Intraoperative near-infrared fluorescence imaging targeting folate receptors identifies lung cancer in a large-animal model.

BACKGROUND: Complete tumor resection is the most important predictor of patient survival with non-small cell lung cancer. Methods for intraoperative margin assessment after lung cancer excision are lacking. This study evaluated near-infrared (NIR) intraoperative imaging with a folate-targeted molecular contrast agent (OTL0038) for the localization of primary lung adenocarcinomas, lymph node sampling, and margin assessment. METHODS: Ten dogs with lung cancer underwent either video-assisted thoracoscopic surgery or open thoracotomy and tumor excision after an intravenous injection of OTL0038. Lungs were imaged with an NIR imaging device both in vivo and ex vivo. The wound bed was re-imaged for retained fluorescence suspicious for positive tumor margins. The tumor signal-to-background ratio (SBR) was measured in all cases. Next, 3 human patients were enrolled in a proof-of-principle study. Tumor fluorescence was measured both in situ and ex vivo. RESULTS: All canine tumors fluoresced in situ (mean Fluoptics SBR, 5.2 [range, 2.7-8.1]; mean Karl Storz SBR 1.9 [range, 1.4-2.6]). In addition, the fluorescence was consistent with tumor margins on pathology. Three positive lymph nodes were discovered with NIR imaging. Also, a positive retained tumor margin was discovered upon NIR imaging of the wound bed. Human pulmonary adenocarcinomas were also fluorescent both in situ and ex vivo (mean SBR, > 2.0). CONCLUSIONS: NIR imaging can identify lung cancer in a large-animal model. In addition, NIR imaging can discriminate lymph nodes harboring cancer cells and also bring attention to a positive tumor margin. In humans, pulmonary adenocarcinomas fluoresce after the injection of the targeted contrast agent. Cancer 2017;123:1051-60. © 2016 American Cancer Society.

Clinical implications of positive margins following non-small cell lung cancer surgery.

Positive margins following pulmonary resection of non-small cell lung cancer (NSCLC) occur in approximately 5-15% of patients undergoing a curative procedure. The presence of positive margins negatively impacts long-term outcomes by setting the stage for local and potentially distant disease recurrence. Despite major clinical ramifications, there are very few dedicated reports that examine the implications of positive margins following surgery for NSCLC. Furthermore, published series are typically retrospective studies from single institutions. In this review we analyze published data with special consideration of four pertinent questions: (i) what are the long term outcomes of a positive margin following pulmonary resection?, (ii) is intraoperative margin assessment by frozen section reliable?, (iii) what is the optimal distance of the tumor margin to the surgical margin?, and (iv) should adjuvant chemotherapy and/or radiation therapy be used in the setting of a positive surgical margin?

Age, Race, and Income Are Associated With Lower Screening Rates at a Safety Net Hospital.

BACKGROUND: While lung cancer screening improves cancer-specific mortality and is recommended for high-risk patients, barriers to screening still exist. We sought to determine our institution's (an urban safety net hospital) screening rate and to identify socioeconomic barriers to lung cancer screening. METHODS: We identified 8935 smokers 55 to 80 years of age evaluated by a primary care physician between March 2015 and March 2017 at our institution. We randomly selected one-third of these (n = 2978) to review for eligibility using the U.S. Preventive Services Task Force criteria for lung cancer screening. Using our institution's Lung Cancer Screening Program clinical tracking database, we identified patients who were screened from March 2015 to March 2017. We collected demographic information (race, primary language, education status, and median income) and evaluated possible associations with screening. RESULTS: Among our institution population, 99 patients meeting U.S. Preventive Services Task Force screening criteria underwent screening computed tomography, whereas 516 eligible patients were not screened, making our institution's estimated screening rate 16.1%. Comparing the unscreened population with those who received screening at our institution, the unscreened population was significantly older (median age of screened patients was 63 years, of unscreened patients was 66 years; P < .001). African Americans had a lower screening rate (37.6% of the screened population and 47.5% of the unscreened population; P < .001). Unscreened patients had a lower annual household income. CONCLUSIONS: The lung cancer screening rate at our hospital is 16.1%. Unscreened patients were older, were more likely to be African American, and had a lower median income. These findings highlight possible screening barriers and potential areas for targeted strategies to decrease disparities in lung cancer screening.

Near-Infrared Intraoperative Molecular Imaging Can Locate Metastases to the Lung.

BACKGROUND: Pulmonary metastasectomy is widely accepted for many tumor types because it may prolong survival and potentially cure some patients. However, intraoperative localization of pulmonary metastases can be technically challenging. We propose that intraoperative near-infrared (NIR) molecular imaging can be used as an adjunct during disease localization. METHODS: We inoculated 50 C57BL/6 mice with Lewis lung carcinoma (LLC) flank tumors. After flank tumor growth, mice were injected through the tail vein with indocyanine green (ICG) before operation, and intraoperative imaging was used to detect pulmonary metastases. On the basis of these experiments, we enrolled 8 patients undergoing pulmonary metastasectomy into a pilot and feasibility clinical trial. Each patient received intravenous ICG 1 day before operation, followed by wedge or segmental resection. Samples were imaged on the back table with an NIR camera to confirm disease presence and margins. All murine and human tumors and margins were confirmed by pathologic examination. RESULTS: Mice had an average of 4 ± 2 metastatic tumors on both lungs, with an average size of 5.1 mm (interquartile range [IQR] 2.2 mm to 7.6 mm). Overall, 200 of 211 (95%) metastatic deposits were markedly fluorescent, with a mean tumor-to-background ratio (TBR) of 3.4 (IQR 3.1 to 4.1). The remaining tumors had a TBR below 1.5. In the human study, intraoperative NIR imaging identified six of the eight preoperatively localized lesions. Intraoperative back table NIR imaging identified all metastatic lesions, which were confirmed by pathologic examination. The average tumor size was 1.75 ± 1.4 cm, and the mean ex vivo TBR was 3.3 (IQR 3.1 to 3.7). Pathologic examination demonstrated melanoma (n = 4), osteogenic sarcoma (n = 2), renal cell carcinoma (n = 2), chondrosarcoma (n = 1), leiomyosarcoma (n = 1), and colorectal carcinoma (n = 1). CONCLUSIONS: Systemic ICG identifies subcentimeter tumor metastases to the lung in murine models, and this work provides proof of principle in humans. Future research is focused on improving depth of penetration into the lung parenchyma.

Neoadjuvant intratumoral immuno-gene therapy for non-small cell lung cancer.

Non-small Cell Lung Cancer (NSCLC) remains a deadly disease despite aggressive treatment protocols which incorporate chemotherapy, radiation and surgery. These traditional approaches have reached a plateau in therapeutic benefit. There is emerging evidence suggesting that immunotherapy can serve as an alternative treatment modality for NSCLC. Our group has nearly two decades of experience involving immuno-gene therapy with Ad.hIFN-α and Ad.hIFN-ß in human mesothelioma trials, and has observed both safety and efficacy in treatment of Thoracic malignancies. We have expanded the scope of our work and have obtained encouraging pre-clinical evidence suggesting a role for immunotherapy as a surgical adjuvant for NSCLC cancers. By combining immunotherapy with surgery, synergistic results have been observed. Based on these observations, we have prepared a Phase I Clinical Trial that pairs Ad.hIFN-α with surgery for patients with resectable NSCLC. Patient enrollment is likely to begin in the Summer of 2016. We hope that this trial will serve as a platform for future trials aimed at pairing immunotherapy with surgery for patients diagnosed with NSCLC.

Intraoperative imaging identifies thymoma margins following neoadjuvant chemotherapy.

Near infrared (NIR) molecular imaging is useful to identify tumor margins during surgery; however, the value of this technology has not been evaluated for tumors that have been pre-treated with chemotherapy. We hypothesized that NIR molecular imaging could locate mediastinal tumor margins in a murine model after neoadjuvant chemotherapy. Flank thymomas were established on mice. Two separate experiments were performed for tumor margin detection. The first experiment compared (i) surgery and (ii) surgery + NIR imaging. The second experiment compared (iii) preoperative chemotherapy + surgery, and (iv) preoperative chemotherapy + surgery + NIR imaging. NIR imaging occurred following systemic injection of indocyanine green. Margins were assessed for residual tumor cells by pathology. NIR imaging was superior at detecting retained tumor cells during surgery compared to standard techniques (surgery alone vs. surgery + NIR imaging, 20% vs. 80%, respectively). Following chemotherapy, the sensitivity of NIR imaging of tumor margins was not significantly altered. The mean in vivo tumor-to-background fluorescence ratio was similar in the treatment-naïve and chemotherapy groups ((p = 0.899): 3.79 ± 0.69 (IQR 3.29 - 4.25) vs. 3.79 ± 0.52 (IQR 3.40 - 4.03)). We conclude that chemotherapy does not affect tumor fluorescence or identification of retained cancer cells at margins.

Intraoperative Near-Infrared Optical Imaging Can Localize Gadolinium-Enhancing Gliomas During Surgery.

BACKGROUND: Although real-time localization of gliomas has improved with intraoperative image guidance systems, these tools are limited by brain shift, surgical cavity deformation, and expense. OBJECTIVE: To propose a novel method to perform near-infrared (NIR) imaging during glioma resections based on preclinical and clinical investigations, in order to localize tumors and to potentially identify residual disease. METHODS: Fifteen patients were identified and administered a Food and Drug Administration-approved, NIR contrast agent (Second Window indocyanine green [ICG], 5 mg/kg) before surgical resection. An NIR camera was utilized to localize the tumor before resection and to visualize surgical margins following resection. Neuropathology and magnetic resonance imaging data were used to assess the accuracy and precision of NIR fluorescence in identifying tumor tissue. RESULTS: NIR visualization of 15 gliomas (10 glioblastoma multiforme, 1 anaplastic astrocytoma, 2 low-grade astrocytoma, 1 juvenile pilocytic astrocytoma, and 1 ganglioglioma) was performed 22.7 hours (mean) after intravenous injection of ICG. During surgery, 12 of 15 tumors were visualized with the NIR camera. The mean signal-to-background ratio was 9.5 ± 0.8 and fluorescence was noted through the dura to a maximum parenchymal depth of 13 mm. The best predictor of positive fluorescence was enhancement on T1-weighted imaging; this correlated with signal-to-background ratio (P = .03). Nonenhancing tumors did not demonstrate NIR fluorescence. Using pathology as the gold standard, the technique demonstrated a sensitivity of 98% and specificity of 45% to identify tumor in gadolinium-enhancing specimens (n = 71). CONCLUSION: With the use of Second Window ICG, gadolinium-enhancing tumors can be localized through brain parenchyma intraoperatively. Its utility for margin detection is promising but limited by lower specificity. ABBREVIATIONS: 5-ALA, 5-aminolevulinic acidEPR, enhanced permeability and retentionFDA, Food and Drug AdministrationGBM, glioblastomaICG, indocyanine greenNIR, near-infraredNPV, negative predictive valuePPV, positive predictive valueROC, receiver operating characteristicROI, region of interestSBR, signal-to-background ratioWHO, World Health Organization.