Determination and delineation of nodal target volumes for head-and-neck cancer based on patterns of failure in patients receiving definitive and postoperative IMRT.
OBJECTIVE
We present the guidelines for target volume determination and delineation of head-and-neck lymph nodes based on the analysis of the patterns of nodal failure in patients treated with intensity-modulated radiotherapy (IMRT).


METHODS
Data pertaining to the natural course of nodal metastasis for each head-and-neck cancer subsite were reviewed. A system was established to provide guidance for nodal target volume determination and delineation. Following these guidelines, 126 patients (52 definitive, 74 postoperative) were treated between February 1997 and December 2000 with IMRT for head-and-neck cancer. The median follow-up was 26 months (range 12-55), and the patterns of nodal failure were analyzed.


RESULTS
These guidelines define the nodal target volume based on the location of the primary tumor and the probability of microscopic metastasis to the ipsilateral and contralateral (Level I-V) nodal regions. Following these guidelines, persistent or recurrent nodal disease was found in 6 (12%) of 52 patients receiving definitive IMRT, and 7 (9%) of 74 patients receiving postoperative IMRT had failure in the nodal region.


CONCLUSIONS
On the basis of our clinical experience in implementing inverse-planning IMRT for head-and-neck cancer, we present guidelines using a simplified, but clinically relevant, method for nodal target volume determination and delineation. The intention was to provide a foundation that enables different institutions to exchange clinical experiences in head-and-neck IMRT. These guidelines will be subject to future refinement when the clinical experience in head-and-neck IMRT advances.
Department of Radiation Oncology, Washington University Medical School, St. Louis, MO, USA. cchao@mdanderson.org
K S Clifford
KS
Chao
Franz J
FJ
Wippold
Gokhan
G
Ozyigit
Binh N
BN
Tran
James F
JF
Dempsey
D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000532:radiotherapy* / Q000601:surgery*; D006801:Humans; D008198:Lymph Nodes / Q000528:radiation effects; D008207:Lymphatic Metastasis; D009062:Mouth Neoplasms / Q000378:metabolism; D009362:Neoplasm Metastasis; D020266:Radiotherapy, Conformal / Q000379:methods*; D013997:Time Factors; D014057:Tomography, X-Ray Computed