Spray cryotherapy prevents need for palliative stenting in patients with esophageal cancer-associated dysphagia.

BACKGROUND: Dysphagia is the most common symptom in advanced esophageal cancer patients. Esophageal stent placement (SP) is a common palliation method but can be associated with significant morbidity. Limited data exist regarding the ability of spray cryotherapy (SC) prolong time to SP. METHODS: A Mayo Clinic (Rochester, MN) patient database was reviewed for cases with a SC indication of esophageal cancer palliation from 2007-2019. Procedures were performed using a liquid nitrogen SC system to apply 2-5 separate 20 second freeze and 60 second thaw cycles based on tumor characteristics. Primary outcome was time to subsequent palliative SP. RESULTS: Of 56 patients (71.4% male, mean age 77.8 ± 10.2 years) who underwent a total of 199 SC sessions (mean 3.6 ± 2.7, range 1-12 per patient), 41 had adenocarcinoma and 15 squamous cell carcinoma (SCC). Overall, 13 patients underwent subsequent SP within a mean duration of 15.7 ± 11.0 months over a mean follow-up duration of 25.6 ± 29.4 months. Treatment did produce stenosis in 16 patients, who required dilation within a mean period of 193.1 ± 294.1 days; notably, 10 patients had a history of preceding malignant strictures requiring dilation. Two patients experienced bleeding requiring transfusion, whereas 1 experienced perforation at the start of SC. Prior chemotherapy and/or radiation was not associated with developing an SC-related complication (risk ratio (RR) 1.5; 95% CI 0.6-3.7, P > 0.4). CONCLUSIONS: SC appears to be an effective and safe modality to palliate esophageal cancer in appropriate candidates. Majority of patients who undergo SC avoid the need for future SP. If patients eventually require SP, they are able to, on average, defer stenting for >1 year from SC initiation.

EUS-guided verteporfin photodynamic therapy for pancreatic cancer.

BACKGROUND AND AIMS: Locally advanced pancreatic cancer (LAPC) often causes obstruction. Verteporfin photodynamic therapy (PDT) can feasibly "debulk" the tumor more safely than noncurative surgery and has multiple advantages over older PDT agents. We aimed to assess the feasibility of EUS-guided verteporfin PDT in ablating nonresectable LAPC. METHODS: Adults with LAPC with adequate biliary drainage were prospectively enrolled. Exclusion criteria were significant metastatic disease burden, disease involving >50% duodenal or major artery circumference, and recent treatment with curative intent. CT was obtained between days -28 to 0. On day 0, verteporfin .4 mg/kg was infused 60 to 90 minutes before EUS, during which a diffuser was positioned in the tumor and delivered light at 50 J/cm for 333 seconds. CT was obtained on day 2, with adverse event monitoring occurring on days 1, 2, and 14. The primary outcome was presence of necrosis. RESULTS: Of 8 patients (62.5% men, mean age 65 ± 7.9 years) included in the study, 5 were staged at T3, 2 at T2, and 1 at T1. Most (n = 4) had primary lesions in the pancreatic head. Mean pretrial tumor diameter was 33.3 ± 13.4 mm. On day 2 CT, 5 lesions demonstrated a zone of necrosis measuring a mean diameter of 15.7 ± 5.5 mm; 3 cases did not develop necrosis. No adverse events were noted during the procedure or postprocedure observation period (days 1-3), and no changes in patient-reported outcomes were noted. CONCLUSIONS: In this pilot study, EUS-guided verteporfin PDT is feasible and shows promise as a minimally invasive ablative therapy for LAPC in select patients. Tumor necrosis is visible within 48 hours after treatment. Patient enrollment and data collection are ongoing. (Clinical trial registration number: NCT03033225.).

CT radiomic features of photodynamic priming in clinical pancreatic adenocarcinoma treatment.

Photodynamic therapy (PDT) offers localized focal ablation in unresectable pancreatic tumors while tissues surrounding the treatment volume experience a lower light dose, termed photodynamic priming (PDP). While PDP does not cause tissue damage, it has been demonstrated to promote vascular permeability, improve drug delivery, alleviate tumor cell density, and reduce desmoplasia and the resultant internal pressure in pre-clinical evaluation. Preclinical data supports PDP as a neoadjuvant therapy beneficial to subsequent chemotherapy or immunotherapy, yet it is challenging to quantify PDP effects in clinical treatment without additional imaging and testing. This study investigated the potential of radiomic analysis using CT scans acquired before and after PDT to identify areas experiencing PDT-induced necrosis as well as quantify PDP effects in the surrounding tissues. A total of 235 CT tumor slices from seven patients undergoing PDT for pancreatic tumors were examined. Radiomic features assessed included intensity metrics (CT number in Hounsfield Units) and texture analysis using several gray-level co-occurrence matrix (GLCM) parameters. Pre-treatment scans of tumor areas that resulted in PDT-induced necrosis showed statistically significant differences in intensity and texture-based features that could be used to predict the regions that did respond (paired t-test, response versus no response,p < 0.001). Evaluation of PDP effects on the surrounding tissues also demonstrated statistically significant differences, in tumor mean value, standard deviation, and GLCM parameters of contrast, dissimilarity and homogeneity (t-test, pre versus post,p < 0.001). Using leave-one-out cross validation, six intensity and texture-based features were combined into a support-vector machine model which demonstrated reliable prediction of treatment effects for six out of seven patients (ROC curve, AUC = 0.93). This study provides pilot evidence that texture features extracted from CT scans could be utilized as an effective clinical diagnostic prediction and assessment of PDT and PDP effects in pancreatic tumors. (clinical trial NCT03033225).