Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
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...
Do you recommend adjuvant RT for positive margins of dermatofibrosarcoma protuberans?
The combination of surgery and radiation results in excellent local control for DFSP: Castle et al., PMID 23628134.Radiation is, of course, likely especially valuable when margins are less than secure. The above paper describes dose and volume considerations.However, it's a risk/benefit discussion. ...
Would you consider re-irradiation for a prostate local failure for a patient who initially received standard fractionation with a focal SIB to 95 Gy, or a SBRT boost with cyberknife after EBRT?
In general, I am not an advocate of re-irradiation for prostate cancer, and I am especially not an advocate of re-irradiation in settings where very high dose boosts have been delivered previously, such as focal SIB, SBRT, or brachytherapy. In this situation, you have demonstrated pretty conclusivel...
What is the role of radiotherapy in medically inoperable, large and or recurrent aggressive basal cell or squamous cell cancer of the skin in high risk areas?
When treating small to moderate size skin cancers in an area with good circulation (face, trunk, upper extremity) my standard regimen for BCC is 4500 cGy in 15 fractions, and for SCC I use 4800 cGy in 16 fractions. For large tumors I use 5000 cGy in 20 fractions for both histologies, and this is als...
What adverse features would prompt you to give post-TORS radiation therapy to completely resected early stage (T0-2) p16+ tonsillar cancer?
I would base my recommendation on the standard and conventional indications for PORT, which in this case of an early-stage primary tumor with negative margins, would comprise the presence of PNI, LVI, close (<3-5 mm) margins, single node >3 cm, or multiple positive nodes. I assume there is no extrac...
Do you hold anticoagulation prior to LDR or HDR prostate brachytherapy?
Yes, we have an algorithm for holding prior to brachytherapy/spaceoar/fiducial placement and the patient generally resumes 2-3 days later when they do not notice any blood from urine/bowel. We have a recommendation for each agent. Here are some general examples. Indocin and voltaren: 1 day prior t...
How would you approach treatment of an unresectable paraspinal chondrosarcoma causing cord compression?
For unresectable chondrosarcoma, RT is usually recommended. If conventional fractionated regimens (1.8-2 Gy per fraction) are used, RT of over 70 Gy will be needed to control the disease (per NCCN). In recent years, a limited number of published studies evaluated SBRT (5 fractions) for chondrosarcom...