Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
What is the risk of local recurrence in a high grade muscle invasive bladder cancer (MIBC) s/p incomplete TURBT treated with concurrent chemoradiation compared to a complete TURBT?
One source I’m aware of that could shed light on this specific question is a 2017 publication from MGH (Giacalone et al., PMID 28081860), reporting the outcomes of 475 patients with T2-4a N0 M0 bladder cancer treated with various protocols from 1986-2013. Not all patients had high-grade tumors, but ...
How would you manage a pre-menopausal woman with extranodal marginal zone lymphoma confined to the bladder wall?
Marginal Zone Lymphoma (MZL) when localized is curable in most instances with modest doses of RT (24-30 Gy), perhaps even less when the primary site is the orbit. It typically responds to rituximab but relapses occur in most cases. Therefore, definitive RT is the treatment of choice in the great maj...
For primary MZL of the breast, do you do whole breast to 24 Gy or ISRT?
Without knowledge of the age of this patient and whether the concern of carcinogenicity from half the normal dose of traditional whole breast radiation (which we obviously do all the time for breast cancer) is enough to warrant omission of curative intent therapy in what is otherwise described as a ...
When using FAST Forward, how important is it for the treatment to be delivered Monday through Friday in one week as opposed to spanning a weekend?
Presumably unimportant. From the protocol: "13. TREATMENT SCHEDULING AND GAPSTreatment can start on any day of the week.A gap of up to 3 days is acceptable in the event of machine service or breakdown. This is preferable to transferring the patient to a machine on which daily verification imaging is...
How do you manage an unresectable high-grade glioma of the distal cord/cauda equina?
Doses may vary by institution. Our typically practice is to cover the gross disease to 54 to 50.4 Gy in 1.8’s for conus/cauda and then approximately two vertebral bodies above and below to 50.4-45 Gy (for instance if the superior extent is in true cord, then it’s typically prescribed to 45 Gy with p...
Do you recommend adjustment of lung dose constraints in the setting of stage III lung cancer treated with definitive concurrent chemoradiation followed by planned consolidation immunotherapy?
No, the normal tissue constraints have not changed now that adjuvant durvalumab is the new standard of care. Of course we should always be trying to make our normal tissue dose constraints as low as possible, without underdosing the target. And we should probably assume that all patients are going t...
How do you create an ITV for liver SBRT (metastatic lesions) when you don't have a 4D-CT or fiducials?
I will add a comment about ITV generation. Even with abdominal compression, there can still be movement of 8-10 mm or more depending on the abdominal compression system, body habitus of the patient, and breathing pattern. Fusing the MR and PET-CT only helps you delineate a GTV but it does not addres...
What is your IGRT motion management approach for liver SBRT?
For liver SBRT, there are a number of ways to address IGRT. All patients should have been simulated with either a 4DCT scan (can consider 4DCT with a compression belt) to generate an ITV or motion management or most ideally, a breath hold technique to maximally limit tumor/liver motion. Trying to re...
Is it feasible to use MV fluoroscopy to monitor the treatment port for left-sided breast cancer with DIBH?
Absolutely. When we first started doing DIBH, I used to stand at the machine with the MV fluoro on to watch the treatment. It was indeed very reassuring. As I recall, I was able to see the beating heart beneath the block, or maybe was just able to see the edge of the beating heart at the field edge....
Do you routinely offer spine SBRT for vertebral metastases regardless of overall patient disease burden or response?
I presume this will be controversial, but I tend to offer SBRT if feasible for palliation of pain from bone metastases. We have two positive studies (MDACC for non-spine, Canadian for spine) and one negative study. In addition, these are just 1-2 treatments. Billing becomes an issue, as I’ve continu...