Feasibility and diagnostic performance of hybrid PET/MRI compared with PET/CT for gynecological malignancies: a prospective pilot study

Purpose

The purpose of the study was to assess the feasibility and diagnostic performance of FDG-PET/MR imaging compared to PET/CT for staging of patients with a gynecological malignancy.

Methods

25 patients with a gynecological malignancy were prospectively enrolled into this pilot study. Patients underwent sequential full-body PET/CT and PET/MR of the abdomen and pelvis after administration of a single dose of F-18 FDG. PET/MRI and PET/CT images were independently reviewed by two expert radiologists. Readers were blinded to the results of the other imaging procedures. Clinical and pathologic information was abstracted from medical charts.

Results

18 patients were included in the final analysis with a median age of 62 years (range 31–88). 61% of patients (11/18) had cervical cancer, while the remaining patients had endometrial cancer. PET/MRI as compared to PET/CT detected all primary tumors, 7/7 patients with regional lymph nodes, and 1/1 patient with an abdominal metastasis. Two patients had additional lymph nodes outside of the abdominopelvic cavity detected on PET/CT that were not seen on PET/MRI, whereas 6 patients had parametrial invasion and one patient had invasion of the bladder seen on PET/MRI not detected on PET/CT. Five cervical cancer patients had discordant clinical vs. radiographic staging based on PET/MRI detection of soft tissue involvement. Management changed for two patients who had clinical stage IB1 and radiographic stage IIB cervical cancer.

Conclusions

PET/MRI is feasible and has at least comparable diagnostic ability to PET/CT for identification of primary cervical and endometrial tumors and regional metastases. PET/MRI may be superior to PET/CT for initial radiographic assessment of cervical cancers.

     

Air Quality Status During Diwali Festival of India: A Case Study

The PM_2.5 and PM₁₀ samples were collected during Diwali celebration from study area and characterized for ionic concentration of four anions (NO₃ ⁻, NO₂ ⁻, Cl⁻, SO₄ ²⁻) and five cations (K⁺, Mg²⁺, NH₄ ⁺, Ca²⁺, Na⁺). The results showed that the ionic concentrations were three times compared to those on pre and post Diwali days. Predominant ions for PM_2.5 were K⁺ 33.7 μg/m³, Mg⁺ 31.6 μg/m³, SO₄ ²⁻ 22.1 μg/m³, NH₄ ⁺ 17.5 μg/m³ and NO₃ ⁻ 18 μg/m³ and for PM₁₀ the ionic concentrations were Mg⁺ 29.6 μg/m³, K⁺ 26 μg/m³, SO₄ ²⁻ 19.9 μg/m³, NH₄ ⁺ 16.8 μg/m³ and NO₃ ⁻ 16 μg/m³. While concentration of SO₂ and NO₂ were 17.23, 70.33 μg/m³ respectively.     

Prospective evaluation of 18F‐fluorodeoxyglucose positron emission tomography in patients receiving hepatic arterial and systemic chemotherapy for unresectable colorectal liver metastases

BackgroundThe prognostic and predictive abilities of 18F‐fluorodeoxyglucose (FDG) positron emission tomography (PET) coupled with conventional computed tomography (CT) have not been studied in patients with unresectable colorectal liver metastases (uCRLM) treated with combined hepatic arterial infusion (HAI) and systemic chemotherapy.ObjectivesThe ability of PET‐CT metabolic response parameters to predict conversion to resectability and oncologic outcome in this setting was evaluated.MethodsThirty‐eight patients undergoing serial PET‐CT as part of a Phase II trial of HAI and systemic chemotherapy for uCRLM were included. Metabolic response was determined as the percentage change in standard uptake value (SUV) and total lesion glycolysis (TLG). Conversion to resection, overall survival (OS), progression‐free survival (PFS) and recurrence‐free survival were evaluated using standard statistics.ResultsVolumetric response sufficient to facilitate resection was seen in 53% of patients after a median of 5 months of therapy. Median follow‐up was 38 months (range: 32–52 months). Median OS was not reached [95% confidence interval (CI) 32 months–unknown] and 3‐year OS was 54% (range: 33–71%). Median PFS was 13 months (95% CI 6–21 months) and 3 year PFS was 10% (range: 3–20%). Neither baseline values nor the percentage change in any of the metabolic parameters evaluated correlated with conversion to resection, survival variables or hepatic recurrence on Cox regression analysis.ConclusionsPre‐ and post‐treatment PET‐related metabolic parameters do not predict conversion to resection or oncologic outcome in patients with uCRLM treated with HAI and systemic chemotherapy. Metabolic parameters should not be used to monitor response or to determine prognosis in these patients.     

Asymptomatic SARS-CoV-2 infection: Incidental findings on FDG PET/CT

Rationale and ObjectivesIdentify the incidental findings of Covid-19 pneumonitis on ¹⁸F-FDG PET/CT scan in asymptomatic oncologic patients. The goal was to detect clinically unsuspected Covid-19 infections to prevent community spread.Materials and MethodsRetrospective analysis was conducted to recognize the pattern of metabolic and radiographic alterations on ¹⁸F-FDG PET/CT scans in Covid-19 patients. 492 ¹⁸F-FDG PET/CT scans were reviewed for pulmonary and systemic abnormalities.Results¹⁸F-FDG PET/CT demonstrated new lung infiltrates in 29 asymptomatic patients. 13/29 patients had Covid-19 infection confirmed by nasopharyngeal nucleic acid PCR test. The most common lung abnormality was pure ground-glass opacity (GGO) (90%) in peripheral distribution (100%), involving 1 lobe in four patients (30.8%), 2–3 lobes in four patients, and 4-5 lobes in five patients (38.4%). Mean SUVmax was 4.7 (range 1.3–13.1). Ten patients developed symptoms, mainly fever, fatigue, and dry cough, within 6.4 ± 7.8 days (range 1–24). Of the available laboratory data of 12 patients, eight developed lymphopenia, and five patients had neutrophilia. Five patients required hospitalization, and two died of complications.ConclusionFor a given geographic region in the later stage of a pandemic, such as Covid-19, community spread of the disease is common. Therefore, it is not surprising to find it in asymptomatic being imaged for other indications. Recognition of its manifestation and effectively mounting mitigation protocols is essential to further reduce SARS-CoV-2 spread, especially to susceptible groups, predominantly the elderly and people with comorbidities.