M. Nevinny-stickel et al., Comparison of standard and individually planned infradiaphragmatic fields in irradiation of retroperitoneal lymph nodes, INT J RAD O, 48(1), 2000, pp. 147-151
Citations number
8
Categorie Soggetti
Radiology ,Nuclear Medicine & Imaging","Onconogenesis & Cancer Research
Journal title
INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS
Purpose: In prophylactic irradiation of infradiaphragmatic lymphatic nodes
(LN), the width of the paraaortic and pelvic field is given by a line joini
ng the tips of the transverse processes of the 11th thoracic to the 4th lum
bar vertebrae. Then the field boundary follows a straight line to the most
lateral point of the acetabulum seen on the simulation film. Another method
of setting the field border is to project the lateral contours of the larg
e abdominal vessels from T-1-weighted coronal MR images of the abdomen onto
the simulator radiographs and add a 2-cm margin along the so delineated ve
ssels. In our study, we compared both methods as to full enclosure of paraa
ortic and pelvic lymphatics or nodal miss.
Material and Methods: Abdominal CT scans of 81 patients with involvement of
paraaortic lymph node regions with LN sizes not exceeding 2.5 cm were exam
ined. The distance from the center of the appropriate vertebra to the cente
r of the most lateral lymph node was referred to the transverse process as
well as to the outside contour of the aorta on the left and the vena cava o
n the right side. Respectively, the LN were measured referenced to the ilia
c vessels from the 5th lumbar through to the 2nd sacral vertebra. At the le
vel of the hip joint the distance was measured from the midline as determin
ed by a line through the center of the sacrum, pependicular to a line conne
cting center of both femoral heads.
Results: Our measurements showed that lymph nodes do occur (1) lateral to t
he transverse processes of the thoracic and lumbar vertebrae as well as (2)
outside the 2-cm safety margin from the lateral contour of the large abdom
inal vessels.
Conclusion: These data clearly show that the traditional fields for radiati
on of infradiaphragmatic lymphatic nodes have not been large enough to encl
ose almost all retroperitoneal and pelvic lymph nodes with certainty. We re
commend an expansion of the fields. (C) 2000 Elsevier Science Inc.