Dosimetric Comparison of Two Kinds of Radiotherapy Techniques for Intractable Keloids
SUN Shuai1
, YU Lang1
, WANG Bei1
, WU Qinhong2
, ZHANG Fuquan1
1. Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking
Union Medical College, Beijing 100730, China;
2. Department of Radiation Oncology, National Center of Gerontology, Beijing Hospital, Beijing 100730, China
Abstract:Objective To compare the dosimetric difference of external beam radiotherapy with 6 MeV electron beam and iridium
192 (192Ir) high dose rate (HDR) superficial brachytherapy for intractable keloids. Methods On the head and neck phantom and solid
water phantom, intractable keloids in common sites (mandibular region and long keloids, so that two irradiation fields are needed
for radiotherapy) were marked. Under the conditions of application of Flap tubular applicator or not, four sets of CT images were
obtained by CT scanning. Then, the planning system was used to simulate the dosimetric distribution of external beam radiotherapy
with 6 MeV electron beam and 192Ir GDR superficial brachytherapy. Results Compared with external beam radiotherapy with 6 MeV
electron beam, 192Ir HDR superficial brachytherapy showed obvious advantages in dosimetry. 192Ir HDR superficial brachytherapy
achieved more concentrated exposure in areas requiring irradiation, reduced radiation to surrounding healthy skin, maintained the
uniform dose distribution of the reference point plane on the uneven surface, and avoided problems such as poor dosage cohesion
at the field In the cases with long incisions and external irradiation requiring separate field irradiation. Conclusion Compared with
external beam radiotherapy with 6 MeV electron beam, 192Ir HDR superficial brachytherapy has an obvious dosimetric advantage in
the treatment of cases with long or uneven surface wounds.