title: PTD classification: proposal for a new classification of gastric cancer location based on physiological lymphatic flow.
abstract: BACKGROUND
  We propose a new classification for the location of gastric cancer - the PTD classification (i.e., zones P, T, and D; see below), with the zones classified according to the physiological lymphatic flow.
  
  
  METHODS
  Three hundred and thirty-six patients with T1 or small T2 gastric cancer who underwent sentinel node mapping at our hospital were enrolled. The relationship between the location of the gastric cancer and the physiological lymphatic flow derived from sentinel node mapping was investigated. Lymphatic basins were defined as lymphatic zones divided by the stream of stained lymphatic canals.
  
  
  RESULTS
  One hundred and forty-six patients underwent standard gastrectomy with more than D2 dissection and the other 190 patients underwent function-preserving gastrectomy with the omission of lymph node dissection outside the lymphatic basin. In the former group, the progression pattern of lymph node metastasis was observed; nodal metastasis occurred in sentinel nodes first, and rarely extended outside the lymphatic basin. In the latter group, none of the patients have had a recurrence. The PTD classification we propose is as follows: the dividing line between the proximal region (zone P) and the transitional region (zone T) is the line that links the point of the watershed between the left gastroepiploic artery and right gastroepiploic artery, to the point that is the inflow point of the first descending branch of the left gastric artery; and the dividing line between zone T and the distal region (zone D) is an arc at a radius of 8 cm from the pylorus. There were no lymphatic basins within the right gastric artery area for tumors located in zone T.
  
  
  CONCLUSIONS
  The advantage of the PTD classification is that if the PTD classification were to be used as a guide for gastric resection procedures, preservation of the pylorus would become possible without diminishing the prognosis in patients with cT1N0 cancer located in zone T.
authors.affiliation: Department of Gastroenterologic Surgery, Kanazawa University Hospital, 13-1 Takara-machi, Kanazawa, Ishikawa, Japan. kinami@surg2.m.kanazawa-u.ac.jp
authors.forename: Shinichi
authors.initials: S
authors.lastname: Kinami
authors.forename: Takashi
authors.initials: T
authors.lastname: Fujimura
authors.forename: Eisuke
authors.initials: E
authors.lastname: Ojima
authors.forename: Sachio
authors.initials: S
authors.lastname: Fushida
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Ojima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Funaki
authors.forename: Hideto
authors.initials: H
authors.lastname: Fujita
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takamura
authors.forename: Itasu
authors.initials: I
authors.lastname: Ninomiya
authors.forename: Genichi
authors.initials: G
authors.lastname: Nishimura
authors.forename: Masato
authors.initials: M
authors.lastname: Kayahara
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ohta
authors.forename: Zen
authors.initials: Z
authors.lastname: Yoh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005743:Gastrectomy; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D042601:Lymphatic Vessels / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D021701:Sentinel Lymph Node Biopsy; D013274:Stomach Neoplasms / Q000145:classification* / Q000473:pathology / Q000601:surgery