Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
Do you think it makes a difference to fractionate at 2 Gy versus 1.8 Gy per fraction?
This is a great question and is an example of how a single clinical decision can change practice. In the era of radiation alone the standard fractionation was 2 Gy/day. With the introduction of concurrent chemoradiation the radiation dose was decreased to 1.8 Gy/day. This 10% dose attenuation was su...
When do you recommend PMRT for individuals with spindle cell carcinoma of the breast?
These cancers are in a broad category of metaplastic cancer of the breast. They are triple negative but are not chemoresponsive like ductal triple negative breast cancer and tend to have poor outcome. Our threhold for adding RT is lower in these patients.
When would you consider using radiation for cardiac metastases?
I would consider it if it's likely to be effective based on histology. If it it a relatively radioresistant tumor, I would consider if there's no other viable option.
What is a standard field for LN+ paratesticular rhabdomyosarcoma (ie aorta + ivc + ipsi common iliac)?
Though there is some variation, most clinicians who have enrolled patients on the IRSG or COG studies use a "hockey-stick" field that parallels what would be used for seminoma. These would include the para-aortic and ipsilateral iliac nodes. A minority of clinicians exclude the iliac nodes if they a...
What is your method for delineation of the hippocampal avoidance structure in patients who are unable to undergo MRI?
The hypothetical benefit of conformal avoidance of the hippocampus during cranial irradiation centers on the memory-specific and radiosensitive neural stem cell compartment within the hippocampal dentate gyrus. The hippocampal dentate gyrus is a gray matter structure surrounded by white matter struc...
How does your prescribed SRS dose vary with cavity size for treatment of resected brain metastases?
I generally follow SRS dose for postop cavities as I do for unresected lesions. 20 Gy for < 2cm, 18 Gy for <3 cm, and 16 Gy for <4cm. For tumors greater than 3 cm I have been favoring hypofractionated RT.
When is it too far out from CRT to the chest to be considered for PCI for limited-stage SCLC?
How about this answer that was not listed - "don't give it!" The evidence we hang our hat for PCI in SCLC is not just weak, it is also outdated. With the medical technology available they had at the time, it made logical sense that staging would miss brain metastases. ~50% of the studies in the meta...
Would you offer PMRT after NAC in a boderline patient with a pCR based on suspicious pre-chemotherapy IM nodes?
We do run into this situation, ecspecially in the MRI era, when it picks up the IM nodes. Older data with MRI imaging suggested if node is more than 5 mm the likelihood of disease based on bx was more than 90%. With advancement in MRI now 5 mm node have been reported in benign breast disease also. W...
What are your indications for treating a pelvic desmoid tumor in a young woman concerned with fertility?
I would generally try to avoid radiation therapy in desmoid tumor unless it is symptomatic and not responsive to medical management and/or surgical management. Although unresected desmoid tumor can respond to radiation therapy with doses in the 55 to 60 Gy range, I would avoid it in a young woman co...
What is the sensitivity of SLNB after neoadjuvant chemotherapy for cN0 patients?
The sensitivity of SNLN for clinical N0 disease is high and can be treated like node negative. One has to be cautious about clinical positive patients which normalizes after chemo, as based on ASOCOG and SENTINA trial it can be less than 90% unless due diligence is done like clipping the involved no...