Andrew C. Prince

Oncologic Procedures Amenable to Fluorescence-guided Surgery

Objective: Although fluorescence imaging is being applied to a wide range of cancers, it remains unclear which disease populations will benefit greatest. Therefore, we review the potential of this technology to improve outcomes in surgical oncology with attention to the various surgical procedures while exploring trial endpoints that may be optimal for each tumor type. Background: For many tumors, primary treatment is surgical resection with negative margins, which corresponds to improved survival and a reduction in subsequent adjuvant therapies. Despite unfavorable effect on patient outcomes, margin positivity rate has not changed significantly over the years. Thus, patients often experience high rates of re-excision, radical resections, and overtreatment. However, fluorescence-guided surgery (FGS) has brought forth new light by allowing detection of subclinical disease not readily visible with the naked eye. Methods: We performed a systematic review of clinicatrials.gov using search terms “fluorescence,” “image-guided surgery,” and “near-infrared imaging” to identify trials utilizing FGS for those received on or before May 2016. Inclusion criteria: fluorescence surgery for tumor debulking, wide local excision, whole-organ resection, and peritoneal metastases. Exclusion criteria: fluorescence in situ hybridization, fluorescence imaging for lymph node mapping, nonmalignant lesions, nonsurgical purposes, or image guidance without fluorescence. Results: Initial search produced 844 entries, which was narrowed down to 68 trials. Review of literature and clinical trials identified 3 primary resection methods for utilizing FGS: (1) debulking, (2) wide local excision, and (3) whole organ excision. Conclusions: The use of FGS as a surgical guide enhancement has the potential to improve survival and quality of life outcomes for patients. And, as the number of clinical trials rise each year, it is apparent that FGS has great potential for a broad range of clinical applications.

Effects of an Unlabeled Loading Dose on Tumor-Specific Uptake of a Fluorescently Labeled Antibody for Optical Surgical Navigation

PurposeIntraoperative optical imaging to guide surgeons during oncologic resections offers a unique and promising solution to the ambiguity of cancer margins to tactile and visual assessment that results in devastatingly high rates of positive margins. Sequestering of labeled antibodies by normal tissues with high expression of the antibody target, or “antigen sinks”, diminishes the efficacy of these probes to provide contrast between the tumor and background tissues by decreasing the amount of circulating probe available for uptake by the tumor and by increasing the fluorescence of non-tumor tissues. We hypothesized that administering a dose of unlabeled antibody prior to infusion of the near-infrared (NIR) fluorescently labeled antibody would improve tumor-specific uptake and contrast of the fluorescently labeled probe by occupying extra-tumoral binding sites, thereby increasing the amount of labeled probe available for uptake by the tumor.ProceduresIn this study, we explore this concept by testing two different “pre-load” doses of unlabeled cetuximab (the standard 10-mg test dose, and a larger, experimental 100-mg test dose) in six patients receiving cetuximab conjugated to the fluorescent dye IRDye800CW (cetuximab-IRDye800CW) in a clinical trial, and compared the amount of fluorescent antibody in tumor and background tissues, as well as the tumor-specific contrast of each.ResultsThe patients receiving the larger preload (100xa0mg) of unlabeled cetuximab demonstrated significantly higher concentrations (9.5 vs. 0.1xa0μg) and a longer half-life (30.3 vs. 20.6xa0days) of the labeled cetuximab in plasma, as well as significantly greater tumor fluorescence (32.3 vs. 9.3 relative fluorescence units) and tumor to background ratios (TBRs) (5.5 vs. 1.7).ConclusionsAdministering a preload of unlabeled antibody prior to infusion of the fluorescently labeled drug may be a simple and effective way to improve the performance of antibody-based probes to guide surgical resection of solid malignancies.

Characterizing the Utility and Limitations of Repurposing an Open-Field Optical Imaging Device for Fluorescence-Guided Surgery in Head and Neck Cancer Patients

The purpose of this study was to assess the potential of U.S. Food and Drug Administration–cleared devices designed for indocyanine green–based perfusion imaging to identify cancer-specific bioconjugates with overlapping excitation and emission wavelengths. Recent clinical trials have demonstrated potential for fluorescence-guided surgery, but the time and cost of the approval process may impede clinical translation. To expedite this translation, we explored the feasibility of repurposing existing optical imaging devices for fluorescence-guided surgery. Methods: Consenting patients (n = 15) scheduled for curative resection were enrolled in a clinical trial evaluating the safety and specificity of cetuximab-IRDye800 (NCT01987375). Open-field fluorescence imaging was performed preoperatively and during the surgical resection. Fluorescence intensity was quantified using integrated instrument software, and the tumor-to-background ratio characterized fluorescence contrast. Results: In the preoperative clinic, the open-field device demonstrated potential to guide preoperative mapping of tumor borders, optimize the day of surgery, and identify occult lesions. Intraoperatively, the device demonstrated robust potential to guide surgical resections, as all peak tumor-to-background ratios were greater than 2 (range, 2.2–14.1). Postresection wound bed fluorescence was significantly less than preresection tumor fluorescence (P < 0.001). The repurposed device also successfully identified positive margins. Conclusion: The open-field imaging device was successfully repurposed to distinguish cancer from normal tissue in the preoperative clinic and throughout surgical resection. This study illuminated the potential for existing open-field optical imaging devices with overlapping excitation and emission spectra to be used for fluorescence-guided surgery.

Characterizing the detection threshold for optical imaging in surgical oncology

Optical imaging to guide cancer resections is rapidly transitioning into the operating room. However, the sensitivity of this technique to detect subclinical disease is yet characterized. The purpose of this study was to determine the minimum range of cancer cells that can be detected by antibody‐based fluorescence imaging.

Antiangiogenic antibody improves melanoma detection by fluorescently labeled therapeutic antibodies

Evaluate if vascular normalization with an antiangiogenic monoclonal antibody improves detection of melanoma using fluorescently labeled antibody‐based imaging.

Evaluation of fluorescence-guided surgery agents in a murine model of soft tissue fibrosarcoma

Soft tissue sarcomas (STS) are mesenchymal malignancies. Treatment mainstay is surgical resection with negative marginsu2009±u2009adjuvant treatment. Fluorescence‐guided surgical (FGS) resection can delineate intraoperative margins; FGS has improved oncologic outcomes in other malignancies. This novel strategy may minimize resection‐associated morbidity while improving local tumor control.

Sinus hypoplasia in the cystic fibrosis rat resolves in the absence of chronic infection

Sinus hypoplasia is a hallmark characteristic in cystic fibrosis (CF). Chronic rhinosinusitis (CRS) is nearly universal from a young age, impaired sinus development could be secondary to loss of the cystic fibrosis transmembrane conductance regulator (CFTR) or consequences of chronic infection during maturation. The objective of this study was to assess sinus development relative to overall growth in a novel CF animal model.

Evaluation of optical imaging agents in a fluorescence-guided surgical model of head and neck cancer

BACKGROUNDnTumor proliferation often occurs from pathologic receptor upregulation. These receptors provide unique targets for near-infrared (NIR) probes that have fluorescence-guided surgery (FGS) applications. We demonstrate the use of three smart-targeted probes in a model of head and neck squamous cell carcinoma.nnnMETHODSnA dose escalation study was performed using IntegriSense750, ProSense750EX, and ProSense750FAST in mice (nu202f=u202f5) bearing luciferase-positive SCC-1 flank xenograft tumors. Whole body fluorescence imaging was performed serially after intravenous injection using commercially available open-field (LUNA, Novadaq, Canada) and closed-field NIR systems (Pearl, LI-COR, Lincoln, NE). An exxa0vivo, whole-body biodistribution was conducted. Lastly, FGS was performed with IntegriSense750 to demonstrate orthotopic and metastatic disease localization.nnnRESULTSnDisease fluorescence delineation was assessed by tumor-to-background fluorescence ratios (TBR). Peak TBR values were 3.3 for 1u202fnmol ProSense750EX, 5.5 for 6u202fnmol ProSense750FAST, and 10.8 for 4u202fnmol IntegriSense750u202fat 5.5, 3, and 4u202fd post administration, respectively. Agent utility is unique: ProSense750FAST provides sufficient contrast quickly (TBR: 1.5, 3u202fh) while IntegriSense750 produces strong (TBR: 10.8) contrast with extended administration-to-resection time (96u202fh). IntegriSense750 correctly identified all diseased nodes in situ during exploratory surgeries. Exxa0vivo, whole-body biodistribution was assessed by tumor-to-tissue fluorescence ratios (TTR). Agents provided sufficient fluorescence contrast to discriminate disease from background, TTR>1. IntegriSense750 was most robust in neural tissue (TTR: 64) while ProSense750EX was superior localizing disease against lung tissue (TBR: 13).nnnCONCLUSIONnAll three agents appear effective for FGS.

Utility of the Surgical Apgar Score in Head and Neck Squamous Cell Carcinoma.

Objectives To recognize the utility of the surgical Apgar score (SAS) in a noncutaneous head and neck squamous cell carcinoma (HNSCC) population. Study Design Retrospective case series with chart review. Setting Academic tertiary medical center. Subjects and Methods Patients (n = 563) undergoing noncutaneous HNSCC resection between April 2012 and March 2015 were included. Demographics, medical history, intraoperative data, and postoperative hospital summaries were collected. SASs were calculated following the published schema. The primary outcome was 30-day postoperative morbidity. A 2-sample t test, analysis of variance, and χ2 (or Fisher exact) test were used for statistical comparisons. A multivariable logistic regression analysis was conducted to identify independent predictors of 30-day morbidity. Results Mean SAS was 6.2 ± 1.5. SAS groups did not differ in age, sex, or race. Sixty-five patients (11.6%) had a SAS between 0 and 4, with 40 incidences of morbidity (61.5%), while 31 (5.5%) patients with SAS from 9 to 10 had 3 morbidity occurrences (9.7%). Results show that 30-day postoperative morbidity is inversely related to increasing SAS (P < .0001). Furthermore, lower SAS was associated with significantly increased operative time (SAS 0-4: 9.3 ± 2.6 hours vs SAS 9-10: 3.0 ± 1.1 hours) and lengths of stay (SAS 0-4: 10.0 ± 7.3 days vs SAS 9-10: 1.6 ± 1.0 days), P < .0001. SAS remained highly significant after adjusting for potential confounding variables in the multivariable analysis (P < .0001). Conclusions An increasing SAS is associated with significantly lower rates of 30-day postoperative morbidities in a noncutaneous HNSCC patient population.

Utility of the Modified Surgical Apgar Score in a Head and Neck Cancer Population

Objective The Surgical Apgar Score (SAS) is a validated postoperative complication prediction model. The purpose of this study was to investigate the utility of the SAS in a diverse head and neck cancer population and to compare it with a recently developed modified SAS (mSAS) that accounts for intraoperative transfusion. Study Design Case series with chart review. Setting Academic tertiary care medical center. Subjects and Methods This study comprised 713 patients undergoing surgery for head and neck cancer from April 2012 to March 2015. SAS values were calculated according to intraoperative data obtained from anesthesia records. The mSAS was computed by assigning an estimated blood loss score of zero for patients receiving intraoperative transfusions. Primary outcome was 30-day postoperative morbidity. Results Mean SAS and mSAS were 6.3 ± 1.5 and 6.2 ± 1.7, respectively. SAS and mSAS were significantly associated with 30-day postoperative morbidity, length of stay, operative time, American Society of Anesthesiologists status, race, and body mass index (P < .05); however, no significant association was detected for age, sex, and smoking status. Multivariable analysis identified SAS and mSAS as independent predictors of postoperative morbidity, with the mSAS (P = .03) being a more robust predictor than the SAS (P = .15). Strong inverse relationships were demonstrated for the SAS and mSAS with length of stay and operative time (P < .0001). Conclusion The SAS serves as a useful metric for risk stratification of patients with head and neck cancer. With the inclusion of intraoperative transfusion, the mSAS demonstrates superior utility in predicting those at risk for postoperative complications.