Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
When treating an intact whole breast using breath-hold technique with a planned electron boost, do you generate a separate plan for the boost with a free-breathing scan, or plan the electron boost on the breath-hold scan, but treat free-breathing?
It is our practice to acquire a free breathing and breath hold scan. I evaluate the boost plan on the free breathing. The "plan sum" is on the breath hold, but I would be reluctant to not have the free breathing for evaluation of dose, particularly on the left side, as the cardiac displacement may s...
How do you manage dental extractions in a patient getting reirradiation to the mandibular area?
Taking into account the poor prognosis of re-irradiated HNC (for example, Ward MC et al, Oral oncology 2019, reported in a recent 9-institution study of more than 500 patients, cancer progression or death in 64% after re-irradiation), teeth/mandibular damage risk is a moot issue. If cancer is eradic...
How would you approach a locally advanced, node positive oral cavity squamous cell carcinoma of the H&N with cCR after induction chemotherapy?
I would use consolidative full-dose chemo-RT to the pre-chemo CTVs. I would not reduce the extent of the CTVs or treatment intensity. Before the TPF era, randomized studies of induction followed with RT vs RT alone in HNC did not result in improved outcomes in the induction arms, despite achieving a...
Would you consider post-operative radiation therapy for resected malignant melanoma with in-transit metastasis?
I don’t know of any evidence that RT is helpful in this situation.
Would you radiate a multiply recurrent basal cell adenoma of the parotid?
Yes, after gross total resection with carcinoma doses.
Would you consider preoperative radiation for a retroperitoneal sarcoma in a patient with Li Fraumeni syndrome where upfront surgery is likely to yield a positive margin?
This is a scenario where multi-disciplinary discussion is key. First, what is the histology of the RP sarcoma? Second, where is the likely positive margin, and do we expect potential downstaging with RT to impact this margin? Consideration for systemic therapy with restaging and consideration for RT...
How do you approach SRS to a thalamic metastasis?
I am not aware of high-quality data to guide us here, but there is abundant published retrospective experience. A model by Flickinger et al. predicted higher toxicity rates after SRS in AVM patients for brainstem and other deep locations. That said, low toxicity has been reported for treatment of AV...
Would you consider SBRT to a perirectal node after previous external beam and prostate brachytherapy?
It is dependent on many variables. If the perirectal lymph nodes are the only site of metastatic disease, then radiation should be considered. The risk of radiation needs to weighed against the possibility of cure. For instance, if the patient presented with a PSA of 80, then the likelihood that the...
Is there a subset of patients with metastatic breast cancer in whom you would consider locoregional therapy?
E2108 is a negative trial for LRT for stage IV disease. We need to see the publication to see details. The issue is if this trial had enough power to detect a difference. The trial was designed to detect an improvement in 3 year OS rate from 30% with OST alone to 49.3% for OST+LRT. The final results...
Are there any specific planning techniques that are used to avoid underdosing the match line in a single isocenter breast plan treating the chest wall and supraclavicular region?
I tend to use a high single iso match when possible to limit lung dose through the AP SCV. What we do is open up a segment from the SCV into the tangent to heat up the match and avoid underdosing of the axilla. Well seen in Figure 6.16 in this treatment planning book.