Radiation therapy of external iliac lymph nodes with lateral pelvic portals: identification of patients at risk for inadequate regional coverage.
OBJECTIVE
To determine whether "standard" lateral pelvic radiation therapy portals provide adequate margins for treating the external iliac lymph nodes (EILNs).


METHODS
With computed tomographic (CT) data and a computerized algorithm, the course of the EILN chain was reconstructed in 48 patients. The marginal distance between a consistently localized portion of the EILNs and the anterior field border that was placed at the front of the pubic symphysis was recorded for each patient.


RESULTS
The EILNs were covered adequately in only 50% of both men and women. More adequate EILN margins were observed in (a) women older than 68 years, (b) women with small anteroposterior separations, (c) men older than 70 years, and (d) men and women with a low central obesity index. Less adequate margins were observed in men who were obese or men with large anteroposterior separations. In the study population, no correlation was observed for sex, race, or tumor site.


CONCLUSIONS
The authors recommend portals that are designed specifically for patients rather than standard portals that may inadequately cover the intended targets.
Chun
M
M
Department of Radiation Oncology, Ajou University Hospital, Suwŏn, South Korea.
Timmerman
R D
RD
Mayer
R
R
Ling
M N
MN
Sheldon
J
J
Fishman
E K
EK
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D010386:Pelvic Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D010388:Pelvis / Q000000981:diagnostic imaging* / Q000528:radiation effects*; D011829:Radiation Dosage; D011878:Radiotherapy / Q000379:methods; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed