Clinical Features of Radiation-induced Carotid Atherosclerosis

Carotid artery stenosis and ischemic cerebrovascular events after radiotherapy in patients with head and neck cancer

Radiotherapy is the main treatment for patients with head and neck cancer (HNC) and is associated with an increased risk of ischemic cerebrovascular events (ICVE). The purpose of this cross-sectional study was to determine the incidence of ICVE and carotid artery stenosis (CAS) in patients with HNC who receive radiotherapy and the risk factors for CAS. We enrolled 907 patients with HNC who underwent radiotherapy between February 2011 and June 2022 and obtained information on their clinical and tumor characteristics and their treatment from the clinical records. Data on risk factors for atherosclerosis, medications used, and radiotherapy were also collected. The patients were followed through to the end of 2023 unless they died or were lost to follow-up. The overall incidence of ICVE was 1.98%, with a cumulative incidence of 1.65% over 5 years. In patients who did not have a preexisting carotid artery lesion, the cumulative incidence of significant CAS was 1.3% at 12 months, 2.2% at 24 months, and 2.5% at 36 months post-radiotherapy. The most important risk factors for new CAS were age >65 years (aHR = 2.60, p = 0.008, 95% confidence Interval: 1.28-5.30), laryngeal cancer (aHR = 2.36, p<0.017, 95% confidence Interval: 1.01-5.55), and total plaque score (aHR = 1.38, p<0.001, 95% confidence Interval: 1.23-1.56). There was a significant increase in stenosis, plaque score, and wall thickness in all areas in the carotid artery (p<0.001). The incidence of ICVE and the cumulative incidence of CAS was found to be lower in the Thai population than in other populations. The main risk factors for new CAS were age >65 years, laryngeal cancer, and total plaque score. Changes in the carotid artery were detected early and affected all areas in the artery. Patients with HNC treated by radiotherapy should be assessed for risk factors for CAS and undergo vascular surveillance during follow-up.

Lipidomic Expression Analysis In Carotid Atherosclerotic Disease: A Systematic Review

OBJECTIVE

Lipids are key molecules for atherosclerosis, with tight regulation mechanisms, making them potential biomarkers for disease-specific diagnostics and therapeutics. Therefore, we aim to perform a systematic literature review on lipidomic analysis in serum/plasma and plaque samples of patients with carotid atherosclerosis.

METHODS

We performed a systematic review following the PRISMA guidelines on the lipidomic profile in serum/plasma and carotid artery plaques from patients with significant carotid disease by degree of stenosis in preoperative imaging and clinical presentation (symptomatic, asymptomatic, radiation-induced carotid disease). Main outcome was the differential lipidomic expression of serum/plasma, and plaque lipids of patients with carotid artery atherosclerosis. Studies were screened using the Newcastle-Ottawa Scale to determine the quality of the design and content of the selected manuscripts.

RESULTS

We included fourteen studies, from which ten included plaque analysis. The lipidomic analysis revealed that sterols and hydroxycholesterols were consistently found in both blood and plaque across studies. Triacylglycerols were present in both sample types, with specific forms linked to radiation-induced carotid artery disease. Symptomatic patients exhibited esterified hydroxyeicosatetraenoic acids and arachidonic acid precursors exclusively in plaque with an inflammatory profile of the disease. In contrast, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) were associated with plaque stability. Diabetics showed nonesterified fatty acids and specific phospholipids only in plaque, indicating localized lipid changes. Other pathways relevant to disease progression include the sphingolipids and ceramide pathways with inflammatory profiling.

CONCLUSION

Lipidomic provides an innovative approach to stratify carotid atherosclerotic disease. Integrating lipidomic data with other -omics approaches may further enhance our understanding of disease mechanisms and aid in the development of precision medicine approaches, specifically in those patients at risk for early carotid atherosclerotic disease.

Comprehensive review of post-treatment imaging in head and neck cancers: from expected to unexpected and beyond

Head and neck cancer management requires multidisciplinary approach in which radical surgery with or without flap reconstructions and neck dissection, along with radiotherapy (RT)/chemoradiotherapy (CRT) serve as the key components. Neoadjuvant chemotherapy and immunotherapy are used in selected cases based on the institutional preference. Knowledge of expected post-treatment changes on imaging is essential to differentiate it from recurrence. In addition, awareness of various post-treatment complications is imperative for their early detection on imaging. Distorted anatomy after treatment poses diagnostic challenge, hence, proper choice of imaging modality and appropriate timing of scan is pertinent for accurate post-treatment evaluation. In this article, we have comprehensively reviewed expected post-treatment appearances and complications on imaging. We have discussed imaging appearances of recurrences at the primary and lymphnodal sites and discussed documentation of findings using Neck Imaging Reporting and Data Systems (NI-RADS). We have also delved into the patterns of recurrence in human papillomavirus (HPV) positive HNSCC. Furthermore, we have provided flowcharts and discussed recommendations on the site-specific and treatment-related imaging modalities to be used along with their appropriate timing, for adequate evaluation of HNSCC after treatment. In addition, we have also touched upon the role of advanced imaging techniques for post-treatment HNSCC evaluation.

Assessing radiation-induced carotid artery injury using ultrasound in patients with head and neck cancer

BACKGROUND AND PURPOSE

Radiotherapy (RT) can damage neck vessels in patients with head and neck cancer (HNC). This study investigated the early effects of RT on carotid artery, including the internal media thickness (IMT) and carotid plaques of the common carotid artery (CCA).

MATERIALS AND METHODS

This study included 69 patients with HNC who underwent RT at the First Hospital of Jilin University from March 2017 to September 2022, and 69 healthy participants as controls. Color Doppler ultrasound (CDUS) of the carotid artery was used to measure the CCA IMT and plaques.

RESULTS

Left CCA IMT increased from 0.60 mm (0.60, 0.70) before RT to 0.70 mm (0.60, 1.20) after RT (P < 0.0001). Right CCA IMT changed from 0.60 mm (0.60, 0.71) before RT to 0.60 mm (0.60, 1.10) after RT (P = 0.0002). CCA IMT was 0.60 mm (0.60, 0.70) and 0.80 mm (0.60, 1.20) in the ≤40 Gy and >40 Gy groups (P = 0.0004). The CCA plaques number increased significantly after RT on both the left and right sides (Pleft < 0.0001; Pright <0.0001). The CCA plaques volume increased from 0 mm3 (0, 11.35) and 0 mm3 (0, 8.55) before RT to 8.8 mm3 (0, 21.5) and 5.8 mm3 (0, 16.1) on the left and right sides. Correlation analysis revealed a correlation between CCA IMT and age (r = 0.283, P = 0.001), smoking status (r = 0.179, P = 0.020), and radiation dose (r = 0.188, P = 0.028).

CONCLUSION

RT significantly increased CCA IMT, and the growth was related to the radiation dose. The number and volume of the CCA plaques also increased after RT.

Dosimetric comparison between carotid-sparing IMRT and 3DCRT in early glottic cancer patients treated with definitive radiation therapy

BACKGROUND

The purpose of this study was to evaluate the dosimetric benefits of carotid-sparing IMRT (intensity-modulated radiation therapy) over 3DCRT (three-dimensional conformal radiation therapy) in early glottic cancer patients.

MATERIAL AND METHODS

Ten patients with histologically proven early-stage squamous cell cancer of glottis (T1N0), treated with definitive radiotherapy, were selected retrospectively for the dosimetric analysis. Patients were originally treated with 3DCRT technique. For comparison purpose, IMRT plans were generated for each patient. Dosimetric comparison was done between two techniques (IMRT and 3DCRT) in terms of PTV (planning target volume) coverage, HI (homogeneity index), CI (conformity index), and doses to right carotid artery, left carotid artery, and spinal cord.

RESULTS

V95% for the PTV was higher in IMRT plans (98.26%) as compared to 3DCRT plans (95.12%) (P-value <0.001), whereas V105% for PTV was significantly higher in 3DCRT plans (16.77%) as compared to IMRT plans (0.32%) (P-value 0.11). In terms of both HI and CI, IMRT plans showed better conformity as compared to 3DCRT plans, with statistically significant difference. Both right and left carotid arteries' average mean and maximum doses were significantly lower in IMRT plans as compared to 3DCRT plans (P-value <0.001). IMRT plans resulted in significant carotid-sparing as compared to 3DCRT plans in terms of V35 and V50 (P-value <0.001).

CONCLUSION

Carotid-sparing IMRT resulted in better PTV coverage and lower carotid artery dose as compared to 3DCRT in early glottic cancer patients.

Comparison of Arterial Stiffness and Strain Measured with Speckle Tracking Carotid Strain Ultrasonography after Radiation and Surgical Treatment for Head and Neck Cancer-A Clinical Trial

This study assessed arterial stiffness in head and neck cancer patients using speckle tracking carotid strain ultrasonography (STCS-US). It investigated the impacts of neck irradiation and neck dissection on the arterial stiffness of these patients by comparing their stiffness parameters with those of healthy controls. A total of 101 participants (67 patients and 34 healthy controls) were enrolled in this study. Fifty-two patients received definitive radiation therapy (TD: 60-72 Gy in 30 days) at least two years ago. Participants were grouped into four according to their states of neck irradiation (IR) and neck dissection (ND): Group (IR+/ND-) had 28 patients, Group (IR+/ND+) had 24 patients, Group (IR-/ND+) had 15 patients, and Group (IR-/ND-) had 34 healthy controls. All the participants underwent STCS-US. Arterial stiffness parameters relating to arterial compliance (AC) and elastic modulus (EM) were significantly changed in Group (IR+/ND-) and Group (IR+/ND+) in the transverse plane (p < 0.001, p < 0.001) and in the longitudinal plane (p < 0.001, p < 0.001); the change in β-stiffness index (β-SI) was more significant in the transverse plane (p = 0.002). Group (IR+/ND+) had significant transverse circumferential (p = 0.001) and radial strain parameters (p = 0.001). The carotid intimal medial thickness (CIMT) significantly changed in Group (IR+/ND+) compared to controls (p = 0.001). Our findings indicate that neck irradiation and neck dissection increase arterial stiffness as single treatments; however, double treatment is associated with a higher increase. Neck irradiation affects strain parameters more than neck dissection alone. The study demonstrated the feasibility and clinical value of the STCS method in assessing arterial stiffness and its potential use in cardiovascular risk assessment for patients with head and neck cancer.

Prediction of Coronary Heart Disease Events in Blood or Marrow Transplantation Recipients

Background

The long-term risk of coronary heart disease (CHD) and clinical models that predict this risk remain understudied in blood or marrow transplantation (BMT) recipients.

Objectives

This study sought to examine the risk of CHD after BMT and identify the associated risk factors.

Methods

Participants included patients transplanted between 1974 and 2014 at City of Hope, University of Minnesota, or University of Alabama at Birmingham and those who survived ≥2 years after BMT. Multivariable logistic regression models assessed CHD risk in BMT survivors compared with a sibling cohort. A self-reported questionnaire and medical records provided information regarding sociodemographics, comorbidities, and therapeutic exposures, which were used to develop a CHD risk prediction nomogram.

Results

Overall, 6,677 BMT recipients participated; the mean age at BMT was 43.9 ± 17.7 years, 58.3% were male, and 73.3% were non-Hispanic Whites. The median length of follow-up was 6.9 years (range: 2-46.2 years) from BMT. CHD was reported in 249 participants, with a 20-year cumulative incidence of 5.45% ± 0.39%. BMT survivors had a 1.6-fold greater odds of CHD compared with a sibling cohort (95% CI: 1.09-2.40). A nomogram was then developed to predict the risk of CHD at 10 and 20 years after BMT including age at BMT (HR: 1.06/y; 95% CI: 1.04-1.08), male sex (HR: 1.89; 95% CI: 1.15-3.11), a history of smoking (HR: 1.61; 95% CI: 1.01-2.58), diabetes (HR: 2.45; 95% CI: 1.23-4.89), hypertension (HR: 2.02; 95% CI: 1.15-3.54), arrhythmia (HR: 1.90; 95% CI: 0.89-4.06), and pre-BMT chest radiation (yes vs no: HR: 2.83; 95% CI: 1.20-6.67; unknown vs no: HR: 0.88; 95% CI: 0.34-2.28). The C-statistic was 0.77 in the test set (95% CI: 0.70-0.83).

Conclusions

This study identified BMT recipients at high risk for CHD, informing targeted screening for early detection and aggressive control of risk factors.

Case report of intracranial large vessel occlusion in glioblastoma multiforme patient after radiation therapy

INTRODUCTION

Vasculopathy of the large arteries is a prominent complication of radiotherapy. Radiation-induced cerebral vasculopathy can cause arterial stenosis/occlusion, cerebral hemorrhage, and aneurysm formation. We report a cases of glioblastoma multiforme (GBM) with occlusive radiation vasculopathy (ORV).

CASE PRESENTATION

This 28-year-old patient who suffered from GBM had surgery for cytoreduction and received postoperative CCRT. We adopted the radiotherapy and oncology group radiation guideline. This patient had cerebrovascular accident episodes without any known risk. Therefore, ORV was highly suspected and vascular stenosis was confirmed using magnetic resonance angiography (MRA) or digital subtraction angiography. Extracranial-intracranial bypass was performed and patency was confirmed. The patient had not suffered from recurrent symptoms of transient ischemic attack or ischemic stroke for 1.5 years.

DISCUSSION

This is the first article to report bypass surgery for GBM patients. Although the median survival rate of GBM is approximately 15 months, the short survival time may be sufficient for occlusive vasculopathy to occur. Regular follow-up magnetic resonance imaging assessments are recommended, as is MRA as a screening tool for the early diagnosis of ORV.The Stenting versus Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial focused on atherosclerotic intracranial arterial stenosis, revealing that aggressive medical management was superior to stenting for secondary stroke prevention; however, it did not mention radiation-induced vasculopathy. Bypass surgery has yielded some positive outcomes. In the absence of contraindications, antiplatelet or anticoagulation agents could be added, and bypass surgery could be performed because there was no stent in the distal intracranial arteries.

CONCLUSION

MRA is a potential screening tool for ORV in GBM patients and bypass surgery could be performed to improve brain perfusion. Bypass surgery could help patient with occlusive radiation vasculopathy.

Ischemic Stroke with Multiple Cerebral Artery Stenosis in a Patient with an Anaplastic Astrocytoma during Bevacizumab Treatment: A Case Report

It has been reported that bevacizumab, an agent administered as an adjuvant therapy for high-grade gliomas, causes thromboembolic complications. We report a cerebral infarction with newly developed cerebral artery stenosis occurring during treatment with bevacizumab for an anaplastic astrocytoma. A 48-year-old female underwent excision surgery for an anaplastic astrocytoma on the right temporal lobe and received radiation therapy and chemotherapy with temozolomide. Twenty months after the maintenance therapy, treatment with bevacizumab was introduced for tumor recurrence. After the 14th course of bevacizumab at 6 months, 27 months after radiation therapy, the patient began experiencing mild right hemiparesis. Magnetic resonance imaging revealed scattered cerebral infarcts on the left frontal lobe and diffuse cerebral artery stenosis of the bilateral internal carotid artery system both inside and outside the radiation-treated area. Antiplatelet medication was commenced, and there was no recurrence of ischemic stroke. The morphological transition of the cerebral arteries should be carefully monitored via magnetic resonance angiography during post-radiation treatment with bevacizumab.

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

Venous thromboembolism and radiation therapy: The final radiation-induced thrombosis study analysis

Background

Thromboembolic events frequently complicate the course of malignancy and represent a major cause of morbidity and mortality in cancer patients. In contrast to chemotherapy and other systemic therapies, little is known about the impact of ionizing radiations on the incidence of venous thromboembolism (VTE) in cancer patients.

Methods

In the present prospective study, we aimed to investigate the incidence, management, and outcome of VTE in newly diagnosed cancer patients who received curative radiotherapy.

Results

VTE was found in 8 patients, out of 401 patients at a median time of 80 days after radiotherapy initiation. The incidence rate of VTE at 6 months post‐treatment was 2% (95% CI, 0.9–3.7), with 50% of cases occurring during the radiotherapy course and 50% of cases in patients who received or were receiving chemotherapy. As none of the patients harbored a personal history of VTE, no prophylactic measure was initiated during cancer therapy. Most patients received monotherapy with low‐molecular‐weight heparin and were still on surveillance at the end of the study. No specific clinical risk factor was identified that might systematically indicate the need of thromboprophylaxis in the context of curative radiotherapy.

Conclusions

Although this pan‐cancer descriptive study did not relate an increased risk of short‐term thrombosis following ionizing radiation, it provides important insight as a basis for future studies with subcategories of cancer, in order to in fine guide further recommendations in frail patients.

Clinical trial registration number

NCT02696447.

Late Outcomes of Carotid Artery Stenting for Radiation Therapy-Induced Carotid Stenosis

PURPOSE

Carotid artery stenting (CAS) appears as a promising alternative treatment to carotid endarterectomy for radiation therapy (RT)-induced carotid stenosis. However, this is based on a poor level of evidence studies (small sample size, primarily single institution reports, few long-term data). The purpose of this study was to report the long-term outcomes of a multicentric series of CAS for RT-induced stenosis.

METHODS

All CAS for RT-induced stenosis performed in 11 French academic institutions from 2005 to 2017 were collected in this retrospective study. Patient demographics, clinical risk factors, elapsed time from RT, clinical presentation and imaging parameters of carotid stenosis were preoperatively gathered. Long-term outcomes were determined by clinical follow-up and duplex ultrasound. The primary endpoint was the occurrence of cerebrovascular events during follow-up. Secondary endpoints included perioperative morbidity and mortality rate, long-term mortality rate, primary patency, and target lesion revascularization.

RESULTS

One hundred and twenty-one CAS procedures were performed in 112 patients. The mean interval between irradiation and CAS was 15 ± 12 years. In 31.4% of cases, the lesion was symptomatic. Mean follow-up was 42.5 ± 32.6 months (range 1-141 months). The mortality rate at 5 years was 23%. The neurologic event-free survival and the in-stent restenosis rates at 5 years were 87.8% and 38.9%, respectively. Diabetes mellitus (p=0.02) and single postoperative antiplatelet therapy (p=0.001) were found to be significant predictors of in-stent restenosis. Freedom from target lesion revascularization was 91.9% at 5 years.

CONCLUSION

This study showed that CAS is an effective option for RT-induced stenosis in patients not favorable to carotid endarterectomy. The CAS was associated with a low rate of neurological events and reinterventions at long-term follow-up.

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

BACKGROUND AND PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Imaging Features of Postradiotherapy Changes in Head and Neck Cancers

Radiation therapy is the mainstay in the treatment of head and neck cancers, in addition to surgery and chemotherapy. Expected radiotherapy changes evolving over time may be confused with recurrent tumor. Conversely, even residual or recurrent tumor in the setting of postradiotherapy changes may be difficult to identify clinically or even by radiological imaging. Therefore, it is important to be familiar with the temporal evolution of these changes. The purpose of this pictorial essay is thus to illustrate distinctly the expected radiotherapy changes and radiotherapy-related complications in the head and neck region and to differentiate them from tumor recurrence on routine cross-sectional imaging techniques (computed tomography and magnetic resonance imaging).

Outcome-based multiobjective optimization of lymphoma radiation therapy plans

At its core, radiation therapy (RT) requires balancing therapeutic effects against risk of adverse events in cancer survivors. The radiation oncologist weighs numerous disease and patient-level factors when considering the expected risk-benefit ratio of combined treatment modalities. As part of this, RT plan optimization software is used to find a clinically acceptable RT plan delivering a prescribed dose to the target volume while respecting pre-defined radiation dose-volume constraints for selected organs at risk. The obvious limitation to the current approach is that it is virtually impossible to ensure the selected treatment plan could not be bettered by an alternative plan providing improved disease control and/or reduced risk of adverse events in this individual. Outcome-based optimization refers to a strategy where all planning objectives are defined by modeled estimates of a specific outcome's probability. Noting that various adverse events and disease control are generally incommensurable, leads to the concept of a Pareto-optimal plan: a plan where no single objective can be improved without degrading one or more of the remaining objectives. Further benefits of outcome-based multiobjective optimization are that quantitative estimates of risks and benefit are obtained as are the effects of choosing a different trade-off between competing objectives. Furthermore, patient-level risk factors and combined treatment modalities may be integrated directly into plan optimization. Here, we present this approach in the clinical setting of multimodality therapy for malignant lymphoma, a malignancy with marked heterogeneity in biology, target localization, and patient characteristics. We discuss future research priorities including the potential of artificial intelligence.

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.

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

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

Arterial stiffness as an ultrasound biomarker of radiation-induced carotid artery disease

Background: Radiation-induced carotid artery disease (RICAD) is an important issue in head and neck cancer (HNC) survivors after radiotherapy (RT). The risk of cerebrovascular disease in these patients is doubled. The aim of this study was to assess the effect of RT on carotid artery stiffness in HNC patients. Patients and methods: Conventional arterial stiffness parameters were measured in a total of 50 HNC survivors treated with RT for at least 5 years and compared to 50 unirradiated HNC patients. Elastic modulus (Ep) and Beta stiffness index (β) were measured in proximal, mid and distal common carotid artery (CCA). Results: The mean age of the subjects was 68±9 years (range: 44-84) in the irradiated group and 67±10 years (range: 45-85) in the control group. The RT group was treated with a mean radiation exposure of 60.3±6.7 Gy (range: 44-72) in the neck. Carotid stiffness parameters showed significant group differences: Ep in the RT group was 2.329±1.222 vs 1.742±828 in the non-RT group (p=0.006) and β index in the RT group was 23±11 vs 15±8 in the non-RT group (p<0.001). Radiation-induced carotid stiffness was quantified and cervical exposure to RT increased Ep in 575 kPa (p=0.014) and β in 7 units (p<0.003). Conclusions: Ep and β index could be suitable ultrasound biomarkers of radiation-induced atherosclerosis in HNC survivors. Further prospective studies are needed to feature RICD in this setting.

Computer-assisted ultrasound assessment of plaque characteristics in radiation-induced and non-radiation-induced carotid atherosclerosis

Background

This study investigated the feasibility of using a computer-assisted method to evaluate and differentiate the carotid plaque characteristics in radiation-induced and non-radiation-induced carotid atherosclerosis.

Methods

This study included 107 post-radiotherapy (post-RT) nasopharyngeal carcinoma (NPC) patients and 110 subjects with cardiovascular risk factors (CVRFs). Each participant had a carotid ultrasound examination, and carotid plaques and carotid intima-media thickness (CIMT) were evaluated with grey scale ultrasound. The carotid plaque characteristics were evaluated for grey-scale median (GSM) and detailed plaque texture analysis (DPTA) using specific computer software. In DPTA, five different intra-plaque components were colour-coded according to different grey scale ranges. A multivariate linear regression model was used to evaluate the correlation of risk factors and carotid plaque characteristics.

Results

Post-RT NPC patients have significantly higher CIMT (748±15.1 µm, P=0.001), more patients had a plaque formation (80.4%, P<0.001) and more plaque locations (2.3±0.2, P<0.001) than CVRF subjects (680.4±10.0 µm, 38.2% and 0.5±0.1 respectively). Among the five intra-plaque components, radiation-induced carotid plaques had significantly larger area of calcification (4.8%±7.7%, P=0.012), but lesser area of lipid (42.1%±16.9%, P=0.034) when compared to non-radiation-induced carotid plaques (3.0%±5.7% and 46.3%±17.9% respectively). Age, radiation and number of CVRF were significantly associated with the carotid atherosclerosis burden (P<0.001). Besides, age was significantly associated with the amount of lipid and calcification within carotid plaques (P<0.001).

Conclusions

Radiation caused more severe carotid artery disease than CVRF with larger CIMT and more prevalent of carotid plaque. Radiation-induced carotid plaques tended to have more intra-plaque calcifications, whereas non-radiation-induced carotid plaques had more lipids. Ultrasound aided by computer-assisted image analysis has potential for more accurate assessment of carotid atherosclerosis.

Assessing the short-term effects of radiotherapy on the shear modulus of the common carotid artery as a new biomarker of radiation-induced atherosclerosis

Purpose

The purpose of this study was to investigate the incidence of short-term atherosclerosis in the common carotid arteries following radiotherapy.

Methods

The mean radiation dose to the arteries was 49.30±15.83 Gy. A computational ultrasound method was introduced to investigate the elastic modulus. Ultrasonography was performed 2-3 cm inferior to the bifurcation region before and after radiotherapy, and sequential images were extracted from a video of each artery. Instantaneous movement of the arterial wall in the radial and longitudinal directions was extracted by implementing the maximum gradient and block matching algorithms, respectively.

Results

There was a significant change in systolic blood pressure after radiotherapy (P=0.008). Irradiated arteries had significantly smaller systolic and end-diastolic diameters than non-irradiated arteries (P<0.001). The shear modulus was significantly different between irradiated and non-irradiated arteries (3.10±2.03 kPa vs. 1.38±0.98 kPa, P<0.001). The shear and Young moduli of radiation-induced arteries were 2.25±1.50 and 1.57±0.59 times higher than those of the pre-irradiation arteries.

Conclusion

The arterial shear modulus can be considered as a new biomarker of radiation-induced atherosclerosis in the common carotid artery.

Total plaque score helps to determine follow-up strategy for carotid artery stenosis progression in head and neck cancer patients after radiation therapy

BACKGROUND

To identify predictors of carotid artery stenosis (CAS) progression in head and neck cancer (HNC) patients after radiation therapy (RT).

METHODS

We included 217 stroke-naïve HNC patients with mild carotid artery stenosis after RT in our hospital. These patients underwent annual carotid duplex ultrasound (CDU) studies to monitor CAS progression. CAS progression was defined as the presence of ≥50% stenosis of the internal/common carotid artery on follow-up CDU. We recorded total plaque score (TPS) and determined the cut-off TPS to predict CAS progression. We categorized patients into high (HP) and low plaque (LP) score groups based on their TPS at enrolment. We analyzed the cumulative events of CAS progression in the two groups.

RESULTS

The TPS of the CDU study at enrolment was a significant predictor for CAS progression (adjusted odds ratio [aOR] = 1.69, p = 0.002). The cut-off TPS was 7 (area under the curve: 0.800), and a TPS ≥ 7 strongly predicted upcoming CAS progression (aOR = 41.106, p = 0.002). The HP group had a higher risk of CAS progression during follow-up (adjusted hazard ratio = 6.15; 95% confident interval: 2.29-16.53) in multivariable Cox analysis, and also a higher trend of upcoming ischemic stroke (HP vs. LP: 8.3% vs. 2.2%, p = 0.09).

CONCLUSIONS

HNC patients with a TPS ≥ 7 in any CDU study after RT are susceptible to CAS progression and should receive close monitoring within the following 2 years.

Hypothyroidism and risks of cerebrovascular complications among patients with head and neck cancer after radiotherapy

BACKGROUND

Hypothyroidism (HT) and carotid artery stenosis (CAS) are complications of radiotherapy (RT) in patients with head and neck cancer (HNC). The impact of post-RT HT on CAS progression remains unclear.

METHODS

Between 2013 and 2014, HNC patients who had ever received RT and were under regular follow-up in our hospital were initially screened. Patients were categorized into euthyroid (EU) and HT groups. Details of RT and HNC were recorded. Total plaque scores and degrees of CAS were measured during annual extracranial duplex follow-up. Patients were monitored for CAS progression to > 50 % stenosis or ischemic stroke (IS). Cumulative time to CAS progression and IS between the 2 groups were compared. Data were further analyzed based on the use or nonuse of thyroxine of the HT group.

RESULTS

333 HNC patients with RT history were screened. Finally, 216 patients were recruited (94 and 122 patients in the EU and HT groups). Patients of the HT group received higher mean RT doses (HT vs. EU; 7021.55 ± 401.67 vs. 6869.69 ± 425.32 centi-grays, p = 0.02). Multivariate Cox models showed comparable CAS progression (p = 0.24) and IS occurrence (p = 0.51) between the 2 groups. Moreover, no significant difference was observed in time to CAS progression (p = 0.49) or IS (p = 0.31) among patients with EU and HT using and not using thyroxine supplement.

CONCLUSIONS

Our results did not demonstrate significant effects of HT and thyroxine supplementation on CAS progression and IS incidence in patients with HNC after RT.

Prevalence of carotid plaque stenosis after head and neck radiotherapy – an observational study of 156 survivors

Summary: Background: Radiotherapy for head and neck cancer (HNC) represents a well-known predisposing factor for asymptomatic carotid artery lesions and acute cerebrovascular accidents. Our aim is to provide contemporary estimates on the prevalence, severity, and characteristics of carotid artery lesions in HNC survivors. Patients and methods: We prospectively included HNC patients who underwent radiotherapy and were free from the disease at the time of duplex ultrasound evaluation. Patients were re-contacted telephonically and those who agreed to participate were invited for an ambulatory visit when the investigators collected clinical information and performed duplex ultrasound examination based on a predefined protocol. Results: A total of 156 patients were included and underwent duplex ultrasound examination after a mean of 65.2 months from the last session of radiotherapy. A total of 36 patients (23.1%) had normal carotid arteries; mild, non-stenotic lesions were observed in 49.4% (n = 77) of patients; severe stenotic plaques were found in 27.5% (n = 43) of patients. One patient found with an asymptomatic occlusion of the left ICA. The prevalence of major cardiovascular risk factors and high radiation dose increased proportionally with plaque severity. Low echogenicity plaque was found in 59 (37.8%) patients on the right side and 57 (36.5%) on the left side; long segment plaque in 49 (31.4%) patients on the right side and in 47 (30.1%) on the left side; an atypical location of the lesions in 42 (26.9%) patients on the right side and in 48 (30.8%) on the left side. Conclusions: The prevalence of occlusion and severe stenosis after radiotherapy for HNC was very low in our study population. Low echogenicity plaque, long segment plaque, and an atypical location were common findings. Classic cardiovascular risk factors appear to have had a causative role: a routine screening of radiotherapy-treated patients might be necessary only in patients with concomitant cardiovascular risk factors or exposed to high-dose neck radiation.

Medical prevention and treatment of radiation-induced carotid injury

Radiotherapy has significantly improved the survival of cancer patients but is also associated with several adversities, including radiation-induced carotid injury (RICI). The RICI mechanisms are complex, including vessel inflammatory injury, carotid atherosclerosis, intimal proliferation, media necrosis, and peri-adventitial fibrosis. The main manifestation and adverse consequence of RICI is carotid artery stenosis (CAS), which can lead to stroke and transient ischemic attack. Currently, carotid artery injury is primarily diagnosed via color-coded duplex sonography. Early detection of traumatic changes in the carotid artery depends on measurements of carotid intima-media thickness; serum biomarker testing also shows great potential. CAS is mainly treated with carotid endarterectomy or carotid angioplasty and stent implantation. Notably, bone marrow mesenchymal stem cells are advantageous in RICI treatment and reduce carotid inflammation, oxidative stress, and delaying atherosclerosis. This review summarizes the mechanisms, examination methods, and latest treatments for RICI to provide data for its clinical prevention and treatment.

Peripheral Artery Disease and Stroke

Peripheral artery disease (PAD) and stroke can occur as vascular complication of anticancer treatment. Although the mechanisms, monitoring, and management of cardiotoxicities have received broad attention, vascular toxicities remain often underrecognized. In addition, the development of new chemotherapeutic drugs bears the risk of vasotoxicities that are yet to be identified and may not be realized with short-term follow-up periods. The propensity to develop PAD and/or stroke reflects the complex interplay between patient's baseline risk and preexisting vascular disease, particularly hypertension and diabetes, while evidence for genetic predisposition is increasing. Chemotherapeutic agents with a prominent vascular side effect profile have been identified. Interruption of vascular endothelial growth factor (VEGF) inhibitors (VEGFIs) signaling (i.e., bevacizumab) is associated with vascular toxicity and clinical sequelae such as hypertension, stroke, and thromboembolism beyond acute coronary syndromes. Cisplatin and 5-fluorouracil are the main drugs involved in the stroke risk. In addition, circulating concentrations of VEGF are reduced by cyclophosphamide administered at continuous low doses, which might underpin some of the observed vascular toxicity, such as stroke, as seen in patients treated with VEGF inhibitors. The risk of stroke is also increased after treatment with anthracyclines that can induce endothelial dysfunction and increase arterial stiffness. Proteasome inhibitors ( bortezomib and carfilzomib) and immunomodulatory agents (thalidomide, lenalidomide, and pomalidomide), approved for use in multiple myeloma, carry a black box warning for an increased risk of stroke. Finally, head-and-neck radiotherapy is associated with a doubled risk of cerebrovascular ischemic event, especially if exposure occurs in childhood. The mechanisms involved in radiation vasculopathy are represented by endothelial dysfunction, medial necrosis, fibrosis, and accelerated atherosclerosis. However, BCR-ABL tyrosine kinase inhibitor (TKI), used for the treatment of chronic myeloid leukemia (CML), is the main antineoplastic drugs involved in the development of PAD. In particular, second- and third-generation TKIs, such as nilotinib and ponatinib, while emerging as a potent arm in contrasting CML, are associated with a higher risk of PAD development rather than traditional imatinib. Factors favoring vascular complication are the presence of traditional cardiovascular risk factors (CVRF) and predisposing genetic factors, high doses of BCR-ABL TKIs, longer time of drug exposure, and sequential use of potent TKIs. Therefore, accurate cardiovascular risk stratification is strongly recommended in patient candidate to anticancer treatment associated with higher risk of vascular complication, in order to reduce the incidence of PAD and stroke through CVRF correction and selection of appropriate tailored patient strategy of treatment. Then, a clinical follow-up, eventually associated with instrumental evaluation through vascular ultrasound, should be performed.

Recognizing Radiation Therapy-related Complications in the Chest

Radiation therapy is one of the cornerstones for the treatment of thoracic malignancies. Although advances in radiation therapy technology have improved the delivery of radiation considerably, adverse effects are still common. Postirradiation changes affect the organ or tissue treated and the neighboring structures. Advances in external-beam radiation delivery techniques and how these techniques affect the expected thoracic radiation-induced changes are described. In addition, how to distinguish these expected changes from complications such as infection and radiation-induced malignancy, and identify treatment failure, that is, local tumor recurrence, is reviewed. ^©RSNA, 2019.

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.

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.

Nontraumatic Vascular Emergencies of the Neck

Nontraumatic vascular emergencies of the head and neck are uncommon, but can occur in patients with central venous catheters, head and neck infections, and in patients with head and neck cancer. Recognizing the imaging findings of vascular complications in these patient populations is critically important to ensure expeditious treatment to avoid significant morbidity and mortality.

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.

HMGB1-modified mesenchymal stem cells attenuate radiation-induced vascular injury possibly via their high motility and facilitation of endothelial differentiation

Background

Vascular injury is one of the most common detrimental effects of cancer radiotherapy on healthy tissues. Since the efficacy of current preventive and therapeutic strategies remains limited, the exploration of new approaches to treat radiation-induced vascular injury (RIV) is on high demands. The use of mesenchymal stem cells (MSCs) to treat RIV holds great promise thanks to their well-documented function of mediating tissue regeneration after injury. Recently, we genetically modified MSCs with high mobility group box 1 (HMGB1) and demonstrated the high efficacy of these cells in treating graft atherosclerosis. The current study was to investigate the protective effect of HMGB1-modified MSCs (MSC-H) on RIV by using a rat model.

Methods

Female F344 rats received an intravenous injection of male F344 MSC-H cells or vehicle control at four doses of 2 × 10⁶ cells with a 15-day interval starting from 30 days after irradiation to the abdominal aorta. The aortas were procured for histological and biomedical analysis at 90 days after irradiation. Cell migration to irradiated aortas was traced by green fluorescent protein and sex determination region on the Y chromosome. In vitro cell migration and endothelial differentiation of MSC-H cells were analyzed by stromal-derived factor 1-induced transwell assay and RNA microarray, respectively. The contribution of extracellular HMGB1 to the bioactivity of MSC-H cells was investigated by inhibition experiments with HMGB1 antibody.

Result

MSC-H cell infusion alleviated neointimal formation, vascular inflammation, and fibrosis in irradiated aortas, which was associated with local migration and endothelial differentiation of MSC-H cells. The MSC-H cells showed high motility and potential of endothelial differentiation in vitro. Microarray analysis suggested multiple pathways like MAPK and p53 signaling were activated during endothelial differentiation. MSC-H cells highly expressed CXC chemokine receptor 4 and migrated progressively after stromal-derived factor 1 stimulation, which was blocked by the antagonist of CXC chemokine receptor 4. Finally, the migration and endothelial differentiation of MSC-H cells were inhibited by HMGB1 antibody.

Conclusion

MSC-H cell infusion significantly attenuated RIV, which was associated with their high motility and endothelial differentiation potential. Multiple pathways that possibly contributed to the efficacy of MSC-H cells were suggested and deserved further investigation.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1197-x) contains supplementary material, which is available to authorized users.

Dose-dependent 60Co γ-radiation Effects on Human Endothelial Cell Mechanical Properties

Exposure to ionizing radiation is unavoidable for noncancerous cells during the external radiotherapy process. Increasing the dose delivery fraction times leads to increasing the endothelial cell damage. Vascular abnormalities are commonly associated with the alternation of endothelium biomechanical properties. The goal of the present study was to quantify the elastic and viscoelastic properties of human umbilical vein endothelial cells (HUVECs) using the micropipette aspiration technique in conjunction with a theoretical model while an 8 Gy dose was given in four fractions. Confocal imaging was performed for evaluation of cytoskeletal changes during fractionation ⁶⁰Co radiotherapy. The results indicated an increase in elastic modulus from 29.87 ± 1.04 Pa to 46.69 ± 1.17 Pa while the fractional doses increased from 0 Gy to 8 Gy along with the obvious cytoskeletal changes. Moreover, in the creep behavior of radiated groups, a significant decrease was shown in the time constant and viscoelastic properties. On the other hand, it was observed that the change in the biomechanical properties of the cells while applying a single fraction of 8 Gy was not exactly the same as that in the properties of the radiation-exposed cells while delivering an 8 Gy dose at 2 Gy per fraction. The observed differences in the biomechanical behavior of endothelium provide a quantitative description of radiobiological effects for evaluating the dose-response relationship as a biological dosimetry procedure.

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.

Cardiovascular effects of radiation therapy

Radiation therapy (RT) plays a prominent role in the treatment of many cancers. With increasing use of RT and high overall survival rates, the risks associated with RT must be carefully considered. Of these risks, the cardiovascular and autonomic toxicities have been of significant concern. In fact, cardiovascular disease is the leading cause of nonmalignancy-related death in cancer survivors. The manifestations of radiation induced cardiac injury include the acute toxicities of myopericarditis and late toxicities including constrictive pericarditis, restrictive cardiomyopathy, coronary artery disease, valvular heart disease, heart failure, and conduction abnormalities. Neck and cranial RT have also been associated with significant long-term toxicities including accelerated occlusive carotid artery disease, autonomic dysfunction due to baroreceptor damage, and development of metabolic syndromes due to damage to the hypothalamic-pituitary axis. The clinical manifestations of radiation induced disease may not present until several years following the delivery of radiation. We review the adverse effects of RT on these organ systems and discuss risk reduction strategies that may effectively mitigate some of these adverse outcomes.

Is Low-Dose Radiation Exposure a Risk Factor for Atherosclerotic Disease?

Nontargeted late effects of radiation include an increased risk of cardiovascular disease, although this is still debatable in the context of low-dose radiation. Tinea capitis patients treated in childhood with X rays to induce scalp epilation received a low dose of radiation to their carotids. To better clarify this issue, we evaluated carotid atherosclerosis in a cohort of such patients treated in 1950-1963 in Portugal. A group of 454 individuals randomly chosen from previously observed Portuguese tinea capitis patients and a control group mainly composed of their spouses (n = 280) were enrolled. Cardiovascular risk factors such as waist circumference, body mass index, blood pressure and tobacco consumption, as well as biochemical measurements were obtained. Ultrasound imaging of carotid arteries for intima media thickness and stenosis evaluation were performed according to a standardized protocol. In comparison to the control group, the irradiated cohort members were significantly older, more frequently never smokers, hypertensive, and presented higher glycated hemoglobin and alkaline phosphatase levels. In addition, the irradiated cohort showed a higher frequency of carotid stenosis ≥30% than the nonirradiated group (13.9% vs. 10.7%), although this was not significant ( P = 0.20). Stenosis was ≥50% in 2.9% of the irradiated group and 0.4% of the nonirradiated group ( P = 0.02). Likewise, the frequency of intima media thickness ≥1 mm was significantly higher in the irradiated group (16.8% vs. 10.7%; P = 0.02). Multivariate analysis, including other cardiovascular risk factors, showed that exposure to low-dose radiation increased the risk of carotid stenosis by ≥50% [odds ratio (OR) = 8.85; P = 0.04] and intima media thickness by ≥1 mm (OR = 1.82; P = 0.02). These findings confirm that low-dose exposure is a risk factor of carotid atherosclerotic disease.

Changes in the Common Carotid Artery after Radiotherapy: Wall Thickness, Calcification, and Atherosclerosis

BACKGROUND AND PURPOSE

Since the long-term survival rate has improved in laryngeal cancer patients who receive radiotherapy, concerns about postradiation complications (including carotid atherosclerosis) have increased. We followed changes in the common carotid artery (CCA) after radiotherapy and identified the underlying risk factors.

METHODS

Consecutive patients with laryngeal cancer who underwent radiotherapy between January 1999 and December 2009 and who had received computed tomography (CT) both pre- and postradiotherapy were enrolled. Changes in the wall thickness and in the vessel and lumen areas as well as the presence of calcification or atherosclerosis were investigated. Demographics and risk factors were compared between patients with and without atherosclerosis at follow-up CT.

RESULTS

In total, 125 patients were enrolled. The wall thickness had increased and the lumen area had decreased several months after radiotherapy. These changes were not associated with vascular risk factors and were not progressive. Calcification and atherosclerosis were observed in 37 (29.6%) and 71 (56.8%) patients, respectively. Diabetes was associated with calcification (p=0.02). The prevalence of hyperlipidemia was higher in patients with atherosclerosis (28.2% vs. 11.1%, p=0.02) and for a longer period postradiation [62.7±32.1 vs. 40.0±24.2 months (mean±SD), p<0.001]. Atherosclerosis occurred mostly in the middle portion of the CCA (n=31, 24.6%), followed by the proximal CCA at the intrathoracic level (n=26, 20.6%) and the distal CCA (n=6, 4.8%). Positive remodeling was also observed, but this was less common in patients with calcification (p=0.02).

CONCLUSIONS

Various types of postradiation changes occur in the CCA and can be easily observed in postradiation CT. The prevalence and burden of postradiation atherosclerosis increased in a close relationship with baseline cholesterol levels and the time after radiotherapy. Postradiation atherosclerosis was observed at unusual sites of the CCA.

[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.

A comparative dosimetric study comparing dose to the carotid artery using 3D conformal radiotherapy and intensity-modulated radiotherapy for T1-T2 glottic cancer at Gharbia Cancer Society, Egypt

Purpose

This is a dosimetric study to compare the feasibility of carotid artery sparing as a primary objective, as well as planning target volume coverage and dose to spinal cord as a secondary objective, by using 3D conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT) for patients with early glottis cancer.

Patients and methods

Six patients who had been treated for early stage glottic carcinoma (stage T1-2 N0M0) were included in this study. All patients were immobilised in the supine position with a thermoplastic mask and treatment planning computed tomography scans were obtained from the top of the skull to the top of aortic arch with a 3-mm slice thickness. Two plans were created for every patient, one using 3DCRT and the second using IMRT. Comparison between the two plans was undertaken and analysis was made regarding the dose to the carotids arteries, target coverage and doses to the organs at risk.

Results

For target coverage, theV95%for both plans was the same with no significant difference, hot spots were the highest in 3DCRT withp=0·002, the homogeneity index for IMRT plan was better than 3DCRT (p=0·0001). Regarding the dose to the carotids, it was significantly lower in the IMRT plan compared with the 3DCRT plan (p=0·01). The spinal cord dose was significantly higher in the IMRT plan.

Conclusion

IMRT significantly reduces the radiation dose to the carotid arteries compared with 3DCRT while maintaining clinical target volume coverage. Such a results assists in decreasing the incidence of radiation-induced carotid stenosis, thus improving the quality of life for patients.

Hemodynamic analysis of radiation-induced damage in common carotid arteries by using color Doppler ultrasonography

Purpose

The aim of this study was to assess vascular changes and blood flow abnormalities in the common carotid arteries of patients with head and neck cancers after external radiotherapy, using color Doppler ultrasonography.

Methods

We studied 24 patients treated with external radiotherapy for various head and neck cancers. In order to study the acute effects of irradiation on common carotid blood flow and arterial diameter changes, color Doppler ultrasonography parameters such as peak systolic velocity, end diastolic velocity, mean velocity, systolic-to-diastolic velocity (S/D) ratio, pulsatility index (PI), resistive index (RI), and instantaneous diameter changes were evaluated before and after external radiotherapy. Additionally, the blood volume flow (VF) values in the peak systolic and end diastolic phases, as well as mean velocity, were evaluated throughout three cardiac cycles using B-mode ultrasonic image processing.

Results

The findings showed significant changes in the S/D ratio, PI, and RI of the common carotid arteries before and after external radiotherapy (P<0.05). Moreover, a significant decrease in artery diameter and blood VF was observed after radiotherapy relative to the pretreatment values. A significant correlation was found between the blood VF values estimated using ultrasonic measurements and mathematical methods throughout three cardiac cycles.

Conclusion

The hemodynamic parameters of the common carotid arteries changed during radiotherapy. These arterial changes may lead to late adverse effects of radiotherapy, such as ischemic strokes and ischemic attacks.

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

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

Standardisation of Target Volume Delineation for Carotid-sparing Intensity-modulated Radiotherapy in Early Glottis Cancer

AIMS

Recently, carotid-sparing intensity-modulated radiotherapy (IMRT) for early laryngeal glottis (T1/T2N0M0) cancer has generated interest in the hope of avoiding long-term carotid toxicity, as well as concerns relating to geographical misses and long-term normal tissue toxicity. The aim of this review was to summarise the current literature on carotid-sparing IMRT for early glottis cancer, with particular focus on definitions of target volumes and the carotid arteries as organs at risk. In addition, we make suggestions for standardisation of these structures, dose constraints and dose reporting.

MATERIALS AND METHODS

From 73 references, 16 articles met the criteria for inclusion in this systematic review. These papers described two case reports, 11 planning studies and three prospective studies.

RESULTS

There was variation in all target volume definitions with no clear consensus. The greatest variability was in clinical target volume definition. Carotid artery and spinal cord delineation were not always defined and most studies did not use a carotid artery constraint. Of the eight studies that reported carotid artery delineation, no two studies delineated the same length of carotid artery, yet most studies reported mean doses. Most studies used IMRT with three to seven fields. Five studies used arc therapy and two studies used tomotherapy.

CONCLUSION

This review highlights a lack of consensus in target volume definitions in carotid-sparing IMRT. Ultimately, long-term prospective data are required to show the benefit of carotid-sparing IMRT. Pooled data will prove useful as most studies will report on small numbers of patients. Therefore, adopting a consensus now on target volume definition, dose constraints and dose reporting will be crucial.

CNS Masson Tumors: Frequent Association With Therapeutic Radiation

Masson tumor (MT, papillary endothelial hyperplasia) is an exaggerated form of thrombus reorganization rarely occurring in the central nervous system (CNS), where it presents as a mass or hemorrhage in parenchyma, meninges, or venous sinuses. MT is subclassified as type 1 arising within a histologically normal vessel, type 2 associated with a ruptured vascular malformation, and extravascular. Limited reports of CNS MT after radiosurgery, or especially external radiation therapy, have emerged. We searched our databases for cases reported from 2008 to present. Nine cases were identified, 6 of which were associated with receipt of therapeutic radiation for known lesions, with intervals of 1 to 25+ years to MT development (4 neoplasms=external beam radiation; 1 neoplasm=external beam radiation+radiosurgery, 1 arteriovenous malformation=radiosurgery). MTs were coassociated with radiation-induced vascular malformations (1 cavernoma-like, 1 massive) only in 2 of 6 irradiated patients, whereas the other 4 had MTs only. The 3 MTs in nonirradiated patients were extravascular, with 1 spontaneously developing in a hemangioblastoma. Seven of 9 MTs were intracerebral, 1 was within the spinal cord, and 1 was subdural. Papillary MT architecture was best appreciated by CD31 or CD34 immunohistochemistry, although ERG verified the endothelial monolayer population. Most CNS MTs at our institution have arisen in patients who have received therapeutic cranial radiation, many of whom received only external beam radiation. Although MTs could conceivably represent early, severe phases in radiation-induced cavernoma development, most were not found coassociated with the latter. This study further extends our knowledge of types of radiation-induced CNS vascular abnormalities.

Carotid sparing intensity modulated radiotherapy on early glottic cancer: preliminary study

Purpose

To compare the dose distribution between carotid sparing intensity modulated radiotherapy (IMRT) and opposed lateral field technique (LAFT), and to determine the effects of carotid sparing IMRT in early glottic cancer patients who have risk factors for atherosclerosis.

Materials and Methods

Ten early glottic cancer patients were treated with carotid sparing IMRT. For each patient, the conventional LAFT plan was developed for comparison. IMRT and LAFT plans were compared in terms of planning target volume (PTV) coverage, conformity index, homogeneity index, and the doses to planning organ at risk volume (PRV) for carotid arteries, spinal cord and pharyngeal constrictor muscle.

Results

Recurrence was not observed in any patients during the follow-up period. V_95% for PTV showed no significant difference between IMRT and LAFT plans, while V_100% was significantly higher in the IMRT plan (95.5% vs. 94.6%, p = 0.005). The homogeneity index (11.6%) and conformity index (1.4) in the IMRT plan were significantly better than those in the LAFT plans (8.5% and 5.1, respectively) (p = 0.005). The median V_5Gy (90.0%), V_25Gy (13.5%), and V_50Gy (0%) for carotid artery PRV in the IMRT plan were significantly lower than those in the LAFT plan (99.1%, 89.0%, and 77.3%, respectively) (p = 0.005).

Conclusion

Our study suggests that carotid sparing IMRT can significantly decrease the dose to carotid arteries compared to LAFT, and it would be considered for early glottic cancer patient with high risk of atherosclerosis.

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.