title: The Feasibility of an Ex-vivo Sentinel Lymph Mapping Using Preoperative Radioisotope Injection in Cases of Extraperitoneal Rectal Cancer.
abstract: OBJECTIVE
  The purpose of this research was to evaluate the feasibility of sentinel lymph node (SLN) mapping involving transanal injection with an ex-vivo mapping in patients with rectal cancer.
  
  
  METHODS
  Between April 2007 and December 2009, 20 consecutive patients with T1-3, N0-1 clinical stage rectal cancer preoperatively underwent a SLN procedure using submucosal (99m)Tc-phytate injection. All the patients underwent a total mesorectal excision. After the standard surgical resection, all specimens were identified on lymphoscintigraphy, and bench work was done to pick up the sentinel node basin. All the lymph nodes (non-SLNs and SLNs) were examined using conventional hematoxylin and eosin staining and immunohistochemistry with anti-cytokeratin antibodies.
  
  
  RESULTS
  SLNs were identified from 19 of 20 patients with rectal cancer. The total number of sentinel nodes retrieved from the surgical specimens was 29, and the mean number per patient was 1.6 (range, 0 to 4). In three patients, the SLN was the only positive lymph node. There was one false-negative case with a sensitivity of 88.8% and two upstaged cases (20.0%). The SLN samples from rectal cancer are mainly localized in the pararectal region, but aberrant nodes receive direct drainage from the rectal cancer. On planar lymphoscintigraphy, 15.7% of all patients had aberrant lymphatic drainage to the sigmoid mesenteric or sigmoid lymph node station.
  
  
  CONCLUSIONS
  In conclusion, the intraoperative transanal injection for ex-vivo SLN navigation is a safe, feasible surgical modality in patients with rectal cancer. Large studies are warranted to determine the clinical significance of the SLN concept and micrometastasis in rectal cancer.
authors: Department of Surgery, Kyungpook National University Hospital, Kyungpook National University School of Medicine, Daegu, Korea.
authors: Jun Seok
authors: JS
authors: Park
authors: Gyu-Seog
authors: GS
authors: Choi
authors: Hye Jin
authors: HJ
authors: Kim
authors: Soo Yeon
authors: SY
authors: Park
authors: Yun Jung
authors: YJ
authors: Park
authors: Sang-Woo
authors: SW
authors: Lee
authors: Ziguang
authors: Z
authors: Xu
authors: Han Ik
authors: HI
authors: Bae
references: Colorectal Dis. 2002 Nov;4(6):447-9
references: 12790917
references: Ann Surg Oncol. 2011 Apr;18(4):1006-14
references: 21080086
references: Colorectal Dis. 2003 Mar;5(2):164-8
references: 12780907
references: Eur J Surg Oncol. 2007 Dec;33(10):1177-82
references: 17449218
references: Arch Surg. 2000 Aug;135(8):926-32
references: 10922254
references: Am J Surg. 2006 Mar;191(3):305-10
references: 16490536
references: J Clin Oncol. 2002 Oct 15;20(20):4232-41
references: 12377967
references: Ann Surg. 2007 Jun;245(6):858-63
references: 17522509
references: Pathol Oncol Res. 1999;5(4):291-6
references: 10607924
references: Arch Surg. 2006 Jun;141(6):527-33; discussion 533-4
references: 16785352
references: Dis Colon Rectum. 1998 Mar;41(3):310-5
references: 9514425
references: J Clin Oncol. 1995 Dec;13(12):2936-43
references: 8523058
references: Ann Surg. 2007 Oct;246(4):568-75; discussion 575-7
references: 17893493
references: Eur J Surg. 1996 Aug;162(8):637-42
references: 8891622
references: Ann Surg. 2009 Jun;249(6):960-4
references: 19474698
references: Am J Surg. 2001 Dec;182(6):707-12
references: 11839343
references: Ann Surg Oncol. 2000 Mar;7(2):120-4
references: 10761790
references: Br J Surg. 1999 Apr;86(4):482-6
references: 10215818
references: Ann Intern Med. 1995 Mar 1;122(5):321-6
references: 7847642
references: Br J Surg. 2005 Dec;92(12):1533-8
references: 16231281
references: Cancer. 1977 Feb;39(2):456-66
references: 837331
references: J Clin Oncol. 1999 May;17(5):1356-63
references: 10334519
references: Int J Colorectal Dis. 2007 Dec;22(12):1509
references: 17622543
references: Dis Colon Rectum. 2004 Nov;47(11):1767-72
references: 15622567
references: Ann Surg Oncol. 2001 Mar;8(2):150-7
references: 11258780
references: Ann Surg. 1990 Aug;212(2):123-4
references: 2375644