Skull base repair following endonasal pituitary and skull base tumour resection: a systematic review

Purpose Postoperative cerebrospinal fluid rhinorrhoea (CSFR) remains a frequent complication of endonasal approaches to pituitary and skull base tumours. Watertight skull base reconstruction is important in preventing CSFR. We sought to systematically review the current literature of available skull base repair techniques. Methods Pubmed and Embase databases were searched for studies (2000–2020) that (a) reported on the endonasal resection of pituitary and skull base tumours, (b) focussed on skull base repair techniques and/or postoperative CSFR risk factors, and (c) included CSFR data. Roles, advantages and disadvantages of each repair method were detailed. Random-effects meta-analyses were performed where possible. Results 193 studies were included. Repair methods were categorised based on function and anatomical level. There was absolute heterogeneity in repair methods used, with no independent studies sharing the same repair protocol. Techniques most commonly used for low CSFR risk cases were fat grafts, fascia lata grafts and synthetic grafts. For cases with higher CSFR risk, multilayer regimes were utilized with vascularized flaps, gasket sealing and lumbar drains. Lumbar drain use for high CSFR risk cases was supported by a randomised study (Oxford CEBM: Grade B recommendation), but otherwise there was limited high-level evidence. Pooled CSFR incidence by approach was 3.7% (CI 3–4.5%) for transsphenoidal, 9% (CI 7.2–11.3%) for expanded endonasal, and 5.3% (CI 3.4–7%) for studies describing both. Further meaningful meta-analyses of repair methods were not performed due to significant repair protocol heterogeneity. Conclusions Modern reconstructive protocols are heterogeneous and there is limited evidence to suggest the optimal repair technique after pituitary and skull base tumour resection. Further studies are needed to guide practice.

The role of a virtual telephone clinic in the follow-up management of lateral skull base tumours

Objective The purpose of this article was to determine the impact of employing a telephone clinic for follow-up of patients with stable lateral skull-base tumours. Method An analysis of 1515 patients in the national lateral skull-base service was performed, and 148 patients enrolled in the telephone clinic to date were identified. The length of time that patients waited for results of their follow-up scans and the travel distance saved by patients not having to attend the hospital for their results was determined. Results The mean time from scan to receiving results was 30.5 ± 32 days, 14 days sooner than in the face-to-face group (p = 0.0016). The average round-trip distance travelled by patients to the hospital for results of their scans was 256 ± 131 km. Conclusion The telephone clinic led to a significant reduction in time until patients received their scan results and helped reduce travel distance and clinic numbers in traditional face-to-face clinics.

RONC-15. OUTCOMES OF BRAIN AND SKULL-BASE TUMOURS IN ADOLESCENTS AND YOUNG ADULTS TREATED WITH PENCIL BEAM SCANNING PROTON THERAPY

BACKGROUND The use of highly conformal proton therapy in adolescents and young adults (AYAs) for management of brain/skull-base tumours is becoming increasingly common. This study aims to assess the long-term clinical outcomes, prognostic factors and employment status of AYAs (15–39 years) treated with pencil-beam-scanning proton-therapy (PT). METHODS Between 1997–2018, 176 AYAs were treated with PT at the Paul Scherrer Institute. Median age was 30 years (range, 15–39) and the male/female ratio was 0.8. RESULTS After a median follow-up of 66 months (range, 12–236), 24 (13.6%) local failures and 1 (0.6%) distant failure were observed between 6 and 152 months after PT. The most common histologies treated were chordomas/chondrosarcomas (61.4%), followed by meningiomas (14.2%) and gliomas (15.3%). The 6-year local-control (LC), distant-progression-free survival and overall-survival (OS) rate was 83.2%, 97.4% and 90.2% respectively. On univariate analysis, age ≥24 years was a negative prognostic factor for LC. Recurrent disease, infratentorial tumours and low-grade-glioma histology were poor prognostic factors for both LC and OS. The 6-year ≥G3 PT-related late toxicity-free survival was 88.5%. The moderate-high grade late toxicity crude rates were 37.8% G2, 12.2% G3, 0.6% G4 and 0.6% G5. No secondary malignancies were observed. The unemployment rate was 7.3% at PT, rising to 25.3% at survivorship. High-grade(≥G3) toxicity rate in the unemployed vs employed group was 21% vs 8.5%. CONCLUSION PT is an effective treatment for AYAs with brain/skull-base tumours with good tumour control and acceptable long-term toxicity. Despite having satisfactory clinical outcomes, around 1 in 4 AYAs surviving brain/skull base tumours are unemployed.

Malignant skull base tumours

Malignant skull base tumours are a rare and diverse group of histological entities that cross the skull base. Their management requires a multidisciplinary approach that aims to achieve microscopically clear margins, dural reconstitution to avoid cerebrospinal fluid (CSF) leak, soft tissue reconstruction and where possible, an en bloc resection. Both traditional craniofacial and more modern endoscopic techniques can be utilized, if the surgical and management goals can be achieved successfully. This is then combined with adjuvant therapy, typically radiotherapy, to maximize prognosis. We discuss both anterior and lateral skull base tumours as well as consider the special case of perineural spread as an example of complex disease at the skull base.