1. Role of Cross-Sectonal Imaging in the Preoperative Evalution of Laryngeal Cancer
Ajinkya Desai MD, Asha Bhatt MD, Parul Patel MD, Sarah Ifthikharuddin MD
ASNR 2016
eEde-135

2. Disclosures
None

3. Introduction
Laryngeal cancer is one of the most common cancers of the head and neck
Approximately 90% of laryngeal malignancy is due to squamous cell carcinoma, with lymphoma being the second most frequent diagnosis
The incidence of laryngeal cancer is highly associated with a history of smoking
Patients commonly present with hoarseness, however other clinical presentations include:
neck mass, dysphagia, stridor and hemoptysis
Steven Connor Article

4. Laryngeal Cancer: Diagnosis and Staging
Laryngoscopy is the gold standard to evaluate mucosal tumor burden and assess for vocal cord mobility
Cross sectional imaging is however critical for pre-operative staging
Cross sectional imaging allows the evaluation of
Extent of submucosal extension
Invasion of adjacent structures
Both CT and MRI are appropriate for the evaluation of laryngeal cancer. Choice of modality depends on availability, as well as radiologist and clinician preference/experience. This presentation will review the role of CT imaging in staging laryngeal cancer.
It is imperative that radiologists who interpret cross sectional imaging studies in laryngeal cancer patients have an understanding of:
Laryngeal anatomy
Patterns of tumor spread
Laryngeal cancer staging and associated imaging findings
How imaging findings and staging affects treatment

5. Laryngeal Cancer Treatment
Therapeutic options for laryngeal cancer include:
surgery, radiotherapy and chemotherapy (alone or in combination)
Low volume T1/T2 supraglottic and glottic tumors may be treated with radiotherapy alone
Advanced tumors typically require a combination of surgical and radiotherapy
Goal of surgical treatment is to treat the tumor while preserving the three primary functions of the larynx as much as possible:
breathing, swallowing and phonation
Surgical treatment options:
Partial, conservative excision, such as cordectomy partial laryngetomy or near total laryngectomy
Preservation of a portion of the larynx so vocal function is preserved as well as respiration (without tracheostomy) and swallowing
Total laryngectomy
Results in total loss of vocal function
Treatment decisions depend on
Tumor location
Disease stage
Patient needs and preferences

6. Review of Laryngeal Anatomy
The larynx is subdivided into three segments
Supraglottis
Epiglottis, aryepiglottic folds and false vocal cords
Preglottic space (fat density space between the hyoid bone anteriorly and epiglottis posteriorly)
Paraglottic space: paired fatty areas deep to the false vocal cords
Glottis
Consists of the true vocal cords and anterior and posterior commissures
Subglottis
Extends from the inferior portion of the true vocal cords to the inferior portion of the cricoid cartilage
Major laryngeal cartilages
Thyroid cartilage: largest laryngeal cartilage
Cricoid cartilage: at the level of the subglottis, the only complete ring of cartilage
Arytenoid cartilage: paired pyramid shape cartilages at the level of the glottis

7. Vallecula
Hyoid Bone
Paraglottic Space
False Cords
Supraglottis
Glottis
True Cords
Subglottis

8. Normal Laryngeal Anatomy: Supraglottis
Hyoid Bone
Valleculae
Paraglottic Space
Paraglottic Space
Epiglottis
Aryepiglottic Folds
Preglottic Space
Thyroid Cartilage
Paraglottic Space
Paraglottic Space
False Vocal Cords
Piriform Sinus

9. Normal Laryngeal Anatomy: Glottis and Subglottis
Anterior Commissure
True Vocal Cords
Thyroid Cartilage
Posterior Commisure
Arytenoid Cartilage
Glottis
Cricoid Cartilage
Cricoid Cartilage
Thyroid Gland
Subglottis

10. CT Staging of Laryngeal Cancer
Cross sectional imaging is critical in the pre-operative staging of laryngeal cancer
T staging of laryngeal cancer is crucial in selecting the appropriate treatment options
Accurate staging depends on specific imaging findings and guides management of laryngeal staging

11. T Stage T Stage Tumor extent and vocal cord (VC) mobility Supraglottic
Tumor limited to one supraglottic subsite with normal VC mobility T2
Tumor involves mucosa of more than one supraglottic subsite or glottis or extralaryngeal spread, with normal VC mobility T3
Tumor limited to larynx with VC fixation and/or invasion of postcricoid space, preglottic space, paraglottic space and/or minor thyroid cartilage erosion (inner cortex) T4
T4a: Tumor invades tissues beyond the larynx and/or laryngeal cartilage (trachea, tongue muscles, strap muscles, strap muscles or esophagus)
T4b: Tumor invades prevertebral space, encases carotid artery or invades mediastinal structures
Glottic
T1a: Tumor limited to one VC with normal mobility
T1b: Tumor involves both VC with normal mobility
Tumor extends to supraglottic and/or subglottic larynx or to region outside the supraglottis (with or without impaired VC mobility)
Tumor limited to the larynx with VC fixation and/or invades the paraglottic space and/or minor thyroid cartilage erosion (inner cortex)
T4a and T4b: Same as in supraglottic CA (see above)
Subglottic
Tumor limited to the subglottis
Tumor extends to the VCs with normal or impaired mobility
Tumor limited to the larynx with VC fixation
American Joint Committee on Cancer. Cancer staging manual. 6th ed. New York, NY: Springer-Verlag, 2002.

12. N Stage M Stage N Stage Regional lymph node (LN) findings M StageNX
Regional nodes cannot be assessed N0
No regional LN metastasis N1
Metastasis in a single ipsilateral LN, ≤ 3 cm in greatest dimension N2
N2a: Metastasis in a single ipsilateral lymph node, > 3 cm but < 6 cm in greatest dimension
N2b: Multiple ipsilateral lymph nodes, none > 6 cm in greatest dimension (N2b)
N2c: Bilateral or contralateral lymph nodes, none > 6 cm in greatest dimension N3
Metastasis in a lymph node > 6 cm in greatest dimension
M Stage
M Stage
Findings MX
Distant metastases cannot be assessed M0
No distant metastases M1
Distant metastases
American Joint Committee on Cancer. Cancer staging manual. 6th ed. New York, NY: Springer-Verlag, 2002.

13. Imaging Features
The following specific imaging features should be evaluated when staging laryngeal cancer on cross sectional imaging
Spread of tumor across the anatomic divisions of the larynx
Spread into the preglottic and paraglottic spaces
assessed by effacement of the normal fat in these spaces
Erosive changes or transmural spread through a laryngeal cartilage
most commonly the thyroid cartilage
Extralaryngeal spread
Nodal involvement
Distant metastasis
most commonly lungs

14. Thyroid Cartilage Erosion
Minor erosion of the thyroid cartilage:
invasion involving the inner cortex but not extending to the outer cortex
Lysis of the thyroid cartilage:
when the tumor invades the inner cortex and just reaches the outer cortex without invading it
Transmural spread:
When the tumor invades the thyroid cartilage and spreads to the extra-laryngeal tissue

15. Extralaryngeal Spread
Laryngeal cancer most commonly spreads outside the larynx through one of the following areas of inherent weakness within the larynx:
Thyrohyoid membrane
Inferior pharyngeal constrictor muscle
Cricothyroid membrane

16. Case Based Review

17. Case 1: 66 y/o male with long history of smoking presenting with right neck mass and throat pain for months A B C
There is a large right supraglottic mass (red arrow), involving the right paraglottic fat but sparing the preglottic fat. There is also extralaryngeal spread, noted by soft tissue density extending past the thyroid cartilage boundary (purple arrow).
Bone window shows extensive erosive changes involving the thyroid cartilage (yellow arrows).
There was no definite evidence for glottic or subglottic involvement; however, there was a palpable, enlarged metastatic node (blue arrow) marked by BB marker.

18. Case 1 Summary T Stage N stage: M stage: TNM : T4, N2, M0
Right supraglottic cancer with transmural extralaryngeal spread through the thyroid cartilage and without evidence for supraglottic or subglottic spread  T4
N stage:
Metastatic disease in a 3.3 cm ipsilateral level III jugulodiagastirc lymph node  N2
M stage:
No distant metastasis
TNM : T4, N2, M0
Patient underwent tracheostomy (due to airway compromise) and chemoradiation
Follow up imaging in 3 months status post chemoradiation showed decrease in tumor burden (red oval)

19. Case 2: 63 y/o male presents to the ED with difficulty breathing
Case 2: 63 y/o male presents to the ED with difficulty breathing. He had also noted hoarse voice and throat fullness in recent months. There was a history of laryngeal CA in the past and patient elected not to undergo total laryngectomy A B C
There is a right glottic mass with extension to the anterior and posterior commissures and marked airway narrowing (red oval).
On bone window, there is multifocal transmural erosive change involving the thyroid cartilage (yellow arrows).
Supraglottic spread involving the right aryepiglottic fold is present (blue arrow), there is no preglottic or paraglottic fat involvement.
and (E) Additionally, there is inferior extension to the subglottis (purple arrows). D E

20. Case 2 Summary D E T stage:
Right glottic tumor with transglottic spread, involvement of the anterior and posterior commissures and transmural extension through the thyroid cartilage
On laryngoscopy, there was fixation of the vocal cords.
 T4
Tracheostomy was performed due to marked airway obstruction
N stage: No nodal metastases  N0
M Stage: No distant metastasis  M0
TNM : T4, N0, M0
The patient refused surgery and underwent chemoradiation
Follow up CT scan performed 6 months after chemoradiation shows significant decrease in tumor burden at the level of the glottis (D) and subglottis (E) D E

21. Case 3: 76 y/o male with 50 year history of smoking, now presenting with hoarse voice (initial scan on 6/20/2011) A B C
There is a right supraglottic mass (red arrow) with involvement of the right paraglottic fat as well as partial effacement of the preglottic fat (yellow arrows). Note the preserved left paraglottic fat (purple arrow).
On bone window, there was no definite erosive change involving the right thyroid cartilage.
There was inferior extension to the right glottis (blue arrow).
Note the supraglottic (red arrow) and glottic (blue arrow) involvement on the coronal reformats. D

22. Case 3: Patient underwent chemoradiation Follow up scan on 10/1/2013 shows recurrent diseaseB C
There is progression with new involvement of the left vocal cord (red arrow) and anterior commissure (purple arrow).
There was new erosive change of the thyroid cartilage, especially anteriorly (blue arrows) .
Note the extralaryngeal spread of the tumor through the thyroid cartilage anteriorly (yellow arrow).

23. Case 3 Summary
T Stage:
Initial scan showed a right supraglottic and glottic mass with involvement of the right paraglottic and preglottic fat. No involvement of the thyroid cartilage or evidence for transmural spread  T3
The patient underwent chemoradiation, but 2 years later, there was progression of disease with new transmural laryngeal spread causing upstaging of the tumor  T4
No nodal or distant metastases were present on both studies
TNM: (T3, N0, M0)  (T4, N0, M0)

24. Case 4: Patient presenting with hoarsenessB C
There is a left glottic mass (yellow arrow).
There is extension to the supraglottis (red arrow) with infiltration of the left paraglottic fat posteriorly (blue arrow) and sparing of the preglottic fat (purple arrow).
There is also subglottic extension (red circle).
Additional findings: There was no definite evidence for thyroid cartilage
involvement. An enlarged left supraclavicular node was also noted.

25. Case 4 Summary T Stage: N Stage: M Stage: TNM: T3, N1, M0
Left glottic cancer with supraglottic and subglottic extension. The tumor involves the left paraglottic fat (T3)
N Stage:
There was a prominent left supraclavicular node measuring < 3.0 cm  N1
M Stage:
There were no distant metastasis  M0
TNM: T3, N1, M0
Patient underwent chemoradiation. Subsequent scans demonstrated post radiation change but not evidence for recurrent tumor

26. Case 5: 71 year old male with history of laryngeal cancer several years ago status post radiation therapy, now presenting with hoarseness A B C
There is a midline anterior and right sided glottic/subglottic mass (red arrows).
On bone window, there is periosteal reaction (blue arrows) involving the inner and outer cortex of the left anterior aspect of the thyroid cartilage (suggestive of transmural extension) and slight erosive change involving the left anterior aspect of the thyroid cartilage (yellow arrow).
There is involvement of the glottis noted as a subtle asymmetric prominence of the right true vocal cord (red arrow).
There is also more inferior extension into the subglottis (purple arrow). D

27. Case 5 Summary
T Stage:
Left glottic and subglottic cancer and probable transmural extension through the thyroid cartilage  T4
No lymph node involvement or distant metastasis
TNM: T4, N0, M0
Pathology demonstrated transmural extension through the thyroid cartilage.
The patient underwent radiation therapy and total laryngectomy

28. Case 6: Long history of smoking, now presenting with stridorB C
There is a large subglottic mass (blue arrows). There is extension into the soft tissues surrounding the cricoid and no clear fat plane between mass and esophagus (red oval).
On bone window, there is marked transmural erosive change involving the cricoid cartilage posteriorly and on the left (yellow arrows).
There is no evidence for extension to the glottis.
Pino Joseph MRN

29. Case 6 Summary
T Stage:
Right subglottic cancer with extralaryngeal spread through the cricothyroid membrane and loss of normal fat plane around the esophagus  T4
No lymph node involvement or distant metastasis
TNM : T4, N0, M0
Patient underwent total laryngectomy with postoperative chemoradiation

30. Case 7: Patient with history of laryngeal cancer treatment many years ago, now presenting with hypoxia and respiratory distress
There is a glottic mass involving both vocal cords, left greater than right (blue arrows).
On bone window there is erosive change involving the arytenoid cartilage (red arrows).
There was subglottic extension with erosive change seen at the central posterior aspect of the cricoid cartilage (yellow arrows).
There was also supragottic extension with involvement of both aryepiglottic folds (purple arrows). A B
Moses Cook C D

31. Case 7 Continued E
(E) There was further inferior extension of the mass with invasion of the left thyroid lobe (yellow arrow). An enlarged right supraclavicular node was also present (red arrow).
(F) In addition, there was more inferior and posterior extension of the mass to involve superior mediastinum. F

32. Case 7 Summary T Stage: N Stage: M stage: No distant metastasis
Tumor involving both vocal cords and eroding the cricoid and arytenoid cartilages
There is supraglottic and subglottic extension of the tumor as well as involvement of the left thyroid lobe and superior mediastinum  T4
N Stage:
Metastatic disease in a single supraclavicular lymph node which measures 1.7 cm  N2
M stage: No distant metastasis
TNM : T4b, N2c, M0
Non surgical candidate, no chemoradiation, patient was referred for palliative care

33. Case 8: 84 y/o male presenting with hoarseness of voice
Case 8: 84 y/o male presenting with hoarseness of voice. Laryngoscopy demonstrated a right laryngeal lesion A B
There is a right glottic mass with translaryngeal spread through the right thyroid cartilage (yellow arrows).
Bone windows demonstrate the extensive erosive change involving the right thyroid cartilage (red oval).
The mass extends superiorly to the supraglottic larynx (blue arrows).
Additionally, there is subglottic extension with asymmetric right anterolateral soft tissue thickening and extralaryngeal spread on the right (purple arrows). C D

34. Case 8 Summary
T stage:
Right glottic cancer with transglottic spread, transmural extralaryngeal spread through the right thyroid cartilage and infiltration of surrounding soft tissue structures  T4
No lymph node involvement or distant metastasis
TNM : T4a, N0, M0

35. Case 9: 72 y/o male with history of smoking, now presenting with 3-4 months of hoarsenessB
There is a right glottic mass (yellow arrow) with extension to the anterior commissure (blue arrow).
Bone windows at the same level demonstrate erosion of the thyroid (red arrows) cartilage compatible with transmural extension.
There is supraglottic extension with asymmetric soft tissue density in the right paralaglottic fat (red oval).
Bone windows at the same level demonstrate erosion of the right thyroid cartilage (purple arrow). C D

36. Case 9 Summary T Stage: No enlarged nodes or distant metastasis
Right glottic cancer with involvement of the left vocal cord, anterior commissure and extralaryngeal spread through the thyroid cartilage  T4
No enlarged nodes or distant metastasis
Patient underwent a total laryngectomy

37. Case 10: 69 y/o male with neck/throat painB
There is a right supraglottic mass at the level of the false VC with invasion of the preglottic and right paraglottic fat (red arrows). Note the normal appearance of the left paraglottic fat (yellow arrow).
There was also involvement of the right piriform sinus (red oval).
and (D) There was no subglottic or glottic involvement. C D

38. Case 10 Summary T Stage No nodal or distant metastasis T3 N0 M0
Right supraglottic mass at the level of the false VC with invasion of the preglottic and right paraglottic fat, No subglottic or glottic involvement  T3
No nodal or distant metastasis
T3 N0 M0
Patient underwent chemoradiation

39. Take Away Points
Cross sectional imaging plays a key role in the preoperative staging of laryngeal cancer
Imaging findings in combination with laryngoscopy findings are used to determine the optimal treatment for the patient
Radiologists interpreting CT exams in laryngeal cancer patients should be aware of laryngeal anatomy, as well key imaging features which affect staging in order to provide detailed and clinically relevant reports to clinicians
Key imaging features to evaluate in laryngeal cancer patients include:
Spread of tumor across the anatomic divisions of the larynx
Spread into the preglottic and paraglottic spaces
Erosive changes or transmural spread through a laryngeal cartilage
Extralaryngeal spread
Nodal involvement
Distant metastasis

40. References
Kuno H, Onaya H, Fujii S, Ojiri H, Otani K, Satake M. Primary staging of laryngeal and hypopharyngeal cancer: CT, MR imaging and dual-energy CT. Eur J Radiol. 2014;83(1):e23-35.
Connor S. Laryngeal cancer: how does the radiologist help?. Cancer Imaging. 2007;7:
Chu MM, Kositwattanarerk A, Lee DJ, et al. FDG PET with contrast-enhanced CT: a critical imaging tool for laryngeal carcinoma. Radiographics. 2010;30(5):
Ferreiro-argüelles C, Jiménez-juan L, Martínez-salazar JM, et al. CT findings after laryngectomy. Radiographics. 2008;28(3):
Dankbaar JW, Pameijer FA. Vocal cord paralysis: anatomy, imaging and pathology. Insights Imaging. 2014;5(6):
Joshi VM, Wadhwa V, Mukherji SK. Imaging in laryngeal cancers. Indian J Radiol Imaging. 2012;22(3):