Proposing the lymphatic target volume for elective radiation therapy for pancreatic cancer: a pooled analysis of clinical evidence.
BACKGROUND
Radiation therapy is an important cancer treatment modality in both adjuvant and definitive setting, however, the use of radiation therapy for elective treatment of regional lymph nodes is controversial for pancreatic cancer. No consensus on proper selection and delineation of subclinical lymph nodal areas in adjuvant or definitive radiation therapy has been suggested either conclusively or proposed for further investigation. This analysis aims to study the pattern of lymph node metastasis through a pooled analysis of published results after radical tumor and lymph nodal resection with histological study in pancreatic cancer.


METHODS
Literature search using electronic databases including MEDLINE, EMBASE, and CANCERLIT from January 1970 to June 2009 was performed, supplemented by review of references. Eighteen original researches and a total of 5954 pancreatic cancer patients underwent radical surgical resection were included in this analysis. The probability of metastasis in regional lymph nodal stations (using Japan Pancreas Society [JPS] Classification) was calculated and analyzed based on the location and other characteristics of the primary disease.


RESULTS
Commonly involved nodal regions in patients with pancreatic head tumor include lymph nodes around the common hepatic artery (Group 8, 9.79%), posterior pancreaticoduodenal lymph nodes (Group 13, 32.31%), lymph nodes around the superior mesenteric artery (Group 14, 15.85%), paraaortic lymph nodes (Group 16, 10.92%), and anterior pancreaticoduodenal lymph nodes (Group 17, 19.78%); The probability of metastasis in other lymph nodal regions were <9%.Commonly involved nodal regions in patients with pancreatic body/tail tumor include lymph nodes around the common hepatic artery (Group 8, 15.07%), lymph nodes around the celiac trunk (Group 9, 9.59%), lymph nodes along the splenic artery (Group 11, 35.62%), lymph nodes around the superior mesenteric artery (Group 14, 9.59%), paraaortic lymph nodes (Group 16, 16.44%), and inferior body lymph nodes (Group 18, 24.66%). The probability of metastasis in other lymph nodal regions were <9%.


CONCLUSIONS
Pancreatic cancer has a high propensity of regional lymphatic metastases; however, clear patterns including the site and probability of metastasis can be identified and used as a guide of treatment in patients with resectable pancreatic cancer. Further clinical investigation is needed to study the efficacy of elective treatment to CTV defined based on these patterns using high-dose conformal or intensity-modulated radiation therapy.
Sun
Wenjie
W
Department of Radiation Oncology, Fudan University Shanghai Cancer Center Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
Leong
Cheng N
CN
Zhang
Zhen
Z
Lu
Jiade J
JJ
D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000528:radiation effects*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D011379:Prognosis; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted
Radiother Oncol. 2003 Jul;68(1):69-74
12885454
Cancer Radiother. 2009 Oct;13(6-7):594-9
19766523
Cancer. 1994 Feb 15;73(4):1155-62
8313317
Surgery. 2005 Oct;138(4):618-28; discussion 628-30
16269290
Ann Surg. 1988 Aug;208(2):215-20
2840866
Eur J Surg Oncol. 2007 Sep;33(7):887-91
17433604
Br J Surg. 1997 Aug;84(8):1090-2
9278647
Cancer. 1996 Dec 15;78(12):2485-91
8952555
Int J Radiat Oncol Biol Phys. 2009 Oct 1;75(2):618-25
19683403
Cancer. 1978 Mar;41(3):880-7
638975
Cancer. 1981 Oct 15;48(8):1705-10
7284971
Pancreas. 2005 Jul;31(1):88-92
15968254
Semin Oncol. 2001 Jun;28(3 Suppl 10):25-33
11510031
Can J Gastroenterol. 2002 Feb;16(2):101-5
11875594
Surgery. 1995 Jun;117(6):616-23
7778025
Oncology (Williston Park). 2003 Dec;17(12 Suppl 13):29-36
14723004
Arch Surg. 1985 Aug;120(8):899-903
4015380
Pancreas. 2006 Oct;33(3):240-5
17003644
Ann Surg. 1998 Oct;228(4):508-17
9790340
World J Surg. 2000 Sep;24(9):1121-9
11036292
Arch Surg. 2003 Dec;138(12):1316-22
14662531
Surgery. 2005 Jun;137(6):606-11
15933626
Int J Radiat Oncol Biol Phys. 1995 Jan 15;31(2):353-9
7836089
Ann Surg. 1995 Jan;221(1):59-66
7826162
Cancer. 1990 Jul 1;66(1):56-61
2354408
Surgery. 1997 Mar;121(3):244-9
9068665
Ann Surg. 1999 Dec;230(6):776-82; discussion 782-4
10615932
Ann Surg. 1986 Jul;204(1):65-71
3015059
Med Phys. 2007 Feb;34(2):521-9
17388169
Int J Radiat Oncol Biol Phys. 2004 Jul 15;59(4):1236-44
15234061
Pancreas. 2004 Apr;28(3):219-30
15084961
Ann Surg. 1999 May;229(5):613-22; discussion 622-4
10235519
Rays. 2000 Oct-Dec;25(4):463-84
11367914
Am J Surg. 2004 Jun;187(6):736-40
15191867
Mol Imaging Biol. 2010 Aug;12(4):452-9
19949988
Int J Radiat Oncol Biol Phys. 2004 Jun 1;59(2):454-9
15145162
Int J Radiat Oncol Biol Phys. 2006 May 1;65(1):274-83
16618582
Int J Radiat Oncol Biol Phys. 2003 Jan 1;55(1):144-53
12504047
J Natl Cancer Inst. 1988 Jul 20;80(10):751-5
2898536
Gastrointest Cancer Res. 2009 Jan;3(1):20-8
19343134
J Gastrointest Surg. 2000 Nov-Dec;4(6):567-79
11307091
Cancer. 1999 Feb 1;85(3):583-90
10091731
Int J Radiat Oncol Biol Phys. 2005 Jul 15;62(4):1021-9
15990004
Cancer. 1992 Oct 15;70(8):2061-6
1327485
Cancer. 1989 Sep 1;64(5):1132-7
2547508
J Clin Oncol. 1997 Jun;15(6):2403-13
9196156
Int J Radiat Oncol Biol Phys. 2009 Dec 1;75(5):1468-74
19464822
J Clin Oncol. 1998 Jan;16(1):317-23
9440759
Int J Pancreatol. 1993 Feb;13(1):15-22
8454914
J Nucl Med. 2008 Sep;49(9):1408-13
18703604
World J Gastroenterol. 2003 Nov;9(11):2561-4
14606097
J Nucl Med. 2004 Aug;45(8):1279-86
15299049