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MANAGEMENT OF THE NECK NODES WITH OCCULT PRIMARY
Dr rekha aryaModerator:-dr anurita
DEFINITION
Carcinomas with an unknown primary site Carcinomas with an unknown primary site (CUP) are tumors that present with lymph (CUP) are tumors that present with lymph
node or distant metastases when node or distant metastases when appropriate investigations fail toappropriate investigations fail to
localize a primary sitelocalize a primary site..
FNAC
Sqamous cell carcinoma,
Adenocarcinoma,
Undifferenciated
Poorly differenciated
Anaplastic carcinoma
FNACLymphoma
SCC suspecting
that primary is in head and neck
EPIDEMOLOGY AND ETIOLOGY Exact incidence is unknown.
POINTS TO CONSIDER WHEN LOOKING FOR A PRIMARY 1) Location of lymph nodes2) Lymphatic drainage of the region3) Possible location of the primary tumor
(hidden sites)4) Histology of nodes5) Past history (relevant)
1) LYMPHATICS
Profuse capillary lymphatic network present in
Nasopharynx & Pyriform sinus Paranasal sinuses, middle ear and true vocal
cords have sparse capillary lymphatics
2) RISK GROUPS BASED ON LOCATION AND SIZE OF PRIMARY TUMOR
Group
Estimated Risk of Subclinical Neck Disease % Stage Site
Low risk <20 T1 FOM, RMT, gingiva, hard palate, buccal mucosa
Intermediate risk
20-30 T1 Oral tongue, soft palate, pharyngeal wall, supraglottic larynx, tonsil
T2 FOM, oral tongue, RMT, gingiva, hard palate, BM
High risk >30 T1-4 Nasopharynx, Pyriform sinus, BOT
T2-4 Soft palate, pharyngeal wall, supraglottic larynx, tonsil
T3-4 FOM, oral tongue, RMT, gingiva, hard palate, BM
3) HISTOLOGICAL DIFFERENTIATION
Proposed explanations for inability to detect the occult primary
The primary tumor may have involuted spontaneously and is no longer detectable, despite the presence of metastatic disease.
The malignant phenotype of the primary tumor favors metastatic biologic behavior over local tumor growth.
In evaluating metastatic SCC to cervical lymph nodes, the occult primary is eventually detected in about half of the cohort.
ROUTES OF SPREAD
Diagnostic work up
DIAGNOSTIC WORKUP History
Physical examination
Careful examination of the neck and supraclavicular regions with attention to skin
Examination of oral cavity, pharynx, and larynx
Mirror & fiberoptic examination to visualise nasopharynx,oropharynx,hypopharynx,larynx
Radiological Studies Chest imaging CT with contrast or MRI with Gd (skull base through thoracic
inlet) PET CT scan (If other tests do not reveal a primary)
Laboratory studies Complete blood cell count Blood chemistry profile
HPV testing (Suggestive of occult primary in BOT or Tonsil, helps in customize radiation targets)
EBV testing
EVIDENCE ON ROLE OF PET CT In a meta-analysis of 16 studies looking at the
role of PET in 302 patients with cervical node metastases where a primary has yet to be discovered through the work up, 25%25% of primaries are identified through PET. Previously unrecognized regional or distant metastases were identified in 27% of patients
Rusthoven, KE, Koshy, M, Paulino, AC, The role of fluorodeoxyglucose PET in cervical lymph node metastases from an unknown primary tumor. Cancer 2004; 101:2461
CHARACTERISTICS OF FDG-PET IMAGING
FNACFNAC
SCC
H & N exam ,radiological studies
Primary found Primary Primary
not foundnot found
MANAGMENT
IF ONLY CN1+ Selective or modified radical neck dissection
ADVANTAGE1) Directs pathology2) Post-op RT dose is lower
DISADVANTAGE1) Surgical morbidity
If no additional lymphadenopathy or extracapsular extension (ECE) - observe
If >2 LN or ECE: post-op RT or chemo-RT
IF > CN2+ Early N2 disease (N2A, early N2B): RT
Advanced N2-N3: chemo-RT
PET/CT 8 weeks after RT or chemo-RT
Risk of residual disease <5% : observe Risk of residual disease >5% 1. Nodes >15 mm, 2. Focal lucency,3. Enhancement or calcification in lymph node, 4. ECE or nodal rupture : neck dissection
NECESSITY FOR ADJUVANT NECK DISSECTION IN SETTING OF CONCURRENT CHEMORADIATION FOR ADVANCED HEAD-AND-NECK CANCER.BRIZEL DM1, PROSNITZ RG, HUNTER S, FISHER SR, CLOUGH RL, DOWNEY MA, SCHER RL.
A total of 154 patients received concurrent chemoradiation. Of these, 108 presented with nodal disease: N1, n = 30; and N2-N3, n = 78. MND was performed in 65 (60%) of 108 patients. The median follow-up was 4 years. The 4-year disease-free survival rate was 75% for N2-N3 patients who had a cCR and underwent MND vs. 53% for patients who had a cCR but did not undergo MND (p = 0.08). The 4-year overall survival rate was 77% vs. 50% for these two groups of patients (p = 0.04).
Int J Radiat Oncol Biol Phys. 2004 Apr 1;58(5):1418-
23.
STUDIES OF POSTRADIOTHERAPY NECK DISSECTION Narayan et al. (1999): Clayman et al. (2001): Brizel (IJROBP 2004): Liauw et al. (2006): Yao et al. (2007): Van der Putten et al. (2009):
NECK DISSECTIONS Radical Gold standard operation
Modified radical Preservation of non lymphatic
structures
Selective Preservation of lymph node
groups
Extended Removal of additional lymph
node groups or non lymphatic structures
Post surgery management depends upon:- 1)Stage 2) Level of LN 3)Presence of extracapsular extension
Typically irradiate nasopharynx, oropharynx, and both sides of neck
Hypopharynx and larynx were irradiated historically; eliminated more recently because they are rarely the primary site and including these sites greatly increases morbidity of treatment
Consider hypopharyngeal and laryngeal irradiation for adenopathy centered in level III/IV
Oral cavity is not irradiated unless submandibular lymphadenopathy is present
If submandibular lymphadenopathy: perform neck dissection and observe, or irradiate oral cavity and oropharynx but not nasopharynx
CONVENTIONAL RADIOTHERAPY PLANNING
Simulation and field designPatient set-up:
supine, hyperextend head, may need bolus, shoulders pulled down with straps, immobilization with thermoplastic mask or bite block.
Volumes:
Nasopharynx,oropharynx,bilateral retropharyngeal nodes and levels IB-IV, ipsilateral ± contralateral supraclavicular nodes
Include oral cavity only if submandibular adenopathy present,and may eliminate nasopharynx in that case
CONVENTIONAL BORDERSUpper Neck FieldsParallel -opposed lateral fields at 1.8–2 Gy/fraction
Superior = covers nasopharynx and level Ib and V to base of tongue
Posterior = behind spinous processes to C2 , cord shielded after 40–44 Gy, with posterior electron field matching to therequired target dose
Anterior = 2 cm margin on nasopharynx and the base of tongue; shield skin and subcutaneous tissue of submentum as much as possible
Inferior = thyroid notch
Lower Neck Fields
Superiorly - the field should match the upper fields with an isocentric or half-beam block technique, Inferior border - including the clavicular heads.
Laterally, the field should cover the medial or entire supraclavicular region, depending on the extent of nodal involvement.
A laryngeal block may be placed to spare the larynx and hypopharynx .
IMRT for HNCUP has survival rates comparable to those with conventional radiotherapy.
By using IMRT the degree of toxicity can be reduced compared with conventional methods.
High OS, DFS, and nodal control can be
achieved for patients with T0N1 or T0N2a disease without ECE spread.
Patients with extra capsular spread or bulky T0N2b–c or T0N3 disease have a worse prognosis and may benefit from the addition of more cytotoxic chemotherapy,molecular targeted therapy, and/or accelerated radiation regimens.
DOSES
COMPLICATIONS
SurgicalOperative mortality 2–3%Morbidity = infection, hematoma/seroma, lymphedema, wound dehiscence, chyle fistula, pharyngocutaneous fistula, cranial nerve VII, X, XI, XII injury, carotid exposure, or rupture
Incidence of complications is greater with RT doses >60 Gy Radiation therapyAcute and chronic mucositis, xerostomiaSkin reactionSubcutaneous fibrosis
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THANK YOU
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