Post-treatment imaging appearances in head and neck cancer

Clinical information:
Histopathology:
TNM staging:
Surgery: Radical/ modified radical neck dissection, laser, no surgery
Reconstruction surgery: yes/ no
If yes, flap details:
Radiotherapy: yes/ no
If yes, type of radiotherapy

Primary site review:
Residual disease/ recurrence/ post-op change
Radiation induced sarcoma: latent period is 5 years, radiation induces SCC, lymphoma and meningioma

Post RT changes:
Acute post-RT changes (within 2-4 weeks): skin, platysma, neck space edema, enhancing salivary glands, enhancement of mucosal lining, increased attenuation of paralaryngeal fat
Subacute post-RT changes (few months to 18 months): chronic mucositis (polyps), chronic sialadenitis, i.e, loss of volume (virtually in ALL), especially parotids, fibrosis (may or may not enhance, stop enhancing after 18 months), persistent reactive nodes

Radionecrosis:
Sites: larynx, mandible, temporal bone, basisphenoid, maxillary bone
6- 15 months
Sclerosis, fragmentation, mottled appearance, sloughing, break of cartilage and bone with sequestration, pathological fracture, loss of trabeculae. Subluxation/ dislocation (of arytenoids). Soft tissue thickening, abscess, fistula, gas in the soft tissue. Enhancement of the adjacent muscles and fat.

Neurological changes:
Radiation cerebral necrosis: Deep white matter of medial and inferior temporal lobes or frontal lobes (depending on site of RT)
Brainstem encepahlopathy, myelopathy and transverse myelitis
RT induced brachial plexopathy
Traumatic neuroma
Denervation od V, XI and XII nerves

Reference:
Post-treatment imaging appearances in head and neck cancer patients