Advancements in photodynamic therapy of esophageal cancer

Abstract

The poor prognosis of patients with esophageal cancer leads to the constant search for new ways of treatment of this disease. One of the methods used in high-grade dysplasia, superficial invasive carcinoma, and sometimes palliative care is photodynamic therapy (PDT). This method has come a long way from the first experimental studies to registration in the treatment of esophageal cancer and is constantly being improved and refined. This review describes esophageal cancer, current treatment methods, the introduction to PDT, the photosensitizers (PSs) used in esophageal carcinoma PDT, PDT in squamous cell carcinoma (SCC) of the esophagus, and PDT in invasive adenocarcinoma of the esophagus. For this review, research and review articles from PubMed and Web of Science databases were used. The keywords used were “photodynamic therapy in esophageal cancer” in the years 2000–2020. The total number of papers returned was 1,000. After the review was divided into topic blocks and the searched publications were analyzed, 117 articles were selected.

Localized Photodynamic Therapy Using a Chlorin e6-Embedded Silicone-Covered Self-Expandable Metallic Stent as a Palliative Treatment for Malignant Esophageal Strictures

“…Localized PDT may induce esophageal strictures; it is well-known that localized ablation modalities such as radiofrequency ablation, irreversible electroporation, microwave, and cryoablation lead to luminal strictures after the procedure. ,,− However, although severe tissue injuries to the PDT-treated esophagus were observed on gross examination, the SEMS was well maintained after the localized PDT procedure, and the placed SEMS may prevent PDT-induced luminal narrowing. Nonetheless, due to its potential to cause necrosis, thermal ablation affects target not only tissues but also normal and/or benign tissues, leading to complications, such as vascular damage, scarring, restenosis, infection, and bleeding with or without perforation. , The Ni–Ti alloy is an important and practical shape-memory alloy with superelasticity and high biocompatibility . The conventional covered SEMS made by the Ni–Ti alloy plays a role in the palliative treatment of patients with malignant esophageal strictures .…”

“…A second-generation PS has advantages such as reduced photosensitivity and is expected to have a more significant effect on the deep-lying tissue areas after being irradiated with near-infrared laser. − Chlorin e6 is expected to reach deeper layers including the muscularis propria because the excitation wavelength of the near-infrared laser used is longer than that in the excimer dye laser used in other PSs . Localized PDT was successfully performed at different energy doses using Ce6-embedded silicone-covered SEMSs in the rat esophagus.…”

“…53−55 Chlorin e6 is expected to reach deeper layers including the muscularis propria because the excitation wavelength of the near-infrared laser used is longer than that in the excimer dye laser used in other PSs. 52 Localized PDT was successfully performed at different energy doses using Ce6embedded silicone-covered SEMSs in the rat esophagus. The histological findings showed that the esophageal epithelium was nearly intact in all PDT-treated rats, but damage to the submucosa, muscularis, and adventitia occurred when energy doses of 200 J/cm 2 and 400 J/cm 2 were delivered.…”

“…Nonetheless, due to its potential to cause necrosis, thermal ablation affects target not only tissues but also normal and/or benign tissues, leading to complications, such as vascular damage, scarring, restenosis, infection, and bleeding with or without perforation. 51,52 The Ni−Ti alloy is an important and practical shape-memory alloy with superelasticity and high biocompatibility. 19 The conventional covered SEMS made by the Ni−Ti alloy plays a role in the palliative treatment of patients with malignant esophageal strictures.…”

Simulating photodynamic therapy for the treatment of glioblastoma using Monte Carlo radiative transport

“…5 PDT is used and being investigated as a targeted and minimally invasive treatment option for many areas of oncology such as for skin, 6 head and neck, 7 bladder, 8 lung, 9 and esophageal cancers. 10 There are several clinical trials, past, present, and future, aiming to explore the potential of PDT for GBM treatment. 2,11…”