LYMPHATIC DRAINAGE IN THE HEAD & NECK Like other parts of the body, the head and neck contains lymph nodes (commonly called glands). Which form part of the overall Lymphatic Drainage system of the body. Lymph nodes are a possible route of spread for cancer cells (metastasis) when they break away from a primary tumour. Image reproduced with permission from Sheffield Hallam University Radiotherapy & Oncology
THE ASSESSMENT OF LYMPH NODE DISEASE It is important to assess if any lymph nodes are positive for metastatic disease (have cancerous cells in them) this is usually investigated by a range of means including: Clinical examination/palpation CT MRI Fine Needle aspiration Biopsy Surgical assessment & Biopsy Increasingly PET (Positron Emission Tomography) is used.
A glucose analogue with the positron-emitting radioactive isotope 18 F- FDG is injected into the patient. Then a PET scanner can form images of the distribution of FDG around the body. In essence the different concentrations of this 'tracer' visualised on the image indicate levels of metabolic activity in the tissues. Cancerous cells typically have a higher metabolic activity, and thus a greater uptake of glucose than normal tissue so these bright spots highlight the possibility of cancer metastasis. On the image below the primary tumour and larger metastatic lymph node are visible in both the CT image (Left) and the PET Image (Right) However a smaller lymph node metastasis is only revealed with the PET scan Image reproduced with permission from http://www.aboutcancer.com
STAGING OF THE DISEASE It is essential to accurately assess the stage of the cancer as this, along with the patients choice, is the key to deciding an appropriate plan of treatment and care. The commonly used staging method is the TNM system. Its is an expression of the anatomical extent of disease and is based on the assessment of 3 components: T = Tumour: the size and extent of local invasion of the primary tumour. N= Nodal Disease: The absence or presence of loco-regional disease: i.e. the number of involved lymph nodes, the size and extent of 'fixation' of any diseased nodes. M =Metastatic Disease The absence or presence of any distant spread to other parts of the body e.g. lungs, liver or brain
TNM STAGING FOR OROPHARYNGEAL AND ORAL CAVITY CARCINOMA Primary tumour (T): TX: Primary tumour cannot be assessed Tis: Pre invasive carcinoma (Carcinoma in situ) T0: No evidence of primary tumour T1: Tumour 2 cm or less in greatest dimension T2: Tumour more than 2 cm but not more than 4 cm in greatest dimension T3: Tumour more than 4 cm in greatest dimension T4: Tumour with extension to bone, muscle, skin, antrum, neck etc. UICC, International Union Against Cancer (2002) TNM Classification of Malignant Tumours. 6th ed.. New York: Wiley-Liss.
TNM STAGING FOR OROPHARYNGEAL AND ORAL CAVITY CARCINOMA Regional Lymph Nodes (N): NX: Regional lymph nodes cannot be assessed N0: No regional lymph node metastasis N1: Metastasis in a single ipsilateral lymph node, 3 cm or less in greatest dimension N2: Metastasis in a single ipsilateral lymph node, more than 3 cm but not more than 6 cm in greatest dimension; or in multiple ipsilateral lymph nodes, none more than 6 cm in greatest dimension; or in bilateral or contralateral lymph nodes, none more than 6 cm in greatest dimension N2a: Metastasis in a single ipsilateral lymph node more than 3 cm but not more than 6 cm in dimension N2b: Metastasis in multiple ipsilateral lymph nodes, none more than 6 cm in greatest dimension N2c: Metastasis in bilateral or contralateral lymph nodes, none more than 6 cm in greatest dimension N3: Metastasis in a lymph node more than 6 cm in greatest dimension UICC, International Union Against Cancer (2002) TNM Classification of Malignant Tumours. 6th ed.. New York: Wiley-Liss.
TNM STAGING FOR OROPHARYNGEAL AND ORAL CAVITY CARCINOMA Distant metastasis (M): MX: Distant metastasis cannot be assessed M0: No distant metastasis M1: Distant metastasis UICC, International Union Against Cancer (2002) TNM Classification of Malignant Tumours. 6th ed.. New York: Wiley-Liss.
LEVEL OF NODAL DISEASE Image reproduced with permission from http://www.aboutcancer.com
STAGE GROUPING: Stage I T1 N0 M0 Stage II T2 N0 M0 Stage III T3 N0 M0 T1 T2 T3 N1 M0 Stage IV T4 N0 N1 M0 Any T N2 N3 M0 Any T Any N M1 UICC, International Union Against Cancer (2002) TNM Classification of Malignant Tumours. 6th ed.. New York: Wiley-Liss.
NECK NODE CHAINS AS OUTLINED ON A CT PLANNING SCAN FOR RADIOTHERAPY Image reproduced with permission from Sheffield Hallam University Radiotherapy & Oncology
TRY LABELLING THESE ANATOMICAL STRUCTURES A- F & NODAL GROUPS G-K (OUTLINED IN YELLOW) A B C D E F G H I J K Image reproduced with permission from Sheffield Hallam University Radiotherapy & Oncology
ANSWERS Image reproduced with permission from Sheffield Hallam University Radiotherapy & Oncology Tongue Mandible (Ramus) Uvula Carotid Artery Jugular Vein Sterno Cleido Mastoid Muscle Facial Nodes Submandibular nodes Parotid nodes Carotid Sheath Internal Jugular Chain Superficial Cervical Chain Post (Deep) Cervical (Spinal Accessory Chain)
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