Treatment Interruptions

Summary:

Can you share your policies regarding management of treatment interruptions?

Treatment Interruptions

b3n 16 Apr 2010 16:23

Treatment interruptions are quite common in the department i'm currently training in. Most often, the cause will be equipment breakdowns or patients having difficulties getting to the department. I read the NHS guidelines on the management of treatment interruptions which mentions that the options to manage treatment interruptions include:
1. Preventing interruptions from happening (prophylactic PEG, preparing redundant equipments, keep operating on bank holidays, etc)
2. Preventing interruptions from causing prolonged treatment time (inserting weekend fractions, modifying dose for remaining fractions, adding second daily fractions on fridays, etc)
3. When prolonged treatment time can't be prevented, compensating with additional fractions

I understand that option #1 has more to do with hospital management (our two equipments are overloaded with waiting time >3 months - so redundancy is clearly not an option at the moment) In our department, it appears that option #3 is chosen most of the time with generic alpha/beta ratio of 10 & 3 and K of 0.5 Gy/d (this is also open to discussion, as K values really differ between tumor sites, with values nearing 0.9 Gy/d for head/neck but much lower for breast/brain/prostate)
Can I have your opinion on this issue? I personally feel that when fractions can not be inserted due to logistic problems (equipment overloads), modifying remaining fractions to prevent OTT prolongation must be a better option than simply compensating it at the end of planned fractions!
One more thing, to what extent will you compensate for prolonged OTT, and when will you accept it as it is without compensating? (How many Gy of compensating dose is your maximum limit?)
Thanks!

Re: Treatment Interruptions

Rohit Malde 16 Apr 2010 17:48

Having been currently working under the NHS, let me try and throw some useful information to you.

If you read that document carefully, it divides patients into category.

https://www.rcr.ac.uk/docs/oncology/pdf/BFCO(08)6_Interruptions.pdf

CAT 1: Rapidly growing tumours such as Squams who are treated with radical intent and the overall RT must not be prolonged by more than 2 days.

CAT 2: Slowly growing tumours such as Adenocas where treatment prolongation of upto 5 days may not be deleterious (but no safe lower limit has been established)

CAT 3: Palliative

The mgt of treatment interruptions is mostly in clinical practice applied to CAT 1 pts, hence the A/B for tumour =10 and K = 0.9 Gy/d

For those readers who do not know K factor
(It is the amount of radiation wated due to ongoing tumour repopulation, its units being — Gy / day )
You may be also amazed to know that there is a meta-analysis to determine this K factor in head and cancers which estimates this to be 0.89 Gy/day and of course this has been verified and supported by RTOG 9003 trial subsequently.

For cat B which is your breast and prostate pts, this is less relevant and there is a wide variation of these values and no consensus on their values has been established (but you are right if you know them for sure from your animal experiments this can perhaps be applied to humans). Dont go after me on this last point, Andrew. But we do this all the time.

However there is no robust data of the exact values for breast or prostates that i can think about nor is there any major consensus on these values as probably its less clinically relevant in terms of detriment on outcome if your overall treatment time was prolonged.

I think you oncology department needs top have a policy for Category 1 patients.
and having worked in Mumbai at Tata memorial Hospital, i know how difficult it is to squeeze patients on already jam pack RT machines.
i also remember we used

Transfer pts to other linacs or cobalts after 5 pm (Dr on duty- many of you may recollect those unpleasant memories of asking the physics dept to calculate the monitor units and get the pt quickly on the other machine before 7pm) if machine breakdown or machine was too busy with backlog.

If the pt missed treatment, we used to

a) to give second fraction (6 h apart)

b) Treat over weekends (Saturday only)

c) last but not the least, recalculate the BED and increase your dose per fraction keeping the same treatment time.

OPTION 3 which you favour and seems to be more common at you institute was our last resort and less favoured option.
i.e

d) Compensate with additional fractions of RT.

In the last 4-5 years in UK, i cant remember a single pt on whom this last option was used.
The first three options does the trick most of the times, of course the radiograhers are much more concerned than doctors here, that might be the reason, but i know its the reverse in India.

Apologies but i have nt done any major literature search for you to tell you confidently about the K values for Breast and Prostate, perhaps a final year MD Radiation oncologist may know the answer from their radiobiology teaching / courses. ( Eric J Hall or Tannock & Hill)

Re: Treatment Interruptions

AAM 16 Apr 2010 21:15

so paranoid!

Re: Treatment Interruptions

AAM 16 Apr 2010 21:33

I worked in a centre where we had 25 week waiting times. So the scenario is not foreign to me.

Some specific questions:

1. how many machines?
2. how many patients per machine each day?
3. how many RTs?
4. any IMRT?

I actually spent my time worrying about other things.

I looked at departmental efficiency, and took every radiation professional off non-radiation tasks. All patient organisation was turned over to clerical staff. A booking clerk did all the bookings for sim, machines and accommodation (65% patients came from peripheral areas). Booking clerk did the job better and cheaper actually! She kept in touch with all the patients and organised all changes to the roster. Clerical person worked in the machine area also to answer the phone.

The ROs were asked to consider the evidence of single fraction treatments and use it if comfortable. ROs were asked to consider the use of hypofractionation for breast and use if comfortable (at the time the RCTs weren't published so we weren't). Prostate ROs put all prostate cases on hormones irrespective of risk. ROs were to ask the patients who would be travelling whether they had another place where they might be better accommodated. We sent people to Australia for treatment.

Booking clerk and ROs negotiated to sim palliatives early and have them ready to go on short notice. If given one hour's notice of a patient not coming to treatment, a palliative case was rung to come in early and fill the slot. Treatment wastage was about 0.1%!

We streamlined sim to free up those staff to work elsewhere. We had a CT for sim and simed about 5 patients per day. The sim staff were enabled to do this in 4 hours, and then deployed onto machines for the second 4 hours.

Once we had been through all parts of the system, the Head RO (me) went to hospital management to inform them of the issues and the resourcing solutions, invite them to review our system to look for additional inefficiencies and then state that we were functioning at maximum capacity and that they either needed to refer patients elsewhere or deal with the political problem of the waiting list. The same was undertaken at the Ministry of Health level.

We then sat back and just let the waiting times grow. So I don't recall doing any calculations, we just added the fractions on at the end and tried to not have anyone pull out.

With the above information, you may or may not have a solution available to you.

Re: Treatment Interruptions

Suruchi Singh 19 Apr 2010 05:05

hi
_{another very practical & relevant question at least in our scenario} shd thank Rohit and Andrew for practical solutions,, but these r interruptions caused on administrative parts,, wat do we do when after all precautions pts default in last wk d/t intolerable reactions and come back after a wk or so (wen reactions settle down a bit).. shd we
1.try n complete prescribed doses?
2.do gap correction (watever values come n treat further)
3.stop treatment as more than 80-90% of doses r already done and benefit of any further treatment is questionable
Suruchi

Re: Treatment Interruptions

Rohit Malde 19 Apr 2010 09:09

Oh Suruchi,

If you miss the last week or last 2 weeks of treatment, which does happen now and again, its a very painful and difficult task for an oncologist.
You have no option but to consider treatment after the reactions have healed which would fall in the week following the date of your anticipated finishing .
The principle is you try and finish the treatment the following week taking into account the BED, the radiation wastage factor and tumour re-population into account.

Its very difficult to explain to you in writing and what i advise you is to look at Example 3 & 4 of this document on Pg 25 & 26.

https://www.rcr.ac.uk/docs/oncology/pdf/BFCO(08)6_Interruptions.pdf

A rough estimate after these painful calculations and estimations is that
if you miss a weeks worth of treatment @ 2 Gy / # —> You give 2.3 Gy / # x 5 #

But of course you do all these ONLY for CATEGORY 1 patients.

If its Category 2 —-> accept delay of upto 5 days

If its Category 3 (palliative) —- No need to make your life difficult.

Over & Out

Rohit !

Re: Treatment Interruptions

Nikhilesh Patil 20 Apr 2010 21:04

thanks for the very nice document Rohit.

Re: Treatment Interruptions

RAJESH R NAIR 21 Apr 2010 03:22

Is now anal canal carcinoma and transitional cell bladder in catergory one.2008 document it is category 2.clarify.

Re: Treatment Interruptions

Rohit Malde 21 Apr 2010 07:35

My pleasure, Nikhilesh.

And Rajesh, sq cell anal cancer and TCC bladder are both Category 2 pts, not 1.
For Sq cell ca Anus, treatment with CTRT should not be prolonged by more than 7 days.

Rohit

Re: Treatment Interruptions

RAJESH R NAIR 21 Apr 2010 08:25

i know the document of 2008 data. i heard ? that there is an update and change made .if no that is fine