Stereotactic radiosurgery and combined immune checkpoint therapy with ipilimumab and nivolumab in patients with melanoma brain metastases: A retrospective monocentric toxicity analysis

Purpose and objective

Adding stereotactic radiosurgery (SRS) to combined immune checkpoint therapy with ipilimumab and nivolumab (IPI + NIVO) has led to promising results for patients with melanoma brain metastases (MBM). This study retrospectively analyzes the toxicity profile depending on the timing of SRS with regard to IPI + NIVO.

Materials and methods

For this study, the clinical database was searched for all patients with MBM who were treated with SRS and IPI + NIVO. The patients were separated into three groups: group A completed IPI + NIVO (usually up to four cycles) >14 days before SRS, in group B IPI + NIVO was initiated>14 days after SRS, and group C received SRS concurrently to IPI + NIVO. Treatment related toxicity was obtained from clinical and neuroradiological records. Analyses were performed using the Fisher-Yates-test.

Results

31 patients were assessed including six (19.4 %), seven (22.6 %) and 18 (58.1 %) patients, in groups A, B and C, respectively. Baseline prognostic markers between groups were balanced. In total, five (16.1 %) patients experienced neurological grade 3 toxicities related to SRS. All of these five patients were in group C, which was near-significantly correlated with a risk for grade 3 toxicities (p = 0.058). Post-hoc analyses showed that a maximum time period of seven days between SRS and IPI + NIVO was significantly correlated with grade 3 toxicity (p = 0.048).

Conclusion

Application of SRS to IPI + NIVO within a seven-day span was related to higher toxicity rates in this retrospective analysis. After previous studies focused on immune checkpoint monotherapies with SRS and declared it as safe, this study indicates that concomitant application of IPI + NIVO and SRS might increase side effects. Prospective validation is warranted to corroborate these findings.

Late-Onset Intractable Cerebrospinal Fluid Leakage After Stereotactic Radiotherapy After Resection of Giant Nonfunctioning Pituitary Adenoma

Background

Late-onset skull base cerebrospinal fluid (CSF) leakage after stereotactic radiotherapy (SRT) is a very rare complication.

Case Description

A 54-year-old woman came to our department for convulsions and was admitted. Brain magnetic resonance imaging revealed a giant tumor in the skull base region, including the sphenoid sinus, pituitary fossa, right cavernous sinus, right middle fossa, and right basal ganglia. Mild left hemiparesis was noted. An ophthalmologic examination revealed left side homonymous hemianopsia. Using an endonasal endoscopic surgical approach, tumor removal was performed, with the residual tumor removed with a transcranial approach. Residual tumor tissue remained around the right cavernous sinus; therefore, SRT was performed 1 month after the second procedure, which resulted in good control of growth. Four years later, spontaneous CSF leakage occurred, for which endoscopic endonasal surgery was performed. One month later, CSF leakage recurred, and the same procedure was again used. A third episode of recurrent CSF leakage occurred 5 days later. A transcranial approach was finally used for repair, and the patient showed complete recovery.

Conclusions

Late-onset CSF leakage after SRT for a pituitary adenoma can be intractable, and several aggressive repair procedures may be needed, including a combination of endonasal and transcranial approaches.