Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
Are there any patients with newly diagnosed GBM in whom you would adopt Early-Start TTFields based on the TRIDENT study?
The authors of EF-32/TRIDENT should be commended for performing this impressive randomized trial of an already FDA-approved therapeutic in GBM maintenance, asking the question of whether an earlier start of TTF, during chemoradiation, improves overall survival. This is also a big ask of the therapeu...
What surrogate(s) do you use to determine toxicity/safety for a SRS plan with numerous metastases?
Before we turn to surrogates let us look at the information that a plan carries and has valuable implications on the quality of the work being done.First we record and report coverage, selectivity, conformity and gradient indices for every patient and every lesion.Second we plan in a consistent mann...
Which normal brain dosimetric constraints are most important when treating brain mets with SRS?
It sounds like you may be starting a new radiosurgery program. May I suggest that if your normal brain tolerance constraints cannot be met with single fraction SRS, or you are worried about tolerance due to prior radiation, consider hypofractionation with 3 or 5 fractions. For 5 fractions x 6 Gray, ...
How should the V10 or V12 be defined when evaluating intracranial SRS plans?
Milano et al., as part of the American Association of Physicists in Medicine Working Group on Stereotactic Body Radiotherapy investigating normal tissue complication probability (HyTEC), published a review of 51 studies in 2020 and evaluated the risk of symptomatic radiation necrosis based on a defi...
When do you recommend patients get vaccinations with respect to their RT course?
I agree with @Dr. First Last's reply, and find that some patients are under the impression they are immunocompromised during radiation therapy and thus should avoid vaccines, when in fact the opposite is true. The skepticism behind the science of vaccination also can lead to avoidance, and so I try ...
Do you modify your radiation planning approach or OAR dose constraints for a patient with stage IIB–IIIB NSCLC who has already received neoadjuvant immunotherapy before proceeding to definitive CRT?
I have not modified the radiation planning approach in this situation. I still treat residual PET-positive disease with customary CTV and PTV margins, motion management, etc. The only difference here is using a shorter course of radiation for some patients who are not getting concurrent chemotherapy...
In light of the recent data indicating increased late toxicities after hypofractionated salvage prostate radiation therapy, will you continue to offer it to patients?
Prior Literature: Prior non-randomized studies seem to suggest excess toxicity with hypofractionated PORT (e.g., Cozzarini et al., PMID 24985964, Tandberg et al., PMID 29559284). In part for this reason, a phase III, randomized controlled non-inferiority trial, NRG-GU003, was conducted (Buyyounouski...
What are your skull constraints when administering cranial SRS/fSRS?
I have never used skull constraints when delivering intracranial SRS. While intuitive to think about any adjacent uninvolved tissue as an organ at risk and limit the dose to said structure, in relation to the skull bone itself the cost of "spray" dose to the skull is much less costly than the altern...
What dose-volume constraint should be used for the normal brain parenchyma in a patient receiving 5-fraction SBRT?
This is tough, because most of the literature is based upon single fraction SRS for 1-3 lesions. There are no one criteria for brain doses for multi-session treatments as stated above. Tumor coverage is most paramount, and I agree with the need to respect the adjacent structure doses and to optimize...
How do you interpret the 5% absolute difference in 6-month locoregional failure between Q3 and weekly cisplatin seen in NRG-HN009 when counseling a patient with H&N SCC?
At our center, we have not deviated from using Q3 weeks despite a strong push towards weekly by many, and this data reaffirms for us: No difference in tox between Q3 and weekly, contrary to what was suggested by others. That is true for both p16+ and negative. It is very concerning to see that at 6...