Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
Is irradiation of the supraclavicular and internal mammary lymph nodes now considered the standard of care in women with node positive breast cancer?
I hope that this question can be answered more definitively in the near future. At the present time, I await publication (and untimately more maturity) of the MA-20 data set as well as data from EORTC 22922 trial. I read that 10 year data from the EORTC trial will be presented in Europe at the end o...
Is post-mastectomy radiation required in patients with cT2N1 breast cancer who undergo neoadjuvant chemotherapy and are then found to have negative lymph nodes at the time of mastectomy?
This particular subset of patients has the most data suggesting that response to neoadjuvant chemotherapy can be used to tailor post-mastectomy radiation (PMRT) decisions. A retrospective study from MD Anderson (McGuire IJROBP 2007) evaluated 106 patients who received neoadjuvant chemotherapy and ac...
In the absence of other risk factors, do you treat the regional lymph nodes in triple negative breast cancer?
At present I don't, but once Canadian and EORTC studies are published with full details available, it may change practice patterns.
Which patients with DCIS can be observed following lumpectomy?
Based on ECOG and RTOG data, patients with small volume (less than 1 cm), grade 1 and 2 DCIS with no necrosis, and a good margin of excision (3mm or more) or those with definitive excision showing no disease have a smaller benefit with RT. After discussing the pros and cons and respecting the patien...
Is there a current 'standard of care' dose and fractionation in treating lung cancer with SBRT?
We have previously discussed the right BED dose equivalence for SBRT; one of the questions that is posed is which schema is "standard"? There is no one single standard scheme. We recommend that as an institution, you develop a process and scheme that works within your structure and workflow; we tend...
What kind of motion control do you use when treating lung cancer?
This is a multi-part question with answers depending on the specific goal and tumor being treated. In general, for advanced stage NSCLC being treated with definitive RT with conventional fractionation, I use shallow regular breathing with a chest mold immobilization device and 4D CT to quantify moti...
What do you consider is an acceptable surgical margin for invasive breast cancer?
It is a number where there is no consistency but nowadays for practical purposes, most people would consider no tumor at ink as negative margin. That being said, close margin in the presence of EIC or multiple close margins in young patients or significant tumor close to the margin (diffuse close ma...
Should we be more concerned about cardiac toxicity following breast radiotherapy?
The way I interpret the data with all caveats that threshold dose and time period for any cardiac morbidity is significantly lower than what was expected. For that reason, all efforts should be made to avoid any direct photon beam wherever possible to go through any portion of heart by using any one...
How much do you deflate a tissue expander prior to beginning post-mastectomy irradiation?
The need for deflation is based on your dosimetry and target volume. If we are not treating the IM nodes, then for most situations we don't deflate and we treat the chest wall with tangential beams. If we are planning to treat the IM nodes, then sometimes to get adequate coverage, the lung and heart...
What is the best imaging study to differentiate between recurrent glioblastoma and pseudoprogression?
Chemo-radiation-induced pseudoprogression (Psp) and/or necrosis present with MRI findings indistinguishable from tumor recurrence on conventional contrast-enhanced MRI. However, while early progressive disease (ePD) indicates treatment failure and necessitates a change in therapy, Psp indicate succe...