Clinical tools do not predict pathological complete response in patients with esophageal squamous cell cancer treated with definitive chemoradiotherapy.

Chemoradiotherapy for locally advanced esophageal squamous cell carcinoma is associated with high rates of pathological complete response. A pathological complete response is recognized to be an important predictor of improved survival, to the extent that observation rather than surgery is advocated by some in patients with presumed pathological complete response based on their clinical response. The goal of this study was to look at the ability of clinical variables to predict pathological complete response after chemoradiotherapy for locally advanced esophageal squamous cell carcinoma. We reviewed retrospectively patients with locally advanced esophageal squamous cell carcinoma who underwent chemoradiotherapy followed by surgery and compared those with pathological complete response to patients with residual disease. Between January 1996 and December 2010, 116 patients met inclusion criteria. Fifty-six percent of patients had a pathological complete response and a median survival of 128.1 months versus 28.4 months in patients with residual disease. When compared with patients with residual disease, patients with a pathological complete response had a lower post-neoadjuvant positron emission tomography (PET) maximum standardized uptake value (SUVmax), a larger decrease in PET SUVmax, a less thick tumor on post-chemoradiotherapy computed tomography and a higher rate of normal appearing post-chemoradiotherapy endoscopy with benign biopsy of the tumor bed. However, none of these characteristics alone was able to correctly identify patients with a pathological complete response, and none has significant specificity. Although the rate of pathological complete response after chemoradiotherapy is high in patients with esophageal squamous cell carcinoma, the ability of identifying patients with pathological complete response is limited. A reduction of the PET SUVmax by >70%, a normal appearing endoscopic examination, and no residual disease on biopsy all were seen in >65% of the patients with a pathological complete response. Even if these findings were unable to confirm the absence of residual disease in the primary tumor, they can help guide expectant management in high-risk patients.

Fluorescent cholangiography in a mouse model: an innovative method for improved laparoscopic identification of the biliary anatomy.

BACKGROUND: Real-time imaging of the biliary anatomy may facilitate safe and timely completion of laparoscopic cholecystectomy. This study sought to determine whether the unique autofluorescent properties of bile could facilitate intraoperative identification of the biliary anatomy in mice using fluorescent cholangiography. METHODS: Fluorimetry was performed on samples of mouse bile to determine excitation and emission spectra. For seven mice, chevron laparotomy was performed, followed by liver retraction to expose the porta hepatis. Using stereomicroscopy, photographs were taken in brightfield and fluorescent modes without a change in depth or focus. Six surgical residents evaluated the pictures and identified the gallbladder, cystic duct, common bile duct, and whether the cystic duct joined the right hepatic duct or the common bile duct. RESULTS: Fluorimetry demonstrated autofluorescence of bile at an excitation wavelength of 475 nm. Intense emission was observed at 480 nm. At these settings, fluorescent stereomicroscopy easily identified the gallbladder and biliary tree in mice. This technique decreased diagnostic errors of the biliary anatomy 11-fold (2% vs 22%; p < 0.01), as compared with brightfield visualization. Fluorescent stereomicroscopy also was used to diagnose bile leak, obstruction, and complex anatomy. Using a prototype 5-mm laparoscope equipped with fluorescent filters, the results were reproduced. CONCLUSIONS: Fluorescent cholangiography based solely on the autofluorescence of bile may facilitate real-time identification of the biliary anatomy during laparoscopic procedures, without the need for extraneous dye administration or the use of radiography. This technique has the potential to decrease the rate of iatrogenic biliary tract injuries during laparoscopic cholecystectomy.

Virally-directed fluorescent imaging (VFI) can facilitate endoscopic staging.

BACKGROUND: Replication-competent, tumor specific herpes simplex virus NV1066 expresses green fluorescent protein (GFP) in infected cancer cells. We sought to determine the feasibility of GFP-guided imaging technology in the intraoperative detection of small tumor nodules. METHODS: Human cancer cell lines were infected with NV1066 at multiplicities of infection of 0.01, 0.1 and 1. Cancer cell specific infectivity, vector spread and GFP signal intensity were measured by flow cytometry and time-lapse digital imaging (in vitro); and by use of a stereomicroscope and endoscope equipped with a fluorescent filter (in vivo). RESULTS: NV1066 infected all cancer cell lines and expressed GFP at all MOIs. GFP signal was significantly higher than the autofluorescence of normal cells. One single dose of NV1066 spread within and across body cavities and selectively infected tumor nodules sparing normal tissue. Tumor nodules undetectable by conventional thoracoscopy and laparoscopy were identified by GFP fluorescence. CONCLUSION: Virally-directed fluorescent imaging (VFI) is a real-time novel molecular imaging technology that has the potential to enhance the intraoperative detection of endoluminal or endocavitary tumor nodules.

Minimally invasive localization of oncolytic herpes simplex viral therapy of metastatic pleural cancer.

Herpes simplex virus-1 (HSV-1) oncolytic therapy and gene therapy are promising treatment modalities against cancer. NV1066, one such HSV-1 virus, carries a marker gene for enhanced green fluorescent protein (EGFP). The purpose of this study was to determine whether NV1066 is cytotoxic to lung cancer and whether EGFP is a detectable marker of viral infection in vitro and in vivo. We further investigated whether EGFP expression in infected cells can be used to localize the virus and to identify small metastatic tumor foci (<1 mm) in vivo by means of minimally invasive endoscopic systems equipped with fluorescent filters. In A549 human lung cancer cells, in vitro viral replication was determined by plaque assay, cell kill by LDH release assay, and EGFP expression by flow cytometry. In vivo, A549 cells were injected into the pleural cavity of athymic mice. Mice were treated with intrapleural injection of NV1066 or saline and examined for EGFP expression in tumor deposits using a stereomicroscope or a fluorescent thoracoscopic system. NV1066 replicated in, expressed EGFP in infected cells and killed tumor cells in vitro. In vivo, treatment with intrapleural NV1066 decreased pleural disease burden, as measured by chest wall nodule counts and organ weights. EGFP was easily visualized in tumor deposits, including microscopic foci, by fluorescent thoracoscopy. NV1066 has significant oncolytic activity against a human NSCLC cell line and is effective in limiting the progression of metastatic disease in an in vivo orthotopic model. By incorporating fluorescent filters into endoscopic systems, a minimally invasive means for diagnosing small metastatic pleural deposits and localization of viral therapy for thoracic malignancies may be developed using the EGFP marker gene inserted in oncolytic herpes simplex viruses.

Treatment of cholangiocarcinoma with oncolytic herpes simplex virus combined with external beam radiation therapy.

Replication-competent oncolytic herpes simplex viruses (HSV), modified by deletion of certain viral growth genes, can selectively target malignant cells. The viral growth gene gamma(1)34.5 has significant homology to GADD34 (growth arrest and DNA damage protein 34), which promotes cell cycle arrest and DNA repair in response to stressors such as radiation (XRT). By upregulating GADD34, XRT may result in greater oncolytic activity of HSV strains deficient in the gamma(1)34.5 gene. The human cholangiocarcinoma cell lines KMBC, SK-ChA-1 and YoMi were treated with NV1023, an oncolytic HSV lacking one copy of gamma(1)34.5. Viral proliferation assays were performed at a multiplicity of infection (MOI, number of viral particles per tumor cell) equal to 1, either alone or after XRT at 250 or 500 cGy. Viral replication was assessed by plaque assay. In vitro cytotoxicity assays were performed using virus at MOIs of 0.01 and 0.1, with or without XRT at 250 cGy and cell survival determined with lactate dehydrogenase assay. Established flank tumors in athymic mice were treated with a single intratumoral injection of virus (10(3) or 10(4) plaque forming units), either alone or after a single dose of XRT at 500 cGy, and tumor volumes measured. RT-PCR was used to measure GADD34 mRNA levels in all cell lines after a single dose of XRT at 250 or 500 cGy. NV1023 was tumoricidal in all three cell lines, but sensitivity to the virus varied. XRT enhanced viral replication in vitro in all cell lines. Combination treatment with low-dose XRT and virus was highly tumoricidal, both in vitro and in vivo. The greatest tumor volume reduction with combination therapy was seen with YoMi cells, the only cell line with increased GADD34 expression after XRT and the only cell line in which a synergistic treatment effect was suggested. In KMBC and SK-ChA-1 cells, neither of which showed increased GADD34 expression after XRT, tumor volume reduction was less pronounced and there was no suggestion of a synergistic effect in either case. Oncolytic HSV are effective in treating human cholangiocarcinoma cell lines, although sensitivity to virus varies. XRT-enhanced viral replication occurs through a mechanism that is not necessarily dependent on GADD34 upregulation. However, XRT-induced upregulation of GADD34 further promotes tumoricidal activity in viral strains deficient in the gamma(1)34.5 gene, resulting in treatment synergy; this effect is cell type dependent. Combined XRT and oncolytic viral therapy is a potentially important treatment strategy that may enhance the therapeutic ratios of both individual therapies.

Thermodynamic analysis of water interaction with excipient films.

The interaction of water with excipients that can form moisture-protective coatings was examined earlier by the application of theoretical models. In this study, thermodynamic analysis of water-excipient film systems has been performed to elucidate the mechanistic details of the water-excipient interaction. Partial molal free energies, enthalpies, and entropies were computed for films of lipidic (glyceryl behenate, GB) and polymeric (polyvinyl alcohol, PVA) coating excipients using the temperature dependence of the adsorption process. The analysis of free energy changes showed that excipient films were not inert participants in the water sorption process. The isoteric heats of adsorption confirmed that water formed hydrogen bonds with the excipient films and allowed estimation of number of hydrogen bonds per water molecule. This result also provided the reason for hysteresis during drying. A comparative evaluation of the application of theoretical models and thermodynamic analysis revealed that results obtained from both approaches were not always complementary. An exponential relationship was found to exist between sorption microrate constants and water activity for the PVA films at all temperatures.

Hot-melt coating: water sorption behavior of excipient films.

Hot-melt coating allows encapsulation of water-labile, drug-laden substrates to form a barrier that resists moisture ingress. To understand the interaction of water with excipients that can form moisture-protective coatings, sorption behavior of films of lipidic (glyceryl behenate) and polymeric (polyvinyl alcohol) coating excipients was investigated. A simple and rapid method using a new, fully automated instrumental technique to investigate the sorption/desorption behavior of excipient films is reported. Further, the influence of temperature and film thickness on the sorption behavior of films is examined. Both excipient films displayed sorption isotherms that were classified as type III and demonstrated hysteresis during desorption. The sorption data for both films did not follow the Langmuir model, and the BET model could only be used restrictively. The GAB model fitted the sorption data at all conditions and over the entire range of water activity studied. The ability of the Young and Nelson model to explain the hysteresis behavior, from analytical and mechanistic perspectives, is evaluated. Temperature and film thickness were found to profoundly influence the nature of moisture interaction and distribution of moisture in the excipient films. An Arrhenius-type relationship was observed between equilibrium moisture content of excipient films and temperature at constant water activity.