Does Time to Initiation of Adjuvant Radiotherapy Affect Reconstruction Outcomes After EEA Resection of Skull Base Malignancies?

Introduction and Objective: Time to initiation of adjuvant radiotherapy has been shown to correlate with long-term oncologic outcomes. With the increased role of endoscopic approaches in the management of cranial base malignancies, it is unclear if time to initiation of adjuvant radiotherapy affects reconstruction outcomes and whether it should be considered. In this study we present our experience with adjuvant radiotherapy after endoscopic endonasal procedures, to determine if the timing to radiation impacts the post-RT reconstruction complication rates.

Methods: A retrospective cohort study of 119 patients with differing malignancies treated between 2014 and 2021 was conducted ([Fig. 1]). Data were extracted from medical records and include clinical and radiological information. Patients were clustered according to the time from surgery to initiation of radiation. Using Cox proportional hazard ratios, we analyzed the complications throughout one year after starting RT and the impact of different clinical variables on the complication free survival.

Results: Fifty-two patients (43.7%) and sixty-seven patients (56.3%) received RT before and after the 6th postoperative week, respectively. The overall post-RT complication rates were 21.8% with 16 patients (13.5%) requiring hospitalization, mainly for severe infectious diseases (n = 11, 9.3%) and delayed CSF leak (n = 3, 2.5%). There was no significant difference in the post-RT complications between the patients receiving postoperative RT before or after 6 weeks (HR: 0.789, CI: 0.364–1.71, p = 0.55), ([Fig. 2]). On univariate analysis of the post-RT complication rate, we found a positive impact with the use of vascularized flaps (HR 2.74, CI 1.147–6.558, p=.023) and age ≤45 years old (HR: 2.64, CI 1.218–5.728, p = 0.029), but a negative impact with the use of neoadjuvant chemotherapy (HR 0.318, CI: 0.058–1.726, p = 0.026). Only age ≤45 years-old could be replicated in a multivariate analysis (HR: 3.46, CI: 1.10–10.97, p = 0.034) ([Fig. 3]).

Conclusion: This study examined the impact of timing of adjuvant radiotherapy after endoscopic endonasal resection of cranial base malignancies. We conclude that in patients under 45 years of age who have undergone repair with a vascularized flap that delaying RT more than 6 weeks has no proven benefit with regard to reconstruction outcomes.

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Artikel online veröffentlicht:
01. Februar 2023