Preliminary observation of the results of external irradiation combined with brachytherapy for inoperable locally advanced rectal cancer / 中华放射肿瘤学杂志

ABSTRACT

Objective:To explore the clinical efficacy and adverse reactions of the combination of external beam radiotherapy followed by three-dimensional intracavitary brachytherapy in patients with inoperable locally advanced rectal cancer.Methods:Clinical data of 11 patients with inoperable locally advanced rectal cancer, 7 male and 4 female, admitted to China-Japan Union Hospital of Jilin University from 2013 to 2015 were retrospectively analyzed. All patients received pelvic external irradiation (50 Gy in 25 fractions), followed by a three-dimensional intracavitary brachytherapy boost (15-20 Gy in 3-4 fractions, 1 fraction/week). External beam radiotherapy was used to boost the dose to the perirectal lymph nodes (60-66 Gy in 30-33 fractions). All patients received concurrent chemotherapy with Capecitabine during external beam radiotherapy. Efficacy evaluation was performed using the RECIST standard. Survival and local control rates were calculated using the Kaplan- Meier method. Early and late radiotherapy responses were assessed using the RTOG lesion grading criteria. Results:The CTV D 90% EQD 2 Gy of HDR 3D-ICBT among 11 patients was (21.3±1.60) Gy. The complete response (CR) and partial response (PR) rates were 64% and 27%, respectively, yielding an objective response rate (CR+PR) of 91%. With a median follow-up time of 36 months, the 1-, 2-, and 3-year overall survival rates were 82%, 64% and 46%, respectively. The 1-, 2-, 3-year disease-free survival rates were 64%, 45% and 27%, respectively. The 3-year local control rate was 46%. One patient presented with lung metastases after 8 months, 7 patients experienced grade 1-2 acute intestinal reactions and 5 patients developed grade 1-2 acute bladder reactions, only one patient had grade 2 myelosuppression; long-term grade 1-2 intestinal reactions occurred in 5 patients, and 1 patient had long-term grade 1-2 bladder reaction. All the radiation-induced toxicities were alleviated by medication administration. Conclusions:External beam radiotherapy followed by three-dimensional intracavitary brachytherapy can be a safe and effective surrogate in patients with inoperable locally advanced rectal cancer, which yields reliable clinical efficacy and tolerable adverse reactions.