Phase 4 Study on the Treatment of Bile Duct Cancer with Radiofrequency Ablation or Photodynamic Therapy

Hilar bile duct cancer (Klatskin tumor) is a malignant disease characterized by the uncontrolled proliferation of cells that line the inner wall of the bile ducts. “Hilar” means that the affected sections of the bile duct are located outside the liver (at the junction of the right and left hepatic ducts). The disease is usually asymptomatic in its early stages; in advanced stages, symptoms may include nonspecific abdominal discomfort or painless jaundice (yellowing of the skin or the whites of the eyes). A blockage of the bile duct caused by the cancer may be a cause of these symptoms. However, due to late diagnosis, the cancer is often diagnosed only incidentally or only at an advanced or metastatic stage. Cancer is considered metastatic when cancer cells are already detectable as distant metastases in other organ systems. The only curative treatment is complete surgical removal of the tumor. If metastases are already present or if surgery is not possible for other reasons, the situation requires palliative care. A complete cure is no longer possible with palliative treatment approaches, and the primary goal is to improve quality of life (symptom relief) and to “keep the disease in check.” As part of palliative therapy, the bile duct is first kept open using an endoscopically inserted stent (a small, mesh-like tube made of metal or plastic). In addition, further treatment involves either photodynamic therapy (PDT) or radiofrequency ablation (RFA). In PDT, patients are administered a light-sensitive agent (photosensitizer) intravenously, which is absorbed by the cancer cells. Laser light is then directed into the bile duct, activating the agent and releasing reactive oxygen species. This allows the cancer cells to be specifically destroyed. In addition to high costs and limited availability, this treatment method also has the disadvantage that the skin becomes significantly more sensitive to light. Therefore, patients should avoid direct sunlight for several weeks. RFA is performed using an electrode that is inserted near the tumor via endoscopy or a catheter. Applying an electric current generates heat, which destroys the cancer cells. RFA technology is widely used and easier to administer. However, it has not yet been extensively studied, and there are no randomized trials that directly compare the two methods.

The goal of this Phase 4 study is to compare radiofrequency ablation with photodynamic therapy in terms of survival rates, the occurrence of side effects, and patients’ quality of life.

As part of the study, patients will be randomly assigned to two groups. Group 1 will be treated with photodynamic therapy, and Group 2 with radiofrequency ablation. The study is open-label, meaning that both the medical staff and the patient know which treatment is being administered. Treatment and follow-up examinations as part of the study will take place over a period of up to 1 year, during which the survival rate, the occurrence of side effects, and patients’ quality of life will be documented. Women and men aged 18 and older with inoperable hilar bile duct cancer are eligible to participate in this study.