|
 
 |
| REVIEW ARTICLE |
|
| Year : 2013 | Volume
: 1
| Issue : 2 | Page : 37-42 |
|
Latest advancements in imaging of oral and maxillofacial neoplasm: A comprehensive review
Devvrat Singh1, Sukant Sahoo2, Vineet Gupta3, Deepti Srivastava2
1 Department of Conservative Dentistry, Shree Bankey Bihari Dental College and Research Centre, Ghaziabad, Uttar Pradesh, India
2 Department of Prosthodontics, Shree Bankey Bihari Dental College and Research Centre, Ghaziabad, Uttar Pradesh, India
3 Department of Oral Surgery, Shree Bankey Bihari Dental College and Research Centre, Ghaziabad, Uttar Pradesh, India
| Date of Web Publication | 21-Oct-2013 |
Correspondence Address:
Devvrat Singh
Department of Conservative Dentistry, Shree Bankey Bihari Dental College and Research Centre, Ghaziabad, Masuri, Utar Pradesh
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/2321-3841.120094
Radiographic imaging is one of the greatest investigative tools that are used in medical sciences since ages. There is an important role of imaging in staging, during treatment planning, and post-treatment follow up of patients with head and neck cancer. To design an effective treatment strategy, two tasks are very important which are accurate staging and timely assessment of the cancer. There lies the importance of pre-treatment imaging in diagnosis. Awareness of the presence of cervical node metastasis is important in treatment planning and in prognostic prediction for patients with head and neck cancer. Currently, MRI and CT are commonly used to evaluate the primary tumor and the neck status. They characterize the cervical lymph nodes dependent on morphological criteria. Doppler ultrasound and Positron emission tomography are also used to overcome some of the limitations of MRI and CT. Keywords: Computed tomography, head and neck carcinoma, magnetic resonance imaging, positron emission tomography
How to cite this article:
Singh D, Sahoo S, Gupta V, Srivastava D. Latest advancements in imaging of oral and maxillofacial neoplasm: A comprehensive review. J Oral Maxillofac Radiol 2013;1:37-42 |
How to cite this URL:
Singh D, Sahoo S, Gupta V, Srivastava D. Latest advancements in imaging of oral and maxillofacial neoplasm: A comprehensive review. J Oral Maxillofac Radiol [serial online] 2013 [cited 2023 Mar 24];1:37-42. Available from: https://www.joomr.org/text.asp?2013/1/2/37/120094 |
| Introduction | |  |
Undoubtedly, the use of radiographic imaging has entirely revolutionized the diagnosis and treatment planning in medical sciences. The role of imaging in oral malignancies can be broadly grouped in those used to evaluate primary disease and those to evaluate metastatic disease. It is a useful tool for staging and management planning in oral cancers. Awareness of the presence of cervical node metastasis is important in treatment planning and in prognostic prediction for patients with head and neck cancer (HNC). Magnetic resonance imaging (MRI) and computed tomography (CT) are commonly used to assess the primary tumor and the neck status. [1],[2],[3],[4],[5] Doppler ultrasound with fine-needle aspiration is also used these days. [6] Positron emission tomography (PET) is a functional imaging that can detect cancer lesions by pinpointing regions of high metabolism. It is also used in cases demanding assessment of metastases to lymph nodes that appear morphologically normal. [7],[8] The main drawback of PET is its poor anatomical resolution. Side-by-side visual correlation of PET and CT/MRI can help determine the anatomical location of abnormal PET uptake and eliminate some false-positive PET findings caused by spatial errors. [9],[10],[11] Fused PET/CT is considered to be the most accurate imaging modality, because it simultaneously provides prompt and accurate coregistration of functional and anatomical images. However, it is expensive, less-often available, and still constrained by technical resolution limits. [12],[13],[14],[15] Diffusion-weighted MRI, dynamic contrast-enhanced MRI, and nanoparticle-enhanced MRI are novel imaging technologies that have also been exploited in this field. To date, neck dissection with detailed pathological examination is the gold standard. There is always a need for further refinement of the imaging techniques that can provide accurate information that approaches this gold standard.
| Evaluation of Primary Disease | | |
- Intraoral radiographic examination is of very limited use though occlusal radiographs (maxillary and mandibular projections) have been occasionally used to determine the medial or lateral extent of the disease and to detect their presence in palate or floor of the mouth. It may aid in evaluating patients with trismus.
- Extraoral radiographic examination includes lateral skull projections and Water projections (occipitomental projections). The former is more useful for pre- and post-treatment records for prosthesis and oral surgery, while the later is useful for evaluating maxillary sinus. Mandibular lateral oblique body/ramus projections are largely replaced by panoramic radiography.
- Panoromic radiography (also called pantomography or rotational radiography) is a radiographic technique for producing a single image of the facial structures that includes both maxillary and mandibular arches and their supporting structures. Its principal advantages include broad anatomic coverage, low radiation dosage for patient, convenience of examination, and the fact that it can be used in patients unable to open their mouth. The usual procedure lasts 3-4 minutes. The main disadvantage is that the resultant image does not resolve the fine anatomic detail that may be seen on intraoral and periapical radiograph. Commonly used panoromic machines include the orthopantomograph and the panorex. Recent panoramic radiographic machines are capable of producing digital images.
CT scan is useful for evaluating bony invasion. A sophisticated software program called Dentascan provides more accurate details of the mandible. [16],[17] CT can identify tumors based upon either anatomic distortion or specific tumor enhancement. Imaging of lymph nodes by CT or MRI is complementary to the clinical examination for the staging of the neck. CT is also highly sensitive for detection of extracapsular spread of tumor. [18]
Compared with MRI, CT provides equal or greater spatial resolution, it can be performed with fast acquisition times thereby virtually eliminating the problem of motion artifact and it is better for the evaluation of bone destruction. CT also has the subjective advantage of being relatively straightforward to interpret. [19],[20] Size criteria for pathologic nodes - using clinical criteria of a palpable node greater than 1.5 cm or fixed or matted nodes, error rates have been shown to range from 20% to 28%. Size criteria for pathologic lymph nodes vary although most agree that homogeneous cervical lymph nodes up to 10 mm in maximum diameter may be considered normal, and in some areas (e.g., jugulodigastric and anterior submandibular nodes), lymph nodes up to 15 mm may be considered normal. [19]
CT imaging protocols - CT imaging depends upon the site and stage of the tumor and also depends on the type of scanner used. We typically obtain thin (2.5 to 3 mm in thickness, depending on scanner technology) axial contiguous sections. Intravenous contrast is administered by a pressure injector in all cases. After a 40 to 60 sec delay, contrast is injected at 2 mL/sec for a total of 100 to120 mL. With ultrafast multidetector scanner technology, scanning after a shorter delay can result in essentially a CT arteriogram, with failure to opacify veins, and inadequate tissue contrast opacification. Soft tissue windows are routinely evaluated. [17],[21] Both soft tissue and bone should be evaluated, but it may not be necessary to routinely reconstruct bone "algorithm" images. CT bone "windows", even if reviewed on a picture archiving and communication system (PACS) with a soft tissue algorithm, are particularly useful to evaluate for erosion of thyroid, cricoid or tracheal cartilage, or erosion of the mandible, vertebra or skull base. When in fact there is none. In these cases, MRI may be helpful, as it may identify tumor invasion of bone marrow [22] [Table 1].
MRI is used for soft tissue evaluation of mainly tongue and floor of the mouth. MRI is complementary to CT and the physical examination in the pretreatment evaluation of patients with HNC. [18],[19] MRI provides superior soft tissue contrast compared to CT. It is therefore particularly useful for assessment of local spread of carcinomas. These are important issues for surgical planning and are sometimes more readily evaluated with MRI. The ability to directly scan in the coronal plane, together with the often sharp delineation of primary tumor with normal mucosa/submucosa, even on unenhanced T1- and T2-weighted images, is particularly helpful for these questions. [20] MR "angiography" (MRA) can generate images of large arteries and veins noninvasively without the use of IV contrast. [21],[22] This is reserved for cases where tumor is thought to encase and/or narrow a major vessel [23],[24] [Table 2]. | Table 2: Advantages and disadvantages of MRI in cancer detection based on tissue:[33]
Click here to view |
MRI involves no exposure to ionizing radiation. The gadolinium chelates used as MRI contrast agents are associated with a much lower incidence of llergic/anaphylactic reactions and are less nephrotoxic in the doses used than the iodinated contrast agents used in CT. [25],[26] First diagnosed in 1997, nephrogenic systemic fibrosis can occur if patients with commonly employed techniques such as fast spin-echo with fat-saturation may permit better delineation of tumor margins and enhanced identification of recurrent tumor. Disadvantages of MRI include long acquisition times, substantial cost, the inability to scan patients with certain indwelling metallic objects such as pacemakers, cerebrovascular shunts, and claustrophobia from closed MRI systems. [25],[26]
| Radioisotope Imaging | | |
It is used for primary bony involvement. It is not very specific and therefore rarely used. Radiological evaluation of early stage tumors of lip is usually not indicated. However, advanced tumors of the lower lip, particularly with adherence to or invasion of the mandible require adequate appraisal. [2],[3] In addition to these neurotrophic carcinomas, particularly melanoma and squamous carcinoma have a tendency to disseminate along the inferior alveolar nerve through the mandibular canal. Therefore, detailed evaluation of the mandible is vitally important in treatment planning. Patients who manifest numbness of the skin of the chin and lower lip are particularly suspect of having invasion of the inferior alveolar nerve. Panoromic radiographs of the mandible provide a good initial assessment of the mandibular canal. More detailed studies require a CT scan and in select circumstance a Dentascan for accurate delineation of the extent of bone invasion as well as for evaluation of the inferior alveolar canal. [4]
Direct extension of a primary tumor of the oral cavity to the mandible or its proximity to the mandible requires appropriate radiological studies to establish the extent of bony involvement. While the absence of bony involvement does not rule out bony invasion, bone destruction seen on the radiograph confirms tumor invasion. Radionucleide bone scans are often positive prior to radiographic appearance of bone destruction but they may seldom provide accurate information regarding the extent of bone invasion. [8] Bone scans may also be positive in nonneoplastic conditions like inflammations. Panoramic view of the mandible is more useful than plain anteroposterior or oblique view of mandible for routine screening. It must however be appreciated that due to technical reasons the midline of mandible near the symphysis is not adequately evaluated by panoromic view. Occlusal films of the body of the mandible and intraoral dental films are most accurate in demonstrating early invasion by tumor. [18]
CT scan of the mandible is generally not optimal for routine screening but may be considered under certain circumstances such as those lesions where soft tissues extend from tumor involving the ascending ramus of the mandible is suspected. [25] Dentascan may be considered in appropriate circumstances when dental details are required. In addition to this, 3D reconstruction of CT images provides an excellent 3D overview of the mandible or maxilla from any desired angle. A 3D CT scan and one to one reproduction of the CT are of great value to the surgeon for mandible reconstruction with microvascular free flap. [26] These images are essential to fabricate and shape the graft to match the resected portion of the mandible. Invasion of the maxilla by primary tumors of the oral cavity such as those arising from the palate or upper alveolus is best assessed by a CT scan. MRI is superior in defining the soft tissue details. [18] Also in situations where extensive soft tissue invasion in the parapharyngeal space is suspected a MRI scan is desirable. Bony details are however not clear on MRI and a CT scan is preferred for that. In the case of the invasion of the mandible or maxilla by tumor, appropriate radiograph of the underlying bone is deemed necessary prior to any bony resection or osteotomy procedures. [19],[26]
Carcinoma of the tongue can be difficult to visualize on a CT scan because the density of the tumor which can be same as that of the musculature. MRI can usually generate different signals of the tumor and tongue muscles and one can define margins of the tumor more precisely. Carcinoma of the tongue gives fewer echoes than the muscles of the tongue. Therefore, margin evaluation using the ultrasound has been tried with variable success. [13]
Floor of the mouth has several regions that contain fat and therefore are candidates for either CT scan or MRI evaluation. The fat in the sublingual space is obliterated with tumor involvement. [16] As the tumor infiltrates the geniohyoid and the genioglossus muscles there is usually enough fat bordering the muscles to allow evaluation. Mylohyoid muscle can pose an evaluation problem as the tumor and the muscle have the same density and hence MRI evaluation could be more reliable. [17]
Generally as observed in the above discussion, CT scan evaluation is more useful for bony invasion and MRI for soft tissue imaging. Radiologically, direct invasion of bone produces a purely destructive lesion and shows little evidence of bony expansion or of subperiosteal new bone formation. The margins of the lesions are irregular and may show erosions of roots of the teeth. [21] Once dense cortical bone is penetrated radiographic findings must always be interpreted with caution. Histology examination may prove negative despite the impression that the bone is involved radiographically. In about one third of the patients without radiographic evidence of bone destruction histology evidence might be present. [22]
| PET Scan | | |
F-Fluorodeoxyglucose positron emission tomography (F-FDG PET) is a functional imaging technique that provides information about tissue metabolism and has been successfully applied to the evaluation of HNCs. [18],[9],[27] PET is based on identifying increased glycolytic activity in malignant cells, in which radiolabeled FDG is preferentially concentrated due to increases in membrane glucose transporters as well as in hexokinase, an enzyme which phosphorylates glucose. After phosphorylation, radiolabeled FDG continues to accumulate in cancer cells instead of glycolysis, allowing imaging by PET. [18],[27] F-FDG PET is more sensitive than CT or MRI in detecting cervical node metastases. It can help identify metastatic nodes which are morphologically normal. Currently available data from various studies [28],[29],[30],[31],[32],[33] demonstrate large variations in the sensitivity and specificity of F-FDG PET in the detection of cervical lymph node metastases in HNCs.
These ranged from 67% to 96% for sensitivity and 82% to 100% for specificity. Intranodal tumor deposits play a determinate role in the sensitivity of F-FDG PET, and those malignant nodes with a mean tumor deposit of less than 5 mm would likely be missed. [27],[34] False positives of F-FDG PET are mainly due to its inherent inability to discriminate inflammatory processes and reactive hyperplasia from tumor infiltration, because high metabolic changes occur in both instances. [34]
The main drawback of PET remains its relatively poor anatomic resolution.
- CT/MRI merely depicts anatomic details but PET provides information about tissue perfusion and metabolism. [29]
- FDG is taken up by tissue cells similarly as natural glucose. [29],[30]
- Neoplastic cells have been shown to incorporate more radio intense images than surrounding tissues:
Thus, PET scan is usually indicated for the identification of metastatic nodal disease post-radiation or recurrent/residual tumor. However, it lacks in anatomic detail reproduction and the thickness of resolution size may prevent micro deposits from being visualized. [31],[32] That is why PET scan is considered as research tool rather than frequently used clinical diagnostic entity. [33],[34]
| Imaging Better in Compendium | | |
Ultrasound: with the deoprint and application of high resolution sonography and color Doppler sonography on cervical lymph nodes efforts have been made to differentiate malignant from benign lymphadenopathy. Among the proposed ones few of the important one are as follows:
| Various Morphologic Criteria Like | | |
- Longitudinal diameters
- Transverse diameter
- Ratio of length of short axis to long axis
- Shape
- Hilar echogenicity
- Nodal border
- Site
- Multiplicity of tumors has been proposed as predictors of malignancy.
| Conclusion | | |
In clinical practice, CT and MRI are commonly because they can delineate the extent of the primary head and neck tumors in the same session. PET is a functional imaging technique that is more sensitive than CT and MRI. However, it lacks anatomical detail and is seldom used alone. Side-by-side visual correlation of PET and CT/MRI is a simple technique that can increase the diagnostic accuracy of PET. The combined PET/CT device is an advance in PET technology that can simultaneously provide precise integrated functional and anatomical information. It is considered to be the most accurate imaging modality to date, but it still has problems of high cost, lower availability, and the inability to detect micrometastases. Further refinement of imaging techniques is mandatory to improve their accuracy until it approaches that of the gold standard.
| References | | |
| 1. | Adams S, Baum RP, Stucken ST, Bitter K, Hor G. Prospective comparison of 18F-FDG PET with conventional imaging modalities (CT, MRI, US) in lymph node staging of head and neck cancer. Eur J Nucl Med 1998;25:1255-60. 
|
| 2. | Bree R, Deurloo EE, Snow GB, Leemans CR. Screening for distant metastases in patients with head and neck cancer. Laryngoscope 2000;110:397-400.
|
| 3. | Brouwer J, Senft A, Bree R, Comans EF, Golding RP, Castelijens JA. Screening for distant metastases in patients with head and neck cancer: Is there a role for 18 FDG-PET? Oral Oncol 2006;60:58-66.
|
| 4. | Rapidis AD, Gullane P, Langdon JD, Lefebvre JL, Scully C, Shah JP. Editorial Major advances in the knowledge and understanding of the epidemiology Aetiopathogenesis, diagnosis, management and prognosis of oral cancer. Oral Oncol 2009;45:299-300.
|
| 5. | Remco de Bree, Jonas AC, Otto S, Hoekstra C, Rene L. Advances in imaging in the work-up of head and neck cancer patients. Oral Oncol 2009;45:930-5.
|
| 6. | Hermans R. Head and Neck cancer: How imaging predicts treatment outcome. Can Imag 2006;6:S145-53.
|
| 7. | Shah PJ, Johnson WN, Batsakin GJ. Oral cancer. 2 nd ed. United Kingdom: Taylor and Francis group; 2003. p. 199.
|
| 8. | Weissman JL, Akindele R. Current imaging techniques for head and neck tumors. Oncol 1999;13:697-709.
|
| 9. | Som PM. Detection of metastasis in cervical lymph nodes: CT and MR criteria and differential diagnosis. Am J Roentgenol 1992;158:961-9.
|
| 10. | Ginsberg LE, DeMonte F. Imaging of perineural tumor spread from palatal carcinoma. Am J Neuroradiol 1998;19:1417-22.
|
| 11. | Mukherji SK, Schiro S, Castillo M, Kwock L, Muller KE, Blackstock W. Proton MR spectroscopy of squamous cell carcinoma of the extracranial head and neck: In vitro and In vivo studies. Am J Neuroradiol 1997;18:1057-72.
|
| 12. | Van den Brekel MW, Runne RW, Smeele LE, Tiwari RM, Snow GB, Castelijns JA. Assessment of tumour invasion into the mandible: The value of different imaging techniques. Eur Radiol 1998;8:1552-7.
|
| 13. | Daisne JF, Duprez T, Weynand B, Lonneux M, Hamoir M, Reychler H, et al. Tumor volume in pharyngolaryngeal squamous cell carcinoma: Comparison at CT, MR imaging, and FDG PET and validation with surgical specimen. Radiology 2004;233:93-100.
|
| 14. | King AD, Tse GM, Yuen EH, To EW, Vlantis AC, Zee B, et al. Comparison of CT and MR imaging for the detection of extranodal neoplastic spread in metastatic neck nodes. Eur J Radiol 2004;52:264-70.
|
| 15. | Goerres GW, Schmid DT, Gratz KW, Von Schulthess GK, Eyrich GK. Impact of whole body positron emission tomography on initial staging and therapy in patients with squamous cell carcinoma of the oral cavity. Oral Oncol 2003;39:547-51.
|
| 16. | Baba Y, Furusawa M, Murakami R, Yokoyama T, Sakamoto Y, Nishimura R, et al. Role of dynamic MRI in the evaluation of head and neck cancers treated with radiation therapy. Int J Radiat Oncol Biol Phys 1997;37:783-7.
|
| 17. | Hoskin PJ, Saunders MI, Goodchild K, Powell ME, Taylor NJ, Baddeley H. Dynamic contrast enhanced magnetic resonance scanning as a predictor of response to accelerated radiotherapy for advanced head and neck cancer. Br J Radiol 1999;72:1093-8.
|
| 18. | Brown AE, Langdon JD. Management of oral cancer. Ann R Coll Surg Engl 1995;77:404-8.
|
| 19. | Leemans CR, Tiwari R, Nauta JJ, van der Waal I, Snow GB. Regional lymph node involvement and its significance in the development of distant metastases in head and neck carcinoma. Cancer 1993;71:452-6.
|
| 20. | Hao SP, Ng SH. The value of magnetic resonance imaging vs clinical palpation in evaluating cervical metastasis from head and neck cancer. Otolaryngol Head Neck Surg 2000;123:324-7.
|
| 21. | Som PM. Brandwei M. Lymph nodes. In: Som PM, Curtin HD, editors. Head and Neck Imaging. 4 th ed, Vol. 2. St. Louis, MO: Mosby; 2003. p. 1865-934.
|
| 22. | Vassallo P, Edel G, Roos N, Naguib A, Peters PE. In-vitro high-resolution ultrasonography of benign and malignant lymph nodes: A sonographic-pathologic correlation. Invest Radiol 1993;28:698-705.
|
| 23. | Ahuja A, Ying M. Sonography of neck lymph nodes. Part II. Abnormal lymph nodes. Clin Radiol 2003;58:359-66.
|
| 24. | Griffith JF, Chan AC, Ahuja AT, Leung SF, Chow LT, Chung SC, et al. Neck ultrasound in staging squamous oesophageal carcinoma: A high yield technique. Clin Radiol 2000;55:696-701.
|
| 25. | McGuirt WF, Williams DW 3rd, Keyes JW Jr, Greven KM, Watson NE Jr, Geisinger KR, et al. A comparative diagnostic study of head and neck nodal metastases using positron emission tomography. Laryngoscope 1995;105:373-5.
|
| 26. | Nowak B, Di Martino E, Janicke S, Cremerius U, Adam G, Zimny M, et al. Diagnostic evaluation of malignant head and neck cancer by F-18-FDG PET compared with CT/MRI. Nuklearmedizin 1999;38:312-8.
|
| 27. | Myers LL, Wax MK. Positron emission tomography in the evaluation of the negative neck in patients with oral cavity cancer. J Otolaryngol 1998;27:342-7.
|
| 28. | McGuirt WF, Greven K, Williams D 3 rd , Keyes JW Jr, Watson N, Cappellari JO, et al. PET scanning in head and neck oncology: A review. Head Neck 1998;20:208-15.
|
| 29. | Safa AA, Tran LM, Rege S, Brown CV, Mandelkern MA, Wang MB, et al. The role of positron emission tomography in occult primary head and neck cancers. Cancer J Sci Am 1999;5:214-8.
|
| 30. | Pereira G, Silva GC, Monteiro E. Positron emission tomography in the detection of occult primary head and neck carcinoma: A retrospective study. Head Neck Oncol 2012;4:34.
|
| 31. | Sercarz JA, Bailet JW, Abemayor E, Anzai Y, Hoh CK, Lufkin RB. Computer coregistration of positron emission tomography and magnetic resonance images in head and neck cancer. Am J Otolaryngol 1998;19:130-5.
|
| 32. | Sham ME, Nishat S. Imaging modalities in head and neck cancer patients overview. J Canc Res Expe Oncol 2011;3:22-5.
|
| 33. | King AD. Multimodality imaging of head and neck cancer. Cancer Imaging 2007;7:37-46.
|
| 34. | Ng SH, Ko SF. Imaging of Neck Metastasis. Chang Gung Med J 2006;29:2-7.
|
[Table 1], [Table 2]
| This article has been cited by | | 1 |
Correlation and accuracy of contrast-enhanced computed tomography in assessing depth of invasion of oral tongue carcinoma |
|
| S.Y. Chin,K. Kadir,N. Ibrahim,K. Rahmat | | International Journal of Oral and Maxillofacial Surgery. 2020; | | [Pubmed] | [DOI] | | | 2 |
Neurotheranostics as personalized medicines |
|
| Bhavesh D. Kevadiya,Brendan M. Ottemann,Midhun Ben Thomas,Insiya Mukadam,Saumya Nigam,JoEllyn McMillan,Santhi Gorantla,Tatiana K. Bronich,Benson Edagwa,Howard E. Gendelman | | Advanced Drug Delivery Reviews. 2018; | | [Pubmed] | [DOI] | | | 3 |
Role of MRI in Evaluation of Malignant Lesions of Tongue and Oral Cavity |
|
| Amandeep Singh,Chuni Lal Thukral,Kamlesh Gupta,Arvinder Singh Sood,Hanish Singla,Kunwarpal Singh | | Polish Journal of Radiology. 2017; 82: 92 | | [Pubmed] | [DOI] | | | 4 |
ADVANCED DIAGNOSTIC TECHNIQUES OF METASTATIC NECK LYMPH NODES |
|
| Maja Jocic,Sladana Petrovic,Dragan Stojanov | | Acta medica medianae. 2013; : 53 | | [Pubmed] | [DOI] | |
|
 |
|
|
|
Search Pubmed for