What is the recommendation for adjuvant radiation therapy (RT) after resection of an esthesioneuroblastoma (olfactory neuroblastoma)?

From the Guidelines

Adjuvant radiation therapy is recommended after resection of an esthesioneuroblastoma, particularly for patients with high-grade tumors, close margins, or other adverse features, as it improves locoregional control and disease-free survival. The decision to offer postoperative RT should be based on the presence of adverse features such as high-grade tumors, positive margins, perineural invasion, lymph node metastases, lymphatic or vascular invasion, and T3-4 tumors, as supported by the study 1.

Key Considerations

• The study 1 provides evidence that postoperative RT increases locoregional control for resected tumors with adverse features.
• Another study 1 also supports the use of adjuvant RT in patients with high-risk disease, including those with extracapsular nodal spread and/or positive resection margins.
• The typical radiation dose ranges from 54-66 Gy delivered in daily fractions of 1.8-2.0 Gy over 6-7 weeks, targeting the tumor bed and regional lymphatics if node-positive.
• Intensity-modulated radiation therapy (IMRT) is preferred to minimize damage to surrounding critical structures like the optic nerves, brain, and brainstem.

Treatment Approach

• Treatment should begin within 4-6 weeks after surgery when adequate healing has occurred.
• For very advanced cases, particularly those with positive margins or extracranial extension, concurrent chemoradiation may be considered, typically using cisplatin-based regimens.
• Regular follow-up imaging with MRI is essential for at least 5 years post-treatment to monitor for recurrence, as esthesioneuroblastoma can recur even years after initial treatment.

From the Research

Adjuvant Radiation Therapy for Esthesioneuroblastoma

The recommendation for adjuvant radiation therapy (RT) after resection of an esthesioneuroblastoma (olfactory neuroblastoma) is supported by several studies.

• The use of adjuvant RT improves local tumor control, particularly for high-grade and high-stage tumors 2, 3, 4.
• A study published in 1993 found that adjuvant RT improved local control, with a 5-year rate of 85.9% compared to 72.7% for those who had surgery alone 2.
• Another study published in 2010 found that post-operative RT improved local control and disease-free survival, with a 5-year disease-free survival rate of 88% for patients who received RT compared to 35% for those who did not 3.
• A study published in 2001 found that the combination of surgery and RT yielded the best treatment outcome, with a 5-year local control rate of 87.4% 4.
• However, a more recent study published in 2021 found that immediate postoperative RT did not demonstrate superiority in tumor control for low-grade esthesioneuroblastoma, although the risk of RT toxicity appears low 5.

Key Findings

• Adjuvant RT improves local tumor control and disease-free survival for esthesioneuroblastoma 2, 3, 4.
• The combination of surgery and RT yields the best treatment outcome 4.
• The use of adjuvant RT is particularly beneficial for high-grade and high-stage tumors 2, 3, 4.
• The timing of RT may not be critical for low-grade esthesioneuroblastoma, and delayed RT may be considered in some cases 5.