Detection of radiation-induced, accelerated atherosclerosis in patients with osteoradionecrosis by panoramic radiography

Incidental findings in cone beam computed tomography volumes: Calcified head-and-neck atheromas detected during dental evaluation

PURPOSE

Atheromas can be detected incidentally in routine dental cone beam computed tomography (CBCT) images. This study aims to assess prevalence and risk factors associated with these vascular lesions.

MATERIALS AND METHODS

The maxillofacial CBCTs of 458 subjects were evaluated and divided into 4 groups based on the presence of calcified atheroma: subjects with no calcified atheroma, subjects with intracranial calcified atheroma (ICA), subjects with extracranial calcified atheroma (ECA), and subjects exhibiting combined lesions. Age, sex, medical conditions, family history, and size were documented. Analysis of variance followed by a multiple comparison test was used for data satisfying parametric test assumptions. Chi-squared tests were used to assess categorical data. The Spearman Rho test was used to assess the correlation between the incidence of calcified atheroma and subjects' medical condition.

RESULTS

Of the 458 CBCTs evaluated, 29.90% presented with calcified atheroma. Calcified atheroma prevalence was significantly higher in older patients versus younger patients (p = 0.004) and in males compared to females (p = 0.004). Males were more likely to have the combination of ICA and ECA, whereas females were more likely to have ICA alone (p ≤ 0.040). Patients with calcified atheroma were significantly more likely to have a history of hyperlipidemia (p = 0.001), hypertension (p = 0.001), and myocardial infarction/coronary artery diseases (p = 0.001). Overall, patients exhibiting both intracranial and extracranial lesions were more likely to have cardiovascular risk factors (p = 0.001).

CONCLUSION

Incidentally detected calcified atheromas in CBCTs are common. Subjects with combined atheroma lesions are at higher risk for cardiovascular disease. The diagnosis of incidental calcified atheromas in CBCT's warrants early referral to medical specialists, especially if there is no medical history of existing cardiovascular disease.

Head and neck radiotherapy-induced changes in dentomaxillofacial structures detected on panoramic radiographs: A systematic review

Purpose

This study aimed to summarize the impact of neck and head radiation treatment on maxillofacial structures detected on panoramic radiographs.

Materials and Methods

In this systematic review, the authors searched PubMed Central, Embase, Scopus, Cochrane Central Register of Controlled Trials, Web of Science, and Google Scholar for original research studies up to February 2020 that included the following Medical Subject Headings keywords: words related to “radiotherapy” and synonyms combined with keywords related to “panoramic radiography” and “oral diagnosis” and synonyms. Only original studies in English that investigated the maxillofacial effects of radiotherapy via panoramic radiographs were included. The quality of the selected manuscripts was evaluated by assessing the risk of bias using Cochrane's ROBINS-I tool for non-randomized studies.

Results

Thirty-three studies were eligible and included in this review. The main objectives pertained to the assessment of the effects of radiation on maxillofacial structures, including bone architecture alterations, periodontal space widening, teeth development abnormalities, osteoradionecrosis, and implant bone loss. The number of participants evaluated ranged from 8 to 176.

Conclusion

The interaction between ionizing radiation and maxillofacial structures results in hazard to the tissues involved, particularly the bone tissue, periosteum, connective tissue of the mucosa, and endothelium. Hard tissue changes due to radiation therapy can be detected on panoramic radiographs.

Challenges in Microsurgical Reconstruction for Craniofacial Osteomyelitis With Resultant Osteonecrosis

INTRODUCTION

Chronic osteomyelitis is characterized by compromised blood supply and eventual osteonecrosis. Definitive treatment requires aggressive resection of affected bone. The resultant defect poses a unique challenge to reconstructive surgeons. Much of the literature on craniofacial osteomyelitis focuses on infection eradication, rather than subsequent reconstruction. This article reports representative cases from our experience with free flap reconstruction for defects secondary to chronic osteomyelitis of the craniofacial skeleton.

METHODS/RESULTS

The authors selected 5 of the most difficult reconstructive cases of craniofacial osteomyelitis from our experience in a single tertiary referral institution with a follow-up of at least 6 months. Three of the 5 cases arose in the setting of previous head and neck cancer treated with resection and radiation therapy. One case had a previous surgical craniotomy complicated by osteomyelitis and multiple failed alloplastic reconstructions. The final case was due to multiple gunshots to the head, with subsequent cerebral and cranial abscess (>1000cc). In each case, the defect was successfully treated with free tissue transfer. Two cases required creation of recipient vessels with an arteriovenous loop.

CONCLUSIONS

Free tissue transfer provides a versatile and effective tool in the reconstruction of extensive craniofacial osteomyelitis defects. Furthermore, the addition of vascularized tissue can protect against further episodes of osteomyelitis. Finally, arteriovenous loops can be employed successfully when prior radiation and infection of the wound bed precludes the use of local recipient target vessels.

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.

Fibular flap for mandible reconstruction in osteoradionecrosis of the jaw: selection criteria of fibula flap

BACKGROUND

Osteoradionecrosis is the most dreadful complication after head and neck irradiation. Orocutaneous fistula makes patients difficult to eat food. Fibular free flap is the choice of the flap for mandibular reconstruction. Osteocutaneous flap can reconstruct both hard and soft tissues simultaneously. This study was to investigate the success rate and results of the free fibular flap for osteoradionecrosis of the mandible and which side of the flap should be harvested for better reconstruction.

METHODS

A total of eight consecutive patients who underwent fibula reconstruction due to jaw necrosis from March 2008 to December 2015 were included in this study. Patients were classified according to stages, primary sites, radiation dose, survival, and quality of life.

RESULTS

Five male and three female patients underwent operation. The mean age of the patients was 60.1 years old. Two male patients died of recurred disease of oral squamous cell carcinoma. The mean dose of radiation was 70.5 Gy. All fibular free flaps were survived. Five patients could eat normal diet after operation; however, three patients could eat only soft diet due to loss of teeth. Five patients reported no change of speech after operation, two reported worse speech ability, and one patient reported improved speech after operation. The ipsilateral side of the fibular flap was used when intraoral soft tissue defect with proximal side of the vascular pedicle is required. The contralateral side of the fibular flap was used when extraoral skin defect with proximal side of the vascular pedicle is required.

CONCLUSIONS

Osteonecrosis of the jaw is hard to treat because of poor healing process and lack of vascularity. Free fibular flap is the choice of the surgery for jaw bone reconstruction and soft tissue fistula repair. The design and selection of the right or left fibular is dependent on the available vascular pedicle and soft tissue defect sites.

Radiation-induced carotid artery atherosclerosis

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Diagnosis and management of calcified carotid artery atheroma: dental perspectives

The calcification of cervical carotid artery atheroma (CCAA) represents maturation of a lumenal atherosclerotic plaque that has been associated with a high risk of cerebral stroke. The demonstration of CCAA on rotational panoramic images has received increasing attention in dentistry since it was first described in 1981. The purposes of this article are to provide a background to the mechanism of arterial calcification, to review the clinical diagnostic and management algorithms for dental practitioners when CCAA are identified radiologically, and to describe and illustrate current appropriate radiographic modalities and medical management strategies used to confirm and assess stenosis associated with CCAA.

Radiation-associated carotid artery atherosclerosis: case report and review of contemporaneous literature

Radiation therapy (RT) is a component of the treatment of patients with head and neck malignancies. This therapy may damage the nearby carotid arteries, thereby initiating or accelerating the atherosclerotic process (atheroma formation). Dentists treating patients who have been irradiated should examine the patient's panoramic radiograph for evidence of atheroma-like calcifications, which appear 1.5 to 2.5 cm posterior and inferior to the angle of the mandible. Patients with evidence of such lesions should be referred to their primary care physician with the suggestion that an ultrasound examination of the carotid arteries is indicated.

Calcified carotid artery atheroma and stroke: a systematic review

BACKGROUND

Calcified carotid artery atheroma (CCAA) and its identification on panoramic radiographs have been advocated as a predictor of a cerebrovascular accident (CVA).

TYPES OF STUDIES REVIEWED

The authors conducted an electronic search using 11 databases to evaluate the evidence from the literature that links CCAA detection on panoramic radiographs and the precipitation of CVAs among those people. They used the Reporting Recommendations for Tumor Marker Prognostic Studies (REMARK) checklist to perform this systematic review.

RESULTS

One study of the 54 studies the authors identified satisfied the REMARK criteria in which CCAA was associated with a negligible increased risk of stroke (95 percent confidence interval, 0 to 0.04 percent) in the population studied.

CLINICAL IMPLICATIONS

This systematic review suggests the data supporting the hypothesis that radiographically detectable CCAA is associated with an increased risk of stroke are incomplete and inconclusive. Further research is needed, as clinical guidelines for risk prediction using panoramic radiographs cannot be established on the basis of the current evidence.

Carotid artery calcification seen on panoramic dental radiographs in the Asian population in Japan

OBJECTIVES

To determine the frequency of carotid artery calcification (CAC) seen on panoramic dental radiographs, the relationship between the condition and a history of cerebral infarction (CI), and the history of the risk factors of CI in patients in Japan.

METHODS

A total of 2374 individuals whose panoramic radiographs were obtained at their first consultation were reviewed.

RESULT

CAC was found in 95 subjects (4.0%) and was found at a higher frequency in patients with a history of CI than in those without a history of CI. The modifiable risk factors (a history of hypertension, diabetes and hypercholesterolaemia) and CAC showed significant relationship in the chi(2) test for pairwise comparison. When age and gender were added and all of these risk factors were considered simultaneously in the multiple logistic regression analysis, age and history of hypercholesterolaemia remained statistically significant.

CONCLUSIONS

CAC may be seen on panoramic dental radiographs and is related to the patients' general history of CI, and the risk factors of CI in the Asian population in Japan.

Radiation dose to the internal pudendal arteries from permanent-seed prostate brachytherapy as determined by time-of-flight MR angiography

PURPOSE

To determine the feasibility of time-of-flight magnetic resonance (MR) angiography to visualize the internal pudendal arteries (IPAs) in potent men undergoing permanent-seed prostate brachytherapy and to calculate the radiation dose received by these arteries.

METHODS AND MATERIALS

Prostate brachytherapy is performed at the University Health Network/Princess Margaret Hospital by use of transrectal ultrasound (TRUS) preplanning and preloaded needles. All patients received (125)I, with a mean seed activity of 0.32 mCi/seed (0.41 U). Postplan evaluation is performed at 1 month by magnetic resonance-computed tomography fusion. Twenty consecutive potent men had time-of-flight MR angiography as part of their postplan evaluation.

RESULTS

The mean V100 was 96.5%, and the mean D90 was171.5 Gy. The IPAs were easily visualized for 18 of the 20 men. The mean peak dose received by the IPA was 17 Gy. The highest peak dose received by any patient was 38.2 Gy, with only 1 other patient receiving a peak dose greater than 30 Gy. Eleven of 18 had a measurable portion of at least 1 IPA that received 10% of the prescribed dose (V10 = 14.5 Gy). Only 2 patients had nonzero values for V25. The distal third of the IPA received the highest dose for 16 of the 18 patients.

CONCLUSIONS

The IPAs can be well visualized in the majority of potent men by use of time-of-flight MR angiography 1 month after brachytherapy. The IPAs receive a low but calculable dose from permanent-seed (125)I brachytherapy. Further research is needed to determine if this outcome has any correlation with subsequent potency.

Carotid artery calcification detected on panoramic radiographs in a group of Thai population

OBJECTIVE

To determine the prevalence of carotid artery calcification (CAC) detected on panoramic radiographs in a Thai population.

STUDY DESIGN

The panoramic radiographs of the patients 50 and older (N = 1,370) visiting Mahidol University from January 1998 through September 2004 were retrospectively reviewed for CAC. The medical records of the positive subjects were then reviewed.

RESULTS

Thirty-four (2.5%) of the 1,370 patients, 16 men and 18 women, with a mean age of 69 and a range of 50 to 87 years, had 1 or more CACs. These calcifications were unilateral in 25 (73.5%) and bilateral in 9 (26.5%) subjects. Of those positive subjects, 18 reported hypertension, 10 reported diabetes mellitus, and 5 reported hyperlipidemia.

CONCLUSIONS

Although it is uncommon to find CAC in the Thai population, dentists should be aware of this calcification on the routine panoramic radiographs and promptly refer for cerebrovascular and cardiovascular evaluation.

Vessel-sparing prostate radiotherapy: Dose limitation to critical erectile vascular structures (internal pudendal artery and corpus cavernosum) defined by MRI

PURPOSE

Most evidence suggests that impotence after prostate radiation therapy has a vascular etiology. The corpus cavernosum (CC) and the internal pudendal artery (IPA) are the critical vascular structures related to erectile function. This study suggests that it is feasible to markedly decrease radiation dose to the CC and the IPA and directly determine the impact of dose limitation on potency.

METHODS AND MATERIALS

Twenty-five patients (10 external beam, 15 brachytherapy) underwent MRI/CT-based treatment planning for prostate cancer. In addition, 10 patients entered on the vessel-sparing protocol underwent a time-of-flight MRI angiography sequence to define the IPA. The distance from the MRI-defined prostate apex to the penile bulb (PB), CC, and IPA was measured and compared to the distance from the CT-defined apex. Doses (D5 and D50) to the PB, CC, and IPA were determined for an 80 Gy external beam course. In 5 patients, CT plans were generated and compared to MRI-based plans.

RESULTS

The combination of coronal, sagittal, and axial MRI data sets allowed superior definition of the prostate apex and its relationship to critical vascular structures. The apex to PB distance averaged 1.45 cm (0.36 standard deviation) with a range of 0.7 cm to 2.1 cm. Peak dose (D5) to the proximal CC in the MRI-planned 80 Gy course was 26 (9) Gy (0.36 of CT-planned dose), and peak dose to the IPA was 39 (13) Gy (0.61 of CT-planned dose).

CONCLUSION

The distance between the prostate apex and critical vascular structures is highly variable. Current empiric rules for CT contouring (apex 1.5 cm above PB) overestimate or underestimate the distance between the prostate apex and critical vascular structures. When defined by MRI T2 and MRI angiogram with CT registration, limitation of dose to critical erectile structures is possible, with a more significant gain than has been previously reported using dose limitation by commonly applied intensity modulated radiation therapy studies based on CT imaging. These techniques make "vessel-sparing" prostate radiotherapy feasible.

Effects of gamma radiation on the noninjured and unprotected left main

The aim of this study was to evaluate the effect of gamma radiation on the noninjured, unprotected left main coronary artery. Noninjured vessel segments are often radiated during treatment of in-stent restenosis with PCI and gamma radiation. Angiographic analysis using QCA methods was performed on 55 left main arteries of patients (32 with radiation of the left main compared to 23 controls) who participated in the Washington Radiation for In-Stent Restenosis Trials (WRIST). Baseline demographics and follow-up were comparable between the two groups, concluding that gamma radiation with long radiation safety margins is feasible and safe. Gamma radiation of noninjured irradiated left main vessels when used to facilitate wide radiation margins for proximal irradiated injured LAD and LCx is safe and does not compromise the vessel integrity and its lumen.

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

BACKGROUND

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

TYPE OF STUDIES REVIEWED

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

RESULTS

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

CLINICAL IMPLICATIONS

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

Reconstructive options in the treatment of osteoradionecrosis of the craniomaxillofacial skeleton

Osteoradionecrosis (ORN) of the craniomaxillofacial skeleton is a serious and debilitating complication that can occur following radiation therapy in the head and neck. Patients require effective treatment, which eradicates diseased tissue and restores function with minimal additional morbidity in a single stage, a requirement fulfilled in many cases by free tissue transfer. In a 6-year period from 1994 to 1999, 21 patients with ORN were treated by wide resection and free-flap reconstruction. The median interval between radiation therapy and ORN was 4 years (range: 1-33 years). The median radiation dose was 6000cGy. The affected areas were the mandible (15 patients), the temporal bone (three patients), the maxilla (one patient), the cervical vertebrae (one patient) and the frontal bone (one patient). Clinical symptoms included pain, ulceration, a persistent draining fistula, exposure of bone or hardware, and pathological fracture or non-union of bone. Six patients had had previous unsuccessful attempts at conservative surgical resection. Ten patients had preoperative hyperbaric oxygen (HBO) therapy. A number of different flaps were used for reconstruction in these patients. These included free fibula flaps (13 patients), iliac crest flaps (two patients), scapula flaps (three patients) and rectus abdominis flaps (three patients). All patients achieved relief from their presenting symptoms and primary bone or wound healing. One flap (4.8%) was lost. This was successfully reconstructed in a subsequent procedure. There were three flap re-explorations, two for arterial thrombosis and one for venous thrombosis. Conservative measures, such as limited debridement and HBO therapy, may be effective in preventing the progression of ORN. However, they fail to eradicate established ORN, which requires radical surgical resection followed by functional reconstruction with well-vascularised tissue.

Three-dimensional intravascular ultrasound assessment of noninjured edges of beta-irradiated coronary segments

BACKGROUND

The "edge effect," late lumen loss at the margins of the treated segment, has become an important issue in the field of coronary brachytherapy. The aim of the present study was to assess the edge effect in noninjured margins adjacent to the irradiated segments after catheter-based intracoronary beta-irradiation.

METHODS AND RESULTS

Fifty-three vessels were assessed by means of 3-dimensional intravascular ultrasound after the procedure and at 6- to 8-month follow-up. Fourteen vessels (placebo group) did not receive radiation (sham source), whereas 39 vessels were irradiated. In the irradiated group, 48 edges (5 mm in length) were identified as noninjured, whereas 18 noninjured edges were selected in the placebo group. We compared the volumetric intravascular ultrasound measurements of the noninjured edges of the irradiated vessels with the fully irradiated nonstented segments (IRS, n=27) (26-mm segments received the prescribed 100% isodose) and the noninjured edges of the vessels of the placebo patients. The lumen decreased (6 mm(3)) in the noninjured edges of the irradiated vessels at follow-up (P:=0. 001). We observed a similar increase in plaque volume in all segments: noninjured edges of the irradiated group (19.6%), noninjured edges of the placebo group (21.5%), and IRS (21.0%). The total vessel volume increased in the IRS in the 3 groups. No edge segment was subject to repeat revascularization.

CONCLUSIONS

The edge effect occurs in the noninjured margins of radiation source train in both irradiated and placebo patients. Thus, low-dose radiation may not play an important role in this phenomenon, whereas nonmeasurable device injury may be considered a plausible alternative explanation.

Detection of radiation-induced cervical atheromas by panoramic radiography

Therapeutic irradiation of the neck is frequently used to treat patients with head and neck carcinoma. The irradiation, however, has been implicated as the cause of cervical carotid artery atherosclerotic lesions and subsequent stroke. Panoramic radiography previously shown capable of demonstrating isolated lesions was used to assess their development over time. Individuals with a pre-irradiation radiograph free of atheromas were enrolled for study. The prevalence rate of atheroma formation on post-irradiation (bilateral portals at >/=45 Gy) radiographs obtained at an interval of >/=36 months was determined. A control group of non-irradiated patients having similar risk factors for head and neck carcinoma and atherosclerosis and having an initial radiograph free of atheroma formation were likewise enrolled for study. The prevalence rate of atheroma formation on a second radiograph obtained from these individuals at an interval of >/=36 months was determined. The study population consisted of 17 patients, with a mean age of 56.5 (range 21.5-77.8) years who received a mean therapeutic irradiation dose of 53.2 Gy (range 45-71) to each side of their neck. The prevalence rate of atheromas manifested on the post-irradiation radiographs was 53%. These radiographs were obtained, on average, 69.7 (range 37-133) months after completion of radiation therapy. The prevalence rate of atheromas manifested on the second radiograph of patients in the control group was 5.9%. These radiographs were obtained, on average, 53.5 (range 52-55) months after the first. The difference in prevalence rates was statistically significant (p=0.0003). Individuals who have received therapeutic irradiation to the neck are more likely to develop carotid artery atheromas after treatment than are risk-matched control patients who have not been irradiated. These lesions can be detected by panoramic radiography.