Microwave hyperthermia radiosensitized iridium-192 for recurrent brain malignancy

Area of Science:

• Oncology
• Neurosurgery
• Radiation Oncology

Background:

• Recurrent brain malignancies often present with Central Nervous System (CNS) symptoms requiring intervention.
• Previous teletherapy for brain tumors necessitates novel treatment approaches for recurrence.

Purpose of the Study:

• To evaluate the efficacy and safety of interstitial microwave hyperthermia, with or without brachytherapy, for recurrent brain malignancies.
• To assess treatment response, complications, and long-term outcomes in patients with recurrent CNS tumors.

Main Methods:

• Twenty-one patients with recurrent brain malignancies received interstitial microwave hyperthermia (43°C for 180 degree-minutes).
• Fifteen patients received hyperthermia alone (toxicity pilot), while six also received interstitial Ir-192 brachytherapy.
• CT-guided stereotactic techniques were employed for biopsy, brachytherapy, and thermal monitoring.

Main Results:

• All 15 patients in the toxicity pilot experienced neurologic improvement; 12 showed symptomatic improvement and objective response (mass reduction/necrosis).
• The 6 patients receiving hyperthermia and brachytherapy also demonstrated neurologic improvement, symptom reduction, and objective tumor response.
• Three patients in the brachytherapy group remain alive, with one experiencing transient improvement.

Conclusions:

• Interstitial microwave hyperthermia is a viable treatment for recurrent CNS malignancies, offering significant patient benefit.
• The combination of hyperthermia and brachytherapy shows potential for improved outcomes in select patients.
• Novel techniques for CT-guided interstitial procedures minimize trauma and enhance treatment delivery.