Dynamic Adaptation of Tumor Immune Response With Nivolumab Demonstrated by 18F-FDG PET/CT

Mechanisms of exercise in the treatment of lung cancer - a mini-review

Lung cancer constitutes a formidable menace to global health and well-being, as its incidence and mortality rate escalate at an alarming pace. In recent years, research has indicated that exercise has potential roles in both the prevention and treatment of lung cancer. However, the exact mechanism of the coordinating effect of exercise on lung cancer treatment is unclear, limiting the use of exercise in clinical practice. The purpose of this review is to explore the mechanisms through which exercise exerts its anticancer effects against lung cancer. This review will analyze the biological basis of exercise's anticancer effects on lung cancer, with a focus on aspects such as the tumor microenvironment, matrix regulation, apoptosis and angiogenesis. Finally, we will discuss future research directions and potential clinical applications.

Utility of 18F-FDG uptake in predicting major pathological response to neoadjuvant immunotherapy in patients with resectable non‑small cell lung cancer

PURPOSE

The aim of present study was to investigate the efficiency of ¹⁸F-FDG uptake in predicting major pathological response (MPR) in resectable non-small cell lung cancer (NSCLC) patients with neoadjuvant immunotherapy.

METHODS

A total of 104 patients with stage I-IIIB NSCLC were retrospectively derived from National Cancer Center of China, of which 36 cases received immune checkpoint inhibitors (ICIs) monotherapy (I-M) and 68 cases with ICI combination therapy (I-C). ¹⁸F-FDG PET-CT scans were performed at baseline and after neoadjuvant therapy (NAT). Receiver-operating characteristic (ROC) curve analyses were conducted and area under ROC curve (AUC) was calculated for biomarkers including maximum standardized uptake value (SUVmax), inflammatory biomarkers, tumor mutation burden (TMB), PD-L1 tumor proportion score (TPS) and iRECIST.

RESULTS

Fifty-four resected NSCLC tumors achieved MPR (51.9%, 54/104). In both neoadjuvant I-M and I-C cohorts, post-NAT SUVmax and the percentage changes of SUVmax (ΔSUVmax%) were significantly lower in the patients with MPR versus non-MPR (p < 0.01), and were also negatively correlated with the degree of pathological regression (p < 0.01). The AUC of ΔSUVmax% for predicting MPR was respectively 1.00 (95% CI: 1.00-1.00) in neoadjuvant I-M cohort and 0.94 (95% CI: 0.86-1.00) in I-C cohort. Baseline SUVmax had a statistical prediction value for MPR only in I-M cohort, with an AUC up to 0.76 at the threshold of 17.0. ΔSUVmax% showed an obvious advantage in MPR prediction over inflammatory biomarkers, TMB, PD-L1 TPS and iRECIST.

CONCLUSION

¹⁸F-FDG uptake can predict MPR in NSCLC patients with neoadjuvant immunotherapy.

Splenic volume as a predictor of treatment response in patients with non-small cell lung cancer receiving immunotherapy

Introduction

The spleen is a lymphoid organ and we hypothesize that clinical benefit to immunotherapy may present with an increase in splenic volume during treatment. The purpose of this study was to investigate whether changes in splenic volume could be observed in those showing clinical benefit versus those not showing clinical benefit to pembrolizumab treatment in non-small cell lung cancer (NSCLC) patients.

Materials and methods

In this study, 70 patients with locally advanced or metastatic NSCLC treated with pembrolizumab; and who underwent baseline CT scan within 2 weeks before treatment and follow-up CT within 3 months after commencing immunotherapy were retrospectively evaluated. The splenic volume on each CT was segmented manually by outlining the splenic contour on every image and the total volume summated. We compared the splenic volume in those achieving a clinical benefit and those not achieving clinical benefit, using non-parametric Wilcoxon signed-rank test. Clinical benefit was defined as stable disease or partial response lasting for greater than 24 weeks. A p-value of <0.05 was considered statistically significant.

Results

There were 23 responders and 47 non-responders based on iRECIST criteria and 35 patients with clinical benefit and 35 without clinical benefit. There was no significant difference in the median pre-treatment volume (175 vs 187 cm3, p = 0.34), post-treatment volume (168 vs 167 cm3, p = 0.39) or change in splenic volume (-0.002 vs 0.0002 cm3, p = 0.97) between the two groups. No significant differences were also found between the splenic volume of patients with partial response, stable disease or progressive disease (p>0.017). Moreover, there was no statistically significant difference between progression-free survival and time to disease progression when the splenic volume was categorized as smaller or larger than the median pre-treatment or post-treatment volume (p>0.05).

Conclusion

No significant differences were observed in the splenic volume of those showing clinical benefit versus those without clinical benefit to pembrolizumab treatment in NSCLC patients. CT splenic volume cannot be used as a potentially simple biomarker of response to immunotherapy.

Imaging Immune Cells Using Fc Domain Probes in Mouse Cancer Xenograft Models

Simple Summary

The immune system responds to abnormal cell growth by sending immune cells to kill them. The immune cell response is very important since it can usually stop abnormal cells from growing and spreading. Immuno-therapeutics used to treat cancer require help from the immune system to be effective. A biopsy is typically performed to determine the therapeutic efficacy of cancer treatment which is invasive and difficult. A simpler and less invasive way to monitor therapeutic efficacy is needed. Here, we show a molecule that can be used as an imaging agent to determine immune cell recruitment to tumors.

Abstract

Tracking immune responses is complex due to the mixture of cell types, variability in cell populations, and the dynamic environment. Tissue biopsies and blood analysis can identify infiltrating and circulating immune cells; however, due to the dynamic nature of the immune response, these are prone to sampling errors. Non-invasive targeted molecular imaging provides a method to monitor immune response, which has advantages of providing whole-body images, being non-invasive, and allowing longitudinal monitoring. Three non-specific Fc-containing proteins were labeled with near-infrared dye IRDye800CW and used as imaging probes to assess tumor-infiltrating immune cells in FaDu and A-431 xenograft models. We showed that Fc domains localize to tumors and are visible by fluorescent imaging. This tumor localization appears to be based on binding tumor-associated immune cells and some xenografts showed higher fluorescent signals than others. The Fc domain alone bound to different human immune cell types. The Fc domain can be a valuable research tool to study innate immune response.

ImmunoPET: harnessing antibodies for imaging immune cells

Dramatic, but uneven, progress in the development of immunotherapies for cancer has created a need for better diagnostic technologies including innovative non-invasive imaging approaches. This review discusses challenges and opportunities for molecular imaging in immuno-oncology and focuses on the unique role that antibodies can fill. ImmunoPET has been implemented for detection of immune cell subsets, activation and inhibitory biomarkers, tracking adoptively transferred cellular therapeutics, and many additional applications in preclinical models. Parallel progress in radionuclide availability and infrastructure supporting biopharmaceutical manufacturing has accelerated clinical translation. ImmunoPET is poised to provide key information on prognosis, patient selection, and monitoring immune responses to therapy in cancer and beyond.

PET/CT and the Response to Immunotherapy in Lung Cancer

Objective

In recent years, the introduction of immune checkpoint inhibitors has significantly changed the outcome of patients affected by lung cancer and cutaneous melanoma. Although the clinical advantages, the selection of patients and the evaluation of response to immunotherapy remain unclear, the immune-related Response Evaluation Criteria in Solid Tumor (irRECIST) was proposed as an update of the RECIST criteria for the assessment of response to immunotherapy. However, morphological images cannot predict early response to therapy that represents a challenge in clinical practice. 18F-FDG PET/CT before and after immunotherapy has an indeterminate role, demonstrating ambiguous results due to inflammatory effects secondary to activation of the immune system. The aim of the present review was to analyze the role of PET/CT as a guide for immunotherapy, by analyzing the current status and future perspectives.

Methods

A literature search was conducted in order to select all papers that discussed the role of PET/CT with FDG or other tracers in the evaluation or prediction of response to immunotherapy in lung cancer patients.

Results

Many papers are now available. Many clinical trials have demonstrated the efficacy of immunotherapy in lung cancer patients. FDG PET/CT can be used for the prediction of response to immunotherapy, while its utility for the evaluation of response is not still clearly reported. Moreover, the standardization of FDG PET/CT interpretation is missing and different criteria, such as information, have been investigated until now.

Conclusion

The utility of FDG PET/CT for patients with lung cancer undergoing immunotherapies is still preliminary and not well addressed. New agents for PET are promising, but large clinical trials are mandatory.

A Multimodal Approach to Evaluate for Cardiac Metastasis in a Case of Non-Small Cell Lung Cancer

Malignancies have demonstrated the ability to metastasize to cardiac tissue. However, an optimal diagnostic algorithm for cardiac tumors has not yet been established, due at least in part to the scarcity of symptomatic cases. Several case reports describe how the usage of ¹⁸F-labeled fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) incidentally revealed cardiac neoplasia. This modality, which indicates uptake sites of the radioisotope ¹⁸F-FDG, allows for whole-body imaging and is often used for preoperative determination of malignant metastasis or for assessing response to therapy over time. However, findings of false positivity are often reported due to increased FDG avidity caused by a range of other, nonmetastatic processes, most notably inflammation and infection. In this case report, an 84-year-old male with stage IV non-small cell lung cancer presented a clinical course, echocardiogram, and ¹⁸F-FDG PET-CT findings that were suggestive of endocardial metastasis. Nine months into therapy, after extensive consultation, the patient finally consented to a more complete workup using cardiac MRI (CMRI), which showed no evidence of cardiac metastasis. This case report supports the utility of CMRI as a means of further interpreting intracardiac, localized FDG uptake foci in PET-CT findings, in order to avoid false positivity and further refine proposed cardiac differential diagnoses in cancer patients.

18F-FET PET for Diagnosis of Pseudoprogression of Brain Metastases in Patients With Non-Small Cell Lung Cancer

PURPOSE

To evaluate whether F-fluoroethyltyrosine (FET) PET can discriminate progression from pseudoprogression of brain metastases in patients with non-small cell lung cancer undergoing immunotherapy and radiotherapy to the brain.

METHODS

Retrospective analysis of F-FET PET scans in cases with documented progression of brain metastases on MRI in a cohort of 53 patients with non-small cell lung cancer receiving immune-checkpoint inhibitors and radiotherapy of brain metastases at the University Hospital of Zürich from June 2015 until January 2019. Response to radiotherapy was assessed by MRI. In case of equivocal findings and/or radiological progression in clinically asymptomatic patients, further assessment with F-FET PET was performed.

RESULTS

From the cohort of 53 patients, the restaging MRI showed in 30 patients (56.6%) progression of at least 1 treated metastasis. Thereof, F-FET PET was performed in 11 patients, based on the absence of neurological symptoms or presence of systemic response and physicians' decision. F-FET PET correctly identified pseudoprogression in 9 of 11 patients (81.8%). In patients who did not undergo F-FET PET, 5 of 19 (26.3%) were diagnosed with pseudoprogression.

CONCLUSIONS

Pseudoprogression of brain metastases occurred in 50% of patients diagnosed with progression on MRI. F-FET PET may help differentiate pseudoprogression from real progression in order to avoid discontinuation of effective therapy or unneeded interventions.

The efficiency of 18F-FDG PET-CT for predicting the major pathologic response to the neoadjuvant PD-1 blockade in resectable non-small cell lung cancer

PURPOSE

Investigate whether ¹⁸F-FDG PET-CT has the potential to predict the major pathologic response (MPR) to neoadjuvant sintilimab in resectable NSCLC patients, and the potential of sifting patients who probably benefit from immunotherapy.

METHODS

Treatment-naive patients with resectable NSCLC (stage IA-IIIB) received two cycles of sintilimab (200 mg, intravenously, day 1 and 22). Surgery was performed between day 29 and 43. PET-CT was obtained at baseline and prior to surgery. The following lean body mass-corrected metabolic parameters were calculated by PET VCAR: SUL_max, SUL_peak, MTV, TLG, ΔSUL_max%, ΔSUL_peak%, ΔMTV%, ΔTLG%. PET responses were classified using PERCIST. The above metabolic information on FDG-PET was correlated with the surgical pathology. (Registration Number: ChiCTR-OIC-17013726).

RESULTS

Thirty-six patients received 2 doses of sintilimab, all of whom underwent PET-CT twice and had radical resection (35) or biopsy (1). MPR occurred in 13 of 36 resected tumors (36.1%, 13/36). The degree of pathological regression was positively correlated with SUL_max (p = 0.036) of scan-1, and was negatively correlated with all metabolic parameters of scan-2, and the percentage changes of the metabolic parameters after neoadjuvant therapy (p < 0.05). According to PERCIST, 13 patients (36.1%, 13/36) showed partial metabolic response (PMR), 21 (58.3%, 21/36) had stable metabolic disease, and 2 (5.6%, 2/36) had progressive metabolic disease (PMD). There was a significant correlation between the pathological response and the PET responses which were classified using PERCIST. All (100.0%) the PMR (ΔSUL_peak% < - 30.0%) tumors showed MPR.

CONCLUSIONS

¹⁸F-FDG PET-CT can predict MPR to neoadjuvant sintilimab in resectable non-small cell lung cancer.

18F-FDG PET/CT in non-small-cell lung cancer patients: a potential predictive biomarker of response to immunotherapy

AIM

The aim of this study was to assess the predictive role of fluorine-18-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) in the evaluation of response to immunotherapy in patients affected by metastatic lung cancer.

MATERIALS AND METHODS

From a single-center database, data for 32 patients (median age: 69 years; range: 37-78) with metastatic lung cancer were retrospectively retrieved. All patients were treated with nivolumab. PD-L1 expression was available in 19/32 patients. All patients underwent F-FDG PET/CT before immunotherapy. Whole-body maximum standardized uptake value (SUVmaxwb), metabolic tumor volume (MTVwb), and total lesion glycolysis (TLGwb) were obtained as the sum of SUVmax, metabolic tumor volume, and total lesion glycolysis in all metabolic lesions. The best response to therapy was considered in terms of partial response (PR), stable disease (SD), and progressive disease (PD) on the basis of clinical and radiological follow-up.

RESULTS

F-FDG PET/CT was positive in 30/32 (94%) patients. The majority of them had a pathological F-FDG uptake in the lung, lymph nodes, and bones. SUVmaxwb, MTVwb, and TLGwb were higher in patients with a positive PD-L1 expression than those with negative expression. Twenty-one patients achieved disease control (PR+SD), whereas 11 did not (PD). SUVmaxwb was significantly higher in patients without a response to therapy than those with a response to immunotherapy (median: 48.97 vs. 20.85; Student t-test: P = 0.002). Similarly, TLGwb and MTVwb were also higher in nonresponders than responders, although not statistically significant. However, the difference was more evident in women than men (median SUVmaxwb in responders and nonresponders for women and men: 17.86 vs. 85.89 and 21.38 vs. 44.38, respectively).

CONCLUSION

The entire tumor burden evaluated by F-FDG PET/CT can be predictive of response to immunotherapy in patients with metastatic lung cancer. A large prospective multicenter trial is warranted to definitively assess the usefulness of F-FDG PET/CT as a predictive biomarker of response to immunotherapy.

Comparison Between 18F-FDG PET-Based and CT-Based Criteria in Non-Small Cell Lung Cancer Patients Treated with Nivolumab

Because of the peculiar mechanism of action of immune checkpoint inhibitors (ICIs), evaluation of the radiologic response to them in solid tumors presents many challenges. We aimed to compare evaluation of the first response to nivolumab by means of CT-based criteria with respect to ¹⁸F-FDG PET response criteria in non-small cell lung cancer (NSCLC) patients. Methods: Seventy-two patients with advanced NSCLC were recruited in a single-institution ancillary trial within the expanded-access program (NCT02475382) for nivolumab. Patients underwent CT and ¹⁸F-FDG PET at baseline and after 4 cycles (the first evaluation). In cases of progressive disease, an additional evaluation was performed after 2 further cycles to confirm progression. We evaluated the treatment response on CT using RECIST 1.1 and the immune-related response criteria (irRC) and on ¹⁸F-FDG PET using PERCIST and immunotherapy-modified PERCIST. The concordance between CT- and PET-based criteria and the capability of each method to predict overall survival were evaluated. Results: Forty-eight of 72 patients were evaluable for a first response assessment with both PET- and CT-based criteria. We observed low concordance between CT- and PET-based criteria (κ-value of 0.346 and 0.355 between PERCIST and imPERCIST and RECIST, respectively. κ-value of 0.128 and 0.198 between PERCIST and imPERCIST and irRC, respectively). Regarding overall survival, irRC could more reliably distinguish responders from nonresponders. However, thanks to the prognostic value of partial metabolic response assessed by both PERCIST and immunotherapy-modified PERCIST, PET-based response maintained prognostic significance in patients classified as having progressive disease on the basis of irRC. Conclusion: Even though the present study did not support the routine use of ¹⁸F-FDG PET in the general population of NSCLC patients treated with ICIs, the findings suggest that metabolic response assessment has added prognostic value, potentially improving therapeutic decision making.

Nivolumab-Induced Pneumonitis in Patient With Metastatic Melanoma Showing Complete Remission on 18F-FDG PET/CT

A 49-year-old patient with metastatic melanoma was treated with nivolumab (Opdivo). An early F-FDG PET/CT after 2 cycles showed a progressive metabolic disease. A 4-month optimal follow-up F-FDG PET/CT showed a complete metabolic response. The treatment was stopped after 22 cycles because of immunotherapy-related pneumonitis. After discontinuation of treatment, PET/CT examinations demonstrated a metabolic complete remission during 2 years. The metabolic pattern on early PET was suggestive of pseudoprogression, which is a rare phenomenon reflecting an activation of inflammatory cells within the tumor microenvironment causing lesions to increase in size and to accumulate FDG until a sufficient immune response is developed.

FDG PET/CT for assessing tumour response to immunotherapy : Report on the EANM symposium on immune modulation and recent review of the literature

This paper follows the immunotherapy symposium held during the European Association of Nuclear Medicine (EANM) 2017 Annual Congress. The biological basis of the immune checkpoint inhibitors and the drugs most frequently used for the treatment of solid tumours are reviewed. The issues of pseudoprogression (frequency, timeline), hyperprogression and immune-related side effects are discussed, as well as their implications for patient management. A review of the recent literature on the use of FDG PET for assessment of immunotherapy is presented, and recommendations are provided for assessing tumour response and reporting immune-related side effects with FDG PET based on published data and experts' experience. Representative clinical cases are also discussed.