Volumetric changes and clinical outcome for petroclival meningiomas after primary treatment with Gamma Knife radiosurgery

Abstract

OBJECTIVE Petroclival meningiomas (PCMs) can cause devastating clinical symptoms due to mass effect on cranial nerves (CNs); thus, patients harboring these tumors need treatment. Many neurosurgeons advocate for microsurgery because removal of the tumor can provide relief or result in symptom disappearance. Gamma Knife radiosurgery (GKRS) is often an alternative for surgery because it can cause tumor shrinkage with improvement of symptoms. This study evaluates qualitative volumetric changes of PCM after primary GKRS and its impact on clinical symptoms. METHODS The authors performed a retrospective study of patients with PCM who underwent primary GKRS between 2003 and 2015 at the Gamma Knife Center of the Elisabeth-Tweesteden Hospital in Tilburg, the Netherlands. This study yields 53 patients. In this study the authors concentrate on qualitative volumetric tumor changes, local tumor control rate, and the effect of the treatment on trigeminal neuralgia (TN). RESULTS Local tumor control was 98% at 5 years and 93% at 7 years (Kaplan-Meier estimates). More than 90% of the tumors showed regression in volume during the first 5 years. The mean volumetric tumor decrease was 21.2%, 27.1%, and 31% at 1, 3, and 6 years of follow-up, respectively. Improvement in TN was achieved in 61%, 67%, and 70% of the cases at 1, 2, and 3 years of follow-up, respectively. This was associated with a mean volumetric tumor decrease of 25% at the 1-year follow-up to 32% at the 3-year follow-up. CONCLUSIONS GKRS for PCMs yields a high tumor control rate with a low incidence of neurological deficits. Many patients with TN due to PCM experienced improvement in TN after radiosurgery. GKRS achieves significant volumetric tumor decrease in the first years of follow-up and thereafter.

Treatment Outcome of Gamma Knife Radiosurgery for Petroclival Meningiomas: Retrospective Analysis of a Single Institution Experience

“…In addition, when the tumor presented with a large volume and wide extension into the multi-cranial fossa, they were concerned about a higher failure rate of GKRS. Furthermore, there are not many studies on the outcomes of GKRS for PCMs [ 3 4 5 6 7 8 21 22 ] ( Table 4 ).…”

“…In addition, Gamma Knife radiosurgery (GKRS) can be conducted as an initial alternative treatment for PCM, as in skull base meningiomas. Although the effectiveness of adjuvant or alternative GKRS for PCM has already been demonstrated in several studies [ 3 4 5 6 7 8 ], the precise treatment guidelines have not yet been established.…”

Petroclival meningiomas: update of current treatment and consensus by the EANS skull base section

“…Moreover, they also observed that female patients were more likely to have a favorable outcome after GKRS, confirming that gender is an element that merits consideration in decisionmaking process. Sadik et al [123] recently described the results of RS in 60 patients with small, incidental PCMs with a mean tumor volume of 4.00 cm 3 (range 0.13-11.35 cm 3 ). Local tumor control was 98% at 5 years and 93% at 7 years.…”

Radiosurgery vs. microsurgery for newly diagnosed, small petroclival meningiomas with trigeminal neuralgia

“…From 2 to 12% of patients with posterior fossa tumors such as petroclival meningiomas (PCMs) can present with TN by direct compression of the trigeminal nerve root as it enters the brain stem, regardless of tumor size [5,8,20,29,35]. Current treatment options for tumor-induced TN include glycerol rhizotomy, radiofrequency ablation, percutaneous balloon microcompression, gamma knife radiosurgery (GKRS), and microsurgery (MS) when medication alone is insufficient [4,6,10,12,17,18,21,26,33,36]. Direct removal of mass effect by MS seems to be the most logical and effective method to achieve pain control [8,10,18,21], but there is a debate since PCMs have a deep-seated location within the skull base with multitude of critical neurovascular structures surrounding the tumor.…”

“…reasons, the role of GKRS for small PCMs has gained increasing acceptance over the past decade for its acceptable tumor control and minimal morbidity rates [13,18,21,27,33]. However, there are so far no articles in literature defining the role of MS compared to GKRS for newly diagnosed, small PCMs on TN relief without medications.…”