Endocervical ultrasound applicator for integrated hyperthermia and HDR brachytherapy in the treatment of locally advanced cervical carcinoma

摘要: Purpose: The clinical success of hyperthermia adjunct to radiotherapy depends on adequate temperature elevation in the tumor with minimal rise organs at risk. Existing technologies for thermal treatment cervix have limited spatial control or rapid energy falloff. objective this work is develop an endocervical applicator using a linear array multisectored tubular ultrasound transducers provide 3-D conformal, locally targeted concomitant uterine cervix. catheter-based device integrated within HDR brachytherapy facilitate sequential and potentially simultaneous heat radiation delivery. Methods: Treatment planning images from 35 patients who underwent advanced cervical cancer were inspected assess dimensions target volumes (CTVs) gross (GTVs) surrounding proximity Biothermal simulation was used identify catheter material parameters adequately dose accumulation nontargeted structures. A family applicators fabricated two three operating 6.6-7.4 MHz that are unsectored (360 deg.), bisectored (2x180 trisectored (3x120 deg.) deposition angle alongmore » length order satisfy anatomical constraints. housed 6 mm diameter PET cooling water flow implantation. Devices characterized by measuring acoustic efficiencies, rotational intensity distributions, distributions phantom. Results: CTV plans extends 20.5{+-}5.0 tandem rectum bladder typically 5EM{sub 43 Degree-Sign C} over 4-5 cm T{sub max}<45 deg. C 1 kg m{sup -3} s{sup -1} blood perfusion. 41 contour reduced 3-4 3 Differential power transducer elements sectors demonstrates tailoring heating along angle. Sector cuts associated 14-47 dead zone, depending cut width, resulting {approx}2-4 reduction zone below max}. Dead zones can be oriented protection bladder. Fabricated devices efficiencies 33.4%-51.8% output well collimated length, reflects sectoring strategy, strongly correlated distributions. Conclusions: developed implantation targeted, conformal delivery Feasibility clinically relevant demonstrated treat bladder.« less