Defining hypoxic microenvironments by non-invasive functional optical imaging

Accuracy of whole-body diffusion-weighted MRI (WB-DWI/MRI) in diagnosis, staging and follow-up of gastric cancer, in comparison to CT: a pilot study

Background

Accurate staging of patients with gastric cancer is necessary for selection of the most appropriate and personalized therapy. Computed tomography (CT) is currently used as primary staging tool, being widely available with a relatively high accuracy for the detection of parenchymal metastases, but with low sensitivity for the detection of peritoneal metastases. Magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) has a very high contrast resolution, suggesting a higher diagnostic performance in the detection of small peritoneal lesions. The aim of this study was to retrospectively evaluate the added value of whole-body diffusion-weighted MRI (WB-DWI/MRI) to CT for detection of peritoneal carcinomatosis (PC) and distant metastases in the preoperative staging of gastric cancer.

Methods

This retrospective study included thirty-two patients with a suspicion of gastric cancer/recurrence, who underwent WB-DWI/MRI at 1.5 T, in addition to CT of thorax and abdomen. Images were evaluated by two experienced abdominal radiologists in consensus. Histopathology, laparoscopy and/or 1-year follow-up were used as reference standard.

Results

For overall tumour detection (n = 32), CT sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) was 83.3%, 100%, 100% and 82.4% respectively. For WB-DWI/MRI these values were 100%, 92.9%, 94.7% and 100%, respectively. For staging (n = 18) malignant lymph nodes and metastases, CT had a sensitivity, specificity/PPV/NPV of 50%/100%/100%/71.4%, and 15.4%/100%/100%/31.3% respectively. For WB-DWI/MRI, all values were 100%, for both malignant lymph nodes and metastases. WB-DWI/MRI was significantly better than CT in detecting tumour infiltration of the mesenteric root, serosal involvement of the small bowel and peritoneal metastases for which WB-DWI/MRI was correct in 100% of these cases, CT 0%.

Conclusions

WB-DWI/MRI is highly accurate for diagnosis, staging and follow-up of patients with suspected gastric cancer.

Bioluminescence Imaging Applications in Cancer: A Comprehensive Review

Bioluminescence imaging (BLI), an optical preclinical imaging modality, is an invaluable imaging modality due to its low-cost, high throughput, fast acquisition times, and functional imaging capabilities. BLI is being extensively used in the field of cancer imaging, especially with the recent developments in genetic-engineering, stem cell, and gene therapy treatments. The purpose of this paper is to provide a comprehensive review of the principles, developments, and current status of BLI in cancer research. This paper covers the fundamental BLI concepts including BLI reporters and enzyme-substrate systems, data acquisition, and image characteristics. It reviews the studies discussing the use of BLI in cancer research such as imaging tumor-characteristic phenomena including tumorigenesis, metastasis, cancer metabolism, apoptosis, hypoxia, and angiogenesis, and response to cancer therapy treatments including chemotherapy, radiotherapy, immunotherapy, gene therapy, and stem cell therapy. The key advantages and disadvantages of BLI compared to other common imaging modalities are also discussed.

Surgeons' Ability to Predict the Extent of Surgery Prior to Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy

Background

The extent of surgery (ES) during cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) is a well-known risk factor for major postoperative morbidity. Interestingly, the reliability of surgeons to predict the ES prior to CRS + HIPEC is unknown.

Methods

In this prospective, observational cohort study, five surgeons predicted the ES prior to surgery in all consecutive patients with peritoneal metastases (PM) who were scheduled for CRS + HIPEC between March 2018 and May 2019. After the preoperative work-up for CRS + HIPEC was completed, all surgeons independently predicted, for each individual patient, the resection or preservation of 22 different anatomical structures and the presence of a stoma post-HIPEC according to a standardized ES form. The actual ES during CRS + HIPEC was extracted from the surgical procedure report and compared with the predicted ES. Overall and individual positive (PPV) and negative predictive values (NPV) for each anatomical structure were calculated.

Results

One hundred and thirty-one ES forms were collected from 32 patients who successfully underwent CRS + HIPEC. The number of resections was predicted correctly 24 times (18.3%), overestimated 57 times (43.5%), and underestimated 50 times (38.2%). Overall PPVs for the different anatomical structures ranged between 33.3 and 87.8%. Overall, NPVs ranged between 54.9 and 100%, and an NPV > 90% was observed for 12 anatomical structures.

Conclusions

Experienced surgeons seem to be able to better predict the anatomical structures that remain in situ after CRS + HIPEC, rather than predict the resections that were necessary to achieve a complete cytoreduction.

Electronic supplementary material

The online version of this article (10.1245/s10434-020-08237-8) contains supplementary material, which is available to authorized users.

Diagnostic Laparoscopy as a Selection Tool for Patients with Colorectal Peritoneal Metastases to Prevent a Non-therapeutic Laparotomy During Cytoreductive Surgery

OBJECTIVE

The aim of this study was to evaluate the introduction of diagnostic laparoscopy (DLS) in patients with colorectal peritoneal metastases (PM) to prevent non-therapeutic laparotomies during cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS + HIPEC).

METHODS

Patients with histologically proven colorectal PM who underwent a laparotomy for potential CRS + HIPEC from January 2006 to January 2019 were retrospectively identified from a prospectively maintained database. In 2012, DLS was introduced in the preoperative work-up for CRS + HIPEC in our academic center. The rates of non-therapeutic laparotomies, major postoperative complications (Clavien-Dindo grade III or higher), and survival outcomes were investigated for patients who underwent a laparotomy before (cohort A) and after (cohort B) the introduction of DLS. In cohort B, the reasons to refrain from DLS were retrospectively explored from medical records.

RESULTS

Overall, 172 patients were included [cohort A: 48 patients (27.9%); cohort B: 124 patients (72.1%)]. A significant drop in the rate of non-therapeutic laparotomies occurred in cohort B compared with cohort A (21.0 vs. 35.4%: p = 0.044), despite only 85 patients (68.5%) from cohort B undergoing DLS in our academic center. The most important reason to refrain from DLS was a recently performed DLS or laparotomy in the referring hospital (48.7%). Major postoperative complications, in-hospital mortality, and survival outcomes were similar for both cohorts.

CONCLUSIONS

Performing DLS during the preoperative work-up for CRS + HIPEC prevents non-therapeutic laparotomies in patients with colorectal PM. We recommend performing this laparoscopic screening in an experienced HIPEC center.

A Bio-inspired Hypoxia Sensor using HIF1a-Oxygen-Dependent Degradation Domain

Functional imaging has become an important tool in oncology because it not only provides information about the size and localization of the tumour, but also about the pathophysiological features of the tumoural cells. One of the characteristic features of some tumour types is that their fast growth leads to deficient intratumoral vascularization, which results in low oxygen availability. To overcome this lack of oxygen, tumoural cells activate the neoangiogenic program by upregulating the transcription factor HIF-1α. Herein we report a non-invasive in vitro detection method of hypoxia using designed fluorescent peptide probes based on the oxygen-dependent degradation domain of HIF-1α. The fluorescent probe retains the oxygen-sensing capability of HIF-1α, so that it is stabilized under hypoxia and readily degraded by the proteasome under normoxia, thus providing direct information of the cellular oxygen availability.

Whole-body diffusion-weighted MRI for operability assessment in patients with colorectal cancer and peritoneal metastases

Background

Correct staging of patients with colorectal cancer is of utmost importance for the prediction of operability. Although computed tomography (CT) has a good overall performance, estimation of peritoneal cancer spread is a known weakness, a problem that cannot always be overcome by Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT); especially in infiltrative and miliary disease spread. Due to its high spatial and contrast resolution magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) might have a better performance. Our aim was to evaluate the added value of whole-body diffusion-weighted MRI (WB-DWI/MRI) to CT for prediction of peritoneal cancer spread and operability assessment in colorectal cancer patients with clinically suspected peritoneal carcinomatosis (PC).

Methods

This institutional review board approved retrospective study included sixty colorectal cancer patients who underwent WB-DWI/MRI in addition to CT for clinically suspected peritoneal metastases. WB-DWI/MRI and CT were assessed for detecting PC following the peritoneal cancer index (PCI), determination of PCI-score categorized as PC < 12, PCI = 12–15 and PCI > 15, detection of nodal and distant metastases and estimation of overall operability. Histopathology after surgery and biopsy and/or 6 months follow-up were used as reference standard.

Results

For detection of PC, CT had 43.2% sensitivity, 95.6% specificity, 84.5% positive predictive value (PPV) and 75.2% negative predictive value (NPV). WB-DWI/MRI had 97.8% sensitivity, 93.2% specificity, 88.9% PPV and 98.7% NPV. WB-DWI/MRI enabled better detection of inoperable distant metastases (all 12 patients) than CT (2/12 patients) and significantly improved prediction of PCI category [WB-DWI/MRI PCI < 12: 37/39 patients (94.9%); PCI = 12–15: 4/4 patients (100%); PCI > 15: 16/17 patients (94.1%) versus CT PCI < 12: 38/39 patients (97.4%); PCI = 12–15: 0/4 patients (0%); PCI > 15: 2/17 patients (11.8%); p < 0.0001)]. WB-DWI/MRI improved prediction of inoperability over CT with 90.6% sensitivity compared to 25% (p < 0.0001).

Conclusions

WB-DWI/MRI significantly outperformed CT for estimation of spread of PC, overall staging and prediction of operability. Pending validation in larger prospective trials, WB-DWI/MRI could be used to guide surgical planning and minimize unnecessary exploratory laparotomies.

Fluorescent drug-loaded, polymeric-based, branched gold nanoshells for localized multimodal therapy and imaging of tumoral cells

Here we report the synthesis of PLGA/DOXO-core Au-branched shell nanostructures (BGNSHs) functionalized with a human serum albumin/indocyanine green/folic acid complex (HSA-ICG-FA) to configure a multifunctional nanotheranostic platform. First, branched gold nanoshells (BGNSHs) were obtained through a seeded-growth surfactant-less method. These BGNSHs were loaded during the synthetic process with the chemotherapeutic drug doxorubicin, a DNA intercalating agent and topoisomerase II inhibitior. In parallel, the fluorescent near-infrared (NIR) dye indocyanine green (ICG) was conjugated to the protein human serum albumin (HSA) by electrostatic and hydrophobic interactions. Subsequently, folic acid was covalently attached to the HSA-ICG complex. In this way, we created a protein complex with targeting specificity and fluorescent imaging capability. The resulting HSA-ICG-FA complex was adsorbed to the gold nanostructures surface (BGNSH-HSA-ICG-FA) in a straightforward incubation process thanks to the high affinity of HSA to gold surface. In this manner, BGNSH-HSA-ICG-FA platforms were featured with multifunctional abilities: the possibility of fluorescence imaging for diagnosis and therapy monitoring by exploiting the inherent fluorescence of the dye, and a multimodal therapy approach consisting of the simultaneous combination of chemotherapy, provided by the loaded drug, and the potential cytotoxic effect of photodynamic and photothermal therapies provided by the dye and the gold nanolayer of the hybrid structure, respectively, upon NIR light irradiation of suitable wavelength. The combination of this trimodal approach was observed to exert a synergistic effect on the cytotoxicity of tumoral cells in vitro. Furthermore, FA was proved to enhance the internalization of nanoplatform. The ability of the nanoplatforms as fluorescence imaging contrast agents was tested by preliminary analyzing their biodistribution in vivo in a tumor-bearing mice model.

NIR-light active hybrid nanoparticles for combined imaging and bimodal therapy of cancerous cells

Multifunctional hybrid polymeric-based nanoplatforms for simultaneous fluorescence and magnetic resonance imaging and multimodal chemo- and phothermal therapies.

A flavonoid chrysin suppresses hypoxic survival and metastatic growth of mouse breast cancer cells

Tumor hypoxia commonly occurs in solid tumors, and correlates with metastasis. Current cancer therapies are inefficient in curing metastatic disease. Herein, we examined effect of Thai propolis extract and its major constituent, chrysin, on hypoxic survival of 4T1 mouse breast cancer cells in vitro, and investigated its underlying mechanism. In vivo effect of chrysin on metastatic progression of cancer cells was studied, both as a single agent and in combination with another antimetastatic agent, agonistic monoclonal antibody targeting the DR5 TRAIL receptor (DR5 mAb). Thai propolis extract and chrysin decreased survival of 4T1 cells after exposure to hypoxia (1% O2), for 2 days. Immunoblot analysis revealed that chrysin inhibited hypoxia-induced STAT3 phosphorylation without affecting HIF-1α protein level. Chrysin also abrogated hypoxia-induced VEGF gene expression as determined by qRT-PCR. The in vivo effect of chrysin was determined in a spontaneous metastasis mouse model of breast cancer, either alone or in combination with DR5 mAb. Daily oral administration of chrysin in Balb/c mice implanted with 4T1 cells significantly suppressed growth of lung metastatic colonies. Moreover, antimetastatic activity of DR5 mAb was enhanced when given in combination with chrysin. We demonstrate that chrysin has potential in controlling metastatic progression.