Carotid artery stenosis in patients who have undergone radiation therapy for head and neck malignancy

Impact of radiotherapy for nasopharyngeal carcinoma on carotid stenosis risk: a meta-analysis

OBJECTS

Radiotherapy (RT) serves as the most effective treatment for Nasopharyngeal Carcinoma (NPC) and can cause carotid stenosis. The aim of this study is to assess the impact of RT on carotid stenosis in NPC patients, as well as to explore the risk factors for significant carotid stenosis.

METHODS

Studies reporting the carotid stenosis in NPC patients who underwent RT were found on PubMed, Embase and Web of Science. Outcomes of our interest included incidence of overall/significant stenosis, Common Carotid Artery (CCA) stenosis, External Carotid Artery (ECA) stenosis, Internal Carotid Artery (ICA) stenosis, and risk factors for significant carotid stenosis.

RESULTS

Sixteen studies met the inclusion criteria and were included in this meta-analysis. Pooled estimate showed that RT was associated with a significantly higher incidence of overall stenosis (Risk Ratio [RR = 3.53], 95% CI: 2.32‒5.37; p <  0.001) and significant stenosis (RR = 7.06, 95% CI: 3.61‒13.79; p <  0.001) as compared with controls. Moreover, patients treated with RT had a significantly higher risk of stenosis in CCA (RR = 6.87, 95% CI: 4.08‒11.58; p <  0.001), ICA (RR = 3.43, 95% CI: 1.35‒8.73; p =  0.010), ECA (RR = 9.37, 95% CI: 2.06‒42.68; p =  0.004), and ECA/ICA (RR = 2.18, 95% CI: 1.52‒3.13; p < 0.001). Meta-analysis indicated that age (RR = 1.46, 95% CI: 1.05‒2.04; p =  0.024), smoking habit (RR = 1.20, 95% CI: 1.02‒2.78; p =  0.045) and time interval from radiotherapy (RR = 1.56, 95% CI: 1.07‒2.28; p =  0.02) were independent predictors of significant carotid stenosis.

CONCLUSION

Our results suggested that RT increased the risk of carotid stenosis in patients with NPC. Prevention and control measurements should be made for older NPC patients with longer interval from RT, especially those with smoking habit.

LEVEL OF EVIDENCE: 3

Mechanical thrombectomy combined with stenting for radiation-induced carotid stenosis-related stroke with high-load embolization: A case report

Radiation therapy in patients with nasopharyngeal carcinoma can cause chronic progressive carotid artery injury, but acute ischemic stroke caused by carotid artery high-load thrombosis rarely occurs in patients with tandem lesions. We performed carotid mechanical thrombectomy combined with angioplasty in a 57-year-old man who received radiotherapy for nasopharyngeal carcinoma more than 10 years before presentation. He presented with acute-onset left hemiplegia, confusion, and mixed aphasia. Head CT revealed a hyper-dense sign in the right middle cerebral artery M1 region, and angiography disclosed occlusion in the right internal carotid artery C5 region with extremely severe stenosis in the middle C1 region. Intra-arterial mechanical thrombectomy with carotid stenting was performed, and re-canalization was achieved. Re-examination angiography after 3 months revealed worsening of ulcerative plaques and pseudoaneurysms in the left common carotid artery. Consequently, we performed carotid stenting over the left common carotid artery, and the patient recovered well postoperatively. Our experience suggests that early detection of large blood vessel damage and intervention are necessary to prevent large-vessel ischemic stroke in patients who received radiotherapy for nasopharyngeal carcinoma.

Risk of CVD Following Radiotherapy for Head and Neck Cancer: An Updated Systematic Review and Meta-Analysis

Background

The relative risk for cerebrovascular disease (CVD) is increased in patients with head and neck cancer (HNC) treated with radiotherapy (RT). However, the current relative risk for CVD following RT has not been well clarified. The purpose of this study was to analyze the effect of RT and update the risk of CVD following RT in HNC patients through a systematic review and meta-analysis.

Material and Methods

We conducted an online database search and systematic review of observational studies that reported on CVD and extracranial carotid stenosis in patients with HNC who had undergone RT. Articles published in Medline and PubMed from 1980 to 2021 were identified and collected.

Results

Of the forty-seven articles identified from PubMed and forty-four articles identified from 3 systematic reviews, twenty-two studies were included. We found that neck RT was a significant risk factor for CVD (HR 3.97, 95% CI: 2.89-5.45). Patients with HNC treated by RT had an increased OR (7.36, 95% CI: 4.13-13.11) for CVD, and approximately 26% (95% CI: 22%-31%) of HNC patients treated with RT were at risk for CVD with more than 50% reduction in carotid diameter.

Conclusion

The risk of CVD is increased in patients with HNC treated by RT, and recent improvements in RT techniques may have contributed to the decreased risk of CVD. These results suggest that regular follow-up and appropriate screening for CVD should be required for patients with HNC.

Distinct lipid profiles of radiation-induced carotid plaques from atherosclerotic carotid plaques revealed by UPLC-QTOF-MS and DESI-MSI

BACKGROUND AND PURPOSE

Radiotherapy is a standard treatment for head and neck tumors that significantly increases patients' long-term survival rates. However, late cerebrovascular complications, especially carotid artery stenosis (CAS), have gained increasing attention. Investigation of biomarkers of radiation-induced CAS may help to elucidate the mechanism by which radiation induces damage to blood vessels and identify possible preventive measures against such damage.

MATERIALS AND METHODS

In this study, we used lipidomics strategy to characterize the lipids present in 8 radiation-induced carotid plaques (RICPs) and 12 atherosclerotic carotid plaques (ASCPs). We also used desorption electrospray ionization-mass spectrometry imaging (DESI-MSI) to map the spatial distribution of the screened lipids from 2 RICPs samples and 2 ASCPs samples.

RESULTS

The results showed that 31 metabolites in RICPs were significantly higher than that in ASCPs, 24 of which were triglycerides (TGs). We used four machine learning models to select potential indicators from the 31 metabolites. Six TGs [TG(17:2/17:2/18:0), TG(17:1/17:2/18:0), TG(17:0/17:2/18:0), TG(17:2/17:2/20:0), TG(17:1/17:2/20:0), TG(15:0/22:0/22:2)] were found to be the potential markers for distinguishing RICPs and ASCPs (AUC = 0.83). The DESI-MSI results suggested that the 6 TGs were localized in the collagen fiber regions and confirmed the differences of these TGs between the two kinds of plaques.

CONCLUSIONS

The 6 TGs primarily localized in the collagen fiber regions of plaques are likely to be potential indicators for the differentiation of RICPs from ASCPs which may have implications in the mechanisms and possible preventive measures against RICPs.

Significant Reduction in Vertebral Artery Dose by Intensity Modulated Proton Therapy: A Pilot Study for Nasopharyngeal Carcinoma

Intensity modulated proton therapy (IMPT) with the vertebral artery (VA)-sparing technique has been initially proposed in our institution. This pilot study was conducted to compare the dose to VAs between IMPT and volumetric-modulated arc therapy (VMAT) for patients with nasopharyngeal carcinoma (NPC). A total of six patients with NPC treated by IMPT were enrolled in the study. Target volumes and organs at risk (OARs) were delineated, including 12 samples of right and left VAs, respectively, for each patient. Treatment planning by IMPT and dual-arc VMAT was carried out for comparison. The IMPT plan significantly reduced VA mean dose, V10, V20, V30, V40, and V50, compared to the VMAT plan in all 12 samples (p < 0.001). The average mean dose to VAs for IMPT was 35.2% (23.4–46.9%), which was less compared to VMAT (p < 0.001). Adequate dose coverage was achieved with both IMPT and VMAT plans for three different dose levels of target volumes for all patients. IMPT significantly reduces VA dose while maintaining adequate dose coverage of all target volumes. For patients with head and neck cancer who seek to preserve their blood flow to the brain in order to decrease late vascular and neurologic sequelae, IMPT should be considered. A prospective study with longer follow-up is ongoing to confirm our preliminary results.

Effects of Neck Radiation on Result of Doppler Sonography of Carotid Arteries in Head and Neck Cancer Patients

PURPOSE

The aim of this study was to assess the effects of neck radiation on the results of Doppler sonography of carotid arteries in head and neck cancer patients.

METHODS

In this prospective, cross-sectional study, 25 consecutive patients with head and neck cancers were assessed for carotid artery stenosis (CAS) by carotid color Doppler sonography before external radiotherapy and six months after external radiotherapy. Main outcome measures were peak systolic velocity (PSVs), end-diastolic velocities (EDVs) of the internal carotid artery (ICA), ICA/common carotid (CCA) ratios, and degree of stenosis.

RESULTS

The age of the enrolled patients at the initiation of radiotherapy was 57.9±11.8 years (mean±SD; range, 43-91 years), and only 4 (16%) of the 25 patients were female. The findings showed significant changes in the plaque degree and stenosis degree, and plaque size before and after external radiotherapy (P<0.05). Changes in degree of stenosis were significantly correlated with age (p=0.021).

CONCLUSION

After neck irradiation changes in the carotid artery may occur and cause subsequent neurologic events.

Longitudinal atherosclerotic changes after radio(chemo)therapy of hypopharyngeal carcinoma

Background

Radiotherapy treatment of head and neck cancer affects local arteries and increases the risk of stroke. This study aimed at a closer characterization of this damage and its development in time with a longitudinal study set up.

Methods

Male patients treated between 2011 and 2016 for hypopharyngeal carcinoma were identified from the in-house clinical data base. They were included into the study if besides the planning CT at least one additional CT image was available from follow-up (13 patients) or at least two MRI scans (16 patients of which 2 were already included). All patients received radiotherapy, and chemotherapy was administered to 16 patients. The time from the beginning of radiotherapy to the last available image ranged from 2 months to 4.5 years.

For six segments of the carotid arteries, the number and volume of atherosclerotic plaques were determined from the CT scans, and the intima media thickness from the MRI scans. Information on comorbid cardiovascular disease, hypertension and diabetes mellitus was retrieved from medical records.

Results

Total plaque volume rose from 0.25 cm³ before to 0.33 cm³ after therapy but this was not significant (p = 0.26). The mean number of plaques increased from 5.7 to 8.1 (p = 0.002), and the intima media thickened from 1.17 mm to 1.35 mm (p = 0.002). However, the mean intima media thickness practically did not change in patients with comorbid diabetes mellitus (p-value for homogeneity: 0.03). For patients without diabetes mellitus, dynamics of both plaque number and intima media thickness, was consistent with an increase until about one year after therapy and no further progression thereafter.

Conclusion

Our study confirmed the thickening of artery walls and the increase in the number of plaques. Results imply that definitive radiation damage to the artery walls can be determined not earlier than about one year after radiotherapy and there is no substantial deterioration thereafter. Reasons for the absence of an observable intima media thickening in patients with diabetes are unclear.

Prevalence of carotid stenosis following radiotherapy for head and neck cancer: A systematic review and meta-analysis

BACKGROUND

Radiation to the head and neck is a well-established risk factor for the development of carotid artery stenosis. Our objective was to identify the prevalence, incidence, and degree of carotid stenosis in patients with a history of head and neck irradiation.

METHODS

This study was performed according to the PRISMA guidelines. A random effects model meta-analysis was conducted.

RESULTS

Nineteen studies comprising 1479 patients were included. The prevalence of carotid stenosis >50%, >70%, and carotid occlusion was 25% (95% CI: 19%-32%), 12% (95% CI: 7%-17%), and 4% (95% CI: 2%-8%), respectively. The cumulative 12-month incidence of carotid stenosis >50% was 4% (95% CI: 2%-5%), the 24-month was 12% (95% CI: 9%-15%), and the 36-month was 21% (95% CI: 9%-36%).

CONCLUSIONS

The yearly incidence of carotid stenosis >50% increased every year during the first 3 years following radiotherapy. We propose routine yearly Doppler ultrasound screening beginning 1 year after head and neck radiotherapy.

A population-based study of cardiovascular disease mortality risk in US cancer patients

AIMS

This observational study characterized cardiovascular disease (CVD) mortality risk for multiple cancer sites, with respect to the following: (i) continuous calendar year, (ii) age at diagnosis, and (iii) follow-up time after diagnosis.

METHODS AND RESULTS

The Surveillance, Epidemiology, and End Results program was used to compare the US general population to 3 234 256 US cancer survivors (1973-2012). Standardized mortality ratios (SMRs) were calculated using coded cause of death from CVDs (heart disease, hypertension, cerebrovascular disease, atherosclerosis, and aortic aneurysm/dissection). Analyses were adjusted by age, race, and sex. Among 28 cancer types, 1 228 328 patients (38.0%) died from cancer and 365 689 patients (11.3%) died from CVDs. Among CVDs, 76.3% of deaths were due to heart disease. In eight cancer sites, CVD mortality risk surpassed index-cancer mortality risk in at least one calendar year. Cardiovascular disease mortality risk was highest in survivors diagnosed at <35 years of age. Further, CVD mortality risk is highest (SMR 3.93, 95% confidence interval 3.89-3.97) within the first year after cancer diagnosis, and CVD mortality risk remains elevated throughout follow-up compared to the general population.

CONCLUSION

The majority of deaths from CVD occur in patients diagnosed with breast, prostate, or bladder cancer. We observed that from the point of cancer diagnosis forward into survivorship cancer patients (all sites) are at elevated risk of dying from CVDs compared to the general US population. In endometrial cancer, the first year after diagnosis poses a very high risk of dying from CVDs, supporting early involvement of cardiologists in such patients.

Dosimetric Comparison of Four Different Techniques for Supraclavicular Irradiation in 3D-conformal Radiotherapy of Breast Cancer

This study aimed to compare and evaluated the dosimetric characteristics of esophagus, spinal cord, carotid artery, lungs, and brachial plexus in patients with breast cancer undergoing four various techniques of supraclavicular irradiation. By keeping unchanged the breast tangential radiotherapy fields, four different treatment field arrangements were created to irradiate the supraclavicular region as follows: (1) four field (4F; 1 anterior-posterior and 1 posterior-anterior), (2) six field (6F; 2 anterior-posterior and 2 posterior-anterior), (3) five field-1 (5F-1; 2 anterior-posterior and 1 posterior-anterior), and (4) five field-2 (5F-2; 1 anterior-posterior and 2 posterior-anterior). Then, the dosimetric parameters for the above-mentioned organs were evaluated. The mean dose (Dmean) of the esophagus had significant difference between 6F and 5F-2 techniques. For the spinal cord, the Dmean dosimetric parameter demonstrated significant difference between the 4F and 6F techniques, and between the 4F and 5F-1 techniques, with lower values for the 4F technique. There was no significant difference between the different irradiation techniques in all the dosimetric parameters for the carotid artery. The Dmean of the left lung significantly differed between the 4F and 5F-2 techniques, with lower values for the 5F-2 technique. Furthermore, the V20Gy dosimetric parameter had significant difference between the 4F and 6F, and also 4F and 5F-2, techniques with lower values for 5F-2. The maximum dose (Dmax) of the brachial plexus showed significant difference between the two techniques of 5F. The V45Gy dosimetric parameter of the brachial plexus revealed significant difference between the 4F and 6F techniques, and also between the 4F and 5F-1 techniques, with lower values for 5F-1. In general, these techniques had similar dosimetric results, with little differences. The dosimetric parameters for the esophagus and lung showed better results with the 5F-2 technique in comparison with other techniques. Dosimetric results for the brachial plexus and spinal cord improved with the 5F-1 and 4F techniques, respectively, against other techniques. Dose distribution for the carotid artery did not differ in the four irradiation techniques.

The risk of carotid stenosis in head and neck cancer patients after radiation therapy

OBJECTIVES

Head and neck radiotherapy (RT) is a risk factor for cerebrovascular disease. We performed a retrospective cohort study to evaluate carotid artery stenosis (CAS) incidence in head and neck cancer (HNC) patients undergoing RT, characterizing associated risk factors.

MATERIALS AND METHODS

Records were retrospectively reviewed for HNC patients undergoing carotid ultrasound screening after definitive or adjuvant RT between January 2000 and May 2016. CAS was defined as ≥50% stenosis on imaging, stroke, or transient ischemic attack. Actuarial CAS rates were calculated by Kaplan-Meier method. Univariate and multivariate analyses predicted CAS risk based on carotid dosimetric and clinical parameters.

RESULTS

366 patients met inclusion criteria. Median time from RT completion to last follow-up was 4.1 yr. Actuarial risk for CAS was 29% (95% CI 22-36%) at 8 years. Univariate analysis showed that smoking (HR 1.7; 95% CI 1.1-2.7), hyperlipidemia (HR 1.6; 95% CI 1.03-2.6), diabetes (HR 2.8; 95% CI 1.6-4.8), coronary artery disease (HR 2.4; 95% CI 1.4-4.2), and peripheral artery disease (HR 3.6; 95% CI 1.1-11.6) were significantly associated with increased CAS. In multivariate analysis, diabetes was predictive of time to CAS (HR 1.9; 95% CI 1.1-3.4). Carotid dose parameters were not significantly associated with CAS.

CONCLUSIONS

CAS incidence is high after head and neck radiotherapy, gradually rising over time. No clear dose-response effect between carotid dose and CAS was identified for HNC patients. Carotid artery screening and preventative strategies should be employed in this high-risk patient population.

Head and Neck Cancer Survivorship Care Guideline: American Society of Clinical Oncology Clinical Practice Guideline Endorsement of the American Cancer Society Guideline

Purpose This guideline provides recommendations on the management of adults after head and neck cancer (HNC) treatment, focusing on surveillance and screening for recurrence or second primary cancers, assessment and management of long-term and late effects, health promotion, care coordination, and practice implications. Methods ASCO has a policy and set of procedures for endorsing clinical practice guidelines that have been developed by other professional organizations. The American Cancer Society (ACS) HNC Survivorship Care Guideline was reviewed for developmental rigor by methodologists. An ASCO Expert Panel reviewed the content and recommendations, offering modifications and/or qualifying statements when deemed necessary. Results The ASCO Expert Panel determined that the ACS HNC Survivorship Care Guideline, published in 2016, is clear, thorough, clinically practical, and helpful, despite the limited availability of high-quality evidence to support many of the recommendations. ASCO endorsed the ACS HNC Survivorship Care Guideline, adding qualifying statements aimed at promoting team-based, multispecialty, multidisciplinary, collaborative head and neck survivorship care. Recommendations The ASCO Expert Panel emphasized that caring for HNC survivors requires a team-based approach that includes primary care clinicians, oncology specialists, otolaryngologists, dentists, and other allied professionals. The HNC treatment team should educate the primary care clinicians and patients about the type(s) of treatment received, the likelihood of potential recurrence, and the potential late and long-term complications. Primary care clinicians should recognize symptoms of recurrence and coordinate a prompt evaluation. They should also be prepared to manage late effects either directly or by referral to appropriate specialists. Health promotion is critical, particularly regarding tobacco cessation and dental care. Additional information is available at www.asco.org/HNC-Survivorship-endorsement and www.asco.org/guidelineswiki .

Intensity-modulated radiotherapy for early glottic cancer: transition to a new standard of care?

For decades, the standard of care for radiation treatment of early larynx cancers has been conventional treatment using opposed lateral fields encompassing the larynx and overlying neck structures, including the adjacent carotid arteries. While intensity-modulated radiotherapy (IMRT) has replaced conventional radiotherapy for all other head/neck cancer situations, the use of IMRT to treat early glottic cancers remains controversial. The article reviews the published experience with IMRT for this clinical situation and provides a detailed review of the literature on radiation-induced carotid toxicity and how it might apply to the controversy. Finally, we discuss whether the radiation oncology community should transition to IMRT as a new standard of care for the treatment of early glottic cancers.

Do traditional risk stratification models for cerebrovascular events apply in irradiated head and neck cancer patients?

BACKGROUND

Primary radical radiotherapy (RT) for head and neck cancer (HNC) often results in significant radiation dose to the carotid arteries.

AIM

We assessed whether HNC patients are at increased risk of a cerebrovascular event primarily due to RT or other risk factors for atherosclerosis by (i) risk-stratifying patients according to validated QRISK-2 and QSTROKE scores and (ii) comparing the prevalence of carotid artery stenosis (CAS) in irradiated and unirradiated carotid arteries.

DESIGN

HNC patients treated with an RT dose >50 Gy to one side of the neck ≥2 years previously were included.

METHODS

QRISK-2 (2014) and Q-STROKE (2014) scores were calculated. We compared the prevalence of CAS in segments of the common carotid artery on the irradiated and unirradiated sides of the neck.

RESULTS

Fifty patients (median age of 58 years (interquartile range (IQR) 50-62)) were included. The median QRISK-2 score was 10% (IQR 4.4-15%) and the median QSTROKE score was 3.4% (IQR 1.4-5.3%). For both scores, no patient was classified as high risk. Thirty-eight patients (76%) had CAS in one or both arteries. There was a significant difference in the number of irradiated arteries with stenosis (N = 37) compared with unirradiated arteries (N = 16) (P < 0.0001). There were more plaques on the irradiated artery compared with the unirradiated side - 64/87 (73.6%) versus 23/87 (26.4%), respectively (P < 0.001). 

CONCLUSIONS

Traditional vascular risk factors do not play a role in radiation-induced carotid atherosclerosis. Clinicians should be aware that traditional risk prediction models may under-estimate stroke risk in these patients.

Radiation-induced carotid artery atherosclerosis

PURPOSE

Carotid arteries frequently receive significant doses of radiation as collateral structures in the treatment of malignant diseases. Vascular injury following treatment may result in carotid artery stenosis (CAS) and increased risk of stroke and transient ischaemic attack (TIA). This systematic review examines the effect of radiotherapy (RT) on the carotid arteries, looking at the incidence of stroke in patients receiving neck radiotherapy. In addition, we consider possible surrogate endpoints such as CAS and carotid intima-medial thickness (CIMT) and summarise the evidence for radiation-induced carotid atherosclerosis.

MATERIALS AND METHODS

From 853 references, 34 articles met the criteria for inclusion in this systematic review. These papers described 9 studies investigating the incidence of stroke/TIA in irradiated patients, 11 looking at CAS, and 14 examining CIMT.

RESULTS

The majority of studies utilised suboptimally-matched controls for each endpoint. The relative risk of stroke in irradiated patients ranged from 1.12 in patients with breast cancer to 5.6 in patients treated for head and neck cancer. The prevalence of CAS was increased by 16-55%, with the more modest increase seen in a study using matched controls. CIMT was increased in irradiated carotid arteries by 18-40%. Only two matched-control studies demonstrated a significant increase in CIMT of 36% and 22% (p=0.003 and <0.001, respectively). Early prospective data demonstrated a significant increase in CIMT in irradiated arteries at 1 and 2 years after RT (p<0.001 and <0.01, respectively).

CONCLUSIONS

The incidence of stroke was significantly increased in patients receiving RT to the neck. There was a consistent difference in CAS and CIMT between irradiated and unirradiated carotid arteries. Future studies should optimise control groups.

Sonographic assessment of acute changes in plaque size and echogenicity and in intima-media thickness of carotid arteries after neck radiation therapy

BACKGROUND

Ultrasonic assessment of acute changes in carotid artery walls before and after neck radiation therapy (RT).

METHODS

Fifty cancer patients scheduled for curative neck irradiation were included and underwent sonographic examination of carotid arteries, with assessment of intima-media thickness (IMT) and plaque size and echogenicity before and immediately after completion of RT.

RESULTS

IMT was linearly correlated with age and before RT (r = 0.267, p = 0.007) and increased after RT (0.68 ± 0.11 versus 0.87 ± 0.16, p < 0.001), without correlation with total RT dose and protocol. New plaques (six hypoechoic, one hyperechoic, and one calcified) were found in eight patients after RT, while 17 of the 44 plaques that were present before RT increased in size, and 8 soft and 1 dense plaques in nine patients became calcified.

CONCLUSIONS

Radiation in the acute phase not only increases the IMT but also causes new plaque formation and changes in plaque size and echogenicity.

Risk of haemorrhagic and ischaemic stroke in patients with cancer: a nationwide follow-up study from Sweden

BACKGROUND

Stroke is common in cancer patients, but risk estimates for different cancer sites/types have not been determined. The aim of this nationwide study was to examine whether there is an association between cancer and first hospitalisation for haemorrhagic or ischaemic stroke.

METHODS

All 820,491 individuals in Sweden with a diagnosis of cancer between 1st January 1987 and 31st December 2008 were followed for first hospitalisation for haemorrhagic or ischaemic stroke. The reference population was the total population of Sweden without cancer. Standardised incidence ratios (SIRs) for haemorrhagic and ischaemic strokes were calculated.

RESULTS

Overall risk of haemorrhagic stroke and ischaemic stroke during the first 6 months after diagnosis of cancer was 2.2 (95% confidence interval (CI)= 2.0-2.3) and 1.6 (CI = 1.5-1.6), respectively. For 18 and 20 of the 34 cancers studied, respectively, risk of haemorrhagic and ischaemic strokes was increased. Overall stroke risk decreased rapidly, but remained elevated, even 10+years after diagnosis of cancer 1.2 (CI = 1.1-1.3) for haemorrhagic stroke and 1.1 (CI = 1.1-1.2) for ischaemic stroke. The risk of stroke was highest during the first 6 months after diagnosis of cancer of the nervous system (29 (CI = 25-34) for haemorrhagic stroke and 4.1 (CI = 3.4-4.8) for ischaemic stroke)) or leukaemia (13 (CI = 10-16) for haemorrhagic stroke and 3.0 (CI = 2.5-3.7) for ischaemic stroke)). Metastasis was associated with an increased risk of haemorrhagic stroke 2.2 (CI = 1.8-2.7) and ischaemic stroke 1.5 (CI = 1.3-1.7).

INTERPRETATION

Several cancer sites/types are associated with an increased risk of haemorrhagic and ischaemic strokes.

Ocular ischemic syndrome secondary to carotid artery occlusion as a late complication of radiotherapy of nasopharyngeal carcinoma

A 39-year-old Chinese man developed ocular ischemic syndrome (OIS) in both eyes 14 years after radiation therapy for nasopharyngeal squamous cell carcinoma. Digital subtraction angiography disclosed occlusion of common carotid arteries and stenosis of both vertebral arteries. Following stenting of the vertebral arteries, visual function improved and ophthalmoscopic abnormalities of OIS regressed in the right eye. Radiation therapy of the head and neck has a relatively high likelihood of causing vascular stenosis. However, we believe this to be the first reported case of OIS following radiotherapy for nasopharyngeal carcinoma.

Increased risk of stroke in young head and neck cancer patients treated with radiotherapy or chemotherapy

BACKGROUND

Chemo-radiotherapy-induced carotid stenosis and cerebrovascular events in head and neck cancer patients can cause severe disability and death. We aimed to estimate the risk of stroke in such patients over a six-year follow-up period.

PATIENTS AND METHODS

The study cohort consisted of head and neck cancer patients (n=10,172). Cox proportional hazard model was used to compare the stroke-free survival rate between the patients treated with radiotherapy or chemotherapy, surgery alone, and surgery with adjuvant therapy after adjusting for possible confounding factors.

RESULTS

At the end of follow-up, 384 patients had strokes: 126 (4.3%) from the surgery alone group, 167 (3.8%) from the radiotherapy or chemotherapy group, and 91 (3.2%) from the surgery with adjuvant therapy (P=0.222). Head and neck cancer patients aged less than 55 years treated with radiotherapy or chemotherapy conferred a 1.8-fold higher risk for stroke (95% CI, 1.22-2.56; P=0.003) after adjusting for patient characteristics, co-morbidities, geographic region, urbanization level, and socio-economic status. There was no statistical difference in stroke risk between different treatment modalities in head and neck cancer patients aged 55 years and more.

CONCLUSIONS

Young head and neck cancer patients treated with radiotherapy or chemotherapy have higher risks for stroke. Different treatment strategies should be considered in such patients.

Ischemic stroke and transient ischemic attack after head and neck radiotherapy: a review

BACKGROUND AND PURPOSE

Cerebrovascular disease can complicate head and neck radiotherapy and result in transient ischemic attack and ischemic stroke. Although the incidence of radiation vasculopathy is predicted to rise with improvements in median cancer survival, the pathogenesis, natural history, and management of the disease are ill defined.

METHODS

We examined studies on the epidemiology, imaging, pathogenesis, and management of medium- and large-artery intra- and extra-cranial disease after head and neck radiotherapy. Controlled prospective trials and larger retrospective trials from the last 30 years were prioritized.

RESULTS

The relative risk of transient ischemic attack or ischemic stroke is at least doubled by head and neck radiotherapy. Chronic radiation vasculopathy affecting medium and large intra- and extra-cranial arteries is characterized by increasing rates of hemodynamically significant stenosis with time from radiotherapy. Disease expression is the likely consequence of the combined radiation insult to the intima-media (accelerating atherosclerosis) and to the adventitia (injuring the vasa vasorum). Optimal medical treatment is not established. Carotid endarterectomy is confounded by the need to operate across scarred tissue planes, whereas carotid stenting procedures have resulted in high restenosis rates.

CONCLUSIONS

Head and neck radiotherapy significantly increases the risk of transient ischemic attack and ischemic stroke. Evidence-based guidelines for the management of asymptomatic and symptomatic (medium- and large-artery) radiation vasculopathy are lacking. Long-term prospective studies remain a priority, as the incidence of the problem is anticipated to rise with improvements in postradiotherapy patient survival.

Dual-Acquisition Extracranial Computed Tomographic Angiography-Enhanced Neck Computed Tomography before Transoral Laser Microsurgery in Head and Neck Cancer Patients. Preliminary results

Transoral laser microsurgery (TLM) is an alternative surgical technique for piecemeal endoscopic resection of mucosal-based aerodigestive tract tumors. Though uncommon, potentially catastrophic postoperative bleeding may occur with this technique secondary to vascular injury along invasive tumor inner margins. We describe our preliminary results using a preoperative dual-acquisition extracranial computed tomographic angiography (CTA)-enhanced neck computed tomographic (CT) imaging and postprocessing protocol developed to improve visualization of mucosal-based head and neck tumors and adjacent arterial branches with the objective of facilitating TLM surgery and reducing secondary bleeding complications. Twenty patients with known head and neck cancers anticipated for TLM resection were selected for a dual-acquisition CTA-CT scanning and postprocessing protocol. The mucosal-based pharyngeal tumors and peritumoral vessel enhancement were compared on matched CTA and enhanced neck CT axial images. Operative reports and clinical notes were retrospectively reviewed to identify patients in whom the TLM surgical approach was altered or changed to conventional open surgery as a result of presurgical CTA-CT findings. Enhancement of peritumoral vasculature was almost uniformly superior (19 of 20 patients) on extracranial CTA compared with enhanced neck CT images. In six candidates for TLM surgery (30%), CTA findings resulted in a change in surgical approach to improve intraoperative peritumoral vascular control. In this small pilot series, primary tumor-peritumoral vessel relationships delineated by the addition of extracranial CTA to preoperative enhanced neck CT frequently impacted the surgical approach and facilitated TLM planning.

Carotid Tortuosity in Patients With Prior Cervical Radiation

Introduction: Anatomic distortion associated with radiation-induced tissue changes may pose challenges for patients with prior cervical irradiation undergoing carotid stenting. We sought to evaluate the effect of these changes on carotid intervention. Methods: Carotid angioplasty and stenting (CAS) for high-grade stenosis was performed in 203 patients. In all, 12 consecutive patients with prior ipsilateral cervical irradiation were age-/sex-matched to 24 controls. Degree of internal carotid (IC) tortuosity was assessed by 4 methods: ( a) deviation of IC from common carotid (CCA) axis, ( b) number of intersections between this axis and the course of the IC, ( c) total degrees of angulation along the course of the extracranial IC, and ( d) the IC length to straight-line distance ratio. Results: Carotid angioplasty and stenting was successful in all patients. Mean age was 72.8 ± 10 years; 58.4% were male. Twenty-nine percent were symptomatic (14.4% transient ischemic attack [TIA], 8.5% cardiovascular accident [CVA], and 6.5% amaurosis). Comorbidities were similar between the entire cohort and the subgroups of irradiated/control patients. The IC revealed a higher degree of deviation from the axis of the CCA in the previously irradiated patients compared to those without radiation (29.2° ± 4.5° vs 13.0° ± 2.0°, P = .001) and was more likely to intersect this axis in those with a history of cervical irradiation (83.3% vs 14.3%, P < .05). Irradiated patients also exhibited a significantly greater degree of tortuosity versus nonirradiated patients when assessed by total angulation along the course of the carotid (171.8° ± 26.0° vs 74.2° ± 20.2°, P = .014) and by the IC length:distance ratio (1.14 ± 0.05 vs 1.04 ± 0.03, P = .020). Despite increased IC tortuosity in patients with prior irradiation, all procedures were successfully completed and there did not appear to be a predilection for a specific filter type. Conclusions: A history of cervical irradiation is associated with increased tortuosity of the IC, leading to potential challenges for filter and stent deployment. However, this increased procedural complexity did not affect technical success rate or device selection in this series.

Stenting in the remnant of the third aortic arch in a case of post-irradiation occluded internal carotid artery

Collateral networks between the external carotid artery and internal carotid arteries become crucial for cerebral perfusion after occlusion of internal carotid arteries. We report the first case of a patient who received percutaneous transluminal angioplasty and stenting in a collateral vessel between the external and internal carotid artery for treatment of radiation induced severe stenosis of the internal carotid artery in the context of a contralateral internal carotid artery occlusion.

Management of head and neck cancer in elderly patients

Head and neck cancer (HNC) represents a heterogeneous group of tumours requiring multimodality approaches. It is debatable whether HNC treatment in geriatric patients should be different to that delivered for younger patients. Furthermore, the risk of death seems to be higher in HNC patients with higher co-morbidity status. Despite the fact that there is no significant difference in outcome in younger versus older patients, older HNC patients are more likely to receive nonstandard, less aggressive therapies than younger patients. Age alone should not be the basis for selecting treatment options in older HNC patients. A thorough pretreatment evaluation of co-morbidities should always be performed, and radical surgical options should not be excluded in older HNC patients treated with curative intent, as postoperative complications occur no more frequently in older patients than in younger patients. Locoregional control and disease-free survival in older patients treated with radiation therapy (either with curative intent or in the palliative setting) are comparable to the results seen in younger HNC patients, with the same acute toxicity profile. In patients receiving systemic therapies, special attention must be given to modification of chemotherapy dosages according to renal and hepatic function. Molecular-targeted therapies appear to be very useful in such patients because of their favourable tolerability. In conclusion, once all physiological and biological risk factors have been addressed, a large proportion of geriatric patients can and should be offered the same HNC treatment as is offered to younger patients.

Early-onset stroke in a patient with nasopharyngeal cancer associated with protein C deficiency

We report a 47-year-old male stroke patient with nasopharyngeal cancer (NPC) and protein C deficiency. The patient was diagnosed with NPC and received a complete course of radiotherapy. Infarction stroke occurred 28 months after radiotherapy and magnetic resonance imaging of the brain confirmed the diagnosis. Carotid duplex sonography showed 50-79% stenosis in his left internal carotid artery. Coagulation profiles indicated protein C deficiency. After medical treatment and rehabilitation, the patient regained the ability to walk and he could perform most of his daily activities. Radiotherapy-induced carotid stenosis is an exacerbating feature of stroke in patients with protein C deficiency. We suggest early carotid duplex sonography and survey of the coagulation profile to prevent a stroke in patients with NPC.

Premature carotid artery disease in pediatric cancer survivors treated with neck irradiation

BACKGROUND

While carotid artery disease and strokes have been documented in adult cancer patients treated with neck irradiation, little information is available on pediatric patients. The purpose of this study is to determine if carotid disease is more prevalent among pediatric cancer survivors treated with neck irradiation than among healthy controls.

PROCEDURE

Thirty pediatric cancer survivors who received neck irradiation (2,000-6,660 cGy) and 30 healthy subjects underwent bilateral carotid ultrasounds. Study outcome measures were common carotid intima-media thickness (IMT) and plaque (present or absent). Multivariate methods were used to compare cases and controls and to identify risk factors related to carotid disease in childhood cancer survivors.

RESULTS

IMT was greater for cancer survivors than controls (0.46 mm (SD 0.12) vs. 0.41 mm (SD 0.06), P < 0.001). Plaque was present in 18% of irradiated vessels and 2% of non-irradiated vessels (P < 0.01). Among cancer survivors, IMT was positively associated with female gender (P < 0.05), non-white ethnicity (P < 0.01), positive family history of stroke/heart attack (P < 0.05), BMI (P < 0.001), total cholesterol (P < 0.01), cancer relapse (P < 0.001), and years off treatment (P < 0.0001). Plaque was positively associated with relapse (P < 0.05) and C-reactive protein (P < 0.01). There was no significant relationship between radiation dose at levels >or=2,000 cGy and IMT or plaque.

CONCLUSIONS

Carotid artery disease was more prevalent among cancer survivors treated with neck irradiation than among controls. Due to the high risk of stroke associated with advanced carotid disease, larger prospective studies are needed to better define disease risk in these long-term survivors.

Predictors of carotid artery stenosis after radiotherapy for head and neck cancers

OBJECTIVE

To study the prevalence of and risk factors associated with carotid artery stenosis (CAS) after radiotherapy (RT) for head and neck cancer.

METHODS

DESIGN OF STUDY

Prospective, cross-sectional study.

SETTING

Patients recruited from a hospital Radiation-Oncology department.

SUBJECTS

From March 2002 to August 2006, 290 consecutive head and neck cancer patients were enrolled in this study. One hundred ninety-two of these patients had previously undergone RT (RT group) and 98 had no RT (control group).

INTERVENTION

After detecting CAS by carotid duplex sonography, the severity of CAS was evaluated by a bilateral plaque scoring system.

MAIN OUTCOME MEASURE

CAS score.

RESULTS

There were no differences in age or gender between the two groups. The RT group had a significantly higher plaque score than the non-irradiated group (P < .05). Multiple regression analysis of the 290 head and neck cancer patients revealed that bilateral plaque score was significantly correlated with age, hyperlipidemia, and RT. Multiple regression analysis was performed in the RT group alone with patients 41-50 years old serving as the reference group. This analysis showed that in RT patients > 50 years old, age was inversely correlated with plaque score; however, in RT patients <or= 41 years old, age was positively correlated with plaque score.

CONCLUSION

In head and neck cancer, the high post-treatment incidence of radiation-induced CAS indicates the importance of regular examination of the carotid duplex and early antiplatelet prophylaxis. Different age groups may require different irradiation strategies to prevent radiation-induced CAS.

The hostile neck does not increase the risk of carotid endarterectomy

INTRODUCTION

Hostile neck anatomy is assumed to be associated with increased surgical risk for patients undergoing carotid endarterectomy (CEA) and is often considered a reason to choose carotid stenting or medical management. This retrospective case-control study evaluated whether, and how much, anatomically hostile necks represent a condition of higher surgical risk of early and late mortality and major or minor morbidity.

METHODS

The data for 966 homogeneous CEA patients was prospectively entered in a computer database. Seventy-seven had a hostile neck anatomy due to previous oncologic surgery or neck irradiation, restenoses after CEA, high carotid bifurcation, or bull-like and inextensible neck. A case-control matched-pair cohort study considered sex, age (5-year intervals), and year of operation. Regional anesthesia was used for all operations for atherosclerotic stenosis >or=70%, conforming to the European Carotid Surgery Trial (ECST) in symptomatic and asymptomatic patients, at a single center and by one surgeon or under his direct supervision.

RESULTS

The hostile neck patients and the control group were matched for age, sex, carotid-related symptoms, degree of stenoses, and main risk factors for cardiovascular diseases. Intraoperative variables were substantially equivalent in the two groups; however, procedure length and clamping time were, respectively, about 22 minutes (P = .0001) and 7 minutes longer (P = .01) in the hostile neck group. Rates of postoperative mortality and neurologic events were equivalent. Peripheral nerve lesions were multiple and significantly more frequent in the hostile neck patients (21% with >or=1 cranial nerve lesion vs 7% of controls, P = .03), yet all were transient and limited to a few months. The subgroups of patients with hostile neck, restenoses, and bull-like inextensible necks required the longest operative and clamping time, and those with bull-like and high bifurcation had the most frequent cranial nerve dysfunctions. At the respective follow-up of 47 and 45 months, survival curves (P = .48) and the incidence of restenoses and fatal and nonfatal strokes were similar (5 and 4, respectively).

CONCLUSIONS

Hostile necks led to more complex CEA procedures but without substantial consequences in early and late morbidity and mortality. Most patients with hostile neck can undergo CEA at low risk, with the benefit of effective long-lasting stroke prevention similar to standard patients. In our opinion, the more frequent but temporary cranial nerve dysfunctions that occur are not sufficient to consider hostile neck patients noneligible for CEA.

Angiographic Characteristics of Radiation-Induced Carotid Arterial Stenosis

Purpose

This study aimed to clarify the angiographic characteristics of radiation-induced carotid stenosis.

Methods

We evaluated 11 carotid arteries of patients after radiotherapy (radiotherapy group) and 26 carotid arteries of age- and gender-matched patients without a history of radiotherapy (control group). All patients had carotid stenosis detected by digital subtraction angiography (DSA). We developed an original coordinate system on the DSA to determine the accurate length and location of the carotid lesion.

Results

Radiation-induced carotid lesions were significantly longer than carotid lesions caused by atherosclerosis. The maximal stenosis of radiation-induced carotid lesions tended to be at the end of the stenotic area and within a wider range than the nonradiation-induced lesions, including in the proximal common carotid artery (CCA).

Conclusions

Radiation-induced stenotic lesions seem to exist in a wide range of carotid artery, including the CCA, along the vessel, and show maximal stenosis near the end of the stenotic area.

The role of the long-term follow-up clinic in discovering new emerging late effects in adult survivors of childhood cancer

Our understanding of late effects in long-term survivors of childhood cancer is continually evolving as significant numbers of survivors are entering middle to later adulthood. Effects of conventional treatment on premature aging are being recognized, as are long-term effects of newer therapies. Clinicians in long-term follow-up clinics are in a unique position to monitor for recognized late effects and to be alert to signs and symptoms of late effects that have not been previously reported in the pediatric cancer literature. This article presents 2 young adult survivors who displayed subtle signs of impaired cerebral blood flow due to carotid artery stenosis many years after being treated with neck irradiation. When the first patient presented nearly a decade ago in the clinic with symptoms, premature carotid artery disease was not a radiation-related late effect that had been reported previously in survivors of childhood cancer. These cases are used to illustrate the key role of long-term follow-up clinics in identifying new and emerging treatment-related late effects and underscore the importance of lifetime surveillance and the need for collaboration between pediatric and adult health care providers.

Ruptured pseudoaneurysm of the internal maxillary artery complicating CT-guided fine-needle aspiration in an irradiated, surgical bed

BACKGROUND

CT-guided fine-needle aspiration (FNA) is a safe procedure, but major complications can occur rarely. Pseudoaneurysm rupture in the head and neck region following CT-guided FNA is an emergency that can result in life-threatening hemorrhage. This case emphasizes the salient risk factors for pseudoaneurysm formation and rupture in the head and neck region following CT-guided FNA.

METHODS

A patient was seen with oral and facial hemorrhage as a result of a ruptured pseudoaneurysm 11 weeks following CT-guided FNA in a previously irradiated surgical bed.

RESULTS

The patient was treated with coil embolization in and around the pseudoaneurysm and discharged without any further complications.

CONCLUSIONS

Although CT-guided FNA is a safe and effective procedure, some patients may be at increased risk for rare but major complications. Caution should be used in proceeding with CT-guided FNA in an irradiated surgical bed of the head and neck.

Cardiovascular effects of breast cancer radiotherapy

Cardiac toxicity has been implicated as the primary reason for excess non-breast cancer mortality in early breast cancer radiotherapy studies. Refinements in radiotherapy techniques have allowed for a considerable reduction of this risk in the majority of breast cancer patients. Recent large population-based studies confirmed an increase of cardiovascular death risk in patients irradiated for cancer of the left breast and in individuals exposed to relatively low (hitherto believed to be of no cardiovascular disease risk) doses of radiation, such as atomic bomb survivors or patients treated for various benign conditions. The issue of potential radiation-related cardiac damage may also be assuming a new significance due to the widespread use of other cardiotoxic agents, such as anthracyclines, paclitaxel and trastuzumab. The aim of this review is to summarize and critically analyze the available evidence on the impact of ionizing radiation on the cardiovascular system, with special attention to recent data demonstrating previously unrecognized adverse effects. This review discusses the pathology of radiation-related cardiovascular disease, its clinical presentation, risk factors and methods of assessment, as well as technical developments minimizing cardiac exposure. Epidemiological data are presented on the incidence of radiation-induced heart disease and cardiovascular mortality in various populations of patients irradiated for breast cancer and in individuals exposed to low radiation doses. Additionally, non-cardiac radiation-related vascular morbidity and mortality in breast cancer patients are addressed.

Premature carotid artery disease in long-term survivors of childhood cancer treated with neck irradiation: a series of 5 cases

BACKGROUND

Follow-up studies find an increase in stroke and carotid artery disease incidence in adult cancer patients treated with neck irradiation. These radiation-related late effects are now being detected in young adult survivors of childhood cancer.

OBSERVATIONS

This report includes 5 pediatric cancer survivors, ages 23 to 40, who presented with advanced carotid artery stenosis 17 to 36 years after receiving neck irradiation. Radiation doses ranged from 3900 to 7350 cGy. Three of the 5 experienced a stroke.

CONCLUSIONS

Prevalence and risk factors associated with premature carotid artery disease after neck irradiation need to be investigated in childhood cancer survivors.

Guidelines for Screening of Extracranial Carotid Artery Disease: A Statement for Healthcare Professionals from the Multidisciplinary Practice Guidelines Committee of the American Society of Neuroimaging; Cosponsored by the Society of Vascular and Interventional Neurology

The aim of this new statement is to provide comprehensive and timely evidence-based recommendations on the screening for asymptomatic carotid artery stenosis in the general population and selected subsets of patients. Recommendations are included for high-risk persons in the general population; patients undergoing open heart surgery including coronary artery bypass surgery; patients with peripheral vascular diseases, abdominal aortic aneurysms, and renal artery stenosis; patients after radiotherapy for head and neck malignancies; patients following carotid endarterectomy, or carotid artery stent placement; patients with retinal ischemic syndromes; patients with syncope, dizziness, vertigo or tinnitus; and patients with a family history of vascular diseases and hyperhomocysteinemia. The recommendations are based on prevalence of disease, anticipated benefit, and concurrent guidelines from other professional organizations in selected populations.

Radiation arteritis: A contraindication to carotid stenting?

BACKGROUND

Carotid artery stenting (CAS) for high-risk anatomic lesions is accepted practice. Neck irradiation and radiotherapy-induced arteritis are common indications. The clinical outcomes of CAS for radiation arteritis have been poorly defined.

METHODS

A prospective database of patients undergoing CAS at a tertiary referral academic medical center was maintained from 1999 to 2006. Patients undergoing primary carotid artery stenting for significant atherosclerotic (ASOD) and radiotherapy (XRT)-induced occlusive disease were analyzed. Life-table analyses were performed to assess time-dependent outcomes. Cox proportional hazard analysis or Fisher's exact test was performed to identify factors associated with outcomes. Data are presented as the mean +/- SEM unless otherwise indicated.

RESULTS

During the study period, 150 patients underwent primary CAS, 75% with embolic protection. Fifty-eight percent were symptomatic. One hundred twenty-seven (85%) were treated for ASOD, and 23 (15%) had XRT. The 30-day all-cause mortality rate was 1% for ASOD and 0% for XRT (P = NS); overall survival at 3 years was equivalent. There was no significant difference in major adverse event rates as defined by the Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) trial between the groups. The 3-year neurologic event-free rate was 85% for ASOD and 87% for XRT (P = NS). Late asymptomatic occlusions were seen only in XRT patients. The 3-year freedom from restenosis rate was significantly worse for the XRT group, at 20%, vs 74% for the ASOD group (P < .05). Likewise, the 3-year patency rate was also worse for the XRT group, at 91%, vs 100% for ASOD by Kaplan-Meier analysis (P < .05). No factor was predictive of occlusion or stenosis by Cox proportional hazards analysis.

CONCLUSION

CAS for radiation arteritis has poor long-term anatomic outcome and can present with late asymptomatic occlusions. These findings suggest that these patients require closer postoperative surveillance and raise the question of whether CAS is appropriate for carotid occlusive lesions caused by radiation arteritis.

Decreased Risk of Stroke Among 10-Year Survivors of Breast Cancer

Purpose

To assess treatment-specific risk of cerebrovascular events in early breast cancer (BC) patients, accounting for cerebrovascular risk factors.

Patients and Methods

We studied the incidence of cerebrovascular accidents (CVA; stroke and transient ischemic attack [TIA]) in 10-year survivors of early BC (n = 4,414) treated from 1970 to 1986. Follow-up was 96% complete until January 2000. Treatment-specific incidence of CVA was evaluated by standardized incidence ratios (SIRs) based on comparison with general population rates and by Cox proportional hazards regression.

Results

After a median follow-up of 18 years, 164 strokes and 109 TIAs were observed, resulting in decreased SIRs of 0.8 (95% CI, 0.6 to 0.9) for stroke and 0.8 (95% CI, 0.7 to 1.0) for TIA. Significantly increased risk of stroke was found in women who had received hormonal treatment (HT; tamoxifen) and in women who had hypertension or hypercholesterolemia, with hazard ratios (HRs) of 1.9, 2.1, and 1.6, respectively. Patients irradiated on the supraclavicular area and/or internal mammary chain (IMC) did not experience a higher risk of stroke (HR = 1.0; 95% CI, 0.7 to 1.6) or TIA (HR = 1.4; 95% CI, 0.9 to 2.5) compared with patients who did not receive radiotherapy or who were irradiated on fields other than the supraclavicular area or IMC.

Conclusion

Long-term survivors of BC experience no increased risk of cerebrovascular events compared with the general population. HT is associated with an increased risk of stroke. Radiation fields including the carotid artery do not seem to increase the risk of stroke compared with other fields.

Carotid stenting for symptomatic radiation-induced arteritis complicated by recurrent aneurysm formation

We describe a 56-year-old male who underwent successful carotid stenting (CS) with adjuvant distal protection in response to symptomatic radiation-induced carotid disease. During the CS procedure, it was incidentally noted that the lesion yield pressure was surprisingly low (2 atm). The patient returned with local symptoms from common carotid aneurysmal dilation at the proximal edge of the stent that was successfully treated with a stent graft. A second aneurysm developed proximal to the stent graft and, based on intravascular ultrasound mapping, he ultimately underwent venous bypass covered by a free-muscle graft. We believe the low lesion yield pressure in this case reflected loss of vessel integrity and it may be prudent to avoid oversizing the stent in such patients.

Supraclavicular radiation for breast cancer does not increase the 10-year risk of stroke

BACKGROUND

Modern radiation techniques, which limit the radiation dose to the heart during treatment for breast cancer, have greatly reduced the risk of radiation-induced cardiac injury. However, the risk of radiation damage to the carotid artery, which is often incidentally included in the supraclavicular radiation field for breast cancer treatment, is not routinely examined, and the technique used to treat this field has not changed significantly from early radiation trials. The purpose of the current study was to compare the incidence of hospitalization for stroke among women with breast cancer treated with supraclavicular radiation with those who received radiation therapy to the breast but not the supraclavicular fossa.

METHODS

Data from the Surveillance, Epidemiology, and End Results (SEER)-Medicare database for 5752 women who were diagnosed with American Joint Committee on Cancer (AJCC) Stage I-III nonmetastatic breast cancer between 1988 and 1997 were analyzed. Women included were age > or = 66 years, had known lymph node (LN) status, had tumors measuring < or = 5 cm, underwent breast surgery, and received adjuvant radiation therapy (with or without supraclavicular irradiation). Patients with < 5 years of follow-up were excluded because events in the first 5 years after radiation were unlikely to be radiation induced. A Cox proportional hazards model was used to compare patients with 0 positive LNs (surrogate group for no supraclavicular radiation, n = 5281) with patients with > 4 positive LNs (surrogate for supraclavicular radiation group, n = 471) for the endpoint of hospitalization for stroke. Time-to-event curves were calculated using the conditional Kaplan-Meier method.

RESULTS

The median follow-up for the 0 and 4+ LN cohorts were 92 months and 90 months, respectively (minimum of 60 months). The 10-year and 15-year actuarial freedom from hospitalization for stroke was 91% (0 LN) versus 89.5% (4+ LN) and 79% (0 LN) versus 81.6% (4+ LN), respectively (P = .28). Estrogen receptor status was balanced between the 2 cohorts. As expected, the 4+ cohort had more advanced tumors, higher stage, larger tumor size, and higher grade (P < .0001). In multivariate analysis including LN group, year of diagnosis, age, race, type of surgery, stage, tumor size, grade, estrogen receptor status, and Charlson comorbidity score, only increased age (hazard ratio [HR] for ages 70-74 years, 1.6; HR for ages 75-79 years, 2.1; and HR for age 80 + years, 2.7) and increasing comorbidity score were predictive of an increased risk of hospitalization for stroke.

CONCLUSIONS

Although patients with nonbreast malignancies treated with higher doses to the carotid arteries have been shown to have an increased risk of carotid injury, no evidence was found that radiation to the carotid delivered during supraclavicular irradiation for breast cancer increases the risk of hospitalization for stroke.

Prevalence of atherosclerosis in relation to atomic bomb radiation exposure: an RERF Adult Health Study

PURPOSE

To determine whether exposure to atomic bomb radiation altered the prevalence of asymptomatic atherosclerosis.

MATERIAL AND METHODS

In a cross-sectional analysis, we examined aortic arch calcification by plain chest radiography and common carotid artery intima-media thickness (IMT) by ultrasonography among 1804 survivors of the atomic bombing in Hiroshima. We evaluated the association between atherosclerotic changes and radiation exposure, while adjusting for potentially confounding factors.

RESULTS

Multivariate logistic regression analysis showed that aortic arch calcification was significantly associated with radiation exposure (p < 0.05). The odds ratio at 1 Gy was 1.30 (95% confidence interval [CI]: 1.05 - 1.53) for men and 1.31 (95% CI: 1.13 - 1.51) for women. Carotid artery IMT did not vary significantly with radiation dose (p = 0.18).

CONCLUSION

Radiation dose contributed to the prevalence of aortic atherosclerosis but not carotid artery atherosclerosis in atomic bomb survivors.

Dose to the intracranial arteries in stereotactic and intensity-modulated radiotherapy for skull base tumors

PURPOSE

To examine retrospectively the maximum dose to the large skull base/intracranial arteries in fractionated stereotactic radiotherapy (FSRT) and intensity-modulated radiotherapy (IMRT), because of the potential risk of perfusion disturbances.

METHODS AND MATERIALS

Overall, 56 patients with tumors adjacent to at least one major artery were analyzed. Our strategy was to perform FSRT with these criteria: 1.8 Gy per fraction, planning target volume (PTV) enclosed by the 95% isodose, maximum dose 107%. Dose limits were applied to established organs at risk, but not the vessels. If FSRT planning failed to meet any of these criteria, IMRT was planned with the same objectives.

RESULTS

In 31 patients (median PTV, 23 cm3), the FSRT plan fulfilled all criteria. No artery received a dose > or =105%. Twenty-five patients (median PTV, 39 cm3) needed IMRT planning. In 11 of 25 patients (median PTV, 85 cm3), no plan satisfying all our criteria could be calculated. Only in this group, moderately increased maximum vessel doses were observed (106-110%, n = 7, median PTV, 121 cm3). The median PTV dose gradient was 29% (significantly different from the 14 patients with satisfactory IMRT plans). Three of the four patients in this group had paranasal sinus tumors.

CONCLUSION

The doses to the major arteries should be calculated in IMRT planning for critical tumor locations if a dose gradient >13% within the PTV can not be avoided because the PTV is large or includes air cavities.

Clinical manifestations of noncoronary atherosclerotic vascular disease after moderate dose irradiation

BACKGROUND

Accelerated atherosclerosis and carotid stenosis are well-established risks occurring after high radiation doses that are used to treat cancers of the head and neck. Noncoronary vascular disease has been observed and may relate to more moderate dose irradiation.

METHODS

A search of patients treated for Hodgkin disease, non-Hodgkin lymphoma, or seminoma was performed to identify cases with noncoronary vascular complications after irradiation. These three groups were chosen because of the use of intermediate dose radiation and prevalence of long-term survivors. Individual patient records were reviewed to document the type and presentation of the stenosis and the clinical factors that may have contributed to this risk.

RESULTS

Twenty-one patients were identified who developed disease in noncoronary arteries after treatment. The median time from irradiation to diagnosis of vascular stenosis was 15 years. Antecedent risk factors for vascular disease were prevalent. Five patients had disease identified by auscultation of bruits before an adverse clinical event occurred. Five patients died from complications related to their vascular disease, which included three deaths after stroke and two after small bowel infarction.

CONCLUSION

Twelve cases arose at an atypically young age for atherosclerotic vascular disease and featured unusual clinical presentations. Nine cases identified occurred at an advanced aged and at a shorter median interval, making a causal relation to irradiation uncertain. Incorporating careful auscultation for bruits in followup evaluation of irradiated patients may identify individuals who are at risk for adverse vascular events. The potential for early vasculopathy in individuals exposed to intermediate dose irradiation suggests a need to manage dyslipidemia and reduce vascular risk factors throughout the posttreatment period.

A historical prospective cohort study of carotid artery stenosis after radiotherapy for head and neck malignancies

PURPOSE

To determine carotid artery stenosis incidence after radiotherapy for head-and-neck neoplasms.

METHODS AND MATERIALS

This historical prospective cohort study comprised 44 head-and-neck cancer survivors who received unilateral neck radiotherapy between 1974 and 1999. They underwent bilateral carotid duplex ultrasonography to detect carotid artery stenosis.

RESULTS

The incidence of significant carotid stenosis (8 of 44 [18%]) in the irradiated neck was higher than that in the contralateral unirradiated neck (3 of 44 [7%]), although this difference was not statistically significant (p = 0.13). The rate of significant carotid stenosis events increased as the time after radiotherapy increased. The risk of ipsilateral carotid artery stenosis was higher in patients who had undergone a neck dissection vs. those who had not. Patients with significant ipsilateral stenosis also tended to be older than those without significant stenosis. No other patient or treatment variables correlated with risk of carotid artery stenosis.

CONCLUSIONS

For long-term survivors after neck dissection and irradiation, especially those who are symptomatic, ultrasonographic carotid artery screening should be considered.

Carotid artery stenosis in asymptomatic patients who have received unilateral head-and-neck irradiation

PURPOSE

To determine the prevalence of carotid artery stenosis in patients who have received ipsilateral head-and-neck radiotherapy and have no symptoms of cerebrovascular disease.

METHODS AND MATERIALS

Forty patients underwent ultrasound and computed tomography angiography of their carotid arteries. The vessels on the irradiated side were compared with those on the unirradiated side in a matched-pair analysis with regard to any stenosis, stenosis > or =60% in the internal carotid artery/carotid bulb, intima medial thickness (IMT), and grade of wall abnormalities. History, physical, and fasting blood levels were taken to detect risk factors for carotid disease.

RESULTS

Fourteen irradiated carotid trees bore one or more stenosis vs. five in the unirradiated ones (p = 0.03). There were six bulb/internal carotid artery stenoses > or =60% in the irradiated carotids vs. one in the unirradiated (OR 6:1, p = 0.13). IMT and grade of vessel wall abnormality were higher in the irradiated carotids, but only at doses > or =50 Gy, and only at measurement points that lay within the radiation portals.

CONCLUSION

Radiation appears to cause carotid artery stenosis. There may be a dose threshold for carotid wall changes, which has relevance for radiotherapy in several tumor sites.