Stability of endoscopic ultrasound-guided fiducial marker placement for esophageal cancer target delineation and image-guided radiation therapy

PurposeFiducial markers have been integrated into the management of multiple malignancies to guide more precise delivery of radiation therapy (RT). Fiducials placed at the margins of esophageal tumors are potentially useful to facilitate both RT target delineation and image-guided RT (IGRT). In this study, we report on the stability of endoscopic ultrasound (EUS)-guided fiducial placement for esophageal cancers and utilization for radiation treatment planning and IGRT.MethodsAn institutional review board-approved database was queried for patients treated for esophageal cancer with chemoradiotherapy (CRT). Patients included in the analysis had a diagnosis of esophageal cancer, were referred for treatment with CRT, and had fiducials placed under EUS guidance. Images acquired at time of radiation treatment planning, daily IGRT imaging, post-treatment restaging, and surveillance scans were analyzed to determine the stability of implanted markers.ResultsWe identified 60 patients who underwent EUS-guided fiducial marker placement near the margins of their esophageal tumors in preparation for RT treatment planning. A total of 105 fiducial markers were placed. At time of CT simulation, 99 markers were visualized. Fifty-seven patients had post-treatment imaging available for review. Of the 100 implanted fiducials in these 57 patients, 94 (94%) were visible at time of RT simulation. Eighty-eight (88%) fiducials were still present post-treatment imaging at a median of 107 days (range, 33-471 days) after implantation.ConclusionsEUS-guided fiducial marker placement for esophageal cancer aids in target delineation for radiation planning and daily IGRT. Fiducial stability is reproducible and facilitates conformal treatment with image-guided RT techniques.     

Identification of broadly protective human antibodies to Pseudomonas aeruginosa exopolysaccharide Psl by phenotypic screening

Pseudomonas aeruginosa is a leading cause of hospital-associated infections in the seriously ill, and the primary agent of chronic lung infections in cystic fibrosis patients. A major obstacle to effective control of P. aeruginosa infections is its intrinsic resistance to most antibiotic classes, which results from chromosomally encoded drug-efflux systems and multiple acquired resistance mechanisms selected by years of aggressive antibiotic therapy. These factors demand new strategies and drugs to prevent and treat P. aeruginosa infections. Herein, we describe a monoclonal antibody (mAb) selection strategy on whole P. aeruginosa cells using single-chain variable fragment phage libraries derived from healthy individuals and patients convalescing from P. aeruginosa infections. This approach enabled identification of mAbs that bind three distinct epitopes on the product of the Psl. This exopolysaccharide is important for P. aeruginosa attachment to mammalian cells, and for the formation and maintenance of biofilms produced by nonmucoid and mucoid P. aeruginosa isolates. Functional screens revealed that mAbs to one epitope exhibit superior activity in opsonophagocytic killing and cell attachment assays, and confer significant protection in multiple animal models. Our results indicate that Psl is an accessible serotype-independent surface feature and promising novel protective antigen for preventing P. aeruginosa infections. Furthermore, our mAb discovery strategy holds promise for application to other bacterial pathogens.     

Outcomes Associated with Surgery for T4 Esophageal Cancer

Background

T4 esophageal cancer often portends a dismal prognosis even after surgical resection. Historical incomplete resections and poor survival rates often make surgery palliative rather than curative.

Methods

Using a comprehensive esophageal cancer database, we identified patients who underwent an esophagectomy for T4 tumors between 1994 and 2011. Neoadjuvant treatment (NT) and pathologic response variables were recorded, and response was denoted as complete response (pCR), partial response (pPR), and nonresponse (NR). Clinical and pathologic data were compared. Survival was calculated using Kaplan–Meier curves with log-rank tests for significance.

Results

We identified 45 patients with T4 tumors all who underwent NT. The median age was 60 years (range, 31–79 years) with a median follow-up of 27 months (range, 0–122 months). There were 19 pCR (42 %), 22 pPR (49 %), and 4 NR (9 %). R0 resections were accomplished in 43 (96 %). There were 18 recurrences (40 %) with a median time to recurrence of 13.5 months (2.2–71 months). In this group pCR represented 7 (38.9 %), whereas pPR and NR represented 10 (55.5 %), and 1 (5.5 %) respectively. The overall and disease-free survival for all patients with T4 tumors were 35 and 36 %, respectively. Patients achieving a pCR had a 5 year overall and disease-free survival of 53 and 54 %, compared with pPR 23 and 28 %, while there were no 5 year survivors in the NR cohort.

Conclusion

We have demonstrated that neoadjuvant therapy and downstaging of T4 tumors leads to increased R0 resections and improvements in overall and disease-free survival.