Neoadjuvant chemotherapy for pineal region tumors

Pineal region tumors are frequently large at diagnosis, often presenting with obstructive hydrocephalus. Surgical resection can be challenging due to intrinsic tumor vascularity and the surrounding eloquent neurovascular anatomy. For patients with large pineal region tumors, particularly young children, neoadjuvant chemotherapy may decrease both the size and vascularity of the tumor before definitive resection. Herein we present our experience.

A single-center retrospective review of pediatric patients with pineal region/posterior third ventricular tumors was performed. Each patient received at least 2 rounds of neoadjuvant chemotherapy (carboplatin, etoposide, cyclophosphamide) prior to definitive resection. The primary outcome measure for this study was the radiographic effect of said chemotherapy on the tumor. Pre- and post-chemotherapy tumor volumes were calculated using magnetic resonance imaging tumor volume analytics. Secondary outcomes were estimated intraoperative blood loss, extent of resection, operative complications, readmission rates, and patient survival. Blood loss was calculated as a percentage of estimated total blood volume.

We identified thirty-one children and young adults (16 males, 15 females) who underwent neoadjuvant chemotherapy for pineal region tumors. The mean age of the population was 7.42 years (5 mo-22 yr). Pathologies were predominantly embryonal and included pineoblastoma (n=22; 71%), atypical teratoid rhabdoid tumor (n=5; 16%), pineal parenchymal tumor of intermediate differentiation (n=3; 10%), and embryonal tumor with multilayered rosettes (n=1; 3%). The average percent tumor volume reduction post chemotherapy was 51% (range, -12.4-90.0%); only 1 patient had an increase in tumor volume. There were no complications related to chemotherapy. All surgeries resulted in gross total or near total resections. Average blood loss as a percentage of preoperative total blood volume was 11.7% (1.1-38.8%). Average length of follow-up was 6.33 years (range, 1-14 years) with 20 patients (64.5%) alive at last follow-up.

Neoadjuvant chemotherapy for certain pineal region tumors is a safe and effective means to decrease tumor volume. While we believe this reduction in tumor size facilitates subsequent resection, further multicenter studies are needed.