Radiation injury to the spinal cord in head and neck cancers: does field arrangement have a role.
METHODS
A study of eight cases of head and neck cancers, to see if the cord was getting a higher dose in the antero-posterior (A-P) fields, compared to the bilateral (B/L) fields.


OBJECTIVE
Radiation damage to the spinal cord is a critical issue for the radiation oncologists. This study was conducted to evaluate, if the dose to the spinal cord is higher by the antero-posterior (A-P) fields, compared to the bilateral (B/L) fields.


METHODS
Eight cases of head and neck cancer were taken in our study. Two beam arrangements were placed in the treatment planning system, the B/L and the A-P fields. The DVH's for the cord dose were recorded and compared in both plans, with a standard fraction size of 200 cGy/fraction.


RESULTS
The mean dose to the spinal cord was 168.06 cGy in A-P arrangement, while it was 133.75 cGy in the B/L arrangement.


CONCLUSIONS
A-P field arrangement in head and neck malignancies delivers a higher dose to the spinal cord. Therefore, we need to spare the cord at an earlier dose limit.
Anusheel
Munshi
M
Department of Radiation Oncology, All India Institute of Medical Sciences, New Delhi, India. anusheel8@hotmail.com
Prabhakar
Ramachandran
R
Mohanti
Bidhu Kalyan
BK
D004307:Dose-Response Relationship, Radiation; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D011832:Radiation Injuries; D011878:Radiotherapy / Q000379:methods*; D013116:Spinal Cord / Q000473:pathology / Q000528:radiation effects*; D013118:Spinal Cord Diseases / Q000209:etiology*