Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
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
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.
Should additional radiation be added to the total course in a HN patient who has an extended break during treatment?
Extending standard RT overall time, without chemotherapy, results in a "loss" of about 0.7 Gy/day for each day treatment is extended beyond standard (on the other hand, acceleration results in a "gain" of 0.7 Gy per each day). These data are based both on pre-clinical experiments and clinical experi...
What clinical factors help you to determine whether or not a patient is an appropriate candidate for spine SRS/SBRT in the setting of metastatic disease?
Although there are no right or wrong answers, I think there is the least controversy when using SBRT/SRS for progressive disease after previous conventional/palliative RT or for radio-resistant tumor (melanoma, renal cell carcinoma) in patients with limited systemic disease (oligometastatic). As som...
What is your opinion on IORT for breast with electron brachytherapy?
I have used the Intrabeam system. I use strict selection criteria, following both the TARGiT A eligibility and the ASTRO suitability criteria. I think this is a good modality for lower risk disease. I do consider this a form of APBI. The mechanism of action is not completely understood, like many ra...
How do you stereotactically treat brain metastases greater than 3 cm +/- additional brain mets?
Interestingly, we have had a number of cases where a patient presents with several small (0.5-1 cm mets) and a single dominant lesion (3-5 cm), particuarly in melanoma. Becuase of a presumed radioresistance for melanoma, we have desired to use as much single fraction or hypo-fractionation as possibl...