Relationship between histologic features and outcomes of carotid revascularization for radiation-induced stenosis

Risk, prevention, screening and management of carotid artery stenosis in head & neck cancer patients-An evidence based review

Our review aims to clarify the incidence of carotid artery stenosis, risks of development, screening, management, and primary prevention strategies documented in the literature after radiation therapy for head and neck cancers. The high prevalence of carotid stenosis after radiation therapy for head and neck cancers has made surveillance and risk stratification critical. In addition to general cardiovascular risk factors such as smoking, diabetes, and dyslipidemia, risk factors for carotid artery stenosis after head and neck radiation included total plaque score, radiotherapy use and dosage, length of time after radiotherapy, and age greater than 50. Cancer subtype, namely nasopharyngeal cancer, may be correlated with increased risk as well, though contrasting results have been found. Interestingly, however, no significant relationship has been found between radiotherapy dose and stroke risk. Surgical management of post-radiation carotid stenosis is similar to that of stenosis unrelated to radiation, with carotid endarterectomy considered to be the gold standard treatment and carotid artery stenting being an acceptable, less-invasive alternative. Medical management of these patients has not been well-studied, but antiplatelet therapy, statins, and blood pressure control may be beneficial. The mainstay of screening for radiation-induced stenosis has been Doppler ultrasound, with measurement of changes in the intima-media thickness being a primary marker of disease development. A literature review was carried out using the MeSH terms "Carotid Artery Stenosis," "Head and Neck Neoplasms," and "Radiotherapy."

Carotid Artery Stenosis and Ischemic Stroke in Patients With Head and Neck Cancer Treated With Radiation Therapy: A Critical Review

The purpose of this review is to summarize the literature on carotid artery stenosis (CAS) and ischemic stroke (IS) in patients with head and neck cancer (HNC) treated with radiation therapy (RT) to guide assessment, screening, and management strategies. Patients treated with RT for HNC are at an elevated risk of developing CAS, with published meta-analyses demonstrating that CAS >50% occurs in approximately 25% of patients. Previous research suggests a 10-year cumulative incidence of stroke between 5.7% and 12.5%. Cardiovascular disease (CVD) risk prediction tools such as Qstroke, QRISK-2, and Framingham risk score perform poorly for predicting IS for patients with HNC who received RT. Duplex ultrasound is the most common imaging modality to assess CAS, but controversy remains as to the utility of screening asymptomatic individuals. Only 3 of the 5 major HNC survivorship guidelines acknowledge RT as a risk factor for CAS or IS, while only 1 makes a specific recommendation on screening for CAS (American Head and Neck Society). Within the general population, only 1 CVD guideline discusses RT as a risk factor for CAS (Society for Vascular Surgery). Clinicians involved in the care of patients with HNC treated with RT should be aware of the increased risk of CAS and IS and the challenges in risk prediction. Although there is a lack of evidence to make firm recommendations, HNC survivorship recommendations should ensure HNC survivors and primary care providers are informed of these risks and the importance of assessment and management of CVD risk factors. Future studies are required to refine risk prediction models in patients with HNC and to determine those most likely to benefit from targeted screening and initiation of early preventative strategies.

Stroke in Asia

BACKGROUND

There is a significant burden of stroke in Asia. Asia has the largest population in the world in 2023, estimated at 4.7 billion. Approximately 9.5-10.6 million strokes will be anticipated annually in the backdrop of a diverse group of well-developed and less developed countries with large disparities in stroke care resources. In addition, Asian countries are in varying phases of epidemiological transition.

SUMMARY

In this review, we examined recent epidemiological features of ischaemic stroke and intracerebral haemorrhage in Asia with recent developments in hyperacute stroke reperfusion therapy and technical improvements in intracerebral haemorrhage. The article also discussed the spectrum of cerebrovascular diseases in Asia, which include intracranial atherosclerosis, intracerebral haemorrhage, infective aetiologies of stroke, moyamoya disease, vascular dissection, radiation vasculopathy, and cerebral venous thrombosis.

KEY MESSAGES

The review of selected literature and recent updates calls for attention to the different requirements for resources within Asia and highlights the breadth of cerebrovascular diseases still requiring further research and more effective therapies.

Length and location of post-PIRCS predict percutaneous transluminal angioplasty and stenting-related restenosis in nasopharyngeal cancer

PURPOSE

Post-irradiated carotid stenosis (PIRCS) commonly occurs in patients with nasopharyngeal cancer (NPC) after receiving radiotherapy. A high in-stent restenosis (ISR) is observed in these patients after percutaneous transluminal angioplasty and stenting (PTAS) for PIRCS. Risk factors for ISR in these patients remain unclear.

METHODS

Data were retrospectively analyzed from 68 NPC patients with 70 lesions treated with PTAS for PIRCS. The median follow-up was 40 months (range: 4-120). Evaluations of demographic and clinical characteristics included stenotic severity, stenotic lesion length (SLL), stenotic lesion location, and ISR-related stroke during follow-up. The risk for ISR was evaluated using multiple Cox regression analysis.

RESULTS

The median age of the patients was 61 (35-80) years and 94.1% were male. The median stenosis was 80% (60-99%) and the median SLL was 2.6 cm (0.6-12.0 cm) before PTAS. Compared to those without ISR, patients with longer SLL were at significantly greater risk of developing significant ISR, defined as > 50% after PTAS (hazard ratio [HR] and 95% confidence interval [CI]: 2.06 [1.30-3.28]). PTAS for lesions from the internal carotid artery (ICA) to common carotid artery (CCA) was associated with a significantly greater risk of ISR than lesions located only in the ICA (HR: 9.58 [1.79-51.34]). The baseline cut-off value for SLL that best predicted significant ISR was 1.6 cm (area under the curve 0.700, sensitivity 83.3% and specificity 62.5%).

CONCLUSION

Stenotic lesions located from the ICA to CCA with longer SLL at baseline appear to predict ISR in NPC patients with PIRCS after PTAS. Intensive post-procedural follow-up is advised for this patient population.

Continuous and Early Progression of Carotid Intima-Media Thickness after Radiotherapy for Head and Neck Cancer: 5-Year Prospective Observational Study

INTRODUCTION

Radiation-induced carotid artery stenosis (RI-CS) is known as one of long-term side effects of radiotherapy for head and neck cancer (HNC). However, the clinical time course after irradiation has been poorly understood. We aimed to investigate the natural history of radiation-induced carotid atherosclerosis, comparing the patients who received radiotherapy for HNC with the patients who were treated without radiotherapy.

METHODS

The patients who received treatment of HNC at Department of Otolaryngology, Head and Neck Surgery of Kyoto University Hospital, from November 2012 to July 2015 were enrolled. The patients were assigned into the RT group and the control group, depending on whether radiotherapy was planned or not. Annual carotid ultrasound was performed from the enrollment to 5 years. The increase of mean intima-media thickness (IMT) at common carotid artery from the enrollment (Δmean IMT) was evaluated.

RESULTS

Fifty-six patients in the RT group and 25 patients in the control group were enrolled. From 5-year follow-up data, the significant higher increase of Δmean IMT was consistently observed in the RT group than in the control group after 2 years. The RT group presented a 7.8-fold increase of mean IMT compared to the control group (0.060 mm per year in the RT group and 0.008 mm per year in the control group). Cumulative incidence curves obtained from the analysis of all vessels revealed that the RT group presented higher incidence of Δmean IMT ≥0.25 mm than the control group (p < 0.01). In the RT group, the patients with mean IMT ≥1.0 mm at enrollment exhibited significantly higher incidence of Δmean IMT ≥0.25 mm than the patients with mean IMT <1.0 mm (p < 0.01).

DISCUSSION

Radiotherapy for HNC induces continuous carotid mean IMT progression. The irradiated carotid arteries with mean IMT ≥1.0 mm before radiotherapy presented earlier IMT progression than those with mean IMT <1.0 mm.

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.

Carotid Artery Stenting for Patients with Radiation-Induced Carotid Artery Stenosis

Objective

In radiation-induced carotid artery stenosis (RIS), morphological characteristics, such as bilateral and long lesion distances and in-stent stenosis, have been reported as common after carotid artery stenting (CAS). Here, we present 25 cases at our hospital wherein CAS was performed for RIS and compare the morphological characteristics and the safety of the treatment with cases of atherosclerotic carotid artery stenosis (AS).

Methods

Twenty-five lesions from 21 patients underwent CAS for RIS at our hospital between March 2002 and July 2020. The procedure was performed at a mean of 10.0 ± 5.2 years after radiation therapy with 60-72 Gy, with a median follow-up of 45 months. We retrospectively selected consecutive patients with AS with comparable follow-up times from the beginning of the study as controls. We compared the patients' background, stenosis findings including plaque MRI, perioperative period, and postoperative course.

Results

All patients in both groups completed the procedure, and the median follow-up time for the RIS and AS groups was 45 and 40 months, respectively (p = 0.1479). Patients in the RIS group had a lower mean age (69.9 ± 6.9 vs. 75.3 ± 7.04, p = 0.0075), a higher stenosis rate (79.1 ± 8.7% vs. 68.6 ± 11.7%, p = 0.0032), and longer stenosis greater than one vertebra (long lesions) (10 vs. 1, p = 0.0046) compared with the patients in the AS group. Although there was no significant difference in outcomes between the two groups, restenosis tended to be more common in the RIS group. Plaque MRI was characterized by a significantly higher T2WI signal (p = 0.0381) in the RIS group, which was attributable to the fact that a necrotic core has been reported commonly in the plaque tissue of RIS.

Conclusion

RIS has a high likelihood of restenosis both morphologically and in terms of plaque characteristics. Thus, close follow-up is crucial.

Magnetic Resonance Images, Pathological Features of Thrombus, and Expression of NLRP Inflammasome in Patients with Acute Ischemic Stroke

The aim of this study was to investigate imaging features of magnetic resonance imaging (MRI), pathological features of thrombus, and expression of nucleotide-binding oligomerization domain-like receptors protein 3 (NLRP3) inflammasome in acute ischemic stroke (AIS). Their relationship with the prognosis of patients was also explored. Sixty patients with AIS admitted to the hospital were selected as the observation group, and 20 healthy objects were in the control group. The shape of the thrombus was observed by MRI, pathological features of the thrombus were observed under hematoxylin-eosin (HE) staining, and the levels of NLRP3 inflammasome and inflammatory factors in serum were detected. The MRI-T2 weighted imaging (T2WI) signal ratio and plaque enhancement rate in the observation group were higher than those in the control group significantly (P < 0.05). In the observation group, the red/mixed thrombus in 6–12 h and 24 h were also much higher than that in 6 h (P < 0.05). The levels of NLRP3, interleukin-1β (IL-1β), interleukin-18 (IL-18), and tumor necrosis factor-α (TNF-α) in the observation group were higher than those in the control group in 6 h, 6–12 h, and 24 h (P < 0.05), and those reached the highest levels in 24 h. The ratio of fibrins/platelets in the cardiogenic thrombus reached (63.8 ± 15.6) %, which was significantly higher than that in the large-artery atherosclerotic thrombus (49.5 ± 14.2) %, P < 0.05. The ratio of red blood cells (RBCs) in the large atherosclerotic thrombus was (30.7 ± 14.3) %, considerably lower than (42.9 ± 15.2) %, P < 0.05. The prognosis of patients with the fibrin/platelet-rich thrombus was highly lower than that with the RBC-rich thrombus (P < 0.05). The levels with poor prognosis were higher than those with good prognosis (P < 0.05). MRI could be used to assist in the assessment of brain conditions in patients with AIS. NLRP3 inflammasome was involved in the inflammatory response of AIS and can be used for predicting the poor prognosis, having a certain clinical application value. In addition, different types of thrombi also laid a certain impact on prognosis.

Imaging Characteristics and Reintervention in Patients After Radiation Induced Carotid Artery Stenting

OBJECTIVE

To evaluate and describe the radiographic imaging findings in a series of patients who underwent re-intervention after radiation-induced carotid artery stenting (RICAS).

METHODS

Retrospective review of patients with prior RICAS and subsequent re-intervention.

RESULTS

We describe ten patients including eight male and two female patients with twelve re-interventions due to prior diagnosed radiation induced carotid artery stenosis (RICS) and subsequent stenting during the period 2000-2019. The rate of re-intervention was found to be 10%. The pattern of stenosis is unique to this patient population including specifically long-segment stenosis, proximal and distal to the stent location, which tends not to occur in the atherosclerotic patient population.

CONCLUSION

Careful surveillance after RICAS is necessary to assess for the risk and the unusual pattern of stenosis to offer re-intervention in this high-risk patient population.

Plaque Protrusion in a Patient with Left Common Carotid Artery Stenting after Radiation Therapy: A Case Report

Objective

We report a case of additional carotid artery stenting (CAS) for plaque protrusion occurring after initial CAS for radiation-induced common carotid artery (CCA) stenosis.

Case Presentation

A 69-year-old man with a history of radiotherapy for laryngeal cancer presented to our hospital with sudden-onset right hemiparesis. Since vulnerable plaque of the left CCA was considered the embolic source for ischemic stroke, CAS was performed for left CCA stenosis. No perioperative complications were observed and the patient was discharged with a modified Rankin Scale score of 0. However, 1 month after CAS, cerebral embolism recurred. As protruding plaque was found on CTA, additional endovascular treatment was performed with intravascular ultrasonography. He was discharged without complications and showed a good outcome at 3 months.

Conclusion

In CCA stenosis after radiotherapy, accelerated arteriosclerosis may cause drug-resistant cerebral embolism and plaque protrusion after CAS, making determination of the treatment strategy difficult. Appropriate treatment options need to be based on individual underlying diseases and plaque instability.

Irradiation Accelerates Plaque Formation and Cellular Senescence in Flow-Altered Carotid Arteries of Apolipoprotein E Knock-Out Mice

Background

Chronic inflammation through cellular senescence, known as the senescence‐associated secretory phenotype, is a mechanism of various organ diseases, including atherosclerosis. Particularly, ionizing radiation (IR) contributes to cellular senescence by causing DNA damage. Although previous clinical studies have demonstrated that radiotherapy causes atherosclerosis as a long‐term side effect, the detailed mechanism is unclear. This study was conducted to investigate the relationship between radiation‐induced atherosclerosis and senescence‐associated secretory phenotype in murine carotid arteries.

Methods and Results

Partial ligation of the left carotid artery branches in 9‐week‐old male apolipoprotein E‐deficient mice was performed to induce atherosclerosis. The mice received total body irradiation at a dose of 6 Gy using gamma rays at 2 weeks post operation. We compared the samples collected 4 weeks after IR with unirradiated control samples. The IR and control groups presented pathologically progressive lesions in 90.9% and 72.3% of mice, respectively. Plaque volume, macrophage accumulation, and phenotype switching of vascular smooth muscle cells were advanced in the IR group. Irradiated samples showed increased persistent DNA damage response (53BP1 [p53 binding protein 1]), upregulated cyclin‐dependent kinase inhibitors (p16INK4a and p21), and elevated inflammatory chemokines expression (monocyte chemotactic protein‐1, keratinocyte‐derived chemokine, and macrophage inflammatory protein 2).

Conclusions

IR promoted plaque growth in murine carotid arteries. Our findings support the possibility that senescence‐associated secretory phenotype aggravates atherogenesis in irradiated artery. This mice model might contribute to mechanism elucidation of radiation‐induced atherosclerosis.

Radiation-Induced Vascular Disease-A State-of-the-Art Review

Since the 1990s, there has been a steady increase in the number of cancer survivors to an estimated 17 million in 2019 in the US alone. Radiation therapy today is applied to a variety of malignancies and over 50% of cancer patients. The effects of ionizing radiation on cardiac structure and function, so-called radiation-induced heart disease (RIHD), have been extensively studied. We review the available published data on the mechanisms and manifestations of RIHD, with a focus on vascular disease, as well as proposed strategies for its prevention, screening, diagnosis, and management.

Higher Risk for Reintervention in Patients after Stenting for Radiation-Induced Internal Carotid Artery Stenosis: A Single-Center Analysis and Systematic Review

BACKGROUND

This study aimed to review short- and long-term outcomes of all carotid artery stenting (CAS) in patients with radiation-induced (RI) internal carotid artery (ICA) stenosis compared with patients with atherosclerotic stenosis (AS).

METHODS

We performed a single-center, multisite case-control study of transfemoral carotid artery intervention in patients stented for RI or AS. Cases of stented RI carotid arteries were identified using a CAS database covering January 2000 to December 2019. These patients were randomly matched 2:1 with stented patients because of AS by age, sex, and year of CAS. A conditional logistic regression model was performed to estimate the odds of reintervention in the RI group. Finally, a systematic review was performed to assess the outcomes of RI stenosis treated with CAS.

RESULTS

There were 120 CAS in 113 patients because of RI ICA stenosis. Eighty-nine patients (78.8%) were male, and 68 patients (60.2%) were symptomatic. The reasons for radiation included most commonly treatment for diverse malignancies of the head and neck in 109 patients (96.5%). The mean radiation dose was 58.9 ± 15.6 Gy, and the time from radiation to CAS was 175.3 ± 140.4 months. Symptoms included 31 transient ischemic attacks (TIAs), 21 strokes (7 acute and 14 subacute), and 17 amaurosis fugax. The mean National Institutes of Health Stroke Scale in acute strokes was 8.7 ± 11.2. In asymptomatic patients, the indication for CAS was high-grade stenosis determined by duplex ultrasound. All CAS were successfully completed. Reinterventions were more frequent in the RI ICA stenosis cohort compared with the AS cohort (10.1% vs. 1.4%). Reinterventions occurred in 14 vessels, and causes for reintervention were restenosis in 12 followed by TIA/stroke in two vessels. On conditional regression modeling, patients with RI ICA stenosis were at a higher risk for reintervention (odds ratio = 7.1, 95% confidence interval = 2.1-32.8; P = 0.004). The mean follow-up was 33.7 ± 36.9 months, and the mortality across groups was no different (P = 0.12).

CONCLUSIONS

In our single-center, multisite cohort study, patients who underwent CAS for RI ICA stenosis experienced a higher rate of restenosis and a higher number of reinterventions compared with CAS for AS. Although CAS is safe and effective for this RI ICA stenosis cohort, further data are needed to reduce the risk of restenosis, and close patient surveillance is warranted. In our systematic review, CAS was considered an excellent alternative option for the treatment of patients with RI ICA stenosis. However, careful patient selection is warranted because of the increased risk of restenosis on long-term follow-up.

Surgical repair of radiation-induced carotid stenosis

OBJECTIVE

Carotid endarterectomy and carotid artery stenting are both valid therapeutic options for the treatment of radiation-induced carotid stenosis (RICS). The second has the advantage of being less invasive, although it seems to result in more restenosis than the first. Meanwhile, progress in radiation therapy and head and neck surgery has significantly increased the survival of these patients. As a result, treatment of RICS should be considered from a long-term perspective. This works presents perioperative and follow-up outcomes of surgical treatment of RICS.

METHODS

This single-center retrospective study included all patients who underwent carotid endarterectomy for RICS from January 1998 to June 2017. Clinical and duplex ultrasound examination-based follow-up was performed postoperatively, at 1 month, 6 months, 12 months, and yearly thereafter. Kaplan-Meier curves were used for survival plots based on a log-rank test. Any abnormal finding led to angio-computed tomography scan and specialized neurovascular examination.

RESULTS

Between 1998 and 2017, 128 patients (162 lesions) were treated. The median interval between radiation therapy and surgery was 16 years. Forty-five patients (35%) were symptomatic. The eversion technique was performed in 79 cases (49%), and the patch was favored in 24 cases (15%), prosthetic bypass graft in 51 cases (31%), and a venous bypass graft in 8 cases (5%). Two postoperative deaths (1.5%) (one secondary to massive stroke) were noted. The primary end point of early postoperative cerebrovascular event was 2.5%. Two cervical hematomas (1.2%) required surgical revision and seven cases of permanent cranial nerve injury were recorded. The median follow-up was 29 months (range, 2-199 months). There were no additional strokes. The 3-year primary patency rate was 96% and the 3-year freedom from neurologic event was 98%.

CONCLUSIONS

Open surgical treatment of RICS lesions is a safe and durable option. Our results suggest that the outcomes of such treatment are good and in particular that rates of cerebrovascular event and restenosis are low and that cranial nerve injury should not be a concern. As a result, we consider that open surgery for RICS lesions should be offered as a first-line treatment. However, comparative data are mandated to address this issue.

Preliminary Simulation Study of Carotid Artery and Pharyngeal Constrictor Muscle Sparing-Radiotherapy in Glottic Carcinoma

Background:

This preliminary simulation study aimed to compare the dosimetric outcomes of carotid arteries (CAs) and pharyngeal constrictor muscle (PCM) in patients with T1N0M0 glottic carcinoma undergoing helical tomotherapy-intensity modulated radiotherapy (HT-IMRT) and 3-dimensional conformal radiotherapy (3D-CRT) plans.

Methods:

In addition to the clinical target volume (CTV) which was defined as the entire larynx, the CAs and PCM of 11 glottic carcinoma patients were delineated. The CTV was uniformly expanded 5 mm to create a planning target volume (PTV) relative to the PCM and at a distance of 2 mm from the CA. The dosimetric characteristics in HT-IMRT and lateral opposed fields-based 3D-CRT plans were analyzed.

Results:

Median D_95%and V_100% of PTV were significantly higher in HT-IMRT (p < 0.001) compared to 3D-CRT. The right/left CA dosimetric outcomes, including the mean doses (20.7/21.5 Gy versus 48.7/50.5 Gy), D_max (53.6/52.0 Gy versus 67.4/67.7 Gy), V₃₀ (25.0/27.1% versus 77.6/80.3%), V₄₀ (8.0/7.9% versus 74.6/71.9%), and V₅₀ (2.0/1.2% versus 70.0/71.6%) were also significantly lower in HT-IMRT (p < 0.05), similar to the mean PCM doses (49.6 Gy versus 62.6 Gy for 3D-CRT;p < 0.001), respectively.

Conclusions:

Our present results demonstrated the feasibility of simultaneous sparing of the CAs and PCM in HT-IMRT- compared to 3D-CRT plans in glottic carcinoma patients undergoing definitive radiotherapy.

Optical Coherence Tomography Angiography Evaluation of Retinal Microvasculature Before and After Carotid Angioplasty and Stenting

The aim of the study was to evaluate the influence of carotid angioplasty and stenting (CAS) on retinal microvasculature using optical coherence tomography angiography (OCTA) in patients with severe carotid stenosis. 20 patients with severe carotid stenosis underwent comprehensive ophthalmic examinations and OCTA before and one month after CAS. Automated algorithms were used to quantify vessel density in the macular superficial vascular complex (SVC), deep vascular complex (DVC), and radial peripapillary capillary (RPC) around the optic disc. Eyes on the operated side constituted the ipsilateral eye group, and the other eye constituted the fellow eye group. In the ipsilateral eye group, the vessel density in the DVC increased significantly after stent implantation (P = 0.010), but the vessel density change in the SVC was not statistically different (P = 0.999). In the fellow eye group, the vessel density in the SVC (P = 0.028) and DVC (P = 0.034) were significantly increased after stent implantation. The vessel density in the RPC did not significantly change in the ipsilateral (P = 0.363) or fellow (P = 0.878) eye groups. This study shows that unilateral CAS for severe carotid stenosis increases macular vessel densities in both eyes.

Management of Radiation Induced Carotid Stenosis in Head and Neck Cancer

OBJECTIVES: Presentation of radiation-induced lesions in carotid arteries of patients with head and neck squamous cell carcinoma (HNSCC) and the evaluation of the effectiveness of endovascular treatment of symptomatic stenoses. MATERIALS AND METHODS: We retrospectively analyzed 26 patients who underwent surgery and subsequently cervical radiotherapy (RT) for HNSCC, focusing on radiation-induced vascular disease in neck arteries—from the latency period to the occurrence of neurological events—and the endovascular treatment of the internal carotid artery (ICA) and/or of common carotid artery (CCA) stenoses. The vascular lesions were diagnosed with Doppler ultrasonography and selective digital angiography. Patients with >70% stenoses of ICA and/or CCA were scheduled for carotid artery stenting (CAS). They were followed-up with neurological examinations and Doppler ultrasonography at 6, 12, and 24 months after stenting. RESULTS: Radiation-induced vascular diseases occurred in the ICA in 22 patients (85%), CCA in 15 (58%), and in ECA in 15 (58%). The stents were implanted in 25 ICA and 17 CCA. Thirteen patients (50%) had one stent, eight (30%) had two stents, four (15%) had three stents, and one patient had five stents. Overall, 46 stents were implanted. Technical success was achieved in all patients. No cerebrovascular events occurred in the 24-months follow-up. CONCLUSION: RT in patients with HNSCC holds a significant risk factor of developing carotid artery stenosis and cerebrovascular events. Carotid stenting is preferable mode of treatment for radiation-induced stenosis. A screening program with doppler ultrasonography enables pre-stroke detection of carotid stenosis.

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.

Cerebrovascular Insufficiency from Radiation-Induced Progressive Obstruction of Supra-Aortic Vessels

BACKGROUND

Radiation therapy may accelerate atherosclerosis with progressive stenosis and occlusions of supra-aortic trunks.

METHODS AND RESULTS

We report the case of a 44-year-old woman with radiation-induced occlusion of the supra-aortic trunks presenting with recurrent cerebrovascular insufficiency after an unusual surgical revascularization technique (retrograde femoral-axillary bypass) performed for late failure of previous endovascular treatment.

CONCLUSIONS

Customized surgical procedure can be considered as a bailout to improve cerebral blood inflow in selected cases.

Comparison of Significant Carotid Stenosis for Nasopharyngeal Carcinoma between Intensity-Modulated Radiotherapy and Conventional Two-Dimensional Radiotherapy

Radiotherapy (RT) serves as the most efficient treatment for nasopharyngeal carcinoma (NPC) and can cause carotid stenosis. This work compared the incidence of significant carotid stenosis between intensity-modulated radiotherapy (IMRT) and two-dimensional conventional radiotherapy (2D-RT) for NPC and explored the risk factors. We retrospectively reviewed 233 cases with NPC who underwent carotid ultrasound post IMRT or 2D-RT from 2006 to 2015. The incidence of significant stenosis after RT was 19.3%. Significant stenosis was identified in 20 (14.6%) of 137 patients treated with IMRT and 25 (26.0%) of 96 patients with 2D-RT, respectively (p = 0.035). Multivariate logistic analysis indicated age (odds ratio = 1.054, 95% CI = 1.011-1.099, p = 0.014), radiation technique (IMRT) (odds ratio = 0.471, 95%CI = 0.241-0.919, p = 0.027) and time interval (odds ratio = 1.068, 95%CI = 1.033-1.105, p = 0.001) as independent predictors for significant carotid stenosis. Our study suggests that IMRT was associated with decreased incidence of significant carotid stenosis versus 2D-RT for NPC. Prevention and carotid ultrasound should be considered for older NPC survivors with longer interval from RT, especially those treated with 2D-RT.

Crevice sign as an indicator of plaque laceration associated with postoperative severe thromboembolism after carotid artery stenting: a case report

Carotid artery stenting (CAS) is increasingly utilized in patients with carotid artery stenosis. Various intraprocedural and postprocedural complications have been reported in the literature. We present a case of symptomatic major thromboembolism after CAS. The intraprocedural angiogram showed extraordinary slow filling of the contrast medium into the plaque, which we named as "crevice sign." An 83-year-old man presented repeat right amaurosis fugax for 6 months. The radiological examinations revealed 85% stenosis of the origin of the right internal carotid artery. The patient underwent right CAS. The procedure was performed without any problems; however, the angiogram showed slow filling of contrast medium into the carotid plaque through the stent (crevice sign). Sixty minutes later in the ward, the patient presented sudden onset of left hemiparesis and aphasia. Emergency catheter angiography did not show in-stent thrombus, major artery occlusion, or the crevice sign. Magnetic resonance imaging on the next day revealed wide acute infarction of the right cerebral hemisphere. Physicians should be aware of the intraprocedural crevice sign so that a subsequent catastrophic ischemic event can be prevented.

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.

Radiation Toxicity to the Cardiovascular System

Radiation therapy is an important component of cancer treatment, and today, it is applied to approximately 50% of malignancies, including valvular, myocardial, pericardial, coronary or peripheral vascular disease, and arrhythmias. An increased clinical suspicion and knowledge of those mechanisms is important to initiate appropriate screening for the optimal diagnosis and treatment. As the number of cancer survivors has been steadily increasing over the last decades, cardio-oncology, an evolving subspecialty of cardiology, will soon play a pivotal role in raising awareness of the increased cardiovascular risk and formulate strategies to optimally manage patients in this unique population.