Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
In SRS treatment planning, can a dosimetrist take the place of a medical physicist?
Our program has used a physicist and the plan is signed off by a physicist for intracranial cases. For spine SRS cases, we have used dosimetrists, as long as it is overseen by a physicist. I don't believe there are any specific rules that does not allow a dosimetrist to do the planning, as long as i...
How do you manage parathyroid carcinomas with positive microscopic margins?
As parathyroid ca is rare and no reliable data about post-op RT exist, we have to extrapolate from common tumors about which we have data. If this was a sq.c.ca in the low neck, or thyroid ca, we would treat the primary site (positive margins) to 66-70 Gy and neck levels II-IV as well as VI and uppe...
Do you feel that HDR brachytherapy alone is adequate treatment for some intermediate-risk prostate cancer patients?
Based upon a nearly 300 patient retrospective analysis of intermediate-risk prostate cancer patients at GammaWest Cancer Services, the answer appears to be a simple "yes," and for nearly all intermediate-risk patients. We published this in the Journal of Urology in 2012, and did not intend to select...
To what dose do you treat enlarged, but PET negative lymph nodes in laryngeal SCC?
If a node meets criteria for involvement by physical examination (firm, stuck to surrounding structures), or CT (enhancing, loss of fatty hilum, rounded), I give the node (+ 3mm for PTV) 70 Gy in 35 fx. Level II would also be a first-echelon node, raising my suspicion. The remaining level II region ...
Should prophylactic breast radiotherapy still be practiced for patients with prostate cancer taking bicalutamide?
The incidence of gynecomastia is higher with monotherapy bicalutamide 150 mg dose which is not very common in North America where biclutamide 50 mg is given with LHRH analogue. if single agent bicalutamide is planned, then people do practice prophylactic RT.
Is the criteria for RT + PCV for low grade glioma too narrow?
This is an excellent question, which unfortunately does not have a straightforward answer. The first and obvious answer is that 9802 evaluated patients older than 40 or less than 40 only if they had a subtotal resection, and therefore the specific benefit of RT+PCV in those less than 40 with a GTR c...
Do you offer postoperative radiotherapy to patients with stage I-II small cell lung cancer after complete resection?
In the past, when the RT volume for small cell included the entire mediastinum, it made sense to consider for RT for resected small cell carcinoma. In the era when most people treat involved field even for small cell carcinoma (Dutch data supports this in PET/CT staged patients), the value of adding...
For cutaneous SCC of the cheek with microscopic PNI, which nodal levels, if any, do you prophylactically treat?
Adjuvant radiotherapy for cutaneous squamous cell carcinoma (cSCC) can be a complicated subject because of the limited available data. Perineural invasion (PNI) is a reason to consider adjuvant radiotherapy, because several high-quality clinicopathologic correlative analyses have suggested that pati...
Should N1a breast cancer patients with positive intramammary node metastases but negative axillary sentinel node biopsy receive adjuvant post mastectomy radiation?
My philosophy of PMRT for these patients is similar to what I would do for 1 to 3 positive nodes. I recommend PMRT based on other adverse factors. If they have had BCT and the sentinel node is negative (the presumption is the true sentinel node for these patient is the intramammary node with the nex...
Is local failure following SABR higher then previously thought?
The problem really surrounds the common practice of sloppy reporting of patterns of failure in clinical reports. Local failure is failure within the realm of the original T-stage definitions. For lung cancer, failure within the lobe is a local failure. Too many SABR reports have only included failur...