Family history and impact of radiotherapy on aneurysm development - SLICE Next Frontiers 2023 - Stéphane WURST - Sandrine GARIBALDI

Family history and impact of radiotherapy on aneurysm development 

• Family history:

Family history of a ruptured intracranial aneurysm is one of the main factors to increase the risk of subarachnoid hemorrhage related to an intracranial aneurysm. Another important point is that the prevalence ratio of unruptured intracranial aneurysms (UIA) in patients with a positive family history is 3.4 (95% CI, 1.9–5.9) compared with patients without a positive family history[1], which suggests an increased risk of aneurysm development in persons with a positive family history. In addition, a previous study found a 17× increased rupture rate for familial compared with sporadic UIA[2].

Actually, the risk is related with first-degree relatives with SAH and directly related to the number of affected first-degree relatives: The odds ratio of SAH for individuals with one affected first-degree relative was 2.15 (95% CI 1.77-2.59). For individuals with two affected first-degree relatives, the odds ratio was 51.0 (95% CI 8.56-1117)[3].

• Impact of Radiotherapy on Aneurysm development:

There are not many studies evaluating the impact of radiotherapy on the development of intracranial aneurysms. There are some case reports and a national study from Taiwan with more than 70,000 patients[4]. This study evaluated patients diagnosed with nasopharyngeal carcinoma to verify the relationship between radiotherapy and the development of intracranial aneurysm. They were categorized into the following three groups: nasopharyngeal carcinoma (NPC) with RT, non-NPC with RT, and non-NPC without RT. Patients in the NPC with RT had the higher risk of developing intracranial aneurysms (hazard ratio: 2.57; p>0.001).

In this SLICE next frontiers 2023 video, there was a great discussion about the influence of family history on the indication of treatment for an intracranial aneurysm and what are the treatment possibilities even for small aneurysms. In addition, we saw a discussion about aneurysms that are possibly associated with radiotherapy. These aneurysms can be more complex to treat since the arterial wall has been injured and some perforating arteries can be the cause of ischemia especially when we talk about aneurysms of the posterior circulation.

Still on posterior circulation aneurysms, was discussed about the therapeutic possibilities and the high risk of complications in cases of dissecting posterior circulation aneurysms. Literature data show that complications can reach up to 12% in cases of flow diverting stents of posterior circulation aneurysms and dolichoectasia.

• Further reading:

1. Vlak MH, Algra A, Brandenburg R, Rinkel GJ.Prevalence of unruptured intracranial aneurysms, with emphasis on sex, age, comorbidity, country, and time period: a systematic review and metaanalysis. Lancet Neurol. 2011; 10:626–636. 

2. Broderick JP, Brown RD, Sauerbeck L, Hornung R, Huston J, Woo D, et al; FIA Study Investigators. Greater rupture risk for familial as compared to sporadic unruptured intracranial aneurysms.Stroke. 2009; 40:1952–1957. 

3. Bor AS, Rinkel GJ, Adami J, Koffijberg H, Ekbom A, Buskens E, Blomqvist P, Granath F. Risk of subarachnoid haemorrhage according to number of affected relatives: a population based case-control study. Brain. 2008 Oct;131(Pt 10):2662-5. 

4. Yang, WH., Yang, YH., Chen, PC. et al. Intracranial aneurysms formation after radiotherapy for head and neck cancer: a 10-year nationwide follow-up study. BMC Cancer 19, 537 (2019).