Mid-treatment magnetic resonance imaging in pediatric intracranial low-grade gliomas treated with proton beam therapy

Figures & data

Table 1. Patient characteristics.

Demographics	Number of patients (%)
Age (in years)
Median age at diagnosis	6.6 (range, 0.38–17.6)
Median age at start of radiation treatment	9.9 (range, 4.4–18.8)
Sex
Female	25 (45)
Male	30 (55)
Treatment
Prior chemotherapy	18 (33)
Prior surgery	16 (29)
Prior chemotherapy and surgery	9 (16)
No prior treatment	12 (22)
Tumor location
Cerebral hemisphere	7 (13)
Optic pathway/hypothalamus	25 (45)
Thalamus	6 (11)
Tectum	7 (13)
Brainstem	4 (7)
Cerebellum	6 (11)
Pathologic characteristics
WHO grade
WHO Grade I	37 (67)
WHO Grade II	14 (25)
Diagnosed via imaging	4 (7)
Tumor pathology
Juvenile pilocytic astrocytoma	26 (47)
Astrocytoma	8 (15)
Optic pathway low-grade glioma	7 (13)
Ganglioglioma	6 (11)
Tectal low-grade glioma	4 (7)
Pilomyxoid glioma	3 (5)
Oligodendrioglioma	1 (2)

Figure 1. (A) Sagittal view of a computed tomography simulation scan with pretreatment gross tumor volume (GTV; red, inside line) and the 5-mm clinical target volume (CTV) expansion (yellow, outside line). (B) Mid-treatment balanced fast field-echo MRI with the pretreatment GTV (red, inside line), pretreatment 5-mm CTV expansion (yellow, middle line), and mid-treatment GTV contour (green, outside line) extending beyond the pretreatment CTV.