Would you include the tract in your treatment field in a patient with squamous cell carcinoma of the anal canal presenting with an ano-cutaneous fistula?  

If so, would you add it to your high or low dose PTV? Notably, on PET/CT, the fistulous tract has PET tracer uptake with SUV max 5-6 and PET avidity of the primary tumor has an SUV max 12.