Combination hyperthermia and radiation therapy for malignant melanoma

Area of Science:

• Oncology
• Radiation Oncology
• Medical Physics

Background:

• Clinical studies since 1975 have investigated the efficacy of combining radiation therapy with localized hyperthermia.
• Hyperthermia aims to enhance the tumoricidal effects of radiation, potentially improving treatment outcomes.

Purpose of the Study:

• To evaluate the effectiveness of combined radiation and hyperthermia therapy versus radiation alone for tumor control.
• To analyze factors influencing treatment outcomes, including tumor volume and treatment fractionation.

Main Methods:

• Localized hyperthermia was induced using radiofrequency inductive (27.12 MHz) or conductive (13.56 MHz) heating.
• Over 100 lesions in 38 patients were treated with either radiation alone or combined radiation and hyperthermia.
• Treatment schedules varied (once or twice weekly) based on radiation dose fractionation.

Main Results:

• The combined therapy achieved a significantly higher tumor control rate (75%) compared to radiation alone (46%; P < 0.01).
• No increased normal tissue morbidity was observed with the combined treatment.
• Radiation alone was effective for small tumors (<10 cm3) at high doses per fraction (80% control), but less so for larger tumors (30%).
• Combined therapy achieved 80% local tumor control irrespective of initial tumor volume.

Conclusions:

• Combined radiation and hyperthermia therapy offers superior tumor control compared to radiation alone.
• Treatment efficacy is influenced by dose per fraction, total dose, and initial tumor volume.
• Optimal thermal distribution, selective tumor heating, and appropriate sequencing are crucial for combined therapy success.