

Asymptomatic deep vein thromboses in prolonged hospitalized COVID-19 patients.

High incidence of venous thromboembolic (VTE) events in coronavirus disease 2019 (COVID-19) patients has been reported despite pharmacologic thromboprophylaxis. We performed prospective bilateral lower extremity ultrasound evaluation of prolonged hospitalized COVID-19 ward patients from our institution without clinical suspicion of deep vein thrombosis (DVT).A total of 102 patient were included in the study. All patients were receiving pharmacologic thromboprophylaxis, the majority in intermediate or therapeutic doses. Asymptomatic DVT was detected in 26/102 (25.5%) patients: 22 had distal and four had proximal DVT, six had bilateral leg involvement. Pulmonary embolism was highly prevalent (17/70, 24.3%) but similarly grouped among patients with and without asymptomatic DVT. In total 37.2% of patients included in the study were recognized as having VTE.Asymptomatic DVT events were more common in intensive care unit (ICU) survivors (60% in postmechanically ventilated ICU survivors, 21.2% in ward patients, 22% in high-flow oxygen treated patients; P = 0.031), in patients with higher modified International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) VTE risk-score (median 3 vs. 2 points with and without DVT; P = 0.021) and higher body temperature on admission (median 38.7 °C vs. 37.7 °C with and without DVT; P = 0.001). No clear associations with Padua VTE risk score, demographic and other clinical characteristics, intensity of thromboprophylaxis, severity of other COVID-19 symptoms, degree of systemic inflammation or D­dimers on admission were found (P > 0.05 for all analyses).Systematic ultrasound assessment in prolonged hospitalized severe COVID-19 patients prior to hospital discharge is needed, especially in ICU survivors, to timely recognize and appropriately treat patients with asymptomatic DVT.

The value of 18F-DOPA PET/CT in patients with medullary thyroid carcinoma and increased calcitonin values.

AIM: The aim of this prospective observational study was to examine the benefit of a fluorine-18-L-dihydroxyphenylalanine (F-DOPA) PET/computed tomography (CT) scan in patients with medullary thyroid carcinoma (MTC) in terms of increased calcitonin levels. PATIENTS AND METHODS: Twenty-eight MTC patients after initial total thyreoidectomy with increasing follow-up calcitonin levels suggestive for active disease after negative conventional imaging findings (neck ultrasound or thorax, abdomen, pelvis multislice computed tomography as standard imaging) were scanned using F-DOPA PET/CT from November 2012 to April 2016. The mean calcitonin level was 108.5 (range: 6.7-290) pmol/l and the mean carcinoembryonic antigen level was 15.7 (range: 1.1-221.9) µg/l. The mean follow-up period was 19.7 months. RESULTS: F-DOPA PET/CT was positive in 16 out of 28 (57%) patients, mostly because of metabolically active neck and mediastinal lymph nodes metastases. Previously unknown bone metastases were found in six patients. A positive scan was reported in four patients (25% of positive scans) with a very low calcitonin value of less than 49.9 pmol/l. PET/CT findings led to a change of management and therapy in 16 out of 28 patients, with surgical procedure performed in eight patients, radiotherapy in five patients, and chemotherapy in two patients. CONCLUSION: F-DOPA PET/CT is a clinically useful modality in MTC whenever the calcitonin level is increased. There is a clear trend toward more positive scans with the higher calcitonin values, but patients with moderately elevated calcitonin values should also be taken into consideration for molecular imaging with F-DOPA PET/CT as the tumor burden in these patients is probably low, enabling further therapy to be individualized and consequently more efficient.

The nonspecific lymph node uptake of 18F-choline in patients with prostate cancer--a prospective observational study.

BACKGROUND: The aim of this study was to observe and characterize the nonspecific ¹8F-choline lymph node uptake in patients with prostate cancer. MATERIAL AND METHODS: In this single center, prospective observational study which was done in University Hospital Center Zagreb between December 2012 and October 2014, 69 patients (median age 71 years; range 50-92) with prostate cancer were included. Patients underwent ¹8F-choline PET/CT for staging or restaging of prostate cancer. The mean follow-up period was 11.5 months. Kruskal-Wallis test was used to find out if the differences between SUV values of specific and nonspecific accumulation of the tracer are statistically significant. RESULTS: Nonspecific accumulation of ¹8F-choline in lymph nodes was found in 36 patients (52.7%). Most of these findings (n = 24) were nonspecific accumulation of the tracer in mediastinal lymph nodes. Other sites of nonspecific tracer uptake were pulmonary hila (n = 20), inguinal lymph nodes (n = 15), and axillary lymph nodes (n = 10). Mean SUV values for mediastinal lymph nodes, pulmonary hila, axillary and inguinal lymph nodes were 4.8, 4.3, 3.1 and 4.1, respectively. Mean SUV value of nonspecific sites of tracer accumulation was lower (not significantly; (p = 0.2) than tracer uptake values measured in metastases sites (bone metastases mean SUVmax value - 13.2, metastatic lymph nodes mean SUVmax value - 9.2). CONCLUSIONS: ¹8F-choline PET/CT is a valuable and an established functional diagnostic imaging method for staging and restaging prostate cancer. However, nonspecific uptake of the tracer can often be seen in lymph nodes not related to primary disease. Patient history, clinical examination, laboratory tests and correlation with other imaging methods, must be taken into consideration when interpreting ¹8F-choline PET/CT findings.

Reliability of sentinel node assay in vulvar cancer: the first Croatian validation trial.

OBJECTIVE: To evaluate the reliability of sentinel node assay in early stage vulvar cancer patients by using preoperative lymphoscintigraphy. METHODS: Technetium-99m colloid albumin was injected intradermally around the tumor for lymphoscintigraphic mapping and intraoperative hand-held gamma probe detection of sentinel nodes. For all patients, sentinel node biopsy was followed by inguinofemoral lymphadenectomy, regardless of the sentinel lymph node status. RESULTS: From December 2008 until May 2011, 25 consecutive patients with T1 or T2 stage of vulvar squamous cell cancer were enrolled. The median age of patients was 69 years (range, 48-79). The detection of sentinel lymph node was successful in all 25 patients. A total of 36 sentinel lymph nodes were harvested and metastatic carcinoma was identified in 12 sentinel nodes from 8 patients. There was 1 patient with metastatic non-sentinel lymph node despite the negative sentinel node. Two patients with negative sentinel nodes proven by routine histopathological examination were positive by immunohistochemical staining. The sensitivity, specificity and negative predictive value of sentinel node assay with immunohistochemistry included were 89%, 100%, and 94%, respectively. CONCLUSIONS: Lymphoscintigraphy and sentinel lymph node biopsy under gamma-detecting probe guidance proved to be an easy and reliable method for the detection of sentinel node in early vulvar cancer. Immunohistochemical analysis improves the sensitivity for the detection of regional micrometastases. The sentinel node assay is highly accurate in predicting the status of the remaining inguinofemoral lymph nodes. Our results indicate that patients best suited to SLN assay have had a simple punch biopsy to confirm the diagnosis rather than a previous tumor excision. This technique represents a true advance in the selection of patients for less radical surgery.

[Sentinel lymphadenectomy in squamous cell carcinoma of the pharynx and larynx]. / Sentinelna limfadenektomija kod planocelularnih karcinoma larinksa i hipofarinksa.

The study included 20 patients with carcinoma of the pharynx and larynx. The incidence of metastases was compared between sentinel lymph nodes and the rest of lymph nodes in resected material. Patient inclusion criteria were primary tumor verified as squamous cell carcinoma by preoperative histopathology and negative clinical neck finding (cN0). Human serum albumin radiocolloid labeled with radioactive technetium-99m 0.5 mCi (18 MBq) was used. In two patients (with tumors of the hypopharynx and glottis), lymph nodes were not preoperatively visualized by scintigraphy. A total of 32 lymph nodes (range 0-4), were visualized. All nodes were found in regions II-IV, mostly in region II. In three patients, sentinel lymph nodes were detected bilaterally. Twenty six selective neck resections were performed (bilateral in six patients). A total of 319 (mean 12) lymph nodes were isolated in resected material, 7 of them were positive, all ipsilateral. A positive definitive histopathology finding was recorded in five patients. Three patients had one positive lymph node each (pN1), all sentinel lymph nodes. In one patient, positive sentinel lymph node histopathology was associated with tumor lesions detected in other lymph nodes (pN2b). One patient had false negative result. Study results confirmed the lymphatic drainage of the upper aerodigestive tract and metastasizing area from tumors of this localization are constant and predictable.