Endoscopic submucosal dissection and photodynamic therapy of residual lesions after radiotherapy for esophageal cancer

Abstract

An 82-year-old man diagnosed with clinical stage I (cT1N0M0, UICC TNM 8th) esophageal squamous cell carcinoma (ESCC) underwent radiotherapy. A circumferential residual lesion was detected, including a nodular component suspected of invading the shallow muscularis propria (MP) and a flat component presumed to be an intramucosal lesion (Fig. 1a–c). Computed tomography (CT) scan revealed no metastasis. We performed photodynamic therapy (PDT) on the nodular component, followed by endoscopic submucosal dissection (ESD) for the remaining flat lesion. PDT using talaporfin with a diode laser was performed in one session, treating three separate areas with 100 J/cm², totaling 300 J (Fig. 1d,e). Eight weeks post-PDT, esophagogastroduodenoscopy (EGD) revealed scarring at the PDT site (Fig. 2a,b). Subsequently, ESD was performed, and en-bloc resection was achieved with no intraprocedural adverse events, despite submucosal fibrosis due to prior PDT and radiotherapy (Fig. 2c,d). Given the near-circumferential resection, steroid therapy was administered to prevent strictures. Although the vertical margin was negative, the horizontal margin near the post-PDT scar was positive histopathologically, possibly due to the burning effects of ESD. Eight weeks post-ESD, EGD showed no residual lesions or stricture; biopsies confirmed no cancer, achieving a complete response (CR) (Fig. 2e,f). Given the post-PDT status and positive horizontal margin, follow-up with EGD and CT was scheduled every 3 months.

Photodynamic therapy is indicated for lesions involving less than half the circumference that invade the shallow MP^1-3; whereas, salvage ESD is indicated for intramucosal lesions regardless of their circumference. However, a higher recurrence rate is reported in patients undergoing ESD with submucosal invasion and positive vertical margins.⁴ Although the lesion was circumferential, the suspected MP-invaded area was limited, whereas the remaining lesion was suspected to be intramucosal. Combining PDT of the MP-invaded area with salvage ESD of the superficial lesion achieved CR. This combination provides a treatment option for residual ESCC with small invasive and large intramucosal areas (Video S1).

Authors declare no conflict of interest for this article.