# Optimizing Photodynamic Therapy for Cervical Esophageal Cancer: A Novel Technique for Precise Lesion Targeting by Transnasal Thin Endoscopy and Upward-Facing Attachment

## TL;DR

A new technique using a thin endoscope improves photodynamic therapy for cervical esophageal cancer by enabling precise laser targeting and reducing complications.

## Contribution

A novel transnasal thin endoscopy technique with a customized attachment for precise laser targeting in cervical esophageal cancer.

## Key findings

- Two patients with recurrent cervical esophageal cancer achieved complete local control with no recurrence over one to four years.
- The technique reduced laser scattering and enabled stable, perpendicular irradiation using a thin endoscope.
- The method requires specialized equipment and expertise, limiting its immediate widespread use.

## Abstract

Photodynamic therapy (PDT) with talaporfin sodium shows promise as a salvage treatment for locoregional recurrence of esophageal cancer after chemoradiotherapy (CRT). However, its application in cervical esophageal cancer is limited due to anatomical challenges, such as the restricted maneuverability of standard endoscopes and difficulty in achieving stable and perpendicular laser irradiation.

This study introduces a modified PDT technique using a thin endoscope with a customized attachment for lesion stabilization and precise laser targeting. The attachment, wrapped in black plastic tape, facilitated perpendicular irradiation and reduced laser scattering.

Two cases of recurrent cervical esophageal cancer after CRT were successfully treated with this method. The first patient had a 10-mm, 0-IIc+IIa, cT1b lesion with severe stenosis, necessitating the use of a thin endoscope. PDT was performed with 600 J irradiation, achieving complete local control without complications, with no recurrence over four years. The second patient had a 20-mm, 0-IIa, cT1b lesion and was treated with 800 J irradiation, resulting in complete local control within three months and no recurrence at one year.

Despite these promising results, this modified PDT technique has several limitations. The small sample size (two cases) limits generalizability, and long-term outcomes beyond the current follow-up period remain unknown. Additionally, the technique requires specialized equipment and expertise, potentially limiting its widespread adoption. This study presents a novel modification of PDT using transnasal thin endoscopy for precise targeting of cervical esophageal cancer lesions. This approach minimizes laser scattering and enhances procedural accuracy. We report two cases with complete local control and no recurrence over one to four years. While promising, further studies are required to assess its long-term efficacy and broader applicability.