Stereotactic Radiosurgery for Vestibular Schwannomas: Tumor Control Probability Analyses and Recommended Reporting...

Area of Science:

• Radiation Oncology
• Neurosurgery
• Medical Physics

Background:

• Vestibular schwannomas require effective treatment to prevent neurological deficits.
• Stereotactic radiosurgery (SRS) and hypofractionated SRS (fSRS) are established treatment modalities.
• Understanding the tumor control probability (TCP) is crucial for optimizing treatment strategies.

Purpose of the Study:

• To investigate the tumor control probability (TCP) of vestibular schwannomas following single-fraction SRS or hypofractionated SRS (fSRS).
• To correlate dosimetric details with local tumor control rates from published studies.

Main Methods:

• Systematic review of PubMed-indexed studies (1993-2017) reporting SRS/fSRS dosimetric data and tumor control.
• Data extraction on tumor control at 3 or 5 years.
• Poisson modeling to estimate TCP based on equivalent dose in 2 Gy per fraction (EQD2) and number of fractions.

Main Results:

• Analysis of 5162 patients from 35 publications.
• Estimated 3- to 5-year TCP of 95% at an EQD2 of 25 Gy (13.8 Gy single fraction).
• Typical SRS doses (12 Gy single, 18 Gy/3f, 25 Gy/5f) yield >91% TCP.
• fSRS doses of 18 Gy/3f and 25 Gy/5f corresponded to TCPs of 93.6% and 97.2%.

Conclusions:

• Current SRS and fSRS doses for vestibular schwannoma provide high tumor control rates.
• Improved dosimetric reporting and standardized endpoints are essential for future analyses and treatment optimization.
• Further research should focus on detailed reporting to refine TCP models and patient outcomes.