title: Mapping patterns of nodal metastases in seminoma: rethinking radiotherapy fields.
abstract: OBJECTIVE
  To analyze the location of metastatic lymph nodes in seminoma patients relative to vascular and bony anatomy and conventional radiation fields.
  
  
  METHODS
  Cross-sectional scans of 90 seminoma patients with infradiaphragmatic adenopathy were analyzed. The position of each node respective to vascular anatomy was transferred to a standardized template. Conventional radiation fields were overlaid on the template and locations of metastatic nodes were assessed.
  
  
  RESULTS
  One hundred and forty-five nodes were radiographically positive. Eighty-four percent, 9%, and 7% of nodes were located in the para-aortic, common iliac, and pelvic regions, respectively. Ninety-nine percent of nodes were within a 2.5 cm lateral and 2.1cm anterior expansion of the aorta inferior to T12/L1. No radiographically positive nodes were identified within the renal hilum or superior to L1 in left-sided seminomas. For right-sided seminomas, no radiographically positive nodes were superior to L2. Three percent of all radiographically positive nodes would have been located outside of conventional and modified fields.
  
  
  CONCLUSIONS
  Infradiaphragmatic nodal metastases from a contemporary cohort of seminoma patients localized to a smaller area than is targeted by conventional radiation fields. Modified treatment fields based on vascular, rather than bony, anatomy are smaller and may allow for a significant decrease in normal tissue irradiation and toxicity.
authors: Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114, USA.
authors: Jonathan J
authors: JJ
authors: Paly
authors: Jason A
authors: JA
authors: Efstathiou
authors: Sandeep S
authors: SS
authors: Hedgire
authors: Peter W M
authors: PW
authors: Chung
authors: Martin
authors: M
authors: O'Malley
authors: Anand
authors: A
authors: Shah
authors: Justin E
authors: JE
authors: Bekelman
authors: Mukesh
authors: M
authors: Harisinghani
authors: William U
authors: WU
authors: Shipley
authors: Anthony L
authors: AL
authors: Zietman
authors: Clair
authors: C
authors: Beard
mesh_terms: D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D011880:Radiotherapy Planning, Computer-Assisted; D018239:Seminoma / Q000473:pathology / Q000532:radiotherapy*; D013736:Testicular Neoplasms / Q000473:pathology / Q000532:radiotherapy*