INNV-28. A rare case of recurrent astroblastoma: a 5-year follow up of treatment challenges and strategies to achieve local tumor control

Abstract Astroblastoma is a rare glial tumor with significant dilemmas in diagnostic criteria, clinical behavior, and treatment protocol. We present a case of a 22-year old male who presented with progressive headache and blurring of vision, with a large mass in the left temporal lobe with solid and cystic components on imaging. He underwent resection and histopathology confirmed astroblastoma without high-grade features. As gross total excision was not achieved, he received postoperative radiotherapy (54Gy via VMAT) and 12 months of adjuvant temozolomide (150 mg/m² on a 5/28 day schedule). However, despite the absence of high-grade features and postoperative chemoradiation treatment, local recurrence was noted after 23 months. This is consistent with other case reports and cohort studies indicating that patients who undergo gross total resection have longer progression free survival compared to those with subtotal resection. Temozolamide rechallenge was instituted upon recurrence but there was still tumor progression causing neurologic deficits. To address the enlarging cystic component, Ommaya reservoir was inserted, which allowed drainage of the cystic lesion and subsequent improvement of the patient’s clinical status by prompt normalization of intracranial pressure. The solid tumor component was treated with fractionated stereotactic radiotherapy. He was subsequently treated with six cycles of Lomustine administered every six weeks and bimonthly bevacizumab infusions. This treatment regimen achieved local tumor control for the subsequent 24 months and he has remained stable without further recurrence at the time of this report. Due to the rarity of astroblastoma, understanding tumor behavior and characteristics, and establishing effective treatment protocols remain significant challenges. The tumor’s unpredictable clinical course, with a risk of recurrence and rapid progression, further complicates management. This case highlights evolving treatment approaches—including the use of an Ommaya reservoir, radiotherapy, adjuvant chemotherapy, and targeted therapy—as viable options for local tumor control following subtotal resection. It underscores the urgent need for collaborative research to improve outcomes for patients with astroblastoma.