Imaging of the Head and Neck following Radiation Treatment

The Clinical Outcome of Carotid Blowout Syndrome Showing Non-bleeding Angiography

OBJECTIVE

Patient with carotid blowout syndrome (CBS) may demonstrated non-bleeding digital subtraction angiography (DSA) without identifying pseudoaneurysm or contrast extravasation. Our objective is to evaluate the clinical outcomes for this specific subset of patients.

MATERIALS AND METHODS

A retrospective observational study was conducted on 172 CBS patients who received DSA for evaluation of transarterial embolization (TAE) between 2005 and 2022, of whom 19 patients had non-bleeding DSA and did not undergo TAE.

RESULTS

The age (55.2 ± 7.3 vs. 54.8 ± 11.1), male sex (17/19 vs. 135/153), tumor size (5.6 ± 2.4 vs. 5.2 ± 2.2), cancer locations were similar (P > 0.05) between both groups; except for there were more pseudoaneurysm/active bleeding (85.6% vs. 0%) and less vascular irregularity (14.4% vs. 94.7%) in the TAE group (P < 0.001). In the multivariable Cox regression model adjusting for age, sex, and tumor size, non-bleeding DSA group was independently associated with recurrent bleeding compared to TAE group (adjusted hazard ratio = 3.5, 95% confidence interval: 1.9-6.4, P < 0.001). Furthermore, the presence of vascular irregularity was associated with segmental recurrent bleeding (adjusted HR = 8.0, 95% CI 2.7-23.3, P < 0.001).

CONCLUSION

Patient showing non-bleeding DSA thus not having TAE had higher risk of recurrent bleeding, compared to patient who received TAE. Level of Evidence Level 4, Case Series.

Imaging of Neck Nodes in Head and Neck Cancers - a Comprehensive Update

Cervical lymph node metastases from head and neck squamous cell cancers significantly reduce disease-free survival and worsen overall prognosis and, hence, deserve more aggressive management and follow-up. As per the eighth edition of the American Joint Committee on Cancer staging manual, extranodal extension, especially in human papillomavirus-negative cancers, has been incorporated in staging as it is important in deciding management and significantly impacts the outcome of head and neck squamous cell cancer. Lymph node imaging with various radiological modalities, including ultrasound, computed tomography and magnetic resonance imaging, has been widely used, not only to demonstrate nodal involvement but also for guided histopathological evaluation and therapeutic intervention. Computed tomography and magnetic resonance imaging, together with positron emission tomography, are used widely for the follow-up of treated patients. Finally, there is an emerging role for artificial intelligence in neck node imaging that has shown promising results, increasing the accuracy of detection of nodal involvement, especially normal-appearing nodes. The aim of this review is to provide a comprehensive overview of the diagnosis and management of involved neck nodes with a focus on sentinel node anatomy, pathogenesis, imaging correlates (including radiogenomics and artificial intelligence) and the role of image-guided interventions.

AS. Clival and Paraclival Lesions: A Pictorial Review

The clivus is a midline anatomical structure in the central skull base. It is affected by a wide range of non-neoplastic, benign and malignant pathologies, some of which typically affect the clivus because of its strategic location and embryological origins. Clival lesions may often be asymptomatic with occasional complaints like headache or cranial neuropathy in few. Cross-sectional imaging techniques, namely, computed tomographic scan and magnetic resonance imaging, thus, play a key role in approximating to the final diagnosis and estimating the disease extent. In this article, we highlight the important imaging features of various clival and paraclival pathologies to facilitate effective diagnosis, therapeutic planning, and management.

Air-containing necrosis as the imaging predictor for imminent carotid blowout in patients with head and neck cancer

BACKGROUND AND PURPOSE

Carotid blowout syndrome (CBS) is a devastating complication of head and neck cancer (HNC). In this study, we describe radiological features that can predict imminent (<6 months) carotid blowout in patients with HNC.

METHODS

Cross-sectional CT or MRI were interpreted from 25 treated HNC patients with acute CBS and 50 treated HNC patients without CBS (controls). The tumor size and the distance from the tumor to the carotid trunk was measured. The following imaging findings of the tumor were also recorded: carotid trunk involvement, enhancement pattern, and the presence of air-containing necrosis. The odds ratios of imminent CBS for each imaging finding were estimated using a multivariable logistic regression model.

RESULTS

Compared to the controls, the CBS group had larger tumors (49 ± 18 mm vs. 38 ± 18 mm, p = 0.017), tumors closer to the carotid trunk (0.5 ± 1.7 mm vs. 8.2 ± 14.2 mm, p < 0.001), a higher prevalence of 360° involvement (60% vs. 18%, p < 0.001), more heterogeneous enhancement patterns (84% vs. 50% p < 0.001), and more air-containing necrosis (40% vs. 2% p < 0.001). After multivariable adjustment, the presence of air-containing necrosis remained a significant risk factor for imminent CBS (OR: 20.1, 95% CI: 1.98-204.00; p = 0.011).

CONCLUSION

The presence of air-containing necrosis is associated with a higher risk of imminent CBS. This characteristic imaging finding should be evaluated in the follow-up CT or MRI of HNC patients for early warning.

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.

Recurrent Carotid artery blow out in a head & neck patient

Introduction and importance

Carotid artery blowout syndrome is a rare complication of head and neck cancer treatment. It defines a rupture of the carotid artery wall through vessel wall necrosis. This is typically precipitated by radiotherapy, direct tumour invasion, or a combination of these factors. We describe a rare case of three consecutive carotid artery blowouts in a head and neck cancer patient.

Case presentation

A 58-year-old man with a history of T3NO hypopharyngeal squamous cell carcinoma (SCC) treated with chemotherapy and radiation presented with a four-month history of progressive dysphagia and right sided neck pain. Flexible nasendoscopy revealed laryngeal oedema and slough. A panendoscopy and biopsy showed no evidence of tumour recurrence. The patient was discharged and represented with worsening dyspnoea. He subsequently experienced a large volume hemorrhage necessitating ligation of his right external carotid artery. He underwent pharyngolaryngectomy indicated due to the extent of laryngeal radiation necrosis. Thereafter he suffered two additional acute carotid bleeds from his right common carotid necessitating ligation in theatre.

Clinical discussion and conclusion

This case report illustrates the key issues to be considered in patients with locally advanced hypopharyngeal squamous cell carcinoma and subsequent management of acute carotid blowout syndrome, which without prompt management, can be fatal.

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Carotid artery rupture, or blowout, has a high morbidity and mortality.

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Carotid blowout is a rare consequence of head and neck cancer treatment.

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Radiotherapy is the main predisposing risk factor.

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Acute carotid blowout requires prompt resuscitation and bleeding source control.

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Definitive treatment includes endovascular occlusion, stenting or surgical ligation.

Diffusion-weighted and PET/MR Imaging after Radiation Therapy for Malignant Head and Neck Tumors

Interpreting imaging studies of the irradiated neck constitutes a challenge because of radiation therapy-induced tissue alterations, the variable appearances of recurrent tumors, and functional and metabolic phenomena that mimic disease. Therefore, morphologic magnetic resonance (MR) imaging, diffusion-weighted (DW) imaging, positron emission tomography with computed tomography (PET/CT), and software fusion of PET and MR imaging data sets are increasingly used to facilitate diagnosis in clinical practice. Because MR imaging and PET often yield complementary information, PET/MR imaging holds promise to facilitate differentiation of tumor recurrence from radiation therapy-induced changes and complications. This review focuses on clinical applications of DW and PET/MR imaging in the irradiated neck and discusses the added value of multiparametric imaging to solve diagnostic dilemmas. Radiologists should understand key features of radiation therapy-induced tissue alterations and potential complications seen at DW and PET/MR imaging, including edema, fibrosis, scar tissue, soft-tissue necrosis, bone and cartilage necrosis, cranial nerve palsy, and radiation therapy-induced arteriosclerosis, brain necrosis, and thyroid disorders. DW and PET/MR imaging also play a complementary role in detection of residual and recurrent disease. Interpretation pitfalls due to technical, functional, and metabolic phenomena should be recognized and avoided. Familiarity with DW and PET/MR imaging features of expected findings, potential complications, and treatment failure after radiation therapy increases diagnostic confidence when interpreting images of the irradiated neck. Online supplemental material is available for this article.

The Effects of Ionizing Radiation on the Oral Cavity

AIM

The aim of this study is to present a literature review on the effects of the ionizing radiation from radiotherapy treatment on dental tissues.

BACKGROUND

Among the effects of increasing global life expectancy and longevity of the teeth in the oral cavity, increasing rates of neoplastic diseases have been observed. One of the important treatment modalities for head and neck neoplastic diseases is radiotherapy, which uses ionizing radiation as the main mechanism of action. Therefore, it is essential for dentists to be aware of the changes in oral and dental tissues caused by ionizing radiation, and to develop treatment and prevention strategies.

RESULTS

In general, there is still controversy about the effects of ionizing radiation on dental structures. However, qualitative and quantitative changes in saliva and oral microbiota, presence of oral mucositis and radiation-related caries are expected, as they represent the well-known side effects of treatment with ionizing radiation. Points that still remain unclear are the effects of radiotherapy on enamel and dentin, and on their mechanisms of bonding to contemporary adhesive materials.

CONCLUSION

Ionizing radiation has shown important interaction with organic tissues, since more deleterious effects have been shown on the oral mucosa, salivary glands and dentin, than on enamel.

CLINICAL SIGNIFICANCE

With the increasing number of patients with cancer seeking dental treatment before and after head and neck radiotherapy, it is important for dentists to be aware of the effects of ionizing radiation on the oral cavity.

Superimposed infection in mandibular osteoradionecrosis: diagnosis and outcomes

BACKGROUND

Radiation therapy can result in osteoradionecrosis (ORN) and mucosal ulceration predisposing to infection.

METHODS

Fourteen patients presenting with infectious sequelae related to mandibular ORN were retrospectively reviewed.

RESULTS

In most patients, infection followed diagnosis of ORN; but in 4 patients, ORN was not diagnosed until after the time of infection and imaging. An early imaging finding of ORN was lingual cortical defects near the last molar. Pain followed by erythema, purulent drainage, and subperiosteal abscess by imaging were the most common signs of infection. In most patients, conservative management eventually failed and segmental mandibulectomies were required.

CONCLUSIONS

Soft tissue infection with characteristic bone findings such as subperiosteal abscess and cortical bone erosions helps to distinguish infected ORN from recurrent tumor or sterile ORN. In patients previously treated with radiation who present with infection, pain or an avid PET scan with bone involvement, the mandible should be scrutinized.