Department of Radiation Biology, Radiotherapy & Radiodiagnosis

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Browsing Department of Radiation Biology, Radiotherapy & Radiodiagnosis by Author "Adedokun, MB"

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    Open Access
    Evaluation of temperature distributions during microwave ablation of ex vivo bovine liver using two types of antennas.
    (2019-03) Ibitoye, AZ; Nwoye, EO; Saseyi, AO; Adeneye, SO; Adedokun, MB; Aweda, MA
    Introduction: Temperature distributions during microwave ablation are dependent on the antenna types, antenna geometry, tissue properties, input power and ablation. All these factors can significantly affect the coagulation region, ablation length, ablation diameter, aspect ratio, backward heating (comic effect), and degree of necrosis. Temperature distributions during microwave ablation procedures determine the effectiveness of ablating tumours in tissue. Objective: The aim of this study is to evaluate temperature distributions during microwave ablation using sleeved and dual slot antennas. Materials and Methods: In this study, sleeved and dual slot antennas were designed using COMSOL MULTIPHYSICS software version 4.4. Temperature distributions were analyzed at 10 mm and 20 mm from the antennas’ surfaces. Dualslot and sleeved antennas were fabricated from 0.085’ 50 Ω semi-rigid coaxial cable to conform to numerical simulation. The antennas were applied on ex vivo bovine liver. Thermometer probes were placed at 10 mm and 20 mm from the antennas’ surfaces with the input powers set at 30, 50 and 80 W for 300 s. Before each ablation, the initial temperature was recorded whereas subsequent measurements were recorded at 50 s intervals. Numerical simulation and experimental obtained data were analyzed and compared using the student's t-test statistical tool. Results: The findings in this study showed that temperatures produced at the two points of measurements by the sleeved antenna were greater than that of the dual-slot antenna in simulation and experimental procedures. Also, there was no significant difference between simulation and experimentally results for dual-slot antenna and sleeved antenna (p = 0.25). Conclusion: In conclusion, the sleeved antenna has the potential to ablate a tumour faster above the tumoricidal temperatures at the same position than the dual-slot antenna.
  • Item
    Open Access
    Evaluation of the performance of designed coaxial antennas for hyperthermia using simulation and experimental methods
    (Sciendo, 2021-03-31) Ibitoye, AZ; Ogese, CO; Adedokun, MB; Habeebu, MYM; Nwoye, EO; Aweda, MA
    Introduction: Antenna geometries and tissue properties affect microwave energy distributions during microwave ablation procedures. There is a paucity of information on the potential of antenna fabricated from a thick semi-rigid coaxialcable in the field of microwave thermal therapy. This study aimed at comparing the performance of two dual-slotantennas designed from different semi-rigid coaxial cables for the ablation of a liver tumour using numerical simulationand experimental validation methods. Materials and Methods: COMSOL Multiphysics software was used for designing dual-slot antennas and as well as toevaluate microwave energy deposition and heat distribution in the liver tissue. Experimental validations were conductedon the ex-vivo bovine livers to validate the simulation results. Results: Thick antenna developed in this study produced a higher sphericity index, larger ablation diameter and reducedbackward heating along the antenna shaft than the existing one. The experimental validation results also indicatesignificant differences between the two antennas in terms of ablation diameters (p = 0.04), ablation lengths (p = 0.02)and aspect ratios (p = 0.02). Conclusion: Based on the findings in this study, an antenna fabricated from a thick coaxial cable has ahigher potential oflocalizing microwave energy in the liver than conventional antennas.