Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
How would you treat locally advanced melanoma of the scalp with several in transit lesions and a metastatic lesion to the parotid if the patient is progressing on immunotherapy such as pembrolizumab?
I think it is important to first define whether this is truly primary progression or whether the patient may have a delayed response. The Society for Immunotherapy of Cancer (SITC) has some consensus guidelines for defining this:Kluger et al., PMID 32238470 It is important to recognize that these ar...
What is the appropriate RT dose for an advanced stage follicular lymphoma?
Based on the study for patients of early stage low grade lymphoma treated with curative intent, the dose should be 24 Gy.For those treated with palliative intent, 2gy x2 should be preferred, as the majority have good palliation with that dose. In the minority where symptoms persists, one can treat a...
How long after intrathecal chemotherapy do you typically wait before giving whole brain radiation?
This depends on the diagnosis and the reason for pursuing whole brain radiotherapy after intrathecal chemotherapy. For example, if this is a primary CNS lymphoma case with a patient who has progressed despite intrathecal chemotherapy I would likely proceed with whole brain radiotherapy relatively so...
How long would you wait after a cycle of IT MTX to treat a spinal lesion causing cord compression in a patient with stage IV DLBCL?
Intrathecal methotrexate has biphasic half-lives of about 5 hours and 14 hours (Bleyer, Cancer Treat Rep 1977). ILROG recommends typically waiting minimum interval 2 weeks between last IT or high-dose IV methotrexate before starting CNS radiotherapy for CNS leukemia, but urgent radiotherapy may be c...
Do you recommend a washout period for a patient receiving intrathecal chemotherapies prior to/after receiving intracranial SRS?
There are not a whole lot of clinical data. A couple of general points: 1) some chemotherapy agents, especially methotrexate, are known to increase CNS toxicity of radiation (especially whole brain RT) when used concurrently; 2) intrathecally administrated chemotherapy nonetheless has generally limi...
Do you utilize tumor treating fields in patients with anaplastic pleomorphic xanthoastrocytoma (PXA) III?
I would, but I haven't actually had the opportunity. With more information appearing that TTF is effective in brain metastases, mesothelioma, and pancreatic cancer, why wouldn't you use it if you didn't have a better option? The only real risk is financial.
How would you approach surveillance imaging for men with early-stage, hormone receptor-positive breast cancer after unilateral mastectomy?
As always, appreciate others' input. If you're referring to systemic imaging, I do not obtain surveillance systemic imaging as part of surveillance for any patient with early-stage hormone-positive breast cancer (male or female) unless there are symptoms or initial labs that suggest possible metasta...
Is it ever acceptable for high risk prostate cancer patients to be treated with upfront radical prostatectomy?
This is an excellent and timely question. There is definitely an increasing trend of patients with high-risk prostate cancer (PCa) receiving upfront radical prostatectomy (RP). Some of this is spurred by a recent, high-profile meta-analysis (https://www.ncbi.nlm.nih.gov/pubmed/26700655), which poole...
How do you apply brain metastasis velocity in the clinic?
Brain metastasis velocity is calculated by the number of new brain metastases since initial SRS, divided by the time in years of developing those brain metastases. Less than 4 per year is considered low, 4 to 13 per year is considered intermediate, and more than 13 brain mets in a year is considered...
When a patient with pancreatic cancer received neoadjuvant chemo + chemo-RT, how do you manage an in-field, post operative positive margin?
The data from MD Anderson indicates that patients have a similar survival duration when they have an R1 resection after chemoradiation as when they have an R0 resection, and longer than expected with a positive margin. The Mayo Clinic also has data in rectal cancer where there may be an increased ri...