Hi everyone -

I'm currently enrolled in a clinical trial that centers around tumor imaging and selective RT dose deescalation for lymph node tumors in certain circumstances. I wrote and mentioned some details about it and my upcoming decision on deescalation in a thread started about HPV deescalation, but wanted to open a new one, to hopefully get some thoughts and answers.

Here are the details on the study and possibly deescalation of RT:
1. Tumor must be HPV+ - Mine is +ve
2. Tumor must have no hypoxia (low oxygen) within either the primary or secondary (Lymph nodes), by the 2nd hypoxia scan (1.5wks into treatment). This scan is a FMISO PET scan. - Mine has a spot of hypoxia on the primary (tonsil) which disappeared 1.5 weeks into treatment.
3. A early response PET scan (normal PET) will be taken next Monday to determine the response in the lymph node area. RO says that PET will be harder to see a definitive response in tonsil and BOT area, due to inflammation, but in the neck / lymph node area it is easier to see. If there is no activity in the lymph node area on the PET, I'd be a candidate for dose deescalation.

A dose deescalation would only occur in the area of the cancerous lymph nodes and would be from 70Gy to 60Gy. No change in dose occurs to the other side of the neck, top of chest, primary cancer site, BOT, or area around the lymph nodes with tumors in them. My 2 lymph nodes (stacked) were about 4cm, so a sizable part of my neck could have a dose deescalation.

3. If the dose is deescalated, a small neck dissection would occur to check the irradiated nodes for any residual cancer. Additionally, I could request a larger neck dissection, which encompassed additional lymph nodes. My RO says that adding the selective neck dissection allows us to confirm that the lymph node tumor has been completely irradiated and any remaining tissue is only scar tissue.

My RO seems to think that with my age, it makes sense to try to spare the dose to the jaw and neck in order to help reduce any longer term side effects (10-20yrs in the future). She seems confident that the neck dissection will allow them to know if there is any residual cancer in the area that had dose deescalation. While there still may be cancer cells floating around my body somewhere (that would have still received the full normal dose of RT), the area that would be getting less radiation would be checked after the RT has completed, to ensure that the dose deescalation did not compromise local control.

She also says that some cancer centers only use 60Gy on the neck/lymph nodes with mandatory neck dissection on it afterwards. She seems to equate 60Gy for lymph nodes + neck dissection and 70Gy and no neck dissection. Thoughts on that?

Also, she said some centers always do a neck dissection post RT, regardless of dosing.

The main questions/thoughts as I see it are:
1. Does a neck dissection allow for the proof of local control in a specific area? (ie the area which has received 60Gy vs 70Gy)
2. All dosing other than the 2 impacted lymph nodes would remain constant. To me, this would not indicate an increased chance of metastatic disease or a potential loss of local control - assuming that point 1 is true and local control in the 60Gy area can be established with a neck dissection. Thoughts?
3. Are there any longer term side effects that may come up in the 10-20yr time frame? The RO mentioned jaw issues, necrosis, and salivary issues as all potential ones. I wanted to see if anyone had issues that came up a significant period after RT was over.

I have to make a decision on the trial this week, so they can change the treatment protocol if necessary. I'm about 50/50 now. I see positive aspects to both sides, but am not sure what is the right answer (and unfortunately won't know what that is until 5+ years from now!)