Effects of the growth pattern of medulloblastoma on short-term neurological impairments after surgery: results from the prospective multicenter HIT-SIOP PNET 4 study

• OBJECTIVE Extensive resection of a tumor in the posterior fossa in children is associated with the risk of neurological deficits. The objective of this study was to prospectively evaluate the short-term neurological morbidity in children after medulloblastoma surgery and relate this to the tumor's growth pattern and to the extent of resection. METHODS In 160 patients taking part in the HIT-STOP PNET 4 (Hyperfractionated Versus Conventionally Fractionated Radiotherapy in Standard Risk Medulloblastoma) trial, neurosurgeons prospectively responded to questions concerning the growth pattern of the tumor they had resected. The extent of resection (gross, near, or subtotal) was evaluated using MRI. The patients' neurological status before resection and around 30 days after resection was recorded. RESULTS Invasive tumor growth, defined as local invasion in the brain or meninges, cranial nerve, or major vessel, was reported in 58% of the patients. After surgery almost 70% of all patients were affected by one or several neurological impairments (e.g., impaired vision, impaired extraocular movements, and ataxia). However, this figure was very similar to the preoperative findings. Invasive tumor growth implied a significantly higher number of impairments after surgery (p = 0.03) and greater deterioration regarding extraocular movements (p = 0.012), facial weakness (p = 0.048), and ataxia in the arms (p = 0.014) and trunk (p = 0.025) compared with noninvasive tumor growth. This deterioration was not dependent on the extent of resection performed. Progression-free survival (PFS) at 5 years was 80% +/- 4% and 76% +/- 5% for patients with invasive and noninvasive tumor growth, respectively, with no difference in the 5-year PFS for extent of resection. CONCLUSIONS Preoperative neurological impairments and invasive tumor growth were strong predictors of deterioration in short-term neurological outcome after medulloblastoma neurosurgery, whereas the extent of resection was not . Neither tumor invasiveness nor extent of resection influenced PFS. These findings support the continuation of maximal safe resection in medulloblastoma surgery where functional risks are not taken in areas with tumor invasion.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine (hsv//eng)

Nyckelord

neurological sequelae

resection

growth pattern

medulloblastoma

pediatric neurosurgery

cerebellar mutism syndrome

CMS

oncology

posterior-fossa tumors

standard-risk medulloblastoma

cerebellar mutism

syndrome

central-nervous-system

brain-tumors

molecular subgroups

outcome prediction

prognostic-factors

radiation-therapy

controlled-trial

Neurosciences & Neurology

Pediatrics

Surgery

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)