Effect of concurrent radiotherapy and simultaneous oral capecitabine chemotherapy on locally advanced middle and lower rectal cancer

Objective: To assess the safety and efficacy of preoperative intensity-modulated radiotherapy (IMRT) with oral capecitabine in patients with locally advanced mid-low rectal cancer using a simultaneous integrated boost (SIB) of tomotherapy. Methods: Between 2012 and 2014, total Sixteen Patients with resectable locally advanced mid-low rectal cancer patients with T3 to T4 and/or N+ rectal cancer were eligible. The eligible patients received IMRT to 2 dose levels simultaneously 55 and 47.5 Gy in 25 fractions with concurrent capecitabine 825 mg/m(2) twice daily 5 days/week. Total mesorectal excision (TME) was performed 6-9 week after the completion of chemoradiation. The primary end point included toxicity, rate of sphincter-sparing, postoperative complication, and pathological complete response rate (pCR). Result: All patients completed chemoradiation without any treatment break. Tomotherapy showed superiority with respect to target coverage, homogeneity, and conformality 2 patients refused radical surgery because of almost complete primary tumor regression and complete symptom relief after neoadjuvant therapy. Fourteen patients underwent surgical resection and eleven patients 78.6% underwent sphincter-sparing lower anterior resection. 4 patients 28.6% had a pathological complete response (pCR). The incidence of grade 1-2 hematologic, gastro-intestinal toxicities was 62.5% (10/16) and 18.8% (3/16). The incidence of grade 3 skin toxicities were 68.8% (10/16). Grade 4 toxicity was not observed. Surgical complications incisional infection on thirteen after surgery was observed in 1 patients. Conclusion: Preoperative simultaneous integrated boost (SIB) of tomotherapy with concurrent oral capecitabine is safe and well tolerated in patients in a promising local control. However, a larger number of patients and a long follow-up are required to assess its potential superiority.