Radiotherapy is used in the adjuvant setting although there is no prospective or randomised trials for its use. Doses should be 50.4-54 Gy to subclinical disease (nodes, tumour bed) with a boost to 60 Gy for macroscopic disease.
Adjuvant Radiotherapy
Presimulation
Consider differential evaluation of renal function.
Informed consent.
Simulation
Positioning
Supine
Immobilisation
Hands raised on wing board
Kneefix
Bolus/Modifiers
Not required
Image Acquisition
CT scan from hilum to acetabulum, 3 mm slices, with IV contrast.
- Consider 4D CT or fluoroscopy to evaluate ITV
Planning
Volumes
GTV = Gross residual disease
CTVp = Tumour Bed
CTVn = Regional nodes (porta hepatis, coeliac axis, peripancreatic)
ITV = CTV + 1 cm (sup/inf) or based on movement seen on 4D CT/fluoroscopy
PTV54 = ITV + 0.5 cm
PTV60 (boost) = GTV + 1.5 - 2.5 cm expansion if needed
Organs at Risk
Liver < 32 Gy mean dose
Kidney < 18 Gy mean dose (or < 6 Gy if one kidney > 18 Gy)
Peritoneum - volume receiving > 45 Gy is no greater than 195 cc
Stomach - < 55 Gy
Spinal cord < 45 Gy
Outcomes
Disease control
50% 5 year survival
Acute Toxicity
Nausea, vomiting, diarrhoea, fatigue, skin reaction
Late Toxicity
Small bowel obstruction 10%, cosmetic skin changes. Liver and kidney should be fine if dose constraints met.
