[Feasibility study on Xelox (capecitabine plus oxapliplatin) in the volumetric modulated arc therapy (VMAT)-based preoperative chemoradiotherapy for locally advanced rectal cancer].

OBJECTIVE

To investigate the feasibility of Xelox(capecitabine plus oxaliplatin) in the volumetric modulated arc therapy(VMAT)-based preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer(LARC).

METHODS

Clinical data of 141 LARC patients in our hospital from April 2011 to April 2013 treated by preoperative CRT based on VMAT with concurrent Xelox followed by surgery were analyzed retrospectively. There were 95 men and 46 women, and the median age was 56 years old. Clinical staging was stage II( in 33 cases(18 cases with II(a, 11 cases with II(b, 4 cases with II(c) and stage III( in 108 cases(1 case with III(a, 52 cases with III(b, 55 cases with III(c). The target doses were 50 Gy for PTV1 in 25 fractions and 46 Gy for PTV2 in 23 fractions.

RESULTS

All the patients completed the planned radiotherapy, and only 2 cases were interrupted with acute grade 3 diarrhea. The overall incidence of grade 3 hematologic and non-hematologic adverse events during CRT was 9.9% and 16.3% respectively without grade 4 toxicity. Operation was performed after a median interval of 54 days(34-86 days) following CRT. The R0 resection rate was 100%, sphincter preservation rate for low rectal cancer was 45.8%(33/72), postoperative complication morbidity was 17.0%(24/141), pCR rate was 32.6%(46/141), and rates of pathological down-staging for the primary tumor, lymph node and clinical stage were 87.2%, 88% and 90.1%, respectively.

CONCLUSIONS

Xelox is feasible and well tolerated in the treatment of VMAT-based preoperative CRT for patients with LARC, with excellent rates of pCR and pathological down-staging.