Evaluation of spinal cord doses in patients with head and neck cancer receiving radiotherapy

METHODS
Eighteen patients (12 males, 6 females) with head and neck
carcinoma were evaluated. Spinal cord doses were evaluated
for each treatment phase. Biologically effective doses (BED)
were calculated for the maximum spinal doses in all patients
and compared to the 92 Gy, which was the BED of the spinal
cord tolerance dose of 46 Gy.

RESULTS

The maximum spinal cord dose ranged from 4399 to 4954
cGy. The median dose at the junction of the lateral and anterior
fields was 4131 cGy. BED of the maximum spinal doses
ranged between 75-98 Gy (median 91), and in seven patients
it was over 92 Gy; total spinal dose was over 46 Gy in 13
patients.

CONCLUSION

Spinal cord doses in each phase should be calculated separately
with BED values for assessment of the cumulative
spinal cord doses.

Keywords: Head and neck carcinoma, spinal cord, radiotherapy; radiotherapy dosage