Pseudoprogression successfully treated with bevacizumab in a child with spinal pilocytic astrocytoma

Clinical Characteristics and Long-term Outcomes of Spinal Pilocytic Astrocytomas: A Multicenter Retrospective Study by the Neurospinal Society of Japan

OBJECTIVE

The characteristics, imaging features, long-term surgical outcomes, and recurrence rates of primary spinal pilocytic astrocytomas (PAs) have not been clarified owing to their rarity and limited reports. Thus, this study aimed to analyze the clinical presentation, radiological features, pathological findings, and long-term outcomes of spinal PAs.

METHODS

Eighteen patients with spinal PAs who were surgically treated between 2009 and 2020 at 58 institutions were included in this retrospective multicenter study. Patient data, including demographics, radiographic features, treatment modalities, and long-term outcomes, were evaluated.

RESULTS

Among the 18 consecutive patients identified, 11 were women and 7 were men; the mean age at presentation was 31 years (3-73 years). Most PAs were located eccentrically, were solid or heterogeneous in appearance (cystic and solid), and had unclear margins. Gross total resection (GTR), subtotal resection (STR), partial resection (PR), and biopsy were performed in 28%, 33%, 33%, and 5% of cases, respectively. During a follow-up period of 65 ± 49 months, 4 patients developed a recurrence; however, the recurrence-free survival did not differ significantly between the GTR and non-GTR (STR, PR, and biopsy) groups.

CONCLUSION

Primary spinal PAs are rare and present as eccentric and intermixed cystic and solid intramedullary cervical tumors. The imaging features of spinal PAs are nonspecific, and a definitive diagnosis requires pathological support. Surgical resection with prevention of neurological deterioration can serve as the first-line treatment; however, the resection rate does not affect recurrence-free survival. Investigation of relevant molecular biomarkers is required to elucidate the regrowth risk and prognostic factors.

Clinical characteristics and long-term surgical outcomes of spinal pilocytic astrocytoma: a report of twenty cases

BACKGROUND

Primary spinal pilocytic astrocytoma (PA) is an extremely rare low-grade astrocytoma with unclear natural history. The demographic characteristics, imaging features, and long-term surgical outcomes have not been clarified due to low prevalence and limited reports.

METHODS

A retrospective review within a single institution between 2004 and 2018 of all patients with pathologically proven PA was conducted. Patient data including demographics, radiographic features, treatment modalities, and long-term outcomes were evaluated.

RESULTS

Twenty consecutive patients were identified, and 16 (80%) were male patients, with a mean age at presentation of 29 ± 13 years. The lesion was primarily located in cervical (n = 10, 50%), thoracic (n = 7, 35%), cervico-thoracic junction (n = 2), and lumbar level (n = 1, 5%). The tumor had a mean extension of 4 ± 2 (1-7) vertebral segments. Most PAs were located eccentrically (n = 16, 80%), with most being heterogeneous in appearance (cystic and solid) or purely cystic (n = 14, 70%), and had unclear margins (n = 16, 80%). Eleven patients (55%) had associated syringomyelia. Gross total resection (GTR) was achieved in 11 (55%) patients, and subtotal resection (STR) in 9 (45%). During a mean follow-up of 104 ± 56 months, 2 patients died and recurrence was found in 4 patients (20%), translating to a mean progression-free survival of 21 ± 11 months.

CONCLUSION

Primary spinal PA is a rare entity with acceptable progression-free survival if treated appropriately. Surgical resection may provide reasonable prolongation of survival, and GTR should be achieved if possible. A close follow-up is recommended especially for residual lesions, and a further in-depth investigation of molecular biomarkers is needed to stratify risk and prognostic factors.

Primary spinal pilocytic astrocytoma: clinical study with long-term follow-up in 16 patients and a literature review

Primary pilocytic astrocytoma (PA) of the spine is extremely rare and most published case series only include only a few patients. We attempted to explore the clinical features, radiological findings, and treatment outcomes of patients with spinal PA. Sixteen spinal PA patients who were surgically treated in our hospital between April 2008 and June 2018 were included in this retrospective study. An integrative analysis was performed regarding spinal PA patients by extracting from published studies on PubMed. The 16 patients with spinal PA included eight male and eight female patients with a mean age of 29.1 years. Ten cases (62.5%) had masses located in the cervical segments, five (31.3%) had masses in the thoracic segments, and one (6.2%) had masses in the sacral canal. All the patients were treated surgically with 13 gross total resections (GTRs, 81.3%) and three subtotal resections (STRs). The mean follow-up period was 40.4 months. These tumors accounted for a recurrence rate of 37.5% (6 of 16 patients) and no death during the follow-up periods. The influencing factors of recurrence were mainly STR, gene mutation (NF-1 and H2-K27M), and the number of segments involved. The mean recurrence-free survival duration was 19 months. The imaging features of spinal PA are heterogeneous, and the definitive diagnosis requires pathological support. GTR is the standard therapy for spinal PAs, although patients with GTR are still likely to relapse. The regular spinal magnetic resonance imaging follow-ups are required regardless of the resection status. Reoperation is feasible for patients with recurrence.

Rescue bevacizumab following symptomatic pseudoprogression of a tectal glioma post-radiotherapy: a case report and review of the literature

PURPOSE

Radiation-induced pseudoprogression is a subacute clinical entity that is distinct from radiation necrosis and mimics tumor progression. Bevacizumab is a well-described treatment option for radiation necrosis, but its role in pseudoprogression is not clearly defined.

METHODS

We report a case of radiation-induced pseudoprogression rescued with bevacizumab in a 20-year-old man with a biopsy-proven low-grade astrocytoma of the tectum. A review of the literature was also conducted specific to bevacizumab as a treatment for symptomatic pseudoprogression after radiotherapy for CNS tumors.

RESULTS

This patient was treated with definitive intensity modulated stereotactic radiotherapy at a total dose of 54 Gy delivered in 30 daily fractions. Six weeks after radiotherapy the patient developed progressive headache, weakness and a documented deterioration in vision, which was accompanied by worsening of radiographic findings. A diagnosis of pseudoprogression was made and after limited benefit from a trial of dexamethasone, four cycles of bevacizumab were administered which resulted in rapid clinical and radiographic improvement.

CONCLUSIONS

Our findings support the potential use of bevacizumab as a rescue agent for symptomatic pseudoprogression.