| Figures/
TablesFigures/Tables | ReferencesReferences
Purpose
To repor
t early clinical ou
tcomes of helical
tomo
therapy (HT)-based image-guided in
tensi
ty-modula
ted radia
tion
therapy (IMRT) in brain
tumors of varying shape, size, and loca
tion.
Materials and Methods
Patients with residual, recurrent, and/or progressive low-grade intracranial and skull-base tumors were treated on a prospective protocol of HT-based IMRT and followed clinicoradiologically. Standardized metrics were used for plan evaluation and outcome analysis.
Results
Twenty-seven patients with 30 lesions were treated to a median radiotherapy dose of 54 Gy in 30 fractions. All HT plans resulted in excellent target volume coverage with steep dose-gradients. The mean (standard deviation) dose homogeneity index and conformity index was 0.07 (0.05) and 0.71 (0.08) respectively. At first response assessment, 20 of 30 lesions were stable, whereas 9 showed partial regression. One patient with a recurrent clival chordoma though neurologically stable showed imaging-defined progression, whereas another patient with stable disease on serial imaging had sustained neurologic worsening. With a median follow-up of 19 months (interquartile range, 11?6 months), the 2-year clinicoradiological progression-free survival and overall survival was 93.3 % and 100 % respectively.
Conclusions
Careful selection of radiotherapy technique is warranted for benign/low-grade brain tumors to achieve durable local control with minimum long-term morbidity. Large or complex-shaped tumors benefit most from IMRT. Our early clinical experience of HT-based IMRT for brain tumors has been encouraging.
