A 28-year-old man presents with a 3-month history of focal seizures. MRI brain shows a T2/FLAIR hyperintense lesion in the left frontal lobe with indistinct margins and minimal contrast enhancement, as marked **A** in the diagram. Histopathology confirms diffuse astrocytoma with IDH mutation and no CDKN2A/B homozygous deletion. The lesion measures 4 cm and gross total resection is achieved without neurological compromise. Based on WHO 2021 CNS classification and current risk stratification, which of the following is the most appropriate management?
A. Temozolomide monotherapy without radiation
B. Immediate adjuvant radiation (54 Gy) with PCV chemotherapy
C. Palliative care with anti-epileptic drugs only
Watchful waiting with serial MRI every 3–6 months
D.
Explanation
Why "Watchful waiting with serial MRI every 3–6 months" is right
This patient has a WHO Grade 2 diffuse astrocytoma, IDH-mutant, and meets LOW-RISK criteria: age <40 years and gross total resection achieved. According to WHO 2021 CNS classification and current NCCN/RTOG guidelines, low-risk grade 2 astrocytomas are managed with observation and serial imaging. The T2 hyperintense infiltrative lesion marked A with minimal enhancement and no high-grade features does not warrant immediate adjuvant therapy in the low-risk setting. Watchful waiting is acceptable and avoids unnecessary toxicity in young patients with favorable prognosis.
Why each distractor is wrong
Immediate adjuvant radiation (54 Gy) with PCV chemotherapy: This is the standard for HIGH-RISK grade 2 astrocytomas (age ≥40, subtotal resection, IDH-WT, or other adverse features). RTOG 9802 demonstrated survival benefit in high-risk patients, but this patient is low-risk and does not require upfront adjuvant therapy.
Temozolomide monotherapy without radiation: Temozolomide is an alternative chemotherapy agent for grade 2/3 gliomas, but it is not used as monotherapy in the absence of radiation for grade 2 astrocytomas. It is reserved for recurrent disease or high-risk patients requiring adjuvant treatment.
Palliative care with anti-epileptic drugs only: This is inappropriate for a 28-year-old with a resectable, low-grade tumor. Gross total resection has been achieved, and the patient has a favorable prognosis (median survival 10–15 years for IDH-mutant grade 2). Palliative care is not indicated at diagnosis.
High-YieldNEET PG
WHO Grade 2 IDH-mutant diffuse astrocytoma in patients <40 years with gross total resection = watchful waiting; age ≥40 or subtotal resection = adjuvant radiation + PCV (RTOG 9802).
