[Usefulness of neoadjuvant brachytherapy in the treatment of pineoblastoma: a case report]

The treatment strategy and prognosis of pineal cell tumors are still subjects of debate because of their rarity and the mixture of pineoblastoma and pineocytoma as components. Pineoblastoma is believed to be the more malignant tumor and total gross resection of this tumor is very difficult because of its invasive tendency and location. Although the effectiveness of external irradiation and chemotherapy has been reported, the outlook for patients with this tumor is extremely poor. We treated a case of pineoblastoma with a single total resection nine months after interstitial irradiation and chemotherapy. In this case, brachytherapy was successful as neoadjuvant therapy for decreasing the tumor's volume and clarifying its boundary. The patient was a 36-year-old woman who had complained of occipital headache for about a month. On admission, neurological examination revealed bilateral papilloedema but, otherwise, there were no deficits. A magnetic resonance image (MRI) showed a homogeneously enhanced tumor in the pineal region and obstructive hydrocephalus. Two weeks after ventriculo-peritoneal shunting, a stereotactic needle biopsy was performed using a BRW MRI-guided stereotactic apparatus, and three catheters for interstitial brachytherapy were implanted into the tumor through the biopsy tract. Iridium-192 seeds were inserted through the catheters and kept there for 8 days to irradiate 40 Gy at the tumor periphery. Four courses of chemotherapy with carboplatin (400 mg/m2) and VP-16 (400 mg/m2) were administered after brachytherapy. Repeat MRI scans every month showed a gradual regression of tumor volume. However, the tumor did not disappear and no further decrease in tumor volume was observed 8 months after brachytherapy. A suboccipital craniotomy was performed 9 months after brachytherapy and en bloc tumor resection was achieved readily via an infratentorial supracerebellar approach. After receiving another course of chemotherapy and external irradiation at 40 Gy, the patient was discharged without any symptoms and no residual tumor or recurrence was observed for 24 months after brachytherapy and 15 months after surgery. The clinical course of this case suggests that a combination of stereotactic biopsy and brachytherapy with chemotherapy followed by surgery may be a good strategy for the treatment of pineal cell tumors regardless of their histopathological features.