Vertebral artery stenosis predicts cerebrovascular diseases following radiotherapy for nasopharyngeal carcinoma

Post-irradiation vertebral and carotid stenosis heightens stroke risk in head and neck cancer

BACKGROUND

The relative risk of ischemic stroke (IS) in head and neck cancer (HNC) patients developing carotid artery stenosis (CAS) or vertebral artery stenosis (VAS) after radiation therapy (RT) remains uncertain due to limited studies, complicating vascular follow-ups and preventive strategies.

METHODS

We included HNC patients who received RT between 2010 and 2023. The patients were divided into nasopharyngeal carcinoma (NPC) and non-NPC groups. The primary outcome was the occurrence of IS after RT, and the secondary outcomes included the development of > 50% CAS or > 50% VAS after RT.

RESULTS

Of the 1,423 HNC patients, there were 19% of patients developed > 50% CAS, 6.8% of patients developed > 50% VAS, and 2.3% of patients developed IS. In patients with HNC, > 50% CAS (adjusted hazard ratio [HR] = 3.21, 95% confidence interval [CI] = 1.53-6.71), and > 50% VAS (adjusted HR = 2.89, 95% CI = 1.28-6.53) were both the independent predictors of IS. In the patients with NPC, > 50% CAS was an independent predictor of anterior circulation IS (adjusted HR = 4.39, 95% CI = 1.17-16.47). By contrast, > 50% VAS emerged as a predictor of posterior circulation IS in both the NPC (adjusted HR = 15.02, 95% CI = 3.76-60.06) and non-NPC groups (adjusted HR = 13.59, 95% CI = 2.21-83.46).

CONCLUSION

HNC patients with > 50% CAS or > 50% VAS after RT had an increased risk of IS within their corresponding vascular territory. CAS could be an important predictor of IS in NPC patients, whereas VAS might also be a significant predictor of IS in both NPC and non-NPC patients. Evaluation both the carotid and vertebral arteries after RT might be necessary.

TRIAL REGISTRATION

ClinicalTrials.gov identifier No.: NCT06111430.

Vascular events in patients with head and neck cancer: A systematic review and meta-analysis

OBJECTIVE

To assess the incidence of vascular events in patients with head and neck cancer.

REVIEW METHODS

Primary studies identified through April 2023. Meta-analysis was performed.

RESULTS

There were 146 studies included in the systematic review. Rates of events were collected in the overall group, those with chemoprophylaxis, and those that underwent surgery, radiation, or chemotherapy. Of 1 184 160 patients, 4.3% had a vascular event. Radiation therapy had highest risk of overall events and stroke when compared to surgery and chemotherapy. Chemotherapy had a higher risk of stroke and overall events when compared to surgery.

CONCLUSIONS

Vascular events occur in 4%-5% of patients with head and neck cancer. Our data does not support the use of routine anticoagulation. Patients undergoing radiation therapy had the highest frequency of events.

Cause of death during nasopharyngeal carcinoma survivorship: a population-based analysis

Background

Recently, the survival rate of nasopharyngeal carcinoma (NPC) patients has improved greatly due to developments in NPC treatments. But cause-specific mortality in NPC patients remains unclear. This study aims to investigate the common causes of death in NPC patients.

Methods

Eligible patients with NPC were included from the Surveillance, Epidemiology, and End Results (SEER) database. Standardized mortality ratios(SMRs) were calculated to compare death rates in NPC patients with those in the general population.

Results

A total of 3475 patients with NPC were included, of whom 1696 patients died during the follow-up period. 52.83% of deaths were caused by NPC, followed by other cancers (28.13%) and non-cancer causes (18.46%). The proportion of patients who died of NPC decreased over survival time. Moreover, non-cancer causes of death increase from 12.94% to 51.22% over time after 10 years of diagnosis. Heart diseases was the most common non-cancer cause of death in NPC patients.

Conclusions

Although NPC remains the leading cause of death after NPC diagnosis, other non-NPC causes of death represent an increased number of death in NPC patients. These findings support the involvement of multidisciplinary care for follow-up strategy in NPC patients.

Vertebral artery sparing volumetric modulated arc therapy in nasopharyngeal carcinoma

Vascular stenosis is a late radiation complication that develops in long-term survivors of nasopharyngeal carcinoma. Vertebral arteries (VAs) are major vessels responsible for posterior circulation. In this study, we evaluated the feasibility of VA-sparing volumetric modulated arc therapy (VMAT) techniques. A total of 20 patients with nasopharyngeal carcinoma treated by a TrueBeam linear accelerator were enrolled in this study. The original VMAT plan was designed without the contouring of VAs as organs at risk (OARs). The same image set of the original VMAT plan was used to contour the VAs for each patient. A new VA-sparing VMAT plan was developed by avoiding VAs as OARs. Finally, a paired t-test was used to compare the dosimetric differences. The VA-sparing VMAT plan had similar target coverage and dose to those of other OARs. The VA-sparing plan yielded a significantly low VA dose from 53 to 40 Gy, with V35Gy changing from 97% to 56%, V50Gy changing from 67% to 35%, and V63Gy changing from 15% to approximately 7%-10% (p < 0.001 for all comparisons). VAs should be correctly identified as OARs. Photon VMAT with VA sparing can help substantially decrease the VA dose.