Doctor notes Flashcards
What are the four stages of Head and neck cancer treatment?
- Diagnosis
- Therapy
- Follow-up
- Rehabilitation
What does smoking during RT effect?
LRC
OS
DFS
-Patients with high Hb do better, presumably because there is less hypoxia induced radio-resistance
Effect of drinking alcohol during RT?
- synergistic with smoking
- there is also a dose response with alcohol
Why is the Worldwide incidence of oro-pharyngeal cancer is going up despite reduction in smoking rates?
HPV associated H&N Ca
-increased incidence is secondary to changing lifestyle and changing sexual behaviour.
Characteristics of HPV associated H&N cancer?
1) non-keratinizing SCC
2) now-intermediate T stage
3) middle-aged white men, high socio-economic status
4) little/ no tobacco history
5) responds well to therapy (5 year OS Stage III & IV HPV
positive >80% compared with 40% for non HPV positive
disease)
P16 is a surrogate for HPV status
What is the natural history of head and neck cancer?
Clinical behavior depends on site of primary
Tend to recur locally, as opposed to metastasize, which dictates aggressive therapy to achieve local control.
Natural history of Head and neck cancer?
-Clinical behavior depends on site of primary
-Tend to recur locally, as opposed to metastasize, which dictates
aggressive therapy to achieve local control.
Diagnosis of head and neck cancer?
- Fine needle aspiration biopsy (cytology)
- Core Biopsy (histology)
- Incisional biopsy
- Excisional biopsy (to be avoided)
Staging investigations?
1) Investigations to assess the primary lesion and nodal spread
2) Investigations to confirm suitability for therapy
3) Investigations to exclude co-morbidity
How is CT utilised?
-Used to define the primary lesion, may give information about
the operability
-Information about nodal involvement
-Excludes distant metastase
How is MRI used?
-Good for soft tissue assessment (e.g BOT)
-PNI
-Base of skull involvement
-Intracranial extension
(useful sequences include non-contrasted T, contrasted T1 fat
suppressed and T2 with fat suppression)
How is PET used?
-May detect involved nodes that are morphologically normal
(which don’t meet CT criteria for pathological involvement)
-Excludes distant metastases
Pre treatment assessment?
• Pan-endoscopy & EUA Allows biopsy Can use to define primary lesion extent Exclude second primary (2.4-4.5%, more common with laryngeal or hypo-haryngeal primaries) • Dental assessment • OPG • Speech pathology • Social worker
Follow up?
• To detect salvageable recurrence or new H&N primary
• Side-effects of treatment
• Speech therapy
• Try to get them to STOP SMOKING!
• HPV epidemic means an increasing number of survivors.
• Emphasize regular dental care, therapy for dysphagia and
lymphedema
Histology types?
- SCC
- Adeno-carcinoma
- Adenoid cystic
- Muco-epidermoid
How would you treat a low risk T1-2 NOMO head and neck cancer?
Sole modality
- Wide local excision
- Radical resection +/- vascularised flap repair
- Transoral Robotic surgery (TORS) (currently investigational)
- Transoral LASER surgery (TLS)
When would you use sole modality RT and which types can be used?
1) elderly
2) those with poor performance status
IMRT, brachytherapy and altered fractionation
When would you used combined treatment modalities?
1) Medically inoperable
2) Un-resectable disease
3) Preservation of function
When would you use neoadjuvant therapy?
CT/RT +/- surgery for residual disease
Side-effects of radiation in the Head & Neck region: acute
• Lethargy • Nausea and vomiting • Skin erythema, initially dry desquamation, proceeding to moist desquamation • mucousitis, initially patchy, proceeding to confluent • Alteration in taste • Dysphagia • Odynophagia • Alteration in saliva consistency
Side-effects of radiation in the Head & Neck region: Late
• Xerostomia (if can keep parotid dose <25Gy, at 18 months, saliva is back to baseline). • Radiation caries • Second malignancy • Mucosal atrophy and fragility • Alopecia • Loss of sweating • Trismus • Atrophy of subcutaneous tissues • Endocrine abnormalities (hypothyroidism, hypo-pituitarism) • Osteoradionecrosis
IMRT voluming for head and neck cancer?
GTV = gross tumour identified clinically in conjunction with radiological information (from CT, MRI and PET imaging, which are often fused to help with voluming)
• CTV = GTV + 0.5mm is the margin to allow for microscopic
spread (this is “shaved” to remove structures which do not
need to be treated, e.g. bone)
• HRTV (in post-operative setting) = gross disease present preoperatively
+ 1 cm margin = HRCTV
• PTV = CTV + set-up error, which includes patient movement
and allows for beam characteristics (e.g. penumbra). PTV is a
geometrical construct. The more effective the immobilization,
the smaller the set-up error. For H&N tumours, 3-5mm CTV
to PTV margin is appropriate
Biological agents used for treatment of head and neck cancer?
• Cetuximab (EGFR inhibitor) monoclonal antibody.
single RCT Cetuximab/RT versus RT alone, with survival
advantage (10%) and local control advantage to
Cetuximab (but may actually be associated with more
toxicity). Still under investigation.
Indications for PORT?
1) Close margins ( < 5mm),
2) ≥ 2 nodes involved
3) pT3-pT4 tumours with negative margins
4) oral cavity lesion or oropharynx with level IV-V nodes
involved
5) peri-neural or LVI
