Larynx.pptx radiotherapy aiims gorakhpur

larynx

1. LARYNX DR. YAMINI BISHT JUNIOR RESIDENT DEPARTMENT OF RADIOTHERAPY AIIMS GORAKHPUR

2. ANATOMY

3. SUBDIVISIONS OF LARYNX PARTS SUPRAGLOTTIS GLOTTIS SUBGLOTTIS

4. Source: Perez and Brady

5. INCLUDES: epiglottis, false vocal cords, ventricles, aryepiglottic folds, and the arytenoids. SUPRAGLOTTIS The axial line of demarcation between the glottic and supraglottic: apex of the ventricle. LYMPHATIC DRAINAGE: Jugulodigastric (level II) lymph nodes Middle internal jugular chain (level III) lymph nodes. Source: Radiopaedia Coronal CT

6. Source: Radiopaedia Coronal CT

7. Includes: the floor of the ventricle, interarytenoid area, true vocal cords, and the anterior commissure. GLOTTIS The posterior commissure is the mucosa between the arytenoids (interarytenoid area). There are essentially no capillary lymphatics of the true vocal cords Source: Perez and Brady

8. Axial CECT at the level of Glottis

9. Located below the vocal cords SUBGLOTTIS Subglottis is extends from a point 5 mm below the free margin of the vocal cord to the inferior border of the cricoid cartilage or 10 mm below the apex of the ventricle. LYMPHATIC DRAINAGE: The lymphatic trunks pass through the cricothyroid membrane to the pretracheal (delphian) lymph nodes in the region of the thyroid isthmus. The subglottic area also drains to paratracheal (level VI) lymph nodes and inferior jugular (level IV) chain. Source: Perez and Brady

10. Formed by the hyoid bone, thyroid cartilage, and cricoid cartilage SHELL OF LARYNX Cricoid cartilage: complete ring of the upper airway. The more mobile interior framework is composed of : heart-shaped epiglottis and the arytenoid, corniculate, and cuneiform cartilages .

11. The external laryngeal framework is linked together by: Thyrohyoid, Cricothyroid, and Cricotracheal ligaments or membranes The epiglottis is joined superiorly to the hyoid bone by the hyoepiglottic ligament. Source: Perez and Brady

12. Axial CECT of larynx. C: carotid artery E: epiglottis J: Jugular vein PES: Periepiglottis space. T: thyroid cartilage, TAM: Thyroarytenoid muscle Coronal MDCT of larynx. C: carotid artery H: Hyoid bone. T: Thyroid Gland (below) cartilage (above), TAM: Thyroarytenoid muscle

13. CARCINOMA LARYNX

14. Cancer of the larynx represents about 2% of the total cancer burden and accounts for 0.3% of all cancer deaths EPIDEMIOLOGY AND RISK FACTORS Smoking Alcohol Consumption Asbestos Cement Dust Paint Fumes HPV (Human papillomavirus)

15. NEW CASES: 35,855 13 TH MOST COMMON DEATHS: 22,467 INCIDENCE (PER 100,000): 6.9 5 YEAR PREVALENCE: 97,099

16. PATTERNS OF SPREAD

17. LOCAL SPREAD The fat space is an important avenue of submucosal tumor spread for infrahyoid epiglottis, false cord, and true vocal cord lesions. Thyroid cartilage invasion usually occurs in the ossified section of the cartilage, commonly in the region of the anterior commissure tendon or the junction of the anterior one-fourth and the posterior three-fourths of the thyroid lamina . Fixation of the vocal cord from laryngeal cancer is usually caused by invasion or destruction of the vocal cord muscle, invasion of the cricoarytenoid muscle or joint, or, rarely, invasion of the recurrent laryngeal nerve . Glottic-subglottic carcinoma invading and enveloping the crico-arytenoid joint. The tumor shows medial to lateral growth through the conus elasticus: (A) Sagittal scheme; (B) Coronal scheme; (C) Axial T2-weighted MR image obtained at vocal process level demonstrates a right-sided true vocal cord tumor involving the inferior paraglottic space (arrowhead). The right arytenoid cartilage shows intermediate signal intensity alteration (asterisk) indicative of invasion; crico-arytenoid unit involvement is observed (arrow); (D) Axial T2-weighted sequence shows the subglottic spread of the neoplastic mass >10 mm; (E) Endoscopy at vocal cord level; (F) Endoscopy at subglottic level

18. Suprahyoid Epiglottis Supraglottic Larynx The destructive lesions tend to invade: The vallecula and preepiglottic space, The lateral pharyngeal walls The remainder of the supraglottic larynx. Source: Radiopaedia

19. Infrahyoid Epiglottis Lesions of the infrahyoid epiglottis invade the porous epiglottic cartilage and thyroepiglottic ligament into the preepiglottic fat space and extend toward the vallecula and base of the tongue . Lesions of the infrahyoid epiglottis grow circumferentially to involve the false cords, aryepiglottic folds, medial wall of the pyriform sinus, and the pharyngoepiglottic folds. Invasion of the anterior commissure and cords and anterior subglottic extension usually occur only in advanced lesions. Infrahyoid epiglottic lesions that extend onto or below the vocal cords are at a high risk for thyroid cartilage invasion, even if the cords are mobile. Source: Radiopaedia

20. False Cord They involve the paraglottic fat space early in their development and may spread a considerable distance beneath the mucosa without producing physical signs. These carcinomas extend to the perichondrium of the thyroid cartilage quite early, but cartilage invasion is a late phenomenon. Extension to the lower portion of the infrahyoid epiglottis and invasion of the preepiglottic space are common. Submucosal extension involves the true vocal cord, which may appear normal. Vocal cord invasion is often associated with thyroid cartilage invasion. Submucosal extension to the medial wall of the pyriform sinus occurs early. CT scan: heterogeneously enhancing mass lesion on the false vocal cords.  

21. Aryepiglottic Fold/Arytenoid Lesions extend to adjacent sites and eventually cause fixation of the larynx, which is usually a result of involvement of the cricoarytenoid muscle or joint or, rarely, invasion of the recurrent laryngeal nerve. Computed tomography (CT) may distinguish the cause of fixation. Advanced lesions invade the thyroid, epiglottic, and cricoid cartilages and eventually invade the pyriform sinus and postcricoid area. Supraglottic carcinoma encasing the arytenoid from above with fixation due to weight effect, without direct invasion of the CAU: (A) sagittal scheme. (B) Coronal T2-weighted MR image shows a supraglottic tumor that involves the superior paraglottic space on the right side (arrow) and invades the glottis. (C) Sagittal T2-weighted image demonstrates that the lesion encases the right arytenoid that appears diffusely hypointense because of sclerosis suspicious for invasion (arrowhead), without clear evidence of CAU involvement

22. Glottic Larynx Most lesions of the true vocal cord begin on the free margin and upper surface of the cord. The anterior portion of the cord is the most common site. If the lesion crosses to the opposite cord, anterior commissure invasion is certain Tumors at the anterior commissure may extend anteriorly via the anterior commissure tendon (Broyles ligament) Subglottic extension may occur by simple mucosal surface growth, but it more commonly occurs by submucosal penetration beneath the conus elasticus. Advanced glottic lesions eventually penetrate through the thyroid cartilage or via the cricothyroid space to enter the neck, where they may invade the thyroid gland . Glottic carcinoma invading the inferior paraglottic space and extending down to the CAU, limited medially by the conus elasticus and laterally by thyroid cartilage: (A) Coronal scheme; (B) Axial scheme; (C) Axial CE-CT at vocal process level: enhanced neoplastic tissue involves the left true vocal cord and anterior commissure; the inferior paraglottic space is obliterated (asterisk). Posteriorly, the lesion is close to the left arytenoid cartilage which shows slight sclerosis (arrow); (D) CE-CT reconstruction on the coronal plane: the lesion partially invades the left superior paraglottic space becoming a so-called transglottic tumor (arrowhead). Subglottic neoplastic spread > 10 mm is not present; (E) Endoscopic view

23. Subglottic Larynx Most involve the inferior surface of the vocal cords by the time they are diagnosed , so it is difficult to know whether the tumor started on the undersurface of the vocal cord or in the true subglottic larynx. They involve the cricoid cartilages in the early stage because there is no intervening muscle layer. Partial or complete fixation of one or both cords is common ; misdiagnosis or diagnostic delay is frequent. Transglottic-hypoglottic carcinoma with massive invasion of the crico-arytenoid unit and involvement of the posterior crico-arytenoid muscle, reaching the hypopharyngeal submucosa: (A) Axial scheme; (B) Axial CE-CT image at the level of the cricoid lamina shows a right-side neoplastic mass with homogeneous enhancement (asterisk). The right cricoid cartilage demonstrates sclerosis suspicious for neoplastic invasion (arrow); (C) Axial T2-weighted MR image at the same level: right cricoid cartilage shows signal alteration (arrowhead) similar to intermediate tumor signal intensity, indicative of invasion. The lesion extends to the right crico-thyroid space which appears enlarged (asterisk). Thyroid cartilage is invaded and extra-laryngeal neoplastic spread is observed (arrow);

24. Lymphatic Spread The disease spreads mainly to the level II nodes. The incidence of clinically positive nodes is 55% at the time of diagnosis; 16% are bilateral Spread to the pyriform sinus, vallecula, and base of the tongue increases the risk of lymph node metastases Glottic spread is typically associated with metastasis to the level II nodes. Anterior commissure and anterior subglottic invasion are also associated with involvement of the midline pretracheal lymph node (level VI)

25. Clinical presentation and Diagnosis

26. Clinical Presentation Hoarseness of Voice (early stage ) . Odynophagia, otalgia, pain localized to the thyroid cartilage, and airway obstruction are features of advanced lesions. Odynophagia , is the most frequent initial symptom, often described as a sore throat. Sensation of a “lump in the throat.” Pain is referred to the ear by way of the Arnold branch of the vagus nerve. A neck mass may be the first sign of a supraglottic cancer . Late symptoms: weight loss, halitosis, dysphagia, and aspiration.

27. Physical Examination Flexible fiberoptic endoscopes provide the best view of the larynx, hypopharynx, and posterior oropharynx. The scope is inserted through the nasal passage and passed over the nasopharyngeal side of the soft palate to provide a “bird’s-eye” view of the larynx The mucosal surfaces of the base of the tongue, posterior pharyngeal wall, vallecula, hypopharynx, supraglottis, glottis, and subglottis are examined. Vocal cord mobility is determined by asking the patient to say “ee” (adduction) and sniff in (abduction). Subtle distinctions between paresis and paralysis may require multiple examinations or stroboscopy.

28. Normal DL scopy Findings

29. Ulceration of the infrahyoid epiglottis or fullness of the vallecula is an indirect sign of preepiglottic space invasion . Palpation of diffuse, firm fullness above the thyroid notch with widening of the space between the hyoid and the thyroid cartilages signifies invasion of the preepiglottic space. The preepiglottic fat space is a low-density area on the CT scan, and changes resulting from tumor invasion are easily seen. Postcricoid extension may be suspected when the laryngeal click disappears on physical examination. Postcricoid tumor may cause the thyroid cartilage to protrude anteriorly, producing a fullness of the neck. Localized pain or tenderness to palpation or a small bulge over one ala of the thyroid cartilage is suggestive of thyroid cartilage invasion. Physical Examination

30. Imaging CT scan with contrast enhancement (method of choice) Should be performed before biopsy so that abnormalities that may be caused by the biopsy are not confused with tumor. CT slices 1 to 2 mm thick are obtained at 1- to 2-mm intervals through the larynx and at 3-mm intervals for the remainder of the study. The gantry is angled so that the scan slices are parallel to the plane of the true vocal cords. It is also necessary to obtain a CT scan of the entire neck to detect positive, nonpalpable lymph nodes.. Source: Radiopaedia

31. CT vs MRI Imaging CT is preferred to magnetic resonance (MR) imaging because the longer scanning time for MR results in motion artifact. The value of MR imaging includes: Defining subtle exolaryngeal spread or early cartilage destruction Extent of tracheal invasion and esophageal invasion . Sagittal MR may also be useful in detecting early invasion of the base of the tongue.

32. AJCC 2017 STAGING

33. PROGNOSTIC FACTORS The extent of the primary lesion and neck disease are the major determinants of prognosis. AJCC stage and N stage are the major determinants of cause-specific survival. In addition, within each N stage, patients with positive nodes in the low neck below the level of the thyroid notch tend to have a lower cause-specific survival rate than do those with disease confined to the upper neck. Women have a better prognosis than men.

34. RADIOTHERAPY SURGERY CHEMOTHERAPY TREATMENT

35. VOCAL CORD CARCINOMA STAGE RECOMMENDED TREATMENT CARCINOMA IN SITU RADIOTHERAPY> TLM (Transoral laser Microsurgery) EARLY STAGE (T1 & T2) RADIOTHERAPY WITH SALVAGE SURGERY MODERATELY ADVANCED (T3) (FAVOURABLE) RT with surgical salvage or immediate total laryngectomy ADVANCED (T3,T4) (UNFAVOURABLE) Total laryngectomy, with or without adjuvant RT and neck dissection
Definitive RT (medically unfit )

36. SURGERY SURGICAL MANGEMENT INDICATION DEFINITION Cordectomy (TLM or TORS) CARCINOMA INSITU Excision of the vocal cord Vertical partial laryngectomy (i.e., hemilaryngectomy) The maximum subglottic extension suitable for hemilaryngectomy is 8 to 9 mm anteriorly and 5 mm posteriorly Removal of limited cord lesions with preservation of voice Supracricoid partial laryngectomy T2 and T3 glottic carcinomas Removal of both true and false cords as well as the entire thyroid cartilage. Total laryngectomy with or without neck dissection ADVANCED STAGE The entire larynx is removed, and the pharynx is reconstructed. A permanent tracheostomy is required. Speech may be reconstituted with a prosthesis or with an electrolarynx

37. RADIATION THERAPY TECHNIQUES For T1 lesions, RT portals extend from the thyroid notch superiorly to the inferior border of the cricoid and fall off anteriorly. For T2 tumors, the field is extended depending on the anatomic distribution of the tumor The field size ranges from 4 × 4 cm to 5 × 5 cm (plus an additional 1.0 cm of “flash” anteriorly) and is occasionally 6 × 6 cm for a large T2 lesion. Portals larger than this increase the risk of edema without improving the cure rate. Source: Perez and Brady

38. RT of T3 and T4 lesions requires larger portals, which include the levels II and III lymph nodes. The level IV lymph nodes are included in a separate low-neck portal. Source: Perez and Brady

39. Treatment technique for postoperative RT after laryngectomy Source: Perez and Brady

40. Intensity modulated radiotherapy IMRT IMRT may be considered for T1, T2 glottic cancers to reduce the dose to carotid arteries Disadvantages: increased dose inhomogeneity, increased total body dose, and increased labor and expense. The most common indications for IMRT for laryngeal cancers is a node-positive T3–T4 cancer , where the retropharyngeal nodes would be electively irradiated and the dose to the contralateral parotid gland reduced, and/or a difficult low match between the lateral fields used to treat the primary site and upper neck and the anterior lowneck field in a patient with a short neck and large shoulders. . IMRT is especially useful for patients with extensive subglottic invasion , where achieving an adequate inferior margin with conventional lateral portals may not be possible. Source: Perez and Brady

41. DOSE FRACTIONATION 66 Gy for T1 lesions and 70 Gy for T2 cancers given in 2-Gy fractions. Evidence suggests that increasing the dose per fraction may improve the likelihood of local control Concomitant weekly cisplatin 30 mg/m 2 is considered for patients with T2B cancers.

42. SUPRAGLOTTIC CARCINOMA STAGE RECOMMENDED TREATMENT EARLY AND MODERATELY ADVANCED RT or supraglottic laryngectomy, with or without adjuvant RT. ADVANCED Total laryngectomy with or without adjuvant RT EXOPHYTIC ADVANCED LESIONS RT and concomitant chemotherapy,

43. SURGERY SURGICAL MANGEMENT INDICATION DEFINITION Supraglottic laryngectomy lesions involving the epiglottis, a single arytenoid, the aryepiglottic fold, or the false vocal cord Voice sparing laryngectomy with increased tendency to aspirate Supracricoid laryngectomy lesions extending from the supraglottis into one or both vocal cords. At least one arytenoid must be preserved for successful decannulation and phonation Total laryngectomy with or without neck dissection ADVANCED STAGE The entire larynx is removed, and the pharynx is reconstructed. A permanent tracheostomy is required. Speech may be reconstituted with a prosthesis or with an electrolarynx

44. The primary lesion and both sides of the neck are treated with opposed lateral portals Wedges are used to compensate for the contour of the neck. The lower neck nodes are irradiated through a separate anterior portal IMRT may be employed to spare one or both parotids and to avoid a low match line in the occasional patient with a short neck and large shoulders RADIATION THERAPY TECHNIQUES Source: Perez and Brady

45. Dose Fractionation Currently either hyperfractionation or simultaneous integrated boost (SIB) is used. SIB: 70 Gy in 35 fractions over 30 treatment days in 6 weeks with 1 twice-daily fraction during the last 5 weeks (with a minimum 6-hour interfraction interval). The high-risk clinical target volume (CTV) encompasses the gross disease The intermediate-risk CTV receives 63 Gy at 1.8 Gy per fraction The standard-risk CTV receives 56 Gy at 1.65 Gy per fraction. In the case of clinically positive nodes, an electron beam portal may be used to increase the dose to the posterior cervical nodes after the fields are reduced to avoid the spinal cord at 45 Gy if parallel opposed fields are employed.

46. Post Radiation Sequelae Sore throat, loss of taste, and moderate dryness during RT. Edema of the arytenoids may occur and give a sensation of a lump in the throat. Tracheostomy is rarely necessary, even for bulky lesions. Edema of the larynx may persist for several months to a year . (Most Common) . Corticosteroids such as dexamethasone have been used to reduce RT-induced edema after recurrence has been ruled out by biopsy. Approximately 30% treated with twice-a-day RT require temporary gastrostomy feeding tubes because they have difficulty in swallowing .

47. Follow Up Follow-up of patients with early lesions is planned for every 4 to 8 weeks for 2 years, every 3 months for the 3rd year, and every 6 months for years 4 and 5, and then annually for life. If recurrence is suspected but the biopsy is negative, patients are re-examined at 2- to 4-week intervals. Annual Chest Xrays to rule out lung metastasis TSH every 6-12 months CT is obtained 4 weeks after completing RT A neck dissection is added if the residual cancer in the nodes is believed to exceed 5%; otherwise, the patient is observed and a CT is repeated in 3 months. PET-CT is obtained at 3 months , and a neck dissection is added if persistent positive nodes are observed.

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