Guest Speaker - Rectal and Anal Flashcards
What are the treatment options for a ‘good’ (low risk tumour)?
Options:
Good – easy to remove
Will have surgery then short course RT.
What are the treatment options for a ‘bad’ (moderate/high risk tumour)?
Bad – RT to downstage – concurrent 45Gy in 25#, 50.4Gy in 28# with oral capecitabeine alone
Or total neo-adj with chemo 1-2 weeks later
Or RT alone 25Gy in 5# or 45Gy in 25#
OR
RT alone – same fractionation
What are the treatment options for a ‘very bad’ (high risk tumour)?
If patient wants to avoid surgery or they are not fit. Will use RT with aim of complete clinical response, 45Gy in 25#. Only around 20% success rate – not gold standard of care.
Post surgery RT is rare as removal of rectum will lead to the bowel dropping.
What are scan limits for rectal cancer?
- From L2/3 to 4cm below lesser trochanters
- (use oral or IV contrast)
Why would a full bladder patient be optimal?
- Lifts the bowel out of pelvis
- Also benefits the bladder dose
What is GTV P ?
- Primary tumour and involved extramural vascular invasion
What is GTV N?
- Includes involved nodes
What is CTV P composed of?
- GTV P + 10mm (maybe 15mm anteriorly)
What is CTV N?
- GTV N + 5mm
What is CTV Elec?
- All elective nodal groups combined
- 1cm anterior to the mesorectum
- Nodal compartments of the mesorectum (S2/3 junction), presacral, obuturator nodes and internal illiac nodes
What is the final CTV?
- CTV P + CTV N + CTV Elec
What is the PTV for rectal cancer?
- If daily imaging CTV final + 5mm
- If offline/non-daily +10mm
When would radiotherapy be used for anal cancer?
- For curative intent
- With concurrent chemo-radiotherapy (either 5FU and MMC or capeceitabine and MMC)
- Surgery used as salvage if poor response
- Post surgery
What doses of RT will be used for anal cancer?
- Depends on TNM
- T1/2 N0/1 = 50.4Gy in 28#
- T3/4 or N2/N3 - 53.2Gy in 28#
Why do we use 5FU for higher risk cancers?
- Cannot take 5FU back, cannot stop it so will always complete a full course
What are the scan limits for anal cancer?
-L2/3 to 3cm below the anal marker
What is the bladder status for anal cancer?
- Full bladder is the national standard
What is self bolusing ?
- Buttocks cover the tumour
What is setons?
- Wires
- Stops a fistula from healing itself
What is CTV_A?
- GTV_A + 10mm
(ACT 3 and 4) - GTV_A + 15mm (ACT 5)
What is CTV_N? (anal)
- GTV_N + 5mm
ACT 5
What is CTV_E (anal)?
- Elective nodal regions
What are imaging protocols for anal cancer?
- Cone beam CT imaging/ 3D
- Daily imaging needed
How are palliative rectal and anal cancer patients treated?
- long term control vs symptom management
- Metastatic: control of primary vs symptom management
- Re-treatment, previous radical treatment, now recurrence and symptomatic - will require dose calc
- Consider SABR
- Radical conformal planning will be considered
