What dose do you typically prescribe to the primary tumor for definitive treatment of squamous cell carcinoma of the anal canal (given concurrently with chemotherapy)?

With IMRT:

Primary

TX and T1: 50 Gy/ 25 fx SIB to primary and 42 Gy microscopic

T2: 54Gy /27 SIB and 45 Gy microscopic

T3 58Gy /29 SIB and 47Gy microscopic

T4 58Gy /29 SIB and 47Gy microscopic

Nodes (all with no CTV/5mm PTV within the microscopic dose above):

<2cm 50Gy SIB

2-5 cm 54Gy* SIB

>5cm 5...

I just saw this and wanted to comment about the microscopic dose. I think the doses that are "standardly" used to treat "microscopic disease", such as those recommended by Chris Crane, are too high. One needs to remember that the original Nigro regimen used doses of 30 Gy to gross disease and had go...

To clarify the microscopic dose issue, I would add that we also have never seen a recurrence in a microscopically treated area with 30.6 Gy in 17 fractions with 2 agent chemotherapy. 30.6Gy at standard fractionation is an effective microscopic dose for SCCA of the anal canal. The problem came about ...

In the IMRT era, the most important technical consideration is protection of the external genitalia in females with preservation of long-term sexual function. Frog-leg position facilities the use of a vaginal dilator which is critical for sparing the introitus during contouring. Patient reported out...

I agree with Chris' dose recommendations for macroscopic disease. However, depending on the choice of concurrent chemotherapy, I might recommend somewhat lower doses for elective nodal radiation. If the 5FU schedule is similar to what is used for rectal cancer ('low dose" continuous infusion of ~150...

This is a valuable discussion with relevance beyond the anal canal topic alone. However, I am interested in colleague's thoughts on the relevance of patient positioning, immobilization and reproducibility as it contributes to toxicity in the modern era. The topic of margin definition, dose, and clin...