| Objectives:1.To assess the outcome and late complications about the external-beam radiotherapy(EBRT)combined with C f-252 neutron intracavitary brachytherapy(IC BT)in the definitive radiotherapy of cervical cancer.2.To assess the correlation of radiation dose to rectum and bladder with late complications(radiation proctitis and cystitis)following the C f-252 neutron ICBT combined with EBRT in patients with cervical cancer.3.The efficacy of external beam radiotherapy(EBRT)combined with C f-252 neutron ICBT(C f-252 group)was compared with that of EBRT combined with Iridium-192 γ(Ir-192)IC BT and concurrent chemotherapy(Ir-192 group)in pares for treatment of patients with stage IIIb squamous cell carcinoma(SCC)of the uterine cervix.Methods:1.A total of 1431 patients with intact untreated cervical cancer(Stages IB to IIIB)were enrolled into the study between December 2004 and May 2011.The cutoff date of evaluation was December 10,2016.O f all,83 patients were at Stage IB,270 at IIA,792 at IIB,64 at IIIA,and 259 at IIIB.All the patients were treated with C f-252 ICBT in combination of EBRT.C f-252 IC BT was delivered at 7–12 Gy per insertion per week,with a total dose of 28–45 Gy to reference point A in three to five insertions.The whole pelvic cavity was treated with 8-MV X-ray external irradiation at 2 Gy per fraction,four times per week.After 16–38 Gy of external radiation,the center of the whole pelvic field was blocked with a 4-cm-wide lead shield,with a total external irradiation dose of 44–56 Gy.The total treatment course was 5 to 6 weeks.2.A total of 286 cervical cancer patients treated by C f-252 neutron ICBT combined with EBRT between January 2007 and August 2010 were enrolled into this study.At total dose of 40Gy(10Gy per fraction×4 fractions).was given at point A to determine the maximum dose delivered to the rectal anterior and bladder posterior walls.The distance from the maximum dose point of rectal and bladder to tandem center was measured,retrospectively.Furthermore,all the patients were divided into high,moderate and low dose groups according to the dose they received in comparison to the reference maximum radiation dose.To observed the incidence of severe(≧G2)radiation proctitis and cystitis.3.Patients with stage IIIb SCC treated at two cancer centers(Sun Yat-sen University and the Third Affiliated Hospital of the Third Military Medical University)between February 2005 and December 2012 were retrospectively analyzed in this study.Patients were matched for age,tumor size,hemoglobin concentration,and pelvic lymph node metastasis.Mean survival,5-year overall survival,progression-free survival,local control,and severe late complication rates were compared between the C f-252 group;(n=115)and Ir-192 group;(n=115).Results:1.Five year local control,overall survival,disease-free survival and late complications rates for all patients were 87%,70.6%.,68.3% and 13.3% respectively.Furthermore,the mean survival time was 91.8 ±1.2 months for whole patients.Correlation of stage,hemoglobin concentration,tumor size,and pelvic lymph node metastasis assess the five year local control overall survival,disease-free survival and late complications rates.2.In rectum,distance between the maximum dose point and the center of intrauterine applicator was positively correlated to increased number of treatment(r=0.990,p<0.05)whereas a negative correlation was deciphered between the radiation dose and treatment number(r=-0.959,p<0.05.No such correlation was found in the bladder.The inc idences of late radiation-induced proctitis for high,moderate and low dose groups were 13.2%,2.0% and 1.1%,respectively.It has statistically significant(p<0.01),however,the incidences of late cystitis were 4.2%,2.6%,and 4.5%,respectively,and without significant statistically difference.(p=0.270).3.Patients in the C f-252 group had longer mean survival time(82.4 ± 4.9 months [m] vs.73.9 ± 5.2 m,respectively),higher 5-year overall survival(58.3 % vs.55.7%),local control(76.5% vs.75.6%),and progression-free survival rates(57.4% vs.55.7%),as compared to those in the Ir-192 group;however,the differences were not statistically significant(p > 0.05).A significantly lower incidence of severe late complications rate was observed in the former(10.4% vs.22.6%,respectively;p < 0.05)and they were no statistically significant differences between two group for survival time(p>0.05).Conclusions:1.Results of the study suggest that the combination of C f-252 IC BT with EBRT is an effective method for treatment of cervical cancer.The incidence of complication with this scheme is acceptable.2.We can predict the incidences of late radiation proctitis and cystitis through monitoring the delivered radiation dose rectum and bladder by Cf-252 neutron ICBT.3.EBRT plus C f-252 neutron IC BT is particularly valuable in patients with advanced cervical cancer.Prospective studies with larger sample sizes are required to obtain more definitive evidence in this regard. |
PDF Full Text Request