[1] Harbin Med Univ, Canc Hosp, Dept Gastrointestinal Surg, 150 Haping Rd, Harbin 150081, Heilongjiang, Peoples R China
[2] Harbin Med Univ, Canc Hosp, Dept Digest Internal Med, 150 Haping Rd, Harbin 150081, Heilongjiang, Peoples R China
[3] Harbin Med Univ, Canc Hosp, Photodynam Therapy Ctr, 150 Haping Rd, Harbin 150081, Heilongjiang, Peoples R China