TY - JOUR
T1 - Dose to the intracranial arteries in stereotactic and intensity-modulated radiotherapy for skull base tumors
AU - Nieder, Carsten
AU - Grosu, Anca L.
AU - Stark, Sybille
AU - Wiedenmann, Nicole
AU - Busch, Raymonde
AU - Kneschaurek, Peter
AU - Molls, Michael
N1 - Funding Information:
Supported by the Bavarian State Ministry of Environment, Public Health, and Consumer Protection.
PY - 2006/3/15
Y1 - 2006/3/15
N2 - Purpose: To examine retrospectively the maximum dose to the large skull base/intracranial arteries in fractionated stereotactic radiotherapy (FSRT) and intensity-modulated radiotherapy (IMRT), because of the potential risk of perfusion disturbances. Methods and Materials: Overall, 56 patients with tumors adjacent to at least one major artery were analyzed. Our strategy was to perform FSRT with these criteria: 1.8 Gy per fraction, planning target volume (PTV) enclosed by the 95% isodose, maximum dose 107%. Dose limits were applied to established organs at risk, but not the vessels. If FSRT planning failed to meet any of these criteria, IMRT was planned with the same objectives. Results: In 31 patients (median PTV, 23 cm3), the FSRT plan fulfilled all criteria. No artery received a dose ≥105%. Twenty-five patients (median PTV, 39 cm3) needed IMRT planning. In 11 of 25 patients (median PTV, 85 cm3), no plan satisfying all our criteria could be calculated. Only in this group, moderately increased maximum vessel doses were observed (106-110%, n = 7, median PTV, 121 cm3). The median PTV dose gradient was 29% (significantly different from the 14 patients with satisfactory IMRT plans). Three of the four patients in this group had paranasal sinus tumors. Conclusion: The doses to the major arteries should be calculated in IMRT planning for critical tumor locations if a dose gradient >13% within the PTV can not be avoided because the PTV is large or includes air cavities.
AB - Purpose: To examine retrospectively the maximum dose to the large skull base/intracranial arteries in fractionated stereotactic radiotherapy (FSRT) and intensity-modulated radiotherapy (IMRT), because of the potential risk of perfusion disturbances. Methods and Materials: Overall, 56 patients with tumors adjacent to at least one major artery were analyzed. Our strategy was to perform FSRT with these criteria: 1.8 Gy per fraction, planning target volume (PTV) enclosed by the 95% isodose, maximum dose 107%. Dose limits were applied to established organs at risk, but not the vessels. If FSRT planning failed to meet any of these criteria, IMRT was planned with the same objectives. Results: In 31 patients (median PTV, 23 cm3), the FSRT plan fulfilled all criteria. No artery received a dose ≥105%. Twenty-five patients (median PTV, 39 cm3) needed IMRT planning. In 11 of 25 patients (median PTV, 85 cm3), no plan satisfying all our criteria could be calculated. Only in this group, moderately increased maximum vessel doses were observed (106-110%, n = 7, median PTV, 121 cm3). The median PTV dose gradient was 29% (significantly different from the 14 patients with satisfactory IMRT plans). Three of the four patients in this group had paranasal sinus tumors. Conclusion: The doses to the major arteries should be calculated in IMRT planning for critical tumor locations if a dose gradient >13% within the PTV can not be avoided because the PTV is large or includes air cavities.
KW - Brain tumor
KW - Intensity-modulated radiotherapy
KW - Intracranial blood vessel
KW - Skull base tumor
KW - Stereotactic radiotherapy
UR - http://www.scopus.com/inward/record.url?scp=33644533178&partnerID=8YFLogxK
U2 - 10.1016/j.ijrobp.2005.09.015
DO - 10.1016/j.ijrobp.2005.09.015
M3 - Article
C2 - 16338100
AN - SCOPUS:33644533178
SN - 0360-3016
VL - 64
SP - 1055
EP - 1059
JO - International Journal of Radiation Oncology Biology Physics
JF - International Journal of Radiation Oncology Biology Physics
IS - 4
ER -
