This study evaluates the safety and effectiveness of hyperbaric oxygen therapy (HBOT) for the treatment of severe radiation-induced complications in patients previously treated with radiotherapy. Patients with clinically significant late radiation injuries will undergo HBOT sessions in a hyperbaric chamber. The study aims to assess clinical improvement of radiation damage and overall treatment tolerance.

Radiotherapy can cause severe late complications such as tissue necrosis, impaired wound healing, radiation cystitis, radiation proctitis, and other chronic radiation-induced injuries. These conditions may significantly reduce quality of life and can be difficult to treat with standard therapies.

Hyperbaric oxygen therapy (HBOT) involves breathing 100% oxygen under increased atmospheric pressure in a hyperbaric chamber. This increases tissue oxygenation, supports angiogenesis, improves wound healing, and may reduce symptoms associated with radiation injury.

This prospective interventional study will include patients with severe radiation-induced complications referred for HBOT at the Institute of Oncology Ljubljana. Participants will undergo a series of HBOT sessions according to institutional protocol. Clinical outcomes will be documented and analyzed to evaluate treatment effectiveness and safety. Data will be collected prospectively and statistically analyzed to assess the degree of symptom improvement and the occurrence of adverse events related to HBOT.

Inclusion Criteria:

• Adult patients (≥18 years)
• History of radiotherapy
• Clinically significant radiation-induced complications requiring hyperbaric oxygen therapy
• Ability to provide written informed consent

Exclusion Criteria:

• Contraindications to hyperbaric oxygen therapy (e.g., untreated pneumothorax)
• Severe comorbidity preventing safe HBOT treatment
• Inability to tolerate hyperbaric chamber sessions
• Withdrawal of informed consent