For head and neck cancer radiation requiring boost, do you plan using simultaneous integrated boost technique vs cone down technique?
SIB always provides more conformal dose distributions compared with sequential boost IMRT, as the beam placement and intensity of the sequential boost do not take into account the dose distributions of the first plan. This issue, as well as the lower fraction doses to the normal tissue embedded in t...
As always, Dr. @Dr. First Last is correct, this time regarding the superiority of SIB for conformality.
The trade off though is fractionation, since a SIB plan will have varying fraction sizes if you use multiple targets. For most cases, this is acceptable (or even desired). For example, a standard ...
Dr. @Dr. First Last cited this classic paper, "Radiobiological considerations in the design of fractionation strategies for intensity-modulated radiation therapy of head and neck cancers." In it, you can see the genesis of the 56/63/70 Gy in 35 fractions regimen which seems to be the most common SIB...
Have moved almost exclusively to sequential plans for a number of reasons.
While Dr. @Dr. First Last is correct that SIB plans are more conformal, particularly within 1 cm of the high dose PTV, OARs beyond 1 cm receive a lower total dose with SEQ plans (secondary to lower total dose to elective PTV...
For patients with a large dose gap between two dose levels (say 50Gy and 70Gy), I now do a sequential plan. The uninvolved neck skin can start the healing process in the last 10 days while boosting gross disease in say, a p16+ OPhx SCC.
This will be consistent with the adoption of bigger dose changes...
We primarily use sequential plans because we deliver 30 Gy elective neck dosing for HPV+ disease and 40 Gy elective neck dosing for HPV- disease (excluding oral cavity cancer). This is based on our institutional experience and RCT. All targets receive 2 Gy per fraction. We also do a lot of adaptive ...