The role of radiology in head and neck tumours in children

Applications of Multimodal Artificial Intelligence in Non-Hodgkin Lymphoma B Cells

Given advancements in large-scale data and AI, integrating multimodal artificial intelligence into cancer research can enhance our understanding of tumor behavior by simultaneously processing diverse biomedical data types. In this review, we explore the potential of multimodal AI in comprehending B-cell non-Hodgkin lymphomas (B-NHLs). B-cell non-Hodgkin lymphomas (B-NHLs) represent a particular challenge in oncology due to tumor heterogeneity and the intricate ecosystem in which tumors develop. These complexities complicate diagnosis, prognosis, and therapy response, emphasizing the need to use sophisticated approaches to enhance personalized treatment strategies for better patient outcomes. Therefore, multimodal AI can be leveraged to synthesize critical information from available biomedical data such as clinical record, imaging, pathology and omics data, to picture the whole tumor. In this review, we first define various types of modalities, multimodal AI frameworks, and several applications in precision medicine. Then, we provide several examples of its usage in B-NHLs, for analyzing the complexity of the ecosystem, identifying immune biomarkers, optimizing therapy strategy, and its clinical applications. Lastly, we address the limitations and future directions of multimodal AI, highlighting the need to overcome these challenges for better clinical practice and application in healthcare.

Clinical Management and Therapy of Precocious Puberty in the Sapienza University Pediatrics Hospital of Rome, Italy

Puberty identifies the transition from childhood to adulthood. Precocious puberty is the onset of signs of pubertal development before age eight in girls and before age nine in boys, it has an incidence of 1/5000-1/10,000 with an F:M ratio ranging from 3:1 to 20:1. Precocious puberty can be divided into central, also known as gonadotropin-dependent precocious puberty or true precocious puberty, and peripheral, also recognized as gonadotropin-independent precocious puberty or precocious pseudopuberty. Thus, the main aim of this narrative report is to describe the standard clinical management and therapy of precocious puberty according to the experience and expertise of pediatricians and pediatric endocrinologists at Policlinico Umberto I, Sapienza University of Rome, Italy. In the suspicion of early sexual maturation, it is important to collect information regarding the age of onset, the speed of maturation of secondary sexual features, exposure to exogenous sex steroids and the presence of neurological symptoms. The objective examination, in addition to the evaluation of secondary sexual characteristics, must also include the evaluation of auxological parameters. Initial laboratory investigations should include serum gonadotropin levels (LH and FSH) and serum levels of the sex steroids. Brain MRI should be performed as indicated by the 2009 Consensus Statement in all boys regardless of chronological age and in all girls with onset of pubertal signs before 6 years of age. The gold standard in the treatment of central precocious puberty is represented by GnRH analogs, whereas, as far as peripheral forms are concerned, the triggering cause must be identified and treated. At the moment there are no reliable data establishing the criteria for discontinuation of GnRH analog therapy. However, numerous pieces of evidence suggest that the therapy should be suspended at the physiological age at which puberty occurs.

Observer agreement in single computerized tomography use for diagnosing paediatric head and neck malignancies at Uganda Cancer Institute

BACKGROUND

In the Ugandan setting, investigation for PHNM with CT uses a protocol with both unenhanced and contrast enhanced procedures hence doubling the ionizing radiation exposure. The purpose of this study was to determine the feasibility of single CT procedures in diagnosing PHNM.

METHODS

This was a cross-sectional study using CT images from patients, aged fifteen years and below, investigated for head and neck malignancies at the Uganda Cancer Institute. Three radiologists, observers A, B and C, with 12, 5 and 2 years of experience, respectively, participated in the study. They independently reported contrast enhanced images (protocol A), unenhanced images (protocol B), then both unenhanced and contrast enhanced images (protocol C) in 2 months intervals. Inter- and intra- observer agreement was determined using Gwen's Agreement coefficient.

RESULTS

Seventy-three CT scans of 36 boys and 37 girls, with a median age of 9 (3-13) years, were used. Intra-and inter-observer agreement on primary tumour location ranged from substantial to almost perfect with the highest intra-observer agreement observed when protocols A and C were compared. Inter-observer agreement for tumour calcifications was substantial for protocol A. Observers A and C demonstrated an almost perfect intra-observer agreement when protocols A and C were compared. There was a substantial inter-observer agreement on diagnosis for all protocols.

CONCLUSIONS

In our setting and examining a limited number of CT images, we demonstrated that contrast-enhanced CT scans provide sufficient information with no evidence of additional value of unenhanced images. Using contrast-enhanced images alone reduced the radiation exposure significantly.

An operation on placental support in a fetus with a nasopharyngeal teratoma

Airway obstruction diagnosed antenatally in the fetus due to congenital high airway obstruction syndrome or nasopharyngeal masses are the primary indications for performing an operation on placental support. Prenatally diagnosed nasopharyngeal masses pose the risk of total airway obstruction upon delivery. Placental support utilises uteroplacental blood flow to facilitate an airway intervention on the fetus while maintaining oxygenation. These interventions must be completed in under 20 min due to amniotic fluid loss and uterine contractions. This case report describes the anaesthetic management of a fetus with a nasal teratoma. In this report, we discuss the clinical indications and anaesthetic considerations of the operation on placental support procedure for nasopharyngeal masses.

Non-Hodgkin Lymphoma Imaging Spectrum in Children, Adolescents, and Young Adults

In children, adolescents, and young adults (CAYA), non-Hodgkin lymphoma (NHL) is characterized by various age-related dissimilarities in tumor aggressiveness, prevailing pathologic subtypes, and imaging features, as well as potentially different treatment outcomes. Understanding the imaging spectrum of NHL in CAYA with particular attention to children and adolescents is critical for radiologists to support the clinical decision making by the treating physicians and other health care practitioners. The authors discuss the currently performed imaging modalities including radiography, US, CT, MRI, and PET in the diagnosis, staging, and assessment of the treatment response. Familiarity with diagnostic imaging challenges during image acquisition, processing, and interpretation is required when managing patients with NHL. The authors describe potentially problematic and life-threatening scenarios that require prompt management. Moreover, the authors address the unprecedented urge to understand the imaging patterns of possible treatment-related complications of the therapeutic agents used in NHL clinical trials and in practice. Online supplemental material is available for this article. ^©RSNA, 2022.

Update on MR Imaging of Soft Tissue Tumors of Head and Neck

This article reviews soft tissue tumors of the head and neck following the 2020 revision of WHO Classification of Soft Tissue and Bone Tumours. Common soft tissue tumors in the head and neck and tumors are discussed, along with newly added entities to the classification system. Salient clinical and imaging features that may allow for improved diagnostic accuracy or to narrow the imaging differential diagnosis are covered. Advanced imaging techniques are discussed, with a focus on diffusion-weighted and dynamic contrast imaging and their potential to help characterize soft tissue tumors and aid in distinguishing malignant from benign tumors.

Congenital tooth-bearing tumor of the eyelid leading to lacrimal system obstruction

PURPOSE

We present an unusual case of a congenital lesion presenting with concomitant chronic dacryocystitis. The clinical presentation, examination, management, and histopathology are reviewed.

OBSERVATIONS

A healthy male infant born at 37 weeks gestation presented with an isolated painless 5mm congenital mass of the left medial lower eyelid. Parents also reported episodic epiphora and discharge from the left eye. A surgical excision of the mass revealed an underlying dacryocystitis and the presence of a formed tooth. A dacryocystorhinostomy was performed together with a repair of the soft tissue defect. Histopathology revealed components of disorganized epithelial and mesenchymal tissues including a tooth, skeletal muscle, fat, fibrous tissue, nonkeratinized epithelium, and myelinated nerves. A diagnosis of an odontogenic choristoma of the eyelid was made. Furthermore, a lacrimal sac culture was positive for oxacillin-susceptible Staphylococcus aureus with pathological evidence of chronic dacryocystitis.

CONCLUSIONS AND IMPORTANCE

Odontogenic choristoma is a very rare finding in the periocular region with only a few cases reported in the literature. Awareness of clinical findings from this case may allow for a more accurate clinical diagnosis and understanding of the embryologic mechanisms underpinning eyelid and nasolacrimal development. Timely management of this condition is critical to ensure normal oculofacial development and prevent future complications.

Neuroimaging Characteristics of Nasopharyngeal Carcinoma in Children

BACKGROUND AND PURPOSE

Pediatric nasopharyngeal carcinoma (NPC) is a rare epithelial origin tumor associated with undifferentiated histology, Epstein-Barr virus (EBV) infection, and genetic risk factors. Childhood NPC is usually clinically silent, often presenting with advanced locoregional compromise, including skull base invasion and cervical lymphadenopathy, and has a better prognosis than adult NPC. This article describes computed tomography (CT) and magnetic resonance imaging (MRI) features in a cohort of 28 pediatric NPC patients.

METHODS

A retrospective review was performed among children with histopathology proven NPC diagnoses between 1996 and 2019 for this study. The electronic medical records were reviewed to determine demographics, EBV serology, and World Health Organization (WHO) type. Nasopharyngeal CT and/or MRI at presentation for tumor spread as well as density and/or intensity, lymphadenopathy, postcontrast enhancement and diffusion characteristics before treatment were evaluated.

RESULTS

Twenty-eight patients (21 males, 7 females) were included. The mean patient age at diagnosis was 13.3 (range 7 to 17) years. EBV was positive in 71.4% of patients. The majority of patients (78.6%) had a WHO type III tumor, unilateral fossa of Rosenmuller involvement (71.4%). Neuroimaging features were CT isodensity, T1-isointensity, T2-hyperintensity, and heterogeneous postcontrast enhancement for all patients (100%) and restricted diffusion (90%).

CONCLUSIONS

Although uncommon in pediatric patients, NPC should be in the differential diagnosis of adolescents presenting with a nasopharyngeal mass. Recognizing key imaging characteristics is helpful in the diagnosis of NPC.

High-Frequency Ultrasound: A Novel Diagnostic Tool to Measure Pediatric Tonsils in 3 Dimensions

Objective

A wide variety of pathologies can affect the palatine tonsils. Ultrasound is a commonly used modality for assessing head and neck masses in children; however, its use in tonsillar evaluation has not been widely explored. The objective of this study was to measure 3-dimensional tonsillar size with ultrasound, in centimeters, and correlate these measurements with actual ex vivo dimensions on pathology specimens.

Study Design

We performed a prospective cohort study.

Setting

The study was set in a tertiary care children’s hospital.

Subjects and Methods

Children undergoing tonsillectomy were included in the study. Transcervical high-frequency ultrasonography (HFU) was performed prior to surgery to obtain 3-dimensional measurements of the right and left palatine tonsils. Mean sizes were compared to ex vivo tonsil measurements and correlations were obtained.

Results

Seventy-five consecutive children underwent a transcervical HFU, with a total of 150 tonsils analyzed. The mean differences between HFU and pathology measurements were −0.08 cm and −0.24 cm for the right and left craniocaudal axes, −0.19 cm and −0.18 cm for the right and left mediolateral axes, and 0.05 cm and 0.03 cm for the right and left anteroposterior axes. Correlation coefficients between ultrasound and pathology measurements were all above 0.5.

Conclusion

HFU can accurately measure the size of pediatric tonsils in 3 dimensions.

Head and Neck Sarcomas: A Review of Clinical and Imaging Findings Based on the 2013 World Health Organization Classification

OBJECTIVE

Head and neck sarcomas are a complex, heterogeneous group of tumors that present a diagnostic challenge to radiologists because they have many overlapping imaging features. The purpose of this article is to review the imaging and clinical features and highlight distinguishing features of head and neck sarcomas.

CONCLUSION

An understanding of characteristic imaging and clinical features of head and neck sarcomas is important for the radiologist to narrow the differential diagnosis and help guide management.

Benign and Malignant Oral Lesions in Children and Adolescents: An Organized Approach to Diagnosis and Management

Oral lesions in children encompass a wide range of etiologies, including idiopathic entities as well as those related to an underlying systemic illness. In addition, oral masses include benign entities harboring locally destructive behavior and even malignancies in rare cases. Thorough patient history and detailed and efficient physical examination are critical for determining which lesions can be closely observed versus those require further diagnostic work-up. Understanding normal oral cavity anatomy is crucial for performing appropriate evaluation. This review describes the appropriate diagnostic and therapeutic strategies for oral cavity lesions and reviews the broad differential diagnosis of oral cavity masses.

A rare case of embryonal rhabdomyosarcoma of the parapharyngeal space

A 24-year-old man was admitted to our Otolaryngology Department following a head and neck CT scan performed for cranial trauma that showed a bulky neoformation in the right parapharyngeal space. Magnetic resonance imaging confirmed the presence of an oval formation with sharp margins and colliquative areas of necrosis involving the right parapharyngeal space. The mass was completely excised by a latero-cervical approach. Based on histological features and immunohistochemical analysis, a diagnosis of embryonal rhabdomyosarcoma of the parapharyngeal space was made. The incidental detection at this site of an embryonal rhabdomyosarcoma has never been reported in adult males.

Can preoperative computed tomography predict tissue origin of primary maxillary cancer?

Based on the histopathologic origin, malignant maxillary neoplasms may share some clinical characteristics but have different biological behavior, treatments, and prognoses. The aim of the present study was to explore the association between CT characteristics and tissue origin of primary maxillary cancer (MC). A retrospective review of CT findings was performed in patients diagnosed with MC between January 1, 2005 and December 31, 2013. Univariate and multivariable logistic regression analyses were performed to determine the association between tissue of origin and CT characteristics, with adjustment for possible confounding factors. A total of 164 patients (70 male, 94 female, age: 46.8 ± 18.3 years) were included. Patients were divided into epithelial (n = 88) and nonepithelial (n = 76), or odontogenic (n = 15) and nonodontogenic (n = 149) groups. After adjusting for age, sex, smoking status, alcohol use, tumor size, and stage in the multivariable logistic regression model, the lesions with cortical bowing were found more likely to be epithelial (odds ratio [OR] = 7.0, 95% confidence interval [CI], 1.4-36.1) than nonepithelial origin, while lesions with cervical lymphadenopathy were more associated with a nonodontogenic origin (OR = 12.6, 95% CI, 1.1-140.0) rather than odontogenic. Among epithelial cancers, lesions with cortical bowing were 14 times more likely to be salivary gland-type (OR = 13.8, 95% CI, 1.3-141.5). CT characteristics of cortical bowing and cervical lymphadenopathy might be suggestive of tissue origin in MC. Larger prospective studies are warranted to further examine the association.

Juvenile Nasopharyngeal Angiofibroma: Magnetic Resonance Imaging Findings

Purpose:

Juvenile nasopharyngeal angiofibroma (JNA) is a rare tumor that exhibits a predictable spreading pattern. Radiologist’s prior knowledge on the tumor’s characteristics aids in establishing a diagnosis. We aimed to report the characteristic Magnetic Resonance Imaging (MRI) findings and the spread patterns of JNA.

Materials and methods:

We retrospectively evaluated the MRI findings and extension pathways of 6 cases of JNA.

Results:

The patients’ age ranged from 8 to 16 years and all patients were male. The tumors were classified according to the Onerci system. Tumors were largely isointense to muscle on T1-weighted images and hyperintense on T2-weighted images. All lesions had internal signal-void regions and all exhibited intense enhancement after IV contrast injection. Diffusion restriction was not an associated feature. ADC values for these tumors were high. The evaluation of the available MR angiography studies of three patients showed the blood supply to the tumor to be mainly from the internal maxillary branch of the external carotid artery. In all patients, the diagnosis was based on MR images and a surgical excision was planned.

Conclusion:

The diagnosis can be established based on the characteristic imaging findings and the clinical history without performing a biopsy.

Magnetic Resonance Imaging Findings in Childhood Period Nasopharynx Cancer

Background

Nasopharyngeal carcinoma is a rarely seen tumor in childhood. It is mostly detected late as the clinical features are similar to other childhood tumors which affect the nasopharynx and adenoidal hypertrophy. Therefore, the radiological features of childhood tumors of the nasopharynx must be well known. The aim of this study was to investigate the contribution of MR imaging features of childhood nasopharynx cancer.

Material/Methods

The study included 10 nasopharyngeal carcinoma patients under the age of 18 years who presented at hospital between February 2008 and March 2014 and who had tissue diagnosis and MRI of the nasopharynx region. The MRI scans were evaluated by two radiologists. Loco-regional spread, asymmetry, signal intensity of the tumors, and lymph nodes were evaluated.

Results

In all the patients there was a mass which narrowed the nasopharynx. In all cases, unilateral mastoid opacification was observed. In 9 cases (90%), parapharyngeal extension was found. In 8 cases (80%), the mass showed an extension into the nasal cavity or oropharynx. In 5 cases (50%), there was an involvement of the skull base. In 3 patients (30%), an extension to the masticator space and pterygopalatine fossa was found. There were enlarged cervical lymph nodes bilaterally in 10 cases (100%). In 4 cases (40%), a lateral retropharyngeal lymph node was detected.

Conclusions

Childhood nasopharyngeal cancers are often diagnosed at an advanced stage. MR imaging can be helpful in diagnosis and differential diagnosis of childhood nasopharynx cancer from other diseases of the nasopharynx.

Imaging of pediatric head and neck masses

Medical imaging is an important tool in the evaluation and classification of pediatric head and neck masses. Such lesions may include congenital, inflammatory, infectious, vascular, or neoplastic processes. Ultrasound is often the first line modality in the workup of a neck mass in a child, followed by MRI or CT depending on the scenario. This information must be interpreted in the context of the patient's clinical history, physical examination, and demographics. The medical imaging workup of a neck mass in a child must be focused to yield the maximum information possible while minimizing the risks of radiation and sedation.

Head and neck teratoma: from diagnosis to treatment

INTRODUCTION

Head and neck teratoma is a rare entity. Its prognosis mostly depends on the risk of neonatal respiratory distress, its extension and potential malignancy. Surgical management must be as complete as possible to avoid recurrences and malignant transformation. The authors present a retrospective analysis of 6 cervicofacial teratomas and a review of the literature. The aim of the study was to analyse prenatal, neonatal and postnatal management of teratoma.

MATERIALS AND METHODS

Charts of children presenting with a head and neck teratoma, managed by our maxillofacial and plastic surgery unit, were analysed and antenatal, clinical, biological, radiological and pathological characteristics were collected. Surgical treatment, recurrences and surgical outcomes were analysed.

RESULTS

Six patients were included: 2 with a cervical teratoma, 2 with a facial teratoma and 2 with intraoral teratomas. In 2 cases, the lesions were diagnosed antenatally and both patients required neonatal resuscitation. All the patients underwent early surgery, and 3 with complete excisions. All patients with an initial incomplete excision eventually presented a recurrence and therefore second look surgery. No malignant transformation was noted.

CONCLUSION

Early prenatal diagnosis is crucial to neonatal care. Early surgery and meticulous follow-up are critical in the long-term favourable outcome.

Computed tomography and magnetic resonance imaging observations of rhabdomyosarcoma in the head and neck

Head and neck (HN) rhabdomyosarcoma (RMS) is an aggressive malignancy, which is rarely encountered and is commonly misdiagnosed as another type of tumor. The aim of the present study was to investigate the computed tomography (CT) and magnetic resonance imaging (MRI) features of HNRMS and analyze the correlations between the imaging observations and the pathological subtypes. A total of 10 HNRMS patients (three males and seven females; median age, 16 years) were reviewed retrospectively by only CT (n=1), only MRI (n=2), as well as CT and MRI (n=7). In addition, the clinical data, imaging observations and pathological results were recorded and analyzed. The origins of the 10 HNRMSs (eight embryonal and two alveolar subtypes) included the ethmoid sinus (n=4), maxillary sinus (n=1), orbit (n=3), nasopharynx (n=1) and frontotemporal subcutaneous area (n=1). On the CT and MRI images, the soft-tissue masses exhibited ill-defined borders (n=9), bony destruction (n=10), multi-cavity growth (n=7) and cervical lymph node metastasis (n=2), whereas calcification and hemorrhaging were not identified. On CT, eight of the HNRMSs appeared slightly hypodense (2/8) or isodense (6/8) with homogeneous enhancement (4/4). On T1-weighted images (WI), nine tumors exhibited isointensity (9/9) and on T2WI, six tumors demonstrated homogeneous hyperintensity with homogeneous enhancement on contrast-enhanced (CE)-T1WI. In addition, three embryonal RMSs, which originated from the ethmoid sinus, exhibited heterogeneous hyperintensity on T2WI and nodule-shaped enhancement patterns on CE-T1WI. The results of the present study indicated that MRI may accurately demonstrate the location and extent of HNRMS and that the imaging features of HNRMS may be similar to those of other tumors. However, a tumor exhibiting heterogeneous hyperintensity on T2WI and a nodule-shaped enhancement pattern on CE-T1WI in the ethmoid sinus may present specific MRI features, which clearly indicates the botryoid subtype of embryonal RMS.

Magnetic resonance imaging versus computed tomography and different imaging modalities in evaluation of sinonasal neoplasms diagnosed by histopathology

OBJECTIVE

The study purpose was to detect the value of magnetic resonance imaging (MRI) compared to computed tomography (CT) and different imaging modalities as conventional radiology in evaluation of sinonasal neoplasms diagnosed by Histopathology.

METHODS

Thirty patients (16 males and 14 females) were complaining of symptoms related to sinonasal tract. After thorough clinical and local examination, the patients were subjected to the following: conventional radiography, CT, MRI, and histopathological examination.

RESULTS

The nasal cavity was the most commonly involved site with sinonasal malignancies followed by the maxillary sinuses. The least commonly affected site was the frontal sinuses. Benign sinonasal tumors were present in 14 cases. The most common benign lesion was juvenile nasopharyngeal angiofibroma (6 cases), followed by inverted papilloma (3 cases). While malignant sinonasal tumors were present in 16 cases, squamous cell carcinoma was present in 5 cases, and undifferentiated carcinoma, in 3 cases. Lymphoepithelioma and non-Hodgkin lymphomas were present in 2 cases each, while adenocarcinoma, chondrosarcoma, adenoid cystic carcinoma, and rhabdomyosarcoma were present in 1 case each.

CONCLUSION

MRI with its superior soft tissue contrast and multiplanar capability is superior to CT in pretreatment evaluation of primary malignant tumors of sinonasal cavity.

Teratomas: a multimodality review

Germ cell tumors (GCTs) may occur in both children and adults and include a broad array of histologic subtypes, such as teratoma, seminoma (known as dysgerminoma in the ovary and germinoma in the pineal gland), choriocarcinoma, yolk sac tumor, embryonal cell carcinoma, and mixed GCT. In adults, GCTs occur most commonly in the gonads. In children, sacrococcygeal tumors predominate. Teratomas are a common form of GCT. They are defined histologically as containing tissues derived from all 3 germ cell layers: ectoderm, mesoderm (most teratomas contain fat, an imaging hallmark, which is a mesodermal derivative), and endoderm. Teratomas are also classified as mature or immature, depending on the degree of differentiation of its components, and in adults, immature tumors are more likely to exhibit malignant behavior.

Soft tissue tumors of the head and neck: imaging-based review of the WHO classification

The World Health Organization (WHO) system for defining and classifying soft tissue tumors is usually applied to lesions that occur in the trunk and extremities, but it also provides an excellent framework for characterizing nonepithelial extraskeletal tumors of the head and neck. Although nonepithelial extraskeletal tumors are in the minority among head and neck lesions, they are by no means rare. The WHO classification system recognizes nine major types based on histologic differentiation: adipocytic, fibroblastic or myofibroblastic, fibrohistiocytic, smooth muscle, skeletal muscle, vascular, pericytic, and chondro-osseous tumors, as well as soft tissue tumors of uncertain differentiation. Tumors of each histologic type may be further subclassified on the basis of their biologic behavior as benign, intermediate (ie, having malignant potential), or malignant. Imaging plays an important role in the noninvasive diagnosis and characterization of nonepithelial soft tissue tumors of the head and neck, providing clues about tumor grade, composition, extent, and involvement of adjacent structures. Although the imaging characteristics of many such tumors are nonspecific, consideration of the clinical history in concert with the imaging findings may help limit the differential diagnosis or even allow reliable diagnosis of some of these tumors.

A realistic utilization of nanotechnology in molecular imaging and targeted radiotherapy of solid tumors

Precise dose delivery to malignant tissue in radiotherapy is of paramount importance for treatment efficacy while minimizing morbidity of surrounding normal tissues. Current conventional imaging techniques, such as magnetic resonance imaging (MRI) and computerized tomography (CT), are used to define the three-dimensional shape and volume of the tumor for radiation therapy. In many cases, these radiographic imaging (RI) techniques are ambiguous or provide limited information with regard to tumor margins and histopathology. Molecular imaging (MI) modalities, such as positron emission tomography (PET) and single photon-emission computed-tomography (SPECT) that can characterize tumor tissue, are rapidly becoming routine in radiation therapy. However, their inherent low spatial resolution impedes tumor delineation for the purposes of radiation treatment planning. This review will focus on applications of nanotechnology to synergize imaging modalities in order to accurately highlight, as well as subsequently target, tumor cells. Furthermore, using such nano-agents for imaging, simultaneous coupling of novel therapeutics including radiosensitizers can be delivered specifically to the tumor to maximize tumor cell killing while sparing normal tissue.

Imaging of pediatric neck masses

Palpable neck masses are a common indication for pediatric imaging. Such lesions may be caused by infectious, inflammatory, tumoral, traumatic, lymphovascular, immunologic, or congenital etiologies. Radiological assessment of neck masses in young children should be tailored based on patient presentation and physical examination, as well as clinical suspicion. The goal of imaging should be to help arrive at a diagnosis or limited differential in an efficient manner while minimizing radiation exposure.

[Sonographic differential diagnosis of cervical masses]

One of the main indications for the use of ultrasound by the head and neck specialist is the diagnosis of cervical masses. The examination can be easily performed since all structures of interest are located superficially and are not covered by boney or air-filled structures. Further advantages of ultrasound in contrast to other imaging techniques such as MRI or CT include its high resolution and lack of side effects. Even structures of <5 mm in diameter can be interpreted well. Since ultrasound is fast, has no side effects and can be performed as often as necessary, it represents an excellent diagnostic instrument in the follow-up of patients with head and neck cancer. In addition to the conventional B-scan technique, colour duplex sonography is also often performed today to obtain additional information on the nature of cervical masses. Thus, different entities of cervical lymph nodes can be well differentiated by their pattern of vascularization.