Incidence of carotid stenosis in nasopharyngeal carcinoma patients after radiotherapy

Study on carotid artery stenosis after radiotherapy for nasopharyngeal carcinoma

OBJECTIVE

This study investigated carotid artery stenosis (CAS) and associated risk factors in patients with nasopharyngeal carcinoma (NPC) post-radiotherapy.

MATERIALS AND METHODS

The observation group comprised 86 reexamined patients with NPC, divided into Group 1 and Group 2 based on post-radiotherapy duration, alongside 34 newly diagnosed patients with NPC (Group 0). Carotid artery ultrasonography and chi-square analysis were performed.

RESULTS

Moderate-to-severe vascular abnormalities were exclusively in Group 2. Considering mild vascular abnormalities as the standard, the overall vascular abnormality rates in Group 2 and Group 0 were 65.9% and 41.2%, respectively. In Group 2 and Group 0, the abnormality rates for unilateral carotid artery (UCA), common carotid artery (CCA), internal carotid artery (ICA), and external carotid artery (ECA) were 47.4% and 30.9%, 44.3% and 22.1%, 44.3% and 16.2%, and 39.8% and 5.9%, respectively. Comparing group 1 to group 0, only UCA abnormalities were statistically significant (45.4% vs. 30.9%). Considering moderate-to-severe vascular abnormalities as the standard, Group 2 had higher overall vascular, UCA, CCA, ICA, and ECA abnormality rates compared to Group 0. The age at revisit over 45 years, T stage, and N stage may influence CAS.

CONCLUSION

Radiation increasing CAS incidence after 3 years. So, regular examinations are recommended to dynamically monitor CAS after 3 years of radiotherapy.

Progression rate of radiation-induced carotid stenosis in head and neck cancer survivors after statin treatment: a retrospective cohort study

BACKGROUND AND AIMS

Whether statin treatment is effective in retarding the progression of radiation-induced carotid stenosis (RICS) in head and neck cancer (HNC) survivors has not been well studied. The purpose of this study was to assess the association of statin treatment with RICS progression rate in HNC survivors after radiotherapy.

METHODS

We conducted a retrospective cohort study at Sun Yat-sen Memorial Hospital, Sun Yat-sen University in Guangzhou, China. Between January 2010 and December 2021, we screened HNC survivors whose carotid ultrasound scans had shown stenosis of the common and/or internal carotid arteries. The primary outcome was the RICS progression rate. We compared eligible patients treated with statins with those who did not in multivariable Cox regression models.

RESULTS

A total of 200 patients were included in this study, of whom 108 received statin treatment and 92 did not. Over a mean follow-up time of 1.5 years, 56 (28.0%) patients showed RICS progression, 24 (42.9%) and 32 (57.1%) in the statin and control groups, respectively. The statin group showed less RICS progression than the control group (adjusted-HR 0.49, 95% CI 0.30-0.80, P = 0.005). In the subgroup analysis, there was no significant interaction in the effect of statins on lowering RICS progression rate in the subgroups stratified by baseline low-density lipoprotein cholesterol (LDL-C) levels (P for interaction = 0.53) or baseline degrees of stenosis (P for interaction = 0.50).

CONCLUSIONS

Statin treatment was associated with a lower risk of RICS progression in patients with HNC after radiotherapy, regardless of baseline LDL-C level and baseline stenosis degrees.

Statin use reduces radiation-induced stroke risk in advanced nasopharyngeal carcinoma patients

OBJECTIVE

This cohort study aimed to evaluate the impact of statin use on ischemic stroke risk in patients with advanced nasopharyngeal carcinoma (NPC) undergoing standard concurrent chemoradiotherapy (CCRT).

METHODS

Using data from the Taiwan Cancer Registry Database, we conducted an inverse probability of treatment-weighted Cox regression analysis to examine the association between statin use during CCRT and ischemic stroke risk.

RESULTS

The adjusted hazard ratio (aHR) for ischemic stroke in the statin group compared to the non-statin group was 0.70 (95 % CI: 0.54-0.92; P < 0.0107). This protective effect was observed across different statin classes, with hydrophilic statins such as pravastatin showing an aHR of 0.37 (95 % CI: 0.17-0.85) and lipophilic statins including atorvastatin displaying an aHR of 0.32 (95 % CI: 0.21-0.50) compared to non-statin use. Analysis of cumulative defined daily doses (cDDD) revealed a dose-response relationship, with lower stroke risk observed in higher quartiles of cDDD. Additionally, patients with a daily defined dose (DDD) > 1 had a reduced risk of stroke with an aHR of 0.49 (95 % CI: 0.31-0.63), while those with DDD ≤ 1 showed an aHR of 0.59 (95 % CI: 0.40-0.84).

CONCLUSIONS

Our study provides evidence supporting the beneficial effects of statin use during the CCRT period in reducing radiation-induced stroke risk among patients with advanced NPC undergoing definitive CCRT. Notably, pravastatin and atorvastatin demonstrated significant reductions in stroke occurrence. Furthermore, the findings suggest a dose-response relationship, where higher cumulative doses and greater daily dose intensity of statin use were associated with a lower risk of stroke.

The effects of radiotherapy on arterial diameters in patients with high-grade glial tumors who have undergone adjuvant radiotherapy

Background and Aims

Our purpose was to evaluate the M2 branch of the middle cerebral artery (MCA) in high-grade glial tumor patients who undergo adjuvant radiotherapy (RT). For this purpose, the diameter of the M2 branch was measured and evaluated by means of contrast-enhanced magnetic resonance imaging (CE-MRI) before and after RT. Post-radiotherapeutical measurements were made 1, 3, 5, and 7 months after the procedure; and vascular diameter alterations were evaluated.

Materials and Methods

CE-MRI examinations were performed on the 32 patients enrolled in the study, who had undergone radiotherapy of the temporoparietal region. MRI examinations were performed prior to RT (RT0) and 1 (RT1), 3 (RT2), 5 (RT3), and 7 (RT4) months after RT. The M2 branch of the MCA was evaluated on MRI images, and the vessel diameter was measured in millimeters (mm), and then comparisons were made.

Results

Statistically significant results were obtained during RT0-RT1, RT0-RT2, RT0-RT3, RT0-RT4, RT1-RT2, RT2-RT4, and RT3-RT4, and comparisons of the diameters of the M2 branch of the right MCA were performed (P < 0.05). When the same measurements and comparisons were made for the M2 branch of the left MCA, statistically significant results were found for the RT1-RT2, RT1-RT3, and RT1-RT4 comparisons (P < 0.05).

Conclusion

Our study showed that the MCA M2 branch diminished in size following RT. This was demonstrated by means of CE-MRI controls performed up to 7 months after the completion of the RT procedures.

Late Radiation-Induced Carotid Artery Stenosis and Stroke in Pediatric Patient Treated With Proton Radiation Therapy for Skull-Base Chordoma

Radiation vasculopathy is a well-recognized late complication of radiation therapy. We present a case of a stroke 29 years after high-dose proton radiation therapy for skull-base chordoma due to occlusion of bilateral internal carotid arteries.

Percutaneous transluminal angioplasty and stenting of post-irradiation stenosis of the vertebral artery

BACKGROUND

The outcomes of percutaneous transluminal angioplasty and stenting (PTAS) in patients with medically refractory post-irradiation stenosis of the vertebral artery (PISVA) have not been clarified.

AIM

This retrospective study evaluated the safety and outcomes of PTAS in patients with severe PISVA compared with their radiation-naïve counterparts (non-RT group).

METHODS

Patients with medically refractory severe symptomatic vertebral artery stenosis and undergoing PTAS between 2000 and 2021 were classified as the PISVA group or the non-RT group. The periprocedural neurological complications, periprocedural brain magnetic resonance imaging, the extent of symptom relief, and long-term stent patency were compared.

RESULTS

As compared with the non-RT group (22 cases, 24 lesions), the PISVA group (10 cases, 10 lesions) was younger (62.0 ± 8.6 vs 72.4 ± 9.7 years, P = 0.006) and less frequently had hypertension (40.0% vs 86.4%, P = 0.013) and diabetes mellitus (10.0% vs 54.6%, P = 0.024). Periprocedural embolic infarction was not significantly different between the non-RT group and the PISVA group (37.5% vs 35.7%, P = 1.000). At a mean follow-up of 72.1 ± 58.7 (3-244) months, there was no significant between-group differences in the symptom recurrence rate (0.00% vs 4.55%, P = 1.000) and in-stent restenosis rate (10.0% vs 12.5%, P = 1.000).

CONCLUSION

PTAS of severe medically refractory PISVA is effective in the management of vertebrobasilar ischemic symptoms in head and neck cancer patients. Technical safety and outcome of the procedure were like those features in radiation-naïve patients.

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

Spotted Temporal Lobe Necrosis following Concurrent Chemoradiation Therapy Using Image-Guided Radiotherapy for Nasopharyngeal Carcinoma

Background. To explore spotted temporal lobe necrosis (TLN) and changes in brain magnetic resonance imaging (MRI) after image-guided radiotherapy (IGRT) in a patient with nasopharyngeal carcinoma (NPC). Case presentation: a 57-year-old male was diagnosed with stage III NPC, cT1N2M0, in 2017. He underwent concurrent chemoradiation therapy (CCRT) with cisplatin (30 mg/m2) and 5- fluorouracil (5-FU, 500 mg/m2) plus IGRT with 70 Gy in 35 fractions for 7 weeks. The following MRI showed a complete response in the NPC. However, the patient suffered from fainting periodically when standing up approximately 3 years after CCRT. Neck sonography showed mild atherosclerosis (< 15%) of bilateral carotid bifurcations and bilateral small-diameter vertebral arteries, with reduced flow volume. The following MRI showed a 9 mm × 7 mm enhancing lesion in the right temporal lobe without locoregional recurrence, and TLN was diagnosed. The lesion was near the watershed area between the anterior temporal and temporo-occipital arteries. The volume of the necrotic lesion was 0.51 c.c., and the mean dose and Dmax of the lesion were 64.4 Gy and 73.7 Gy, respectively. Additionally, the mean dose, V45, D1 c.c. (dose to 1 ml of the temporal lobe volume), D0.5 c.c. and Dmax of the right and left temporal lobes were 11.1 Gy and 11.4 Gy, 8.5 c.c. and 6.7 c.c., 70.1 Gy and 67.1 Gy, 72.0 Gy and 68.8 Gy, and 74.2 Gy and 72.1 Gy, respectively. Conclusion. Spotted TLN in patients with NPC treated by IGRT may be difficult to diagnose due to a lack of clinical symptoms and radiological signs. Endothelial damage may occur in carotid and vertebral arteries within the irradiated area, affecting the small branches supplying the temporal lobe and inducing spotted TLN. Future research on the relationship between vessels and RT or CCRT and the development of TLN is warranted.

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

Background

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

Material and Methods

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

Results

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

Conclusion

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

Adverse Radiation Therapy Effects in the Treatment of Head and Neck Tumors

Whether used as a single modality or as part of a combined approach, radiation therapy (RT) plays an essential role in the treatment of several head and neck malignancies. Despite the improvement in radiation delivery techniques, normal structures in the vicinity of the target area remain susceptible to a wide range of adverse effects. Given their high incidence, some of these effects are referred to as expected postradiation changes (eg, mucositis, sialadenitis, and edema), while others are considered true complications, meaning they should not be expected and can even represent life-threatening conditions (eg, radionecrosis, fistulas, and radiation-induced neoplasms). Also, according to their timing of onset, these deleterious effects can be divided into four groups: acute (during RT), subacute (within weeks to months), delayed onset (within months to years), and very delayed onset (after several years).The authors provide a comprehensive review of the most important radiation-induced changes related to distinct head and neck sites, focusing on their typical cross-sectional imaging features and correlating them with the time elapsed after treatment. Radiologists should not only be familiar with these imaging findings but also actively seek essential clinical data at the time of interpretation (including knowledge of the RT dose and time, target site, and manifesting symptoms) to better recognize imaging findings, avoid pitfalls and help guide appropriate management. ^© RSNA, 2022.

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

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

Imaging of the Chest After Radiotherapy and Potential Pitfalls

Radiotherapy is one of the cornerstones for the treatment of thoracic malignancies. The goal of radiotherapy is to deliver maximal dose to the tumor while minimizing damage to surrounding normal anatomical structures. Although advances in radiotherapy technology have considerably improved radiation delivery, potential adverse effects are still common. Post radiation changes to the chest may include different structures such as the lung, heart, great vessels, and esophagus. The purpose of this manuscript is to illustrate the post radiotherapy changes to these anatomical structures resulting from external beam radiotherapy, as well as discuss imaging pitfalls to prevent radiologist's interpretation errors.

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.

Reduction of Elective Radiotherapy Treatment Volume in Definitive Treatment of Locally Advanced Head and Neck Cancer-Comparison of a Prospective Trial with a Revised Simulated Contouring Approach

Definitive radiochemotherapy of locally advanced head and neck squamous cell cancer (HNSCC) achieves high locoregional tumor control rates; but is frequently associated with long-term toxicity. A future direction could be a de-escalation strategy focusing on treated volume rather than radiotherapy dose. This analysis evaluates radiotherapy dose and volume parameters of patients treated with a standard contouring approach in a clinical trial context compared with a revised volume-reduced contouring approach. In this case, 30 consecutive patients from the CheckRad-CD8 trial treated at a single study center were included in this analysis. Treatment toxicity and quality of life were assessed at the end of radiotherapy. Standard treatment plans (ST) following state of the art contouring guidelines that were used for patient treatment and volume reduced treatment plans (VRT) according to a revised simulated approach were calculated for each patient. Planning target volumes (PTV) and mean doses to 38 organs-at-risk structures were compared. At the end of radiotherapy patients reported high rates of mucositis; dysphagia and xerostomia. In addition; patient reported quality of life as assessed by the EORTC QLQ-HN35 questionnaire deteriorated. Comparing the two contouring approaches; the elective PTV_56 Gy and the high risk PTV_63 Gy (shrinking field) were significantly smaller in the VRT group. Significant reduction of mean dose to structures of the oral cavity; the larynx as well as part of the swallowing muscles and the submandibular glands was achieved in the simulated VRT-plan. Treatment de-intensification by reduction of the irradiated volume could potentially reduce treatment volume and mean doses to organs at risk. The proposed contouring approach should be studied further in the context of a clinical trial.

Percutaneous transluminal angioplasty and stenting of post-irradiated stenosis of subclavian artery

BACKGROUND/PURPOSE

The therapeutic efficacy of percutaneous transluminal angioplasty and stenting (PTAS) of post-irradiated stenosis of subclavian artery (PISSA) was not well clarified. This retrospective study was designed to evaluate the technical safety and outcome of the patients of severe symptomatic PISSA accepted PTAS.

METHODS

Between 2000 and 2019, 16 cases with 17 lesions of symptomatic and medically refractory PISSA accepted PTAS were included. We evaluated their technical success, peri-procedural complications and diffusion-weight imaging (DWI) of brain magnetic resonance imaging (MRI), results of symptom relief, and long-term stent patency.

RESULTS

The stenosis of the 17 stenotic lesions were 81.2 ± 11.1%. The most common symptom of the 16 patients was dizziness (14/16, 87.5%). All successfully accepted PTAS without neurological complication and had symptom relief after PTAS (17/17, 100%). Of the 12 patients accepted pre-procedural and early post-procedural MRI follow-up, 2 patients had an asymptomatic tiny acute embolic infarct in the territory of vertebrobasilar system. In a 51.9 ± 54.9 months follow-up, all patients had no severe restenosis and no recurrent vertebrobasilar ischemic symptoms.

CONCLUSION

For patients with PISSA and medically refractory ischemic symptoms, PTAS can be an effective alternative management.

Black tea is more effective than green tea in prevention of radiation-induced oxidative stress in the aorta of rats

In the work, the effect of black tea on oxidative stress induced in the aorta by irradiation was studied. The efficiency of black and green tea types was compared, and the effect of the main green tea components (-)-epigallocatechin galate (EGCG) and (-)-epigallocatechin (EGC) on the aorta was studied. The activity of ACE in rat aorta segments was determined by measuring the hydrolysis of hippuryl-L-histidyl-L-leucine, and the production of ROS was estimated from the oxidation of dichlorodihydrofluorescein. Black tea prevented the radiation-induced activation of the ACE and suppressed increased ROS production in the aorta of irradiated rats. The IC₅₀ value for the suppression of the irradiation-induced increase in ACE activity is 1 ml of black tea brewed at a rate of 0.17 g/100 ml. Black tea is 12 times more effective than green tea. The administration of both catechin derivatives from green tea to rats leads to an increase in the activity of ACE and the formation of ROS in the aorta. The dose that provided half maximum activation of ACE (EC₅₀) on intraperitoneal (i. p.) injection of galloylated catechins was found to be the same, 0.06-0.07 μg/kg of body weight. Upon intragastric gavage of EGCG, the EC₅₀ value was by one order of magnitude higher, 0.8 μg/kg. Black tea was more effective than green tea in prevention a radiation-induced increase of ACE activity and oxidative stress in the aorta. This difference was explained by a low content of galloylated catechins in black tea.

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.

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.

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.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Vascular events from carotid artery atherosclerosis after radiation therapy for laryngeal and hypopharyngeal cancer: the incidence and risk factors

In this retrospective cohort study, we evaluated the incidence of vascular events from carotid artery atherosclerosis after radiotherapy indication for laryngeal and hypopharyngeal cancer. From January 2007 to December 2016, we investigated 111 laryngeal/hypopharyngeal cancer patients who underwent curative radiotherapy and were followed up for ≥1 year (median follow-up duration, 60 months). We evaluated the incidence of vascular events from carotid artery atherosclerosis, defined as a transient ischemic attack or an atherothrombotic cerebral infarction, or from undergoing treatment such as carotid artery stenting for carotid artery stenosis. The median radiation dose was 66 Gy (range, 60–74); 48 patients (43.2%) received concurrent chemotherapy. The 5-year overall survival was 86.2%. Six patients required treatment for carotid artery disease. Carotid stenting was performed in three patients with carotid artery stenosis; three patients developed atherosclerotic cerebral infarction and received medical treatment, with a median of 51.7 months (range, 0.3–78.3) after radiotherapy initiation. The vascular event occurrence rate was 5.4% within 5 years and 10.7% within 8 years. In the univariate analysis, dyslipidemia, diabetes mellitus, and carotid calcification were significant factors for event occurrence. Because three out of six cases occurred out of the irradiated field, no carotid artery or carotid bulb dosimetric parameters showed significant correlation. As laryngeal/hypopharyngeal cancer patients, particularly with complications including dyslipidemia and diabetes mellitus, are at a high risk of carotid artery stenosis after radiotherapy, long-term carotid artery evaluation is necessary. Early intervention by stroke specialists can reduce the risk of fatal cerebral infarction.

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.

Limb-Shaking Transient Ischemic Attacks in a Patient with Previous Bilateral Neck Irradiation: The Role of Collateral Flow

Nasopharyngeal carcinoma (NPC) is commonly treated with bilateral neck radiation, which is closely associated with the complication of carotid-occlusive disease. This leads to cerebral hemodynamic compromise and possible ischemic stroke. Another manifestation is limb-shaking transient ischemic attacks (LS-TIAs), characterized by rhythmic jerks which can be easily mistaken as a focal motor seizure. We describe a case of unilateral LS-TIAs from bilateral carotid occlusion that resolved with contralateral carotid revascularization. Our patient is a 65-year-old gentleman who had no significant co-morbidities other than a past history of bilateral neck irradiation for NPC 8 years before. He presented with left-sided limb weakness and subsequently left-sided limb involuntary movements whenever he sat up or stood. His symptoms did not respond to anti-epileptic therapy. Clinical and neurological examination was significant for a left pronator drift and weak left finger abduction. Computed tomography and magnetic resonance imaging of the brain revealed infarcts in the right periventricular and watershed areas; MR angiogram showed bilateral internal carotid artery occlusion. Single photon emission computed tomography showed reduced blood flow in the right frontal, temporal, and parietal regions, that reduced further after acetazolamide challenge. He was diagnosed as having LS-TIA secondary to carotid-occlusive disease. Attempts at endovascular opening the right internal carotid artery failed. Following successful left carotid angioplasty and stenting, his symptoms gradually resolved. The left internal carotid artery remained patent at the 3-month follow-up; the right side remained occluded. Our case supports the hypothesis that LS-TIAs are due to hemodynamic compromise and may respond to improved collateral cerebral blood flow.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

International Guideline on Dose Prioritization and Acceptance Criteria in Radiation Therapy Planning for Nasopharyngeal Carcinoma

PURPOSE

The treatment of nasopharyngeal carcinoma requires high radiation doses. The balance of the risks of local recurrence owing to inadequate tumor coverage versus the potential damage to the adjacent organs at risk (OARs) is of critical importance. With advancements in technology, high target conformality is possible. Nonetheless, to achieve the best possible dose distribution, optimal setting of dose targets and dose prioritization for tumor volumes and various OARs is fundamental. Radiation doses should always be guided by the As Low As Reasonably Practicable principle. There are marked variations in practice. This study aimed to develop a guideline to serve as a global practical reference.

METHODS AND MATERIALS

A literature search on dose tolerances and normal-tissue complications after treatment for nasopharyngeal carcinoma was conducted. In addition, published guidelines and protocols on dose prioritization and constraints were reviewed. A text document and preliminary set of variants was circulated to a panel of international experts with publications or extensive experience in the field. An anonymized voting process was conducted to rank the proposed variants. A summary of the initial voting and different opinions expressed by members were then recirculated to the whole panel for review and reconsideration. Based on the comments of the panel, a refined second proposal was recirculated to the same panel. The current guideline was based on majority voting after repeated iteration for final agreement.

RESULTS

Variation in opinion among international experts was repeatedly iterated to develop a guideline describing appropriate dose prioritization and constraints. The percentage of final agreement on the recommended parameters and alternative views is shown. The rationale for the recommendations and the limitations of current evidence are discussed.

CONCLUSIONS

Through this comprehensive review of available evidence and interactive exchange of vast experience by international experts, a guideline was developed to provide a practical reference for setting dose prioritization and acceptance criteria for tumor volumes and OARs. The final decision on the treatment prescription should be based on the individual clinical situation and the patient's acceptance of optimal balance of risk.

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.

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

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

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.

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.

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Calcified carotid artery atheromas on panoramic radiographs of head and neck cancer patients before and after radiotherapy

Background

The aims of this study were to verify if head and neck radiotherapy (RT) is able to induce calcified carotid artery atheroma (CCAA) in a large head and neck cancer (HNC) population and also to compare the socio-demographic and clinical findings of patients with and without CCAA detected on panoramic radiographs.

Material and Methods

Panoramic radiographs taken before and after head and neck radiotherapy (RT) of 180 HNC patients were selected and analyzed in order to identify the presence of CCAA. In addition, CCAA presence or absence on panoramic radiographs were compared and correlated with clinicopathological findings.

Results

A high overall prevalence of CCAA was found on panoramic radiographs (63 out of 180 = 35%) of HNC patients. No significant difference of CCAA before and after RT was observed. There were also no differences between groups (with and without CCAA) regarding age, gender, tobacco and alcohol use, arterial hypertension, diabetes mellitus, acute myocardial infarction, hypercholesterolemia, tumor location, clinical stage of disease and RT dose. However, there was a greater prevalence of strokes in patients with CCAA (p<0.05).

Conclusions

Although CCAA were frequently found in panoramic radiographs of patients with HNC, RT seems not to alter the prevalence of these calcifications.

Key words:Head and neck cancer, radiotherapy, carotid artery diseases, panoramic radiography.

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

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

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

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

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.

SCAI Expert consensus statement: Evaluation, management, and special considerations of cardio-oncology patients in the cardiac catheterization laboratory (endorsed by the cardiological society of india, and sociedad Latino Americana de Cardiologıa intervencionista)

In the United States alone, there are currently approximately 14.5 million cancer survivors, and this number is expected to increase to 20 million by 2020. Cancer therapies can cause significant injury to the vasculature, resulting in angina, acute coronary syndromes (ACS), stroke, critical limb ischemia, arrhythmias, and heart failure, independently from the direct myocardial or pericardial damage from the malignancy itself. Consequently, the need for invasive evaluation and management in the cardiac catheterization laboratory (CCL) for such patients has been increasing. In recognition of the need for a document on special considerations for cancer patients in the CCL, the Society for Cardiovascular Angiography and Interventions (SCAI) commissioned a consensus group to provide recommendations based on the published medical literature and on the expertise of operators with accumulated experience in the cardiac catheterization of cancer patients.

Radiation Effects in the Mediastinum and Surroundings: Imaging Findings and Complications

Radiotherapy is one of the cornerstones for treatment of patients with cancer. Although advances in radiotherapy technology have considerably improved radiation delivery, potential adverse effects are still common. Postradiation changes to the mediastinum can include different structures such as the heart, great vessels, and esophagus. The purpose of the article was to illustrate the expected variety of changes to the mediastinum and adjacent lung resulting from external beam radiotherapy and radiotherapy-induced complications to the mediastinum and to discuss different radiotherapy delivery techniques.

Radiation-related heart and vascular disease

Improvement in cancer therapy has led to increasing number of cancer survivors, some of whom have previously been treated with mediastinal radiation. Cardiac complication may manifest years after completion of radiation therapy. Hence long-term follow-up is essential in these patients. In this paper, we have discussed the short- and long-term cardiovascular side effects of radiation therapy.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

ADVANCES IN KNOWLEDGE

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

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

Background

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

Methods

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

Results

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

Conclusions

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