ABSTRACT
Objective To investigate the 5-and 10-year survival and complications of patients with stage Ⅱb cervical carcinoma treated by pre-operative photon radiotherapy (POPRT) plus brachytherapy (192Ir) and selective lymphadenectomy hysterectomy (SLH) plus intra-operative electron radiotherapy (IOERT). Methods From February 1997 to May 2007, 160 patients with stage Ⅱb cervical carcinoma were treated by POPRT of 20 Gy in 10 fractions to the whole pelvis, 192Ir brachytherapy of 14 Gy in 2fractions, followed by IOERT of 18 -20 Gy to the whole pelvis during SLH one week after. Results The follow-up rate was 98.1%. The number of patients followed-up for 5 and 10 years was 143 and 135,respectively. The 5-year overall survival rate, disease-free survival rate and local control rate of all patients were 89.4%, 86. 3% and 96. 3%, with the corresponding 10-year rates of 84.4%, 81.0% and 95.0%,respectively. The radiation-induced rectitis and cystitis were 5.0% and 0. 6%, respectivly. The rate of hydronephrosis and lower extremity edema was 6. 3% and 1.3%, respectively. Conclusions Combination of EBRT plus 192Ir brachytherapy and SLH plus IOERT could improve the survival and local control of patiens with cervical carcinoma, with only a few side effects.
ABSTRACT
Objective To commission a Mobetron intra-operative mobile accelerator and analyze the characteristics of its electron beams. Methods The dosimetrie characteristics of the electron beams genera-ted by Mobetron accelerator were measured and compared with those generated by conventional accelerator (Primus, Siemens). M oberton accelerator can generate electron beams of nominal energies of 4,6,9 and 12 MeV. The measurement items were as followings : percentage depth dose perpendicular to water phantom sur-face and beam profiles parallel to water phantom surface, output factors, applicator leakage, electron beam at-tenuation made by lead blocks,and machine output calibration. The measurement devices included a three-dimensional ( 3 D) water scanning phantom, an electrometer, a 0.6 cm3 Farmer ionization chamber, a parallel-plate ionization chamber and solid water slabs. During measurement, all applicators of different tilt angles and diameters were attached to the machine head,and their ends were adjusted to be tangent to the phantom surface. Results Except for the 12 MeV,skin dose for all energies was no more than 90%. The skin dose was higher for Mobetron accelerator electron beams than for regular electron beams. The Dmax depth in water for a 10 cm flat applicator were 0.7,1.3,2.0 and 2.2 cm for the 4 energies,respectively. The depths of 90% dose were 1.0,1.8,2.7 and 3.6 cm, respectively. The selected flat applicator was just 1 cm larger than the tumor bed. But for the beveled applicators,the field flatness and symmetry became worse,and con-sequently,the applicator size had to be selected based on the isodose distribution. The leakage dose at 1 cm outside the applicator was 1.2% ,5.1%, 10.0% and 9.1%, respectively. The lead thickness for full block was 1.5,3.0,4.5 and 6.0 mm,respectively. Conclusions Through the commissioning of Mobetron accel-erator, the machine characteristics are understood, and the data for clinical implementation and routine quality assurance are acquired.