Congenital lung malformations: can we avoid computed tomography? A five-year study.

Purpose: Congenital lung malformations (CLMs) consist of a variety of pulmonary development disorders. In the CLM approach, computed tomography (CT) is considered the gold standard imaging technique due to the high-resolution for the lung parenchyma evaluation, the study of the vascular system after contrast injection, and the multiplanar reconstructions. In the paediatric population CT is considered too invasive due to ionizing radiation and the use of contrast agent. Therefore, the indications for the use of magnetic resonance imaging (MRI) are increasing. The aim of our study is to compare retrospectively MRI and CT in the evaluation of CLMs, to reduce or avoid the use of contrast-enhanced CT in the paediatric population. Material and methods: We retrospectively evaluated 22 paediatric patients with prenatal diagnosis of CLMs. All the patients underwent postnatal MRI in the first 2 weeks of life (except for a patient) and pre-surgery contrast-enhanced CT. A total of 7 blinded radiologists divided into 3 different groups independently reviewed each MRI and CT examination. Sensitivity and specificity of radiologists with different years of experience on the field, as well as of MRI findings regarding every pathology, were evaluated using a ROC curve. The interobserver agreement regarding the MRI findings was also measured. Results: Analysing the ROC curves, we observed that MRI provided a satisfactory accuracy for diagnosing most congenital pulmonary diseases. Conclusions: Our study showed that MRI without contrast agent allows us to reach a CLM diagnosis in good agreement with contrast-enhanced CT, which is considered the gold standard imaging technique.

Monitoring tumor growth rate to predict immune checkpoint inhibitors' treatment outcome in advanced NSCLC.

INTRODUCTION: Radiological response assessment to immune checkpoint inhibitor is challenging due to atypical pattern of response and commonly used RECIST 1.1 criteria do not take into account the kinetics of tumor behavior. Our study aimed at evaluating the tumor growth rate (TGR) in addition to RECIST 1.1 criteria to assess the benefit of immune checkpoint inhibitors (ICIs). METHODS: Tumor real volume was calculated with a dedicated computed tomography (CT) software that semi-automatically assess tumor volume. Target lesions were identified according to RECIST 1.1. For each patient, we had 3 measurement of tumor volume. CT-1 was performed 8-12 weeks before ICI start, the CT at baseline for ICI was CT0, while CT + 1 was the first assessment after ICI. We calculated the percentage increase in tumor volume before (TGR1) and after immunotherapy (TGR2). Finally, we compared TGR1 and TGR2. If no progressive disease (PD), the group was disease control (DC). If PD but TGR2 < TGR1, it was called LvPD and if TGR2 ⩾ TGR1, HvPD. RESULTS: A total of 61 patients who received ICIs and 33 treated with chemotherapy (ChT) were included. In ICI group, 18 patients were HvPD, 22 LvPD, 21 DC. Median OS was 4.4 months (95% CI: 2.0-6.8, reference) for HvPD, 7.1 months (95% CI 5.4-8.8) for LvPD, p = 0.018, and 20.9 months (95% CI: 12.5-29.3) for DC, p < 0.001. In ChT group, 7 were categorized as HvPD, 17 as LvPD and 9 as DC. No difference in OS was observed in the ChT group (p = 0.786). CONCLUSION: In the presence of PD, a decrease in TGR may result in a clinical benefit in patients treated with ICI but not with chemotherapy. Monitoring TGR changes after ICIs administration can help physician in deciding to treat beyond PD.

Tumor Growth Rate Decline despite Progressive Disease May Predict Improved Nivolumab Treatment Outcome in mRCC: When RECIST Is Not Enough.

Treatment response is usually assessed by the response evaluation criteria in solid tumors (RECIST). These criteria may not be adequate to evaluate the response to immunotherapy, considering the peculiar patterns of response reported with this therapy. With the advent of immunotherapy these criteria have been modified to include the evaluation of the peculiar responses seen with this type of therapy (iRECIST criteria), including pseudoprogressions and hyperprogressions. Tumor growth rate (TGR) is a dynamic evaluation that takes into account the kinetics of response to treatment and may help catch the real efficacy of an immunotherapy approach. We performed a retrospective monocentric study to explore the impact of TGR change after nivolumab administration as the second or later line of treatment in patients with metastatic renal cell carcinoma (RCC). We evaluated 27 patients, divided into three categories: Disease control (DC) if there was no PD; lower velocity PD (LvPD) if disease progressed but the TGR at second assessment (TGR2) was lower than the TGR at first assessment (TGR1); higher velocity PD (HvPD) if TGR2 was higher than TGR1. The median OS for the DC group was 11.0 months (95% CI 5.0-17.0) (reference) vs. (not reached) NR (95% CI NR-NR) for LvPD (HR 0.27; 95% CI 0.06-1.30; p 0.102) vs. NR (95% CI NR-NR) for HvPD (HR 0.23; 95% CI 0.06-0.88; p 0.032). There was no difference between LvPD and DC (HR 1.21; 95% CI 0.20-7.28; p 0.838). In patients with metastatic RCC, the second or later line of nivolumab treatment may lead to a deceleration in TGR resulting in an improved survival outcome similar to that observed in patients experiencing tumor regression. In this subgroup, especially in the presence of a clinical benefit, continuing the treatment beyond progression can be recommended.

PD-L1 Expression in Circulating Tumor Cells as a Promising Prognostic Biomarker in Advanced Non-small-cell Lung Cancer Treated with Immune Checkpoint Inhibitors.

BACKGROUND: Circulating tumor cells (CTCs) are a promising source of biological information in cancer. Data correlating PD-L1 expression in CTCs with patients' response to immune checkpoint inhibitors (ICIs) in non-small-cell lung cancer (NSCLC) are still lacking. METHODS: This is a prospective single-center cohort study enrolling patients with advanced NSCLC. CTCs were identified and counted with the CellSearch system. PD-L1 expression on CTCs was assessed with phycoerythrin-conjugated anti-human PD-L1 antibody, clone MIH3 (BioLegend, USA). Primary endpoint was the correlation between the CTCs PD-L1 expression and overall survival (OS). Among secondary objectives, we evaluated the correlation between PD-L1 expression on CTCs and matched tumor tissue and the correlation of CTC number and baseline tumor size (BTS). RESULTS: Thirty-nine patients treated with anti-PD-1/PD-L1 agents as second- or third-line therapy were enrolled. Patients were divided into 3 groups: no CTC detectable (CTCnull, n = 15), PD-L1 positive CTC (CTCpos, n = 13), and PD-L1 negative CTC (CTCneg, n = 11). Median OS in patients with CTCneg was 2.2 months, 95% confidence interval (CI), 0.8-3.6 (reference) versus 3.7 months, 95% CI, 0.1-7.5 (hazard ratio [HR] 0.33; 95% CI, 0.13-0.83; P = .019) in patients with CTCpos versus 16.0 months, 95% CI, 2.2-29.8 (HR 0.17; 95% CI, 0.06-0.45; P< .001) in patients with CTCnull. No correlation was found between PD-L1 expression on CTCs and on tumor tissue. CTC number was correlated with BTS. CONCLUSION: PD-L1 expression on CTCs is a promising biomarker in patients with NSCLC treated with ICIs. Further validation as predictive biomarker is needed.