Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
How were decisions made about what dose constraints to use in the recent RTOG protocols for lung SBRT?
This is a question that is frequently and appropriately asked by SBRT beginners and experienced practitioners. The history of SBRT in that regard replicates much of the historic experience in RT which is that the data generated from treating the patients generated the constraints, so to speak, as op...
Do you cover vasogenic edema surrounding the GTV when treating brain metastasis with SRS?
The edema is not usually covered for brain metastasis during SRS. These changes are likely reactive changes and less likely to represent infiltrative disease, unlike in primary CNS tumors.
What is the appropriate dose for a patient with recurrent vulva VIN III?
I have never treated VIN III by itself without any evidence of invasion, although I have had patients with diffuse VIN with invasion who responded well to RT with regression of both invasive disease and VIN changes. Dose is hard to answer but all these pts get at least 50Gy for invasive disease.
In treating with total body irradiation, how should the lung blocks be drawn and what dose should the lung receive?
I draw lung blocks 1 cm. insde the edge of peripheral lung including apex of the lung . The doses are usally 5% less than the prscribed doses to central axis . The typical TBI schedule as a conditioning regimen for BMT is 150 cGy BID for 1200 cGy . Bharat
What is the role in your clinic for chest imaging in head and neck cancer patients who are free of local disease 1+ years after treatment?
Our multidisciplinary team continues to discuss this controversial area. We tend to obtain annual low-dose non-contrast CT chest scans for 5 years in patients with N2-N3 disease regardless of smoking status, if they would be healthy enough to undergo therapy for metastatic disease. In current/former...
How do you contour distal esophageal cancer in the postop setting after Ivor-Lewis pT3N3 (perigastric and periesophageal LN)?
This case is a tough one--bulky disease at the junction of the esophagus and stomach so both sets of regional lymph nodes are involved. The Ivor-Lewis or transthoracic approach means that the anastomosis between remaining esophagus and stomach is located in the chest.The anastomoses need to be inclu...
If one decides to use a mpMRI to stage a pt with low-risk prostate cancer, how do you work up a focal lesion suspicious for higher grade GS 7-10 disease?
Even though modern mpMRI is sensitive (>90%) at detecting occult GS ≥4+3 cancers that are missed by blind systematic TRUS biopsies, it is not 100% specific. Almost all radiologists will occasionally over-call a radiographic abnormality when it is still only GS 6. When decisions to be made from this ...
What is your approach for a locally advanced (stage IVA secondary to N2 disease in the neck), HPV-negative, squamous cell carcinoma of the base of tongue in a patient without significant comorbidities?
In short, we usually do definitive chemorads. However, this question is more complicated than it seems. With TORS/TLM, surgery seems an option for early Tstage disease, as it is in HPV +ve disease. I believe one of the national studies will try to address this question.For more advanced T-stage, Eve...
What do you do for physician approval of IGRT images?
Our philosophy is as above with the only difference being for CBCT one of the physicians always tries to be there at machine to approve films prior to treatment. Discussing and explaining with the therapist the area of match for each individual case is part of the process.
When do you spare constrictors in head and neck treatment planning?
The best data is from Eisbruch and colleagues at Michigan. I spare them when possible but it is often not feasible without compromising target coverage. That is the case for any OAR, including the optic chiasm, in which case I exceed the OAR thresholds to adequately irradiate the tumor.