radiotherapy and surgical neck node management in head and neck cancers

1. Management of neck nodes in
head and neck cancers
MANAGEMENT OF NECK NODES
Dr. Ankita Pandey
1

2. • The head and neck region has a rich network
of lymphatic vessels draining from the base of
the skull through the jugular nodes, spinal
accessory nodes, and transverse cervical
nodes
• The thoracic duct on the left side and the
lymphatic duct on the right side.
2

3. • The incidence of lymph node metastasis
depends upon relative density of the capillary
lymphatic network.
• The lymphatic drainage is mainly ipsilateral,
but structures such as the soft palate, tonsils,
base of the tongue, posterior pharyngeal wall,
and nasopharynx have bilateral drainage
• True vocal cord, paranasal sinuses, and middle
ear have few or no lymphatic vessels at all
3

4. LN levels
4

5. Imaging of the neck
• CT
• MRI
• PET-CT
• USG neck
5

6. • A lymph node is considered suspicious based on several
criteria:
1. a smallest transverse diameter of more than 10 mm (5–8
mm for retropharyngeal lymph nodes and 12–15 mm for
upper jugular lymph nodes [level II])
2. central necrosis irrespective of the size
3. rounded rather than oval shape
4. loss of fatty hilum
5. Visible peripheral extensions showing evidence of
extracapsular spread
6. the presence of more than three lymph nodes of size
between 6 and 8 mm grouped
6

7. Staging of neck node metastasis
7

8. 8

9. The risk of lymph node metastases is
influenced by -
the location of the primary tumor
histological differentiation
size of the lesion
9

10. 10

11. 11

12. Incidence of involvement of level V LN
• Except for nasopharyngeal tumors, involvement
of ipsilateral level V nodes is rare
• oral cavity tumors = <1%
• oropharyngeal and laryngeal tumors = <10%
• hypopharyngeal tumors = 15%.
• It almost never occurs in contralateral level V
nodes
12

13. Retropharyngeal LN involvement
• not clinically palpable
•Identified on imaging
•Involvement occurs in primary tumors arising from mucosa of
occipital and cervical somites like nasopharynx, pharyngeal wall,
soft palate
•Involvement is higher in N+ cases
13

14. VIIb: Retrostyloid
• Cranially base of skull and
extends caudally upto C1
verteberae
• Drains nasopharynx
VIIa: lateral
Retropharyngeal
• Starts from inferior level
of C1 and caudally upto
superior edge of the
hyoid bone
• Drains nasopharynx, soft
palate, tonsillar fossa,
posterior pharyngeal wall
14

15. Risk group classification in cN0 neck
15

16. HOW TO SELECT BETWEEN RT AND DISSECTION IN NODE NEGATIVE
CASES?
Radiation
oncologist
Surgical
oncologist
I will
give RT
I will do
dissection
Elective neck radiotherapy (RT) has local control (LC)
rates similar to elective neck dissection, and neither has
an effect on survival ( control rate >90%)
16

17. The decision between RT and dissection is given according
to the treatment method for the primary disease
HOW TO SELECT BETWEEN RT AND DISSECTION?
PRIMARY TUMOR IS
TREATED BY
RADIATION
PRIMARY TUMOR IS
TREATED BY
SURGERY
Elective Neck
irradiation
Elective Neck
dissection
The basic rule that should govern the choice between surgery and radiotherapy (RT) is
to favor a single-modality treatment if possible, avoiding overtreatment.
17

18. Treatment algorithm for clinically N0 neck
18

19. Irradiation of
neck
Node negative cases Node positive cases
Elective neck irradiation
Preoperatively or
postoperatively
Depends on the
estimated risk of
subclinical disease
influenced by the number
of lymph nodes, size, and
location.
19

20. Elective Radiation Therapy depends on-
Site and size of the primary lesion
Histological grade
Relative morbidity for adding lymph node coverage
Likelihood of the patient’s returning for follow-up
examinations
Suitability of the patient for a radical neck dissection if the tumor appears
in the neck at a later date
20

21. Risk criteria for elective LN irradiation
• the risk of subclinical disease is 20% or greater
• receive elective neck irradiation to a minimum
dose equivalent to 50-54Gy during 4.5 to 5
weeks
21

22. DO NOT REQUIRE
ELECTIVE RT IN NODE
NEGATIVE CASES
22

23. IPSILATERAL OR BILATERAL NECK
IRRADIATION
Elective nodal
irradiation is
considered
23

24. 24

25. Indications for involvement of contralateral
nodes
Midline tumors like Ca base of tongue,
hypopharyngeal or nasopharyngeal cancer
Tumors approaching or crossing midline
Ipsilateral high tumor burden
N2c / N3 disease
25

26. Lateralised tumours treated
by I/L neck irradiation
• salivary gland
• tonsil
• Paranasal sinus
• middle ear tumors
• small tumors of the buccal
mucosa and retromolar
trigone
• Small tumors of oral tongue
tumors not exceeding
midline
Midline tumours or Tumours
of continuous mucosal
structure treated by B/L neck
irradiation
• nasopharynx
• supraglottic
• infraglottic larynx
• hypopharynx
• soft palate
• base of tongue
• Oral tongue
Ipsilateral or bilateral elective neck irradiation
26

27. Target Volume Determination and Delineation
Guidelines
• Gross Tumor Volume for Lymph Nodes (GTVn ):
It include the grossly involved lymph nodes
detected by clinical examination, CT, MRI,
PET/CT
• CTV for lymph nodes-
Different guidelines has been published
27

28. Why we need guidelines for selection of CTV
Data on clinical and pathologic
neck node distribution as well
as on neck recurrences after
selective dissection procedures
support the concept that not all
nodal levels should be treated
as part of initial management
strategy
28

29. DAHANCA guideline
Margin of 5mm
around GTV
Margin of 10mm
around GTV
Contains CTV2 and
regional elective
lymph nodes
without margin
For the N+ patients, the elective nodal regions are extended 2 cm
cranial and caudal from any pathological lymph nodes (GTV-N)
29

30. 30

31. MD Anderson cancer centre guideline
Dose prescription
CTV 1 = 70Gy/35# or 70Gy /33#
CTV 2 = 63Gy/35# or 59.4Gy/33#
CTV 3 = 56Gy/33# or 54Gy/33#
31

32. CTV LR
CTV HR
32

33. • CTV HR= a margin of 5 mm around the lymph
node metastasis.
• In the case of lymph node metastasis
shrinking after induction chemotherapy, the
CTV-N-HR to be delineated corresponds to the
initial region of the GTV-N before
chemotherapy plus 5 mm
Studies have shown that 5mm margin covers microscopic disease in 96-97%
of cases
33

34. • CTV LR = all LN levels that have a probability to
contain occult metastases of >10–15%
• For clinical lymph node positive (cN+)
patients, it is recommended to extend the
CTV-N-LR to include the adjacent levels
34

35. Level V is not
included
35

36. 36

37. CERVICAL LN DISSECTION
37

38. Classification of neck dissection
38

39. Type of neck dissection
39

40. Selective neck dissection
• The most commonly performed
surgical neck treatment of neck
lymphatics
• preserving all nonlymphatic
structures and only removing the
high-risk lymphatic levels
• The levels to be removed are
determined by site of cancer
• Levels I to III are addressed for oral
cavity cancers.
• Levels II to IV are included for
treatment of oropharyngeal,
laryngeal, and hypopharyngeal
cancers. 40

41. 41

42. Sentinal LN biopsy in node negative cases
•recently introduced method
•The concept is based on identification of the primary
echelon of lymphatic drainage followed by the harvest of the
sentinel lymph node within this basin only, assuming that if
the sentinel lymph node is negative, there is no need for a
comprehensive neck dissection.
•SLNB has been shown to improve staging of cN0 tumors in
patients with early squamous cell carcinoma of the oral
cavity and oropharynx by identifying micrometastases
•sensitivity = 93%
•NPV = 80% to 100%. 42

43. Indications of post operarive RT/CCRT
positive or close margins
extracapsular extension
multiple positive nodes
lymphovascular space invasion
perineural invasion
bone or cartilage invasion
extension into the soft tissues of the neck
invasion of the apex of the pyriform sinus
subglottic extension of 1 cm or more
43

44. How is CTV LN selected in post
operative cases?
44

45. • Too selective selection and delineation of the CTV may
lead to an unacceptable high rate of loco-regional
recurrences
• The entire operative bed should be covered, especially
in case of ECE, as tumors cells might have spilled during
surgery
• In case of pathological involvement of level II include
the retrostyloid space up to the base of skull
• In case of pathological involvement of level IV or Vb,
include the supraclavicular fossa in the CTV
45

46. • When a pathological lymph
node abuts or invades a muscle
not removed in RND or MRND, it
is recommended to include this
muscle into the CTV, at least for
the entire invaded level.
• When a pathological lymph
node is located at the boundary
with a level which has not been
dissected it is recommended to
extend the CTV to include the
adjacent level
46

47. • Author concluded that,
• In the post-operative setting, there is still
ongoing debate whether the full operative
bed should receive a prophylactic dose, with a
boost dose being only applied to the neck
node levels with pathological infiltration, or
whether the entire neck should received a full
dose.
47

48. I, II and III refers to elective nodal regions
DAHANCA guideline
48

49. R0 case
Stage is the only indication for post-
operative radiotherapy (R0) and thus,
no CTV1 is present
CTV 2= 10mm margin around preop
GTV
Tumor removed completely with free
margins
Indications of RT are T3/T4 ds or N2/N3 ds
Pre op
gross node
49

50. R1/2 resection case/ ENE+
5mm margin is given
around surgical bed to
form HR CTV
5mm margin is given
around CTV HR to form IR
CTV
50

51. R1/R2 resection –
margin of 5mm given
to form CTV1
In case of ill defined
nodal region, entire
nodal level is taken in
CTV 2
CTV 3 is elective nodal
irradiation
51

52. North American institutions and cooperative
group guidelines
• The high-risk CTV (CTV66) is defined as the volume harboring
ENE
• The intermediate-risk CTV (CTV60) is defined as the volume
that includes regions of grossly involved adenopathy . The
target volume should include pathologically positive hemineck
• The low-risk CTV (CTV54–56) usually includes the
prophylactically treated neck felt to have a low risk of
harboring microscopic disease
52

53. 53

54. 54

55. CARCINOMA ORAL CAVITY
55

56. Oral tongue
Floor of mouth
Buccal mucosa
Retromolar trigone
Lip
Level I to IV
Retrostyloid space
Medial portion of lower lip
drain in submental nodes
Lateral portion in
submandibular nodes
Upper lip in preauricular,
periparotid, submental and
submandibular nodes
56

57. Elective nodal dissection vs observation in early stage oral
cavity tumors
• Randomised trial by Tata memorial centre, mumbai
Node negative early
stage oral cavity
tumors
Elective neck dissection at
time of primary cancer
surgery
Watchful waiting with therapeutic
neck dissection for nodal relapse
12.5% benefit in OS
23.6% benefit in DFS
With elective neck dissection
57

58. Oral tongue and floor of
mouth
Elective B/L LN irradiation
in N0 cases
For well lateralized oral cavity
tumors ,the general probability
for contralateral lymph node
metastases is typically low
below 10%
Ipsilateral elective LN
irradiation
Note – early lesion of oral tongue well lateralised ,
ipsilateral neck dissection is considered
58

59. Carcinoma lip
59

60. Lymphatic spread is to the level-I and level-II lymph nodes
60

61. Carcinoma oral tongue
• Most common site of LN involvement is level II
followed by level Ib
• 4% of cases presents with contralateral LN mets
• Skip metastasis occur
• Hence, B/L LN are at risk of involvement depending
upon size of lesion
• DOI >4mm carries high chances of LN mets
61

62. Oral cavity tumors except carcinoma lip
62

63. Oral cavity tumors except carcinoma lip
63

64. 64

65. CARCINOMA NASOPHARYNX
65

66. Bilateral metastasis in
50% of cases
66

67. 67

68. CARCINOMA OROPHARYNX
68

69. Carcinoma of Oropharynx
The overall incidence of lymph node metastases is over 60%
soft palate
posterior pharyngeal wall
base of tongue
bilateral neck
treatment
Ca tonsil
Ipsilateral neck
irradiation
69

70. bilateral level II to IV
are included
Inclusion of level V
depends on LN
burden status
70

71. • The inclusion of the retropharyngeal nodes
routinely in the low-risk PTV is controversial as
it often increases radiation dose to the
pharyngeal constrictors, which has been
associated with dysphagia and should depend
on the extent of the primary tumor and
cervical lymphadenopathy.
71

72. 72

73. Problems with conventional neck
irradiation
Lateral fields and LAN portals are
matched at thyroid notch
To include gross LN the lateral
(primary) portals are enlarged
inferiorly it unnecessarily include
larynx in the lateral portals
Because the midneck is smaller in circumference than the upper neck, the
total dose and dose per fraction are higher in the larynx
73

74. cT1N0 well-lateralized
squamous cell
carcinoma of the left
tonsil
the nodal CTV can be
limited to ipsilateral
levels II–IV, ipsilateral
lateral retropharyngeal
lymph nodes
Case 1
74

75. HYPOPHARYNGEAL CANCERS
75

76. Few facts
• more than 50% of patients will manifest clinically positive
cervical lymph nodes at the time of diagnosis
• 30% to 40% of N0 necks harbor micrometastatic disease
when electively dissected
• levels II to IV, as well as retropharyngeal nodes are all at
high risk of harboring regional metastases
• In light of cross-draining lymphatics, there is a significant
risk of bilateral cervical node metastasis
76

77. Nodal distribution in carcinoma hypopharynx
77

78. GLOTTIC CARCINOMA
78

79. T1-2,N0
Because the risk of subclinical
disease in the cervical lymphatics is
low, the portals are limited to the
primary lesion
T3-4,N0
Because of a 20–25% risk of
subclinical involvement of the
level II or level III lymph nodes
electively treated to a dose
of approximately 50 Gy
Elective neck node
irradiation is not done
79

80. Supraglottic cancer
• Even small cancers of the supraglottic larynx are at high
risk for harboring regional lymphatic disease, hence
treatment of the entire cervical neck is generally
recommended
• If the neck is clinically negative and tumor does not
extend beyond the larynx, only the level-II and level-III
nodes are included in the high-risk CTV
• Level IB, level IV, level V and the retropharyngeal lymph
nodes are included in the low-risk CTV
80

81. Case 2
• Clinically node positive multiple cervical
lymphadenopathy
• Primary tumor treated by radiotherapy
• Residual disease in neck
PLAN= RT to primary disease and neck LN followed by neck
dissection
81

82. • The decision to add a neck dissection after RT
for multiple unilateral positive nodes or
bilateral lymph node disease is individualized
and is based on
1. the diameter of the largest node
2. node fixation
3. number of clinically positive nodes in the
neck
82

83. • If clinically positive lymph nodes disappear
completely during RT, the likelihood of control
by RT alone is improved and a neck dissection
may be withheld
83

84. • If a neck dissection is planned to follow RT in
patients with clinically positive lymph nodes,
the preoperative dose varies with the size and
location of the lymph node, fixation, and
response to RT.
Size of LN Pre op dose
3-4cm 50Gy
5-6cm and fixed nodes 60Gy
7-8cm >70Gy
84

85. • Patients with bilateral neck disease require
individualized treatment planning jointly by
the radiation oncologist and the surgeon.
• If disease is minimal on one side, RT alone
may be used to control the disease on that
side of the neck, and a neck dissection may be
used on the side with more disease.
• If major bilateral disease is present, bilateral
neck dissection should follow RT.
85

86. 86

87. Take home message
Although guidelines are meant to be applied
to the vast majority of patients, there will
always be individual cases for whom sound
clinical data preclude their use. More than
ever, oncologic knowledge and wisdom are
requested for appropriate use of the
recommendations proposed by guidelines.
87

88. Thank you
88