Long-term Treatment Outcomes of Temozolomide-Based Chemoradiation in Patients with Adult-Type Diffuse IDH-mutant Grade 2 Astrocytoma.

To report the long-term outcomes in adult patients with grade 2 IDH-mutant astrocytoma treated with temozolomide (TMZ)-based chemoradiation. Methods: One hundred and three patients with histologically proven grade 2 astrocytoma received radiation therapy (RT), 50.4–54 Gy in 1.8 Gy fractions, and adjuvant TMZ up to 12 cycles. Fifty-two patients received RT at the time of tumor progression and 51 in the early postoperative period for the presence of at least one high-risk feature (age > 40 years, preoperative tumor size > 5 cm, large postoperative residual tumor, tumor crossing the midline, or presence of neurological symptoms). Overall survival (OS) and progression-free survival (PFS) were calculated from the time of diagnosis. With a median follow-up time of 9.0 years (range, 1.3–15 years), median PFS and OS times were 9 years (95