KEY POINTS
- The study included 26 patients treated between 2003 and 2025 for progressive meningioma after conventionally fractionated radiotherapy. Patients were considered unsuitable for additional surgery or radiosurgery, generally because of tumour volume.
- The previous radiotherapy dose was a median of 54 Gy, and temporally modulated pulsed reirradiation delivered a median of 54 Gy, usually in daily fractions of 1.8–2 Gy.
- Each fraction was divided into 0.2 Gy pulses delivered every three minutes, producing an apparent dose rate of 0.0667 Gy per minute. Most patients received intensity-modulated radiotherapy, with a median planning target volume of 193 cm³.
- Six-month progression-free survival was 77% (95% confidence interval, 56–89%), 12-month progression-free survival was 65%, and 24-month progression-free survival was 52%. Median progression-free survival was 27.2 months.
- Median overall survival from reirradiation was 27.2 months; six-, 12- and 24-month overall survival was 85%, 77% and 64%, respectively. Two patients remained alive 10.4 and 9.3 years after treatment.
- Thirteen patients remained progression-free at the end of follow-up. Among 13 failures, 11 were in-field and two were out-of-field; larger planning target volume and a greater number of previous surgeries were associated with local recurrence in univariable analysis.
- Grade 3 or higher acute toxicity occurred in 12%, including one grade 4 cerebral-oedema event requiring intensive care. Late grade 3 cerebral oedema occurred in 12%, with no late grade 4 or 5 toxicity.
CLINICAL TAKEAWAY
Temporally modulated pulsed radiotherapy may make large-volume photon reirradiation feasible for selected recurrent meningiomas that cannot be treated with surgery or stereotactic techniques. The evidence remains weak: the cohort was small and heterogeneous, cumulative dose constraints were not applied, and the absence of a conventional-reirradiation or particle-therapy comparator prevents attribution of benefit to temporal pulsing itself.