Clinically underdetected asymptomatic and symptomatic carotid stenosis as a late complication of radiotherapy in Chinese nasopharyngeal carcinoma patients

Incidence of Internal Carotid Artery Stenosis in Oral Squamous Cell Carcinoma Patients After Neck Dissection

OBJECTIVES

To determine the incidence of progressive internal carotid artery stenosis (ICAS) by head and neck contrast-enhanced computed tomography (CT) in 45 patients who underwent neck dissection for oral squamous cell carcinoma (OSCC).

PATIENTS AND METHODS

The study included 45 patients who underwent head and neck contrast-enhanced CT before and after surgery for OSCC by the Hu Yongjie team at the Department of Oral and Maxillofacial-Head & Neck Oncology of Shanghai Ninth People's Hospital in 2016 and were followed up for 5 years.

RESULTS

Comparison of the current CT with previously obtained head and neck contrast-enhanced CT images revealed progressive ICAS in 3 patients with a mean age of 50.0 years. All 3 patients were male, and their OSCC sites were the tongue in 2 patients and the buccal in 1 patient. Tumor resection and neck dissection were performed for all 3 patients. Two patients underwent radiotherapy. In all 3 patients, the ICAS had occurred on the same side as the tumors.

CONCLUSIONS

The results of this study suggest that neck dissection with cervical sheath removal might increase the incidence of ICAS, but this result may need the support of a larger sample size study.

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

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.

Radiotherapy Is Associated with an Accelerated Risk of Carotid Atherosclerosis in Patients with Nasopharyngeal Carcinoma: A Nine-Year Prospective Follow-Up Study

Radiation-related extracranial vasculopathy is a common late effect after radiation in patients with nasopharyngeal carcinoma (NPC). We proposed the hypothesis that radiation-related extracranial vasculopathy is a progressive process that can begin immediately after radiotherapy and persist for a longer period, and inflammation and oxidative stress may play a pivotal role in this process. Thirty-six newly diagnosed NPC patients were assessed with B-mode ultrasound for the common carotid artery (CCA) intima media thickness (IMT) measurement as well as surrogate markers at three different stages (baseline, immediately after concurrent chemoradiation therapy (CCRT), and 9 years after enrollment). A healthy control group was also recruited for comparison. Surrogate markers including a lipid profile, HbA1c, inflammation, oxidative stress, and platelet activation markers were assessed. The mean CCA IMT in the NPC group were increased immediately after CCRT (p = 0.043). The mean CCA IMT value after a 9-year follow-up also showed a significant increase in NPC and control group, respectively (p < 0.0001 and p < 0.0001, paired t test). The annual increase mean CCA IMT (mm) was 0.053 ± 0.025 and 0.014 ± 0.013 in NPC and control group, respectively (p < 0.0001). The baseline high sensitivity CRP (hs-CRP), thiol, TBARS, and CD63 level were significantly higher in the NPC group (hs-CRP, p = 0.001, thiol, p < 0.0001, TBARS, p = 0.05, and CD63 level, p = 0.04). The thiol and TBARS levels were significantly lower in NPC patients immediately after CCRT (thiol, p < 0.0001, and TBARS, p = 0.043). The CD62P level was significantly higher while the thiol level was significantly lower in the NPC group after a 9-year follow-up (CD62P level, p = 0.007; and thiol level, p = 0.004). Radiation-related extracranial vasculopathy is a progressive process that begins immediately after radiotherapy with significantly increased carotid IMT compared to the control group during the 9-year follow-up. Chronic inflammation and oxidative stress might serve to drive the process and also contribute to increased platelet activation.

Early-Stage Glottic Squamous Cell Carcinoma in the Era of Image-Guided Radiotherapy

Early-stage squamous cell cancer (SCC) of the glottis has a good prognosis. Therefore, patients have long survival outcomes and may potentially suffer from late toxicities of radiotherapy. Radiotherapy with a conventional parallel-opposed-pair or anterior-oblique beam arrangements for stage 1 and 2 glottic SCC have field borders that traditionally cover the entire larynx, exposing organs-at-risk (e.g. carotid arteries, contralateral vocal cord, contralateral arytenoid and inferior pharyngeal constrictor muscles) to high radiation doses. The potential long-term risk of cerebrovascular events has attracted much attention to the dose that carotid arteries receive. Swallow and respiratory motion of laryngeal structures has been an important factor that previously limited reduction of the radiation treatment volume. Motion has been evaluated using multiple imaging modalities and this information has been used to calculate PTV margins for generation of more limited target volumes. This review discusses the current literature surrounding dose-effect relationships for various organs-at-risk and the late toxicities that are associated with them. This article also reviews the currently available data and effects of laryngeal motions on dosimetry to the primary target. We also review the current limitations and benefits of a more targeted approach of radiotherapy for early-stage glottic SCCs and the evolution of CT-based IGRT and MR-guided radiotherapy techniques that may facilitate a shift away from a conventional 3D-conformal radiotherapy approach.

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.

Carotid stenosis prevalence after radiotherapy in nasopharyngeal carcinoma: A meta-analysis

PURPOSE

Radiotherapy (RT) is the most effective treatment for nasopharyngeal carcinoma (NPC) but may cause stenosis of the carotid arteries. This meta-analysis evaluates the prevalence of carotid stenosis after radiation therapy.

MATERIALS AND METHODS

Online search for studies reporting carotid stenosis in patients with NPC who received radiation therapy (RT) compared to NPC patients who did not receive RT and compared to healthy controls.

RESULTS

Twelve studies were included for a total analysis of 1928 patients (837 received RT and 1091 were controls). RT patients showed a statistically significant higher incidence of overall stenosis (pooled risk ratio = 4.17 [2.44, 7.10], p < 0.00001) and an even greater incidence of significant stenosis (50% or more) (pooled risk ratio = 8.72 [3.53, 21.55], p < 0.00001). Analyzing by individual blood vessels showed that the RT patients had significantly higher incidence of stenosis in common carotid artery (CCA), external carotid artery (ECA), carotid bulb, CCA and internal carotid artery (ICA), and CCA/ICA/carotid bulb.

CONCLUSIONS

NPC patients who receive RT have increased risk of developing carotid stenosis, and should be screened after treatment.

[Radiation-induced carotid stenosis: A personnalized approach]

INTRODUCTION

Surgical treatment of radio-induced carotid stenosis (RICS) is challenging and burdened by an elevated risk of local complications. Carotid artery stenting (CAS) may be a suitable alternative. The best approach is yet to be defined. We reviewed the results of both techniques following selection based on better-suitability characteristics (anatomic and clinical).

METHODS

We retrospectively reviewed 38 patients treated for 43 RICS from a group of 1230 patients who had carotid interventions between 2008 and 2015 (5 bilateral). Primary endpoints were morbidity and mortality at 30 days (transient ischemic attack, stroke, myocardial infarction, or death). Secondary endpoints were technical success, wound complications, cranial nerve injury (CNI), restenosis (≥50%) and recurrent symptoms.

RESULTS

RICS was symptomatic in 6 patients in the OR group and 3 in the CAS group. Lesions in the OR group were longer (P=0.02) and more calcified (P=0.08). Technical success rate was 100%. Cranial nerve injury rate was 14.2% (3/21). All injuries were completely resolved within several weeks. In the CAS group, technical success rate was 95% (21/22) with the one failure due to a residual stenosis exceeding 30%. Periprocedural stroke rates were 0% and 4.5% in the OR and CAS groups respectively (0/21 vs 1/22, P=0.32). There were no early deaths. Mean follow-up was 19.1 months (3-75). The restenosis rate was 9.5% (2/21) in the OR group and 9% (2/22) in the CAS group.

CONCLUSION

Our results do not support a preferred treatment strategy. The choice of treatment should be considered on an individual basis.

Perioperative stroke in a patient undergoing surgery for oral cancer: A case report

Carotid artery stenosis is a significant risk factor for stroke. In elderly patients with carotid atherosclerosis and stenosis, it is not unusual for oral, head and neck cancer surgery to be performed. The present study describes a case of stroke that occurred during a neck dissection for the treatment of cervical lymph node metastasis of a left maxillary gingival carcinoma. The patient was an 84-year-old female who was considered to be at high risk of a stroke based on pre-operative head and neck computed tomography scans, which detected severe carotid atherosclerosis and stenosis. There was no possible stroke prophylaxis available during the performance of the neck dissection in the present case. However, if patients are evaluated to be high-risk pre-operatively, statin agents should be administered, the surgery should be carefully performed, adequate sedation should be maintained post-operatively and the patient should be followed up, aiming to achieve the early detection of a possible stroke.

Nasopharyngeal carcinoma

Epidemiological trends during the past decade suggest that although incidence of nasopharyngeal carcinoma is gradually declining, even in endemic regions, mortality from the disease has fallen substantially. This finding is probably a result of a combination of lifestyle modification, population screening coupled with better imaging, advances in radiotherapy, and effective systemic agents. In particular, intensity-modulated radiotherapy has driven the improvement in tumour control and reduction in toxic effects in survivors. Clinical use of Epstein-Barr virus (EBV) as a surrogate biomarker in nasopharyngeal carcinoma continues to increase, with quantitative assessment of circulating EBV DNA used for population screening, prognostication, and disease surveillance. Randomised trials are investigating the role of EBV DNA in stratification of patients for treatment intensification and deintensification. Among the exciting developments in nasopharyngeal carcinoma, vascular endothelial growth factor inhibition and novel immunotherapies targeted at immune checkpoint and EBV-specific tumour antigens offer promising alternatives to patients with metastatic disease.

Middle cerebral artery stenosis in patients with nasopharyngeal carcinoma after radiotherapy: the incidence of stenosis and the risk factors

OBJECTIVE

The purpose of the present study was to investigate the incidence of middle cerebral artery (MCA) stenosis by contrast-enhanced MR angiography (CE-MRA), and to evaluate the risk factors for significant (>50%) MCA stenosis in patients with nasopharyngeal carcinoma (NPC) after radiotherapy.

METHODS

116 patients with NPC after radiotherapy were recruited into the irradiation group to investigate the incidence and degree of MCA stenosis by CE-MRA. The results were compared with those of the control group, which comprised 57 newly diagnosed patients with NPC who did not receive radiotherapy. Furthermore, the risk factors for significant MCA stenosis were evaluated.

RESULTS

There was a higher incidence of MCA stenosis in the irradiation group than in the control group in terms of patient number (p = 0.000) and vessel involvement (p = 0.000), respectively. The incidence of significant MCA stenosis in the irradiation group was 8.6% (10/116 patients) and 5.2% (12/232 patients) in terms of patient number and vessel involvement, respectively. However, no significant MCA stenosis was found in the control group. Univariate analysis showed that hypercholesterolaemia, T(3-4) stage and longer time interval from radiotherapy were the risk factors related to significant MCA stenosis. Multivariate analysis demonstrated that only T stage was the independent risk factor for significant MCA stenosis development.

CONCLUSION

The results showed that radiation can cause MCA stenosis in patients with NPC after radiotherapy, especially in those with T(3-4) stage, and further study is needed.

ADVANCES IN KNOWLEDGE

Radiation-induced MCA stenosis exists in patients with NPC after radiotherapy, and its prevalence is more common in patients with clinical T(3-4) stage.

Carotid and vertebral artery stenosis evaluated by contrast-enhanced MR angiography in nasopharyngeal carcinoma patients after radiotherapy: a prospective cohort study

OBJECTIVE

To investigate the incidence of carotid artery (CA) and vertebral artery (VA) stenosis by contrast-enhanced MR angiography (CE-MRA) in patients with nasopharyngeal carcinoma (NPC) after radiotherapy.

METHODS

72 patients with NPC after radiotherapy more than 3 years ago were recruited as irradiation group to investigate the incidence and degree of CA and VA stenosis by CE-MRA. The results were compared with those of the control group, which comprised 50 newly diagnosed patients with NPC who had not received radiotherapy.

RESULTS

There was a higher incidence of CA and VA stenosis in the irradiation group than in the control group in terms of patient number as well as vessel involvement. The incidence of significant (>50%) CA and VA stenosis, except for the basilar artery, was also higher in the irradiation group than in the control group. The most commonly detected stenosis in the irradiation group was found in the internal CA (ICA) and VA, followed by the external CA and common CA (CCA). CCA and/or ICA (CCA/ICA) stenosis was present in 67 (93.1%) of 72 patients, with 27 (37.5%) patients having significant CCA/ICA stenosis. The statistical analysis demonstrated that age at receiving CE-MRA scanning and time interval from radiotherapy were the independent predictors of significant CCA/ICA stenosis.

CONCLUSION

The CE-MRA scanning results showed that the incidence of stenosis seems to exist in a wider range of CAs and VAs in the patients with NPC after radiotherapy than in the patients who had not received radiotherapy, and the incidence of significant CCA/ICA stenosis is higher in patients with older age and longer interval from radiotherapy.

ADVANCES IN KNOWLEDGE

Radiation-induced CA and VA stenosis exists widely in patients with NPC after radiotherapy, and its prevalence is more common in patients with older age and longer interval from radiotherapy.

Association between genetic polymorphisms and carotid atherosclerosis in patients treated with radiotherapy for nasopharyngeal carcinoma

Background

Radiotherapy (RT) of the neck is commonly given to nasopharyngeal carcinoma (NPC) patients for preventing cervical lymph node metastasis. However, neck RT may induce the development of carotid atherosclerosis. The mechanisms of radiation-induced carotid atherosclerosis are still unclear and no previous study has investigated the genetic involvement of radiation-induced carotid atherosclerosis. The present study aims to determine the association between genetic polymorphisms and carotid atherosclerosis in patients treated with RT for nasopharyngeal carcinoma.

Methods

The present study recruited 128 post-RT NPC patients. Carotid plaque score was assessed using ultrasonography. Thirteen single nucleotide polymorphisms (SNPs) that affect the function of anti-atherosclerotic genes, including SOD2, SOD3, CAT, PON1, PPARG, ADIPOQ, IL10, TGFB1 and NOS3, were genotyped. Association between the 13 SNPs and carotid atherosclerosis was evaluated using multiple regression after adjustment for covariates (PLINK). Multiple testing was corrected using Benjamini-Hochberg step-up false discovery rate controlling procedure.

Results

rs662 and rs705379 of PON1 were close to be significantly associated with carotid plaque score (Corrected P value, P_cor = 0.0528 and P_cor = 0.0842). When the two SNPs were combined together, TC haplotype in rs662-rs705379 of PON1 was significantly associated with higher carotid plaque score (P_cor < 0.05). None of the other SNPs showed significant association with carotid plaque score.

Conclusions

TC haplotype in rs662-rs705379 of PON1 is likely to be a genetic risk factor of carotid plaque score. Post-RT NPC patients with the TC haplotype may need earlier and more frequent carotid ultrasound examinations for early detection of carotid atherosclerosis.

Predictors of the extent of carotid atherosclerosis in patients treated with radiotherapy for nasopharyngeal carcinoma

Objective

To determine the predictors of the extent of carotid atherosclerosis in patients treated with radiotherapy (RT) for nasopharyngeal carcinoma (NPC).

Methods

The present study investigated 129 post-RT NPC patients. Carotid atherosclerotic parameters, such as carotid intima-media thickness, carotid arterial stiffness and carotid plaque burden (plaque score, the presence of plaque and ≥50% stenosis) were assessed using ultrasonography. The association between carotid atherosclerotic parameters and nine potential predictors, including age, gender, post-RT duration, radiation dose, chemotherapy, diabetes mellitus, hypertension, hypercholesterolemia, and smoking, were determined using multiple regression. The cutoff values of age, post-RT duration and number of cardiovascular risk factors for the presence of carotid plaque or ≥50% carotid stenosis were analyzed using receiver operating characteristic (ROC) curve analysis. Multiple testing was corrected using Benjamini-Hochberg false discovery rate.

Results

Age, post-RT duration and number of cardiovascular risk factors were significantly associated with carotid plaque burden (corrected P value, P_cor<0.05). Age of 44.5 years (sensitivity = 99.2% and specificity = 50%, P_cor<0.01) and post-RT duration of 8.5 years (sensitivity = 75.7% and specificity = 64.3%, P_cor<0.001) were the cutoff values for detecting carotid plaque, while post-RT duration of 13.5 years (sensitivity = 66.7% and specificity = 71.6%, P_cor<0.001) and 1.5 cardiovascular risk factors (sensitivity = 40.7% and specificity = 84.3%, P_cor<0.05) were the cutoff values for screening ≥50% carotid stenosis.

Conclusions

Age, post-RT duration and number of cardiovascular risk factors are significant predictors of carotid atherosclerosis in post-RT NPC patients. Post-RT NPC patients, who are at least 45 years old, with post-RT duration of 9 years or above, and/or have ≥2 cardiovascular risk factors, are more susceptible to carotid atherosclerosis.

Radiation-induced carotid artery stenosis: a comprehensive review of the literature

In recent decades, with the improvement of radiotherapy (RT) technology and comprehensive treatment, the survival rate of head and neck malignancies has gained remarkable progress. Vascular injury and subsequent carotid stenosis following RT, as the backbone of treatment, have received increasing attention. Many investigations have demonstrated that radiation can result in the increase in carotid intima-media thickness, carotid stenosis and consequently lead to a higher risk of cerebrovascular events such as transient ischemic attack and stroke. In this review, we will examine the incidence of radiation-induced carotid artery stenosis, its morphological and histological characteristics, as well as its pathogenesis. The treatment and prevention methods, including follow-up strategies, will also be discussed at the end of the present review.

Effects of neck radiation therapy on extra-cranial carotid arteries atherosclerosis disease prevalence: systematic review and a meta-analysis

Introduction

Radiation arteritis following neck irradiation as a treatment for head and neck malignancy has been well documented. The long-term sequelae of radiation exposure of the carotid arteries may take years to manifest clinically, and extra-cranial carotid artery (ECCA) stenosis is a well-recognised vascular complication. These carotid lesions should not be regarded as benign and should be treated in the same manner as standard carotid stenosis. Previous studies have noted increased cerebrovascular events such as stroke in this cohort of patients because of high-grade symptomatic carotid stenosis resulting in emboli.

Aim

To evaluate the effect of radiation therapy on ECCA atherosclerosis progression.

Methods

Online search for case-control studies and randomised clinical trials that reported on stenosis in extra-cranial carotid arteries in patients with neck malignancies who received radiation therapy (RT) comparing them to patients with neck malignancies who did not receive RT.

Results

Eight studies were included in the final analysis with total of 1070 patients – 596 received RT compared to 474 in the control group. There was statistically significant difference in overall stenosis rate (Pooled risk ratio  =  4.38 [2.98, 6.45], P  =  0.00001) and severe stenosis (Pooled risk ratio  =  7.51 [2.78, 20.32], P <0.0001), both being higher in the RT group. Pooled analysis of the five studies that reported on mild stenosis also showed significant difference (Pooled risk ratio  =  2.74 [1.75, 4.30], 95% CI, P  =  0.0001).

Conclusion

The incidence of severe ECCA stenosis is higher among patients who received RT for neck malignancies. Those patients should be closely monitored and screening programs should be considered in all patients who receive neck RT.

Cerebral hypoperfusion secondary to radiation arteritis presenting with recurrent syncope

Radiation arteritis can lead to significant extracranial carotid artery stenosis, affecting the circle of Willis. Cerebral hypoperfusion due to arterial insufficiency is often considered as a differential diagnosis in cases of syncope but rarely proven. We present a case of a 61-year-old man with repeated episodes of syncope-negative cardiac investigations. He had a history of cervical radiation therapy for tonsillar squamous cell carcinoma 15 years previously. Carotid duplex revealed bilateral carotid occlusive disease. MR angiography showed severe multilevel extracranial carotid stenosis bilaterally with occluded left vertebral artery. A diagnosis of cerebral hypoperfusion was performed following single-photon emission CT scan. The patient underwent a left subclavian to carotid bypass, which alleviated his symptoms.

Long-term effects on carotid intima-media thickness after radiotherapy in patients with nasopharyngeal carcinoma

Background

Vascular abnormalities are the predominant histologic changes associated with radiation in nasopharyngeal carcinoma (NPC). This study examined if the duration after radiotherapy correlates with the progression of carotid intima-media thickness (IMT) and investigated its relationship with inflammatory markers.

Methods

One hundred and five NPC patients post-radiotherapy for more than one year and 25 healthy control subjects were examined by B-mode ultrasound for IMT measurement at the far wall of the common carotid artery (CCA). Surrogate markers including lipid profile, HbA1c, and high sensitive C-reactive protein (hs-CRP) were assessed.

Results

The IMT of CCA was significantly increased in NPC patients and carotid plaque was detected in 38 NPC patients (38/105, 36.2%). Significant risk factors for carotid plaques included age, duration after radiotherapy, and HbA1c levels. Age, duration after radiotherapy, hs-CRP, HbA1c, and platelet count positively correlated with IMT. The cut-off value of age and duration after radiotherapy for the presence of plaque was 52.5 years and 42.5 months, respectively. In NPC subjects, multiple linear regression analysis revealed that age, gender, duration after radiotherapy and platelet counts were independently associated with CCA IMT. After adjustments for age, gender and platelet counts, IMT increased in a linear manner with duration after radiotherapy.

Conclusions

Radiation-induced vasculopathy is a dynamic and progressive process due to late radiation effects. Extra-cranial color-coded duplex sonography can be part of routine follow-up in NPC patients aged ≥50 years at 40 months post-radiotherapy.

Long-term effects of neck irradiation on cardiovascular autonomic function: a study in nasopharyngeal carcinoma patients after radiotherapy

INTRODUCTION

Baroreflex failure has been reported as a late sequalum of neck radiotherapy. In this study we investigated cardiovascular autonomic function in patients after neck radiotherapy to determine predictive factors associated with outcome.

METHODS

Eighty-nine patients with nasopharyngeal carcinoma were evaluated ≥6 months after radiotherapy for cardiovascular autonomic function and compared with 48 control subjects. Inflammatory markers and carotid intima-media thickness were also assessed.

RESULTS

Autonomic parameters of heart rate response to deep breathing and Valsalva ratio were significantly lower in the patient group. Cardiovascular autonomic impairment was generally mild with relative sparing of the efferent cardiovagal pathway. By univariate and multivariate analyses, the time after radiotherapy and C-reactive protein level were significantly associated with the degree of cardiovascular autonomic dysfunction.

CONCLUSIONS

Radiation-induced cardiovascular autonomic impairment is a dynamic and progressive process that occurs long after radiotherapy. Chronic inflammation plays a major role in this process.

Angiographic features, collaterals, and infarct topography of symptomatic occlusive radiation vasculopathy: a case-referent study

BACKGROUND AND PURPOSE

Occlusive radiation vasculopathy (ORV) predisposes head-and-neck cancer survivors to ischemic strokes.

METHODS

We analyzed the digital subtraction angiography acquired in 96 patients who had first-ever transient ischemic attack or ischemic strokes attributed to ORV. Another age-matched 115 patients who had no radiotherapy but symptomatic high-grade (>70%) carotid stenoses were enrolled as referent subjects. Digital subtraction angiography was performed within 2 months from stroke onset and delineated carotid and vertebrobasilar circulations from aortic arch up to intracranial branches. Two reviewers blinded to group assignment recorded all vascular lesions, collateral status, and infarct pattern.

RESULTS

ORV patients had less atherosclerotic risk factors at presentation. In referent patients, high-grade stenoses were mostly focal at the proximal internal carotid artery. In contrast, high-grade ORV lesions diffusely involved the common carotid artery and internal carotid artery and were more frequently bilateral (54% versus 22%), tandem (23% versus 10%), associated with complete occlusion in one or both carotid arteries (30% versus 9%), vertebral artery (VA) steno-occlusions (28% versus 16%), and external carotid artery stenosis (19% versus 5%) (all P<0.05). With comparable rates of vascular anomaly, ORV patients showed more established collateral circulations through leptomeningeal arteries, anterior communicating artery, posterior communicating artery, suboccipital/costocervical artery, and retrograde flow in ophthalmic artery. In terms of infarct topography, the frequencies of cortical or subcortical watershed infarcts were similar in both groups.

CONCLUSIONS

ORV angiographic features and corresponding collaterals are distinct from atherosclerotic patterns at initial stroke presentation. Clinical decompensation, despite more extensive collateralization, may precipitate stroke in ORV.

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.

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.

Post-treatment imaging appearances in head and neck cancer patients

Surgery and radiotherapy (with or without chemotherapy) for head and neck cancer can create a daunting array of radiological appearances post-treatment. The role of the radiologist lies not only in detecting recurrent neoplastic disease, but also identifying non-neoplastic changes that may account for clinical presentation and symptoms in this patient group. There are a number of non-neoplastic as well as neoplastic changes and disease entities that can present on surveillance imaging, such as primary resection and reconstructive surgical change, surgical neck dissection changes, radionecrosis, post-treatment denervation change, and radiotherapy-related secondary tumours. Some of these require conservative management, while others require more active treatment. Awareness and recognition of the imaging appearances of these post-treatment changes is therefore critical for the radiologist involved in the multidisciplinary care of the head and neck cancer patient.

Cavernous sinus meningiomas: a large LINAC radiosurgery series

One hundred and seventeen patients with cavernous sinus meningiomas had LINAC radiosurgery at our institution in the period 1993-2007. Six cases were lost and 9 had less than 1 year follow up. The remaining 102 patients were prospectively followed up at 1 y intervals with clinical, neuro-ophthalmological and MRI examinations. Patients' age ranged between 31 and 86 years (mean 57). Seventy percent were females. The mean tumor volume was 7 cc. Thirty-three patients had previous microsurgery. Tumors were defined with high resolution MRI obtained 1-2 days before treatment and fused to stereotactic CT. Treatment was mostly delivered through a minimultileaf collimator and multiple dynamic arcs. The minimal dose to the tumor margin was 12-17.5 Gy (mean 13.5) encompassed by the 80% isodose shell. Radiation dose to the optic apparatus was kept below 10 Gy. Follow up ranged from 12 to 180 months (mean 67 months). Tumor control (lack of growth) was 98% (58% of the tumors reduced their volumes). Sixty-four patients presented with cranial nerve deficit. Thirty-nine percent improved or resolved following radiosurgery. Cranial neuropathy had significantly higher resolution rates when radiosurgery was performed early (<1 year) after its appearance (53% as opposed to 26%) even in patients with deficits post surgery. Complications were seen in five patients (1 with deafferentation pain, 1 with facial hypesthesia, 1 with visual loss and 2 with partial VI neuropathy). Radiosurgery had a high control rate for meningiomas of the cavernous sinus with few and mild complications. Cranial neuropathy can be solved by treatment, particularly those of recent onset.

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.

American Society of Clinical Oncology clinical evidence review on the ongoing care of adult cancer survivors: cardiac and pulmonary late effects

PURPOSE

To review the evidence on the incidence of long-term cardiac or pulmonary toxicity secondary to chemotherapy, radiotherapy, or trastuzumab in symptomatic and asymptomatic cancer survivors.

METHODS

An American Society of Clinical Oncology Panel reviewed pertinent information from the literature through February 2006.

RESULTS

Few studies directly addressing the benefits of screening for long-term cardiac or pulmonary toxicity in asymptomatic cancer survivors who received chemotherapy, radiotherapy, or trastuzumab were identified. The reviewed literature included primarily retrospective and cross-sectional studies describing the incidence of cardiac and pulmonary late effects. Anatomic and/or functional abnormalities have been associated with use of all currently available anthracyclines and their derivatives. Trastuzumab-related cardiac dysfunction rarely causes death, and in most cases is reversible with improvement in cardiac function on drug discontinuation and/or treatment with cardiac medications. The estimated aggregate incidence of radiation-induced cardiac disease is 10% to 30% by 5 to 10 years post-treatment, although the incidence may be lower with modern techniques. Radiation pneumonitis is reported in 5% to 15% of lung cancer patients receiving definitive external-beam radiation therapy. A minority of patients may develop progressive pulmonary fibrosis; late complications include cor pulmonale and respiratory failure. Bleomycin-induced pneumonitis is an acute rather than late effect of treatment. Late pulmonary complications in bone marrow or stem cell transplantation patients who develop interstitial pneumonitis include idiopathic pneumonia syndrome and bronchiolitis obliterans.

CONCLUSION

An increased incidence of cardiac and/or pulmonary dysfunction is observed in cancer survivors. Research is needed to identify high-risk patients, and to determine the optimal screening strategies and subsequent treatment.

Delayed complications of radiotherapy treatment for nasopharyngeal carcinoma: imaging findings

Radiotherapy is used to treat a wide variety of head and neck tumours that arise in and around the skull base. The delayed effects of radiation damages a range of structures, including the nervous system, bone, major vessels, mucus membranes, pituitary and salivary glands, as well as increasing the risk of radiation-induced neoplasms. In this review the complications resulting from radiation treatment for nasopharyngeal carcinoma (NPC), a cancer treated with a high dose of radiation to a fairly large region, are illustrated. Many patients with NPC have a long-term survival, so are at risk of developing delayed radiation effects, and hence may demonstrate a wide range of complications on imaging. Other tumours around the skull base treated with radiotherapy include meningiomas, chordomas, chondrosarcomas, pituitary adenomas, paranasal sinus and nasal cavity tumours. In these cases similar complications may be encountered on imaging, although the severity, incidence and location will vary.

Medullary hemorrhagic infarction after radiation for nasopharyngeal carcinoma

Head and neck irradiation may lead to accelerated atherosclerosis over several years. Delayed stroke has been described after head and neck irradiation administered for a number of conditions. However, brain stem stroke has only rarely been associated with irradiation. We report a patient with medullary hemorrhagic infarction 6 years after radiotherapy for nasopharyngeal carcinoma. A 42-year-old normotensive Chinese male had rapid onset of vertigo, diplopia, ataxia, dysphagia, hypophonic dysarthria, hemiparesis, and respiratory distress. Cranial MR imaging 2 days after symptom onset showed medullary infarction, and cranial MR imaging 5 days after symptom onset showed medullary hemorrhage. He needed ventilatory support and died of bacterial pneumonia 1 month later. Other risk factors for stroke were absent. Hemorrhagic infarction in this patient was likely associated with the radiotherapy. Radiotherapy is the first choice of treatment for nasopharyngeal carcinoma, however, it may induce fatal medullary hemorrhagic infarction.

Ionizing radiation accelerates the development of atherosclerotic lesions in ApoE-/- mice and predisposes to an inflammatory plaque phenotype prone to hemorrhage

After radiotherapy treatment, there is an increased incidence of localized atherosclerosis in patients with Hodgkin's disease, breast cancer, and head and neck cancer. Here, we established a mouse model to study the development and progression of radiation-induced atherosclerosis and to compare the phenotype of these lesions with age-related atherosclerosis. Atherosclerosis-prone ApoE-/- mice fed a regular chow diet received single radiation doses of 14 Gy or sham treatments (0 Gy) to the neck, including both carotid arteries. At 22, 28, and 34 weeks after irradiation, blood samples were taken, and the arterial tree was removed for histological examination. Cholesterol levels in irradiated mice were not significantly different from age-matched controls, and markers of systemic inflammation (soluble intercellular adhesion molecule-1, soluble vascular cell adhesion molecule-1, and C-reactive protein) were not elevated. The lesions in irradiated arteries were macrophage rich, with a remarkable influx of inflammatory cells, predominantly granulocytes. Intraplaque hemorrhage and erythrocyte-containing macrophages were seen only in lesions of irradiated arteries. Based on these data, we propose that irradiation accelerates the development of macrophage-rich, inflammatory atherosclerotic lesions prone to intraplaque hemorrhage.

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.

Iatrogenic carotid artery injury in neurosurgery

Iatrogenic carotid artery injury (CAI) results from various neurosurgical procedures. A review of the literature was conducted to provide an update on the management of this potentially devastating complication. Iatrogenic CAIs are categorized according to each diagnostic or therapeutic procedure responsible for the injury, i.e., anterior cervical spine surgery, central venous catheterization, chemical substances, chiropractic manipulation, diagnostic cerebral angiography, middle-ear surgery, percutaneous procedures for trigeminal neuralgia, radiation therapy, skull-base surgery, tracheostomy, and transsphenoidal surgery. The incidence, mechanisms of injury, diagnostic imaging modalities, and reparative procedures are discussed for each procedure. Iatrogenic CAI may be more prevalent than had previously been thought, mostly because of a heightened awareness on the part of physicians and the earlier detection of asymptomatic patients owing to sophisticated and less-invasive imaging modalities. Prevention is the best treatment for every iatrogenic injury, and it is expected that further accumulation of experience with and knowledge of iatrogenic CAI will result in further reduction of this complication. Although some CAIs, such as radiation-induced carotid artery stenosis, may not be preventable, earlier intervention before the patient becomes symptomatic may favorably alter the prognosis. Following the rapid development of endovascular techniques in recent years, surgically inaccessible lesions can be treated in a more reliable and safe manner than before.

Neck irradiation, carotid injury and its consequences

Carotid stenosis is a major sequela of head and neck irradiation that has not received the attention it deserves. Its impact on the quality of life of patients can be substantial. This review discusses the incidence, pathogenesis and consequences of radiation-induced carotid stenosis following head and neck irradiation. This review is based on literature search (Medline and Pub Med) and cross-referencing. The incidence of significant carotid stenosis following head and neck irradiation range from 30% to 50%. Patients with carotid stenosis are at increased risk for stroke. Factors such as hypertension, diabetes, smoking and obesity increase the risk. Increased attention to the clinical signs of carotid stenosis and evaluation of these patients with appropriate imaging studies, together with strict implementation of management of hypertension and diabetes and, counseling on obesity and smoking have the potential to reduce the incidence of this sequela of head and neck irradiation. Those patients with severe carotid stenosis can be managed with endarterectomy or carotid artery stenting.

Surgical treatment of paragangliomas of the carotid bifurcation: Results of 36 patients

BACKGROUND

Paragangliomas of the carotid bifurcation are rare and usually benign neoplasms arising from the carotid body chemoreceptors. The aim of this retrospective study was to report long-term results of carotid bifurcation paragangliomas treated in a single institution over a period of 20 years. The following variables are described: age, sex, localization, diagnostic workup, operative procedure, complications, proportion and characteristics of malignant tumors, and cure rates.

METHODS

Thirty-six patients,10 men and 26 women, were treated. Twenty-three patients had tumors on the right side, 10 patients had tumors on the left side, and three patients had bilateral tumors. All patients were symptomatic. The most common complaint was a neck mass that had been present for 1 to 144 months. All patients had diagnostic procedures done before treatment. The most widely used was ultrasonography (26 patients). Angiography was performed in 14 patients.

RESULTS

All patients underwent complete tumor resection. In three cases, resection of the internal carotid was necessary. In all patients who underwent internal carotid resection, immediate reconstruction was performed. No patients had postoperative strokes. Five patients had postoperative nerve palsies. During the follow-up period of 4 months to 12 years, no patients had local recurrence develop. Four patients had distant metastasis.

CONCLUSION

The complete removal of paragangliomas of the carotid bifurcation is effective with acceptable morbidity. All recurrences of the malignant tumors were distant metastasis.

Incidence of perioperative stroke after neck dissection for head and neck cancer: a regional outcome analysis

OBJECTIVE

To determine the incidence of perioperative stroke in patients undergoing a neck dissection.

SUMMARY BACKGROUND DATA

The incidence of perioperative stroke in non-head and neck surgery is between 0.08 and 0.2%. In contrast, a critical review of the literature identified 2 studies stating the incidence of perioperative stroke in head and neck surgery to be 3.2% and 4.8%. The implications of these results are significant because they suggest a potential need for preoperative screening and/or intervention for carotid artery pathology.

METHODS

This historical cohort study was conducted using discharge data for all neck dissections performed in a geographically-defined health region in Alberta, Canada, from 1994 to 2002. Subjects were selected for study if they had an assigned ICD-9CM procedure code for a neck dissection at one of the region's 3 adult-care hospitals. Our main outcome measure was perioperative stroke.

RESULTS

Patients (n = 499) were identified as having had a neck dissection (mean age 56.5 +/- 15.3 SD, 65.3% male). Seven patients had ICD-9CM codes for postoperative central nervous system complications (incidence of 1.4%). However, on chart review, only one had had a true perioperative stroke corresponding to an incidence of 0.2% (95% confidence interval 0.01, 1.12). No missed strokes were found in a confirmatory random review of 10% of charts.

CONCLUSIONS

The incidence of perioperative stroke in this study is significantly lower than that previously stated in the literature. This suggests that preoperative screening and/or intervention for carotid artery disease may not be necessary in this patient population.

Detection of radiation-accelerated atherosclerosis of the carotid artery by panoramic radiography

BACKGROUND

The authors review the pathophysiology, epidemiology, course of disease, dental findings and dental treatment of patients who developed atherosclerosis of the carotid artery after having received therapeutic radiation to the neck for squamous-cell carcinoma of the oral cavity, pharynx or larynx; salivary gland tumors; and lymphomas involving the cervical lymph nodes.

TYPE OF STUDIES REVIEWED

The authors conducted a MEDLINE search for 1997 through 2002 using the key terms "radiation therapy," "carotid artery" "atherosclerosis," "cancer" and "dentistry." The articles selected for further review included those published in English in peer-reviewed journals, with preference given to articles reporting randomized, controlled trials.

RESULTS

Recent advances in the delivery of radiation therapy to malignancies of the head and neck have resulted in the prolonged survival of increasing numbers of patients. However, the therapy has been implicated as causing atherosclerotic lesions in the cervical component of the carotid artery, which predisposes patients to an increased risk of developing stroke. Panoramic radiography can identify some of these lesions before they can cause a stroke. Radiation-induced atherosclerosis is common, with approximately 40 percent of patients developing hemodynamically significant carotid artery plaques within 10 years of having received irradiation.

CLINICAL IMPLICATIONS

Dentists treating patients who have received therapeutic radiation to the neck should examine the patients' panoramic radiographs for evidence of atheromalike calcifications, which appear 1.5 to 2.5 centimeters posterior and inferior to the angle of the mandible. Patients with evidence of such lesions should be referred to their physician for an ultrasound examination of their carotid arteries.

Cerebral blood flow measurement by color velocity imaging in radiation-induced carotid stenosis

OBJECTIVE

To show whether there is any association between the development of neurologic symptoms and the total cerebral blood flow volume documented by color velocity imaging in patients with carotid stenosis that develops after radiotherapy.

METHODS

Twenty-three patients with nasopharyngeal carcinoma (4 female and 19 male; age range, 39-69 years; mean age, 55.6 years) and major extracranial carotid stenosis underwent color velocity imaging. In this group, 8 patients had symptoms of a stroke or transient ischemic attack, and the other 15 patients were asymptomatic. The color velocity imaging results in the symptomatic group were then compared with those in the asymptomatic group.

RESULTS

The cerebral blood flow in the symptomatic group was significantly lower than that in the asymptomatic group (224.1 +/- 89.0 versus 532.5 +/- 89.0 mL/min; P = .001).

CONCLUSIONS

Cerebral blood flow as measured by color velocity imaging was lower in the symptomatic group. There is an association between the development of neurologic symptoms and blood flow volume.

Aetiological factors and imaging program for severe radiation-induced extracranial carotid stenosis in nasopharyngeal carcinoma

Over a period of 3 years, we have collected the carotid ultrasound findings of 189 post-radiotherapy (RT) nasopharyngeal carcinoma patients. The patients had duplex ultrasound examination for assessment of extracranial carotid stenosis. Factors including age, sex, hyperlipidaemia, diabetes mellitus, smoking history, time lapsed after RT, symptoms of cerebrovascular disease were recorded. Association of individual factor with development of severe stenosis was assessed.

Eighty-two (43%) patients developed moderate to severe stenosis of the common carotid and/or internal carotid artery. Age and time lapsed after RT were the only factors found to be associated with development of severe stenosis. When age >57 years and >12 years post-RT were used as rules to identify patients with severe stenosis, the sensitivity was 46.7%, specificity 98.2%, PPV 77.8% and NPV 95.6%.

Radiation-induced carotid stenosis is a common event. If available resources do not allow routine surveillance, age and time lapsed after RT help to identify high-risk patients.

Nasopharyngeal carcinoma: treatments and outcomes in the 20th century

Nasopharyngeal carcinoma (NPC), although rare in Europe and North America, is not uncommon in parts of Asia such as southern China and Hong Kong. Consequently, very few oncologists in the Western world have extensive experience in treating this neoplasm. Treatment using external beam therapy and/or brachytherapy evolved greatly during the 20th century and is still evolving, particularly with the use of adjunctive chemotherapy regimes. Diagnosis of NPC has also improved with the availability of CT and MRI. This worldwide review is divided into historical, transitional and modern eras, with the latter concerning 1971-2000. Currently, the most controversial aspects of NPC are recommendations for treatment of recurrent disease and the role of chemotherapy in the overall framework of treatment. Comparison of results from different centres is not possible without an understanding of the various staging systems that are, and have been, used; a comparison is given in this review. In the future, early diagnosis, adequate radiation dose to the primary with boost to bulky disease, and regular follow-up with biopsy of any suspicious residual or recurrent disease, are likely to become key issues to improve outcome. Also, apart from direct/indirect nasopharyngoscopy, the role of follow-up CT needs to be studied for early detection of residual or recurrent disease. More clinical trials on chemo-radiation are also required, in order to study optimum doses and agents.