Long term outcome analysis of role of radiotherapy in Grade I meningiomas: A single centre experience from North India

Long Term Outcome and Quality of Life of Intracranial Meningioma Patients Treated with Pencil Beam Scanning Proton Therapy

The aim of this study was to assess the clinical outcome, including QoL, of patients with intracranial meningiomas WHO grade 1-3 who were treated with Pencil Beam Scanning Proton Therapy (PBS PT) between 1997 and 2022. Two hundred patients (median age 50.4 years, 70% WHO grade 1) were analyzed. Acute and late side effects were classified according to CTCAE version 5.0. Time to event data were calculated. QoL was assessed descriptively by the EORTC-QLQ-C30 and BN20 questionnaires. With a median follow-up of 65 months (range: 3.8-260.8 months) the 5 year OS was 95.7% and 81.8% for WHO grade 1 and grade 2/3, respectively (p < 0.001). Twenty (10%) local failures were observed. Failures occurred significantly (p < 0.001) more frequent in WHO grade 2 or 3 meningioma (WHO grade 1: n = 7, WHO grade 2/3: n = 13), in patients with multiple meningiomas (p = 0.005), in male patients (p = 0.005), and when PT was initiated not as upfront therapy (p = 0.011). There were no high-grade toxicities in the majority (n = 176; 88%) of patients. QoL was assessed for 83 (41.5%) patients and for those patients PT did not impacted QoL negatively during the follow-up. In summary, we observed very few local recurrences of meningiomas after PBS PT, a stable QoL, and a low rate of high-grade toxicity.

Patterns of recurrence in patients receiving conformal radiation for intracranial meningioma: a single-institution experience

Aim:

To evaluate the patterns of recurrence following postoperative conformal radiotherapy (RT) for intracranial meningioma.

Materials and methods:

Eighty-six patients who received conformal RT for intracranial meningiomas from 2014 to 2017 were retrospectively analysed. For documented recurrences, recurrence imaging was deformably co-registered to planning CT scan. In-field recurrence was defined as recurrence within the 90% isodose line, and out-of-field recurrences were those that occurred outside the 90% isodose line. We present the demographic details, surgical and RT details, outcomes and patterns of recurrence.

Results:

The median age was 46 years (range 17–72); 82·6% underwent surgery [46·5% had subtotal resection (STR), 43·7% gross tumour resection (GTR), 5·6% biopsy] and 17·4% had no surgery. Among these, 53·5% were WHO grade 2; 27·9% grade 1; and 1·2% grade 3 meningioma. Fifty per cent received stereotactic RT (SRT), 46·5% 3D conformal RT (3DCRT) and 3·5% intensity-modulated RT (IMRT). The mean clinical target volume (CTV) and planning target volume (PTV) margins were 4·5 mm (range 0–15) and 3·9 mm (range 1–5), respectively. The doses ranged from 54 to 59·4 Gy. The median follow-up after RT was 1·7 years (range 0·2–4·7). 17·4% were lost to follow-up, 5·4% had recurrence, and the median time to recurrence after completion of RT was 2 years (range 0·7–2·9). The 3-year recurrence-free rate was 81·5%. Three patients had in-field and two had in-field and out-of-field recurrence. Among the cases with recurrence, three received SRT, one 3DCRT and one IMRT. Four were grade 2 and one was grade 3 tumour, and the CTV margin ranged from 0 to 5 mm, and the PTV margin ranged from 3 to 5 mm.

Conclusion:

Local recurrence was seen in grade 2 and 3 meningiomas. SRT probably had more recurrence as they had lesser CTV margin. Increased CTV margin, escalated dose up to 59·4 Gy and 3DCRT/IMRT may be helpful in preventing local recurrences in grade 2 and grade 3 meningiomas.