Do you ever start patients on a Friday if non-emergent and you're not treating over the weekend?

The data for reducing radiation treatment time/elapsed days are most obvious in the setting of squamous cell carcinomas (SCC), where data have shown in H&N cancers, cervical cancers, and anal cancers that shorter treatment times are important for optimal local control. One study that I find intriguing is one by J. Overgaard in the Lancet 2003 in which H&N cancer patients were randomized to receive either 5 or 6 fractions per week. You guessed it---the 6 fx per week group had significantly better local control of the primary; better voice preservation for laryngeal cancers; and better PFS.

The data may be harder to find for adenocarcinomas in which we usually use RT+chemo in the preoperative or postoperative settings, but one would think that the radiobiology may not be too dissimilar from that of gross disease that we encounter when treating SCC.  I suspect that a similar phenomenon could be discovered with a well-powered study looking at adenocarcinomas.

In the setting of administering chemoradiation, preop or postop or definitively, I try to start on Monday's or Tuesday's if possible.  Many studies and radiobiology would tell us that tumors/cells will repopulate when given the opportunity even on a weekend.

For palliative cases, starting late in the week would be reasonable since we are aiming at symptom control usually.  How many fractions to deliver before a weekend--I am not sure has been studied, but could easily be studied.  For cases that are more urgent, such as bleeding tumors, it would make sense to treat consecutively until bleeding stops.

In the end, I do not believe there is firm data about how much lead in time before a weekend is optimal for local control.  We can only use the available information from SCCs to guide our best care for patients, which suggests a shortened treatment time with as few weekends incorporated may be ideal.

I've often wondered about this same question.  @Dr. First Last's comments seem exceptionally valid.  That said, when I'm faced with this situation, I personally have treated with a larger dose on the Friday and then continue with a more traditional dose per fraction the following week, reducing the total dose as is radiobiologically appropriate.

For palliation, I do exactly what @Dr. First Last does. 4 Gy on Friday, then 3 Gy on Monday for brain mets or lung obstruction or bleeding is typical. I think it makes sense. They are going to eventually get a 2 day break at some point, and it's, in my mind, arbritrary when it is. 

For curative, I think the "week" is arbritrary, and start on Friday without any worries. With a lot of breast patients on the 16 fx program now, if they start on Friday, they end on a Friday. If you start on Monday, they have to come back for one treatment on a Monday. It's all the same. Not sure why it would be any different. The same dose is delivered in the same timespan.