Search

Objective To evaluate long term treatment efficacy and complications of hypofractionated stereotactic radiosurgery (hfSRS) and identify factors that predict outcomes. Methods A retrospective review was conducted on 34 consecutive patients who received hfSRS from 2008 to 2017. Demographic, clinical, angio-architectural characteristics, and radiosurgery data were extracted from the Clinical Data Analysis and Reporting System and our unit’s iPlan (BrainLAB, Munich) system. Data was analysed using SPSS. Results 5-year obliteration rate was 39.1%. Most patients (n = 29, 85.3%) recovered well with GOS of 4–5. 26.9% (n = 9) patients have at least one post-radiosurgery complication including hemorrhage, neurological deficits, radionecrosis. Neurological morbidity and mortality was 17.6% (n = 6). A higher modified radiosurgery arteriovenous malformation score (mRBAS) is associated with a lower 5-year obliteration rate (Rho = -0.486, p = 0.025). None of the bAVM were obliterated once mRBAS exceeds 5.35. As expected, a larger 20-Gy volume outside lesion is associated with more complications and poorer GOS. Interestingly, irradiated drainage vein volume indexed to AVM volume (iiDVV) correlates with increased risks of post-hfSRS haemorrhage (Rho = 0.472, p = 0.031) and reduced event-free survival (Rho = −0.472, p = 0.031). Once iiDVV exceeds 20%, a high rebleeding rate after hfSRS is anticipated (AUC under ROC 0.889). Conclusion Hypofractionated stereotactic radiosurgery is an alternative radiosurgery treatment for bAVM unsuitable for single-fraction SRS. mRBAS predicts obliteration rate and morbidity in hfSRS. Index irradiated drainage vein volume (iiDVV) is associated with event-free survival and rebleeding and should be minimized if feasible.

A nomogram was recently published by Sun et al. to predict overall survival (OS) and the additional benefit of concurrent chemoradiation (CCRT) vs. radiotherapy (RT) alone, in stage II NPC treated with conventional RT. We aimed to assess the predictors of OS and to externally validate the nomogram in the IMRT era. We analyzed stage II NPC patients treated with definitive RT alone or CCRT between 2001 and 2011 under the territory-wide Hong Kong NPC Study Group 1301 study. Clinical parameters were studied using the Cox proportional hazards model to estimate OS. The nomogram by Sun et al. was applied with 1000 times bootstrap resampling to calculate the concordance index, and we compared the nomogram predicted and observed 5-year OS. There were 482 patients included. The 5-year OS was 89.0%. In the multivariable analysis, an age &gt, 45 years was the only significant predictor of OS (HR, 1.98, 95%CI, 1.15–3.44). Other clinical parameters were insignificant, including the use of CCRT (HR, 0.99, 95%CI, 0.62–1.58). The nomogram yielded a concordance index of 0.55 (95% CI, 0.49–0.62) which lacked clinically meaningful discriminative power. The nomogram proposed by Sun et al. should be interpreted with caution when applied to stage II NPC patients in the IMRT era. The benefit of CCRT remained controversial.

The objective of the study is to evaluate the management outcomes of ruptured cerebral arteriovenous malformations (bAVMs) in the paediatric population in a regional hospital in Hong Kong. We performed a retrospective review between 1 January 1999 and 31 December 2017 for ruptured bAVM in a regional neurosurgical centre in Hong Kong. All other vascular pathologies and unruptured cases were excluded. Thirty-three eligible patients were included for analysis. The median age at presentation was 12 (3–18), with a slight male preponderance. Presenting complaints included headache (60.6%), motor deficits (24.2%), and seizure (6.1%). Glasgow coma scale (GCS) on presentation (median, IQR) was 15 (13–15). bAVMs were lobar in 57.6%, infratentorial in 27.3%, and basal ganglia in 9.1%. Follow-up was 101 ± 61 months and ranged from 24 to 229 months. 12 (36.4%) patients underwent emergency haematoma evacuation with or without bAVM excision because of neurological deterioration in the acute phase. 7 (21.2%) patients underwent interval excision and 11(33.3%) patients underwent stereotactic radiosurgery (SRS). There was no residual bAVM and no Clavien-Dindo complications greater than grade II in interval surgery group. Those who underwent SRS had a significantly higher Spetzler-Martin grade; bAVM obliteration was achieved at 73.3%, without any major symptomatic post-radiosurgery complications. There was 1 (3%) mortality and 30 (90.9%) patients recovered well with minor non-disabling deficits (GOS 5). For paediatric patients with ruptured bAVM, a satisfactory management outcome can be achieved with careful patient selection for surgery and radiosurgery.