Advances in hyperthermia applicators for skin and superficial cancer treatment: A comprehensive review report

Skin and superficial cancers remain major global health concerns, demanding effective, minimally invasive, and non-invasive therapies with improved precision and patient safety. Conventional treatment approaches, including surgery, chemotherapy, radiotherapy, and immunotherapy, often cause significant side effects and exhibit limited therapeutic selectivity. Microwave hyperthermia has emerged as a promising complementary treatment that selectively elevates tumor temperatures to 40–45°C without ionizing radiation. This review article aims to comprehensively summarize the evolution of microwave hyperthermia applicators reported between 1990 and 2026 for skin and superficial cancer treatment. The paper presents a comprehensive review and comparative analysis of published work covering cancer fundamentals, microwave–tissue interactions, microwave frequency bands, critical design constraints, and reported invasive and non-invasive applicators. Their electromagnetic characteristics, thermal performance, penetration capability, effective field size, and experimental validations are comparatively evaluated. The review reveals that recent developments increasingly emphasize compact, flexible, dual-band, patient-conforming, and metamaterial-based applicators that improve treatment efficiency, heating localization, and clinical practicality. It is concluded that continued advancements in applicator design are essential for improving microwave hyperthermia performance. The findings provide practical design guidance for researchers, engineers, and clinicians developing next-generation microwave hyperthermia applicators for effective skin and superficial cancer therapy.