Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
Is it feasible to treat craniospinal fields with new generation scanning beam-only proton machines?
Yes, it is feasible to treat craniospinal fields with scanning beam-only technology. Scanning beam proton therapy delivers one discrete Bragg peak "spot" at a time. Large fields require many spots; so treating large fields such as craniospinal fields with scanning beam techniques requires more time ...
Is it preferable to simulate pediatric Hodgkin's lymphoma patients with arms up or akimbo?
We will be moving towards involved site radiotherapy for pediatric Hodgkin lymphoma. Consequently, you may want to match the simulation with the set up of their pre-treatment PET/CT scan (arms up vs arms down). This will allow you to have more certainty regarding the location of axiallary and subpec...
Is it safe to re-irradiate the pelvis after definitive prostate brachytherapy?
Evaluating the brachytherapy dosimetery can be very useful here. It will provide a visual reminder of how conformal such tx can be. The bladder was likely not exposed. Next, if brachytherapy planning software is available, the doses could be reconstructed and superimposed on the new CT sim (if impla...
What is the likelihood of a successful pregnancy following pelvic irradiation?
This is a very important question. The risks on future fertiltiy from radiation therapy to the abdomen/pelvis are twofold.1) Dose to the ovaries. The LD-50 to the ovaries may be as low as 2 Gy, thus the risk of ovarian dysfunction and premature menopause, is high. 2) Dose to the uterus leading to po...
Do HIV/AIDS patients with prostate cancer have increased radiation toxicity?
This small study suggest that outcomes are the same for HIV vs. non-HIV patients. That's also been my general experience.Matched cohort analysis of outcomes of definitive radiotherapy for prostate cancer in human immunodeficiency virus-positive patients. (Kahn S, Jani A, Edelman S, Rossi P, Godette ...
What is the difference between involved node and involved site irradiation?
In both involved node and involved site (ISRT), prechemotherapy GTV determines the CTV. However, ISRT accommodates cases in which optimal prechemotherapy imaging is not available to the radiation oncologist. In ISRT, clinical judgment in conjunction with the best available imaging is used to contour...
Is it time to start incorporating involved site irradiation for all lymphomas?
Involved site radiation is becoming the new standard therapy for lymphomas and the goal is to incorporate the ISRT concept broadly. ISRT evolved to update field design guidelines to take into account 3D imaging rather than base field design on bony anatomy which is the way we designed fields in the ...
Does current data support use of intraoperative breast radiotherapy?
I use the intrabeam IORT system and have treated about 90 patients. 22% have been given adjuvant whole breast or breast/axilla/scf xrt. The toxicity of IORT is significantly lower than other forms of APBI and external beam. The results of the Targit A trial support our experience in regards to toxic...
Should I use Oncotype to determine whether to offer adjuvant radiation to women with DCIS?
The conventional risk factors for risk of recurrence are age, size, margin width, and grade.In the multivariate analysis in the Oncotype study, conventional factors of menopausal status (surrogate for age) and tumor size were still significant for risk of recurrence.Grade and margins were not, but i...
After pelvic irradiation, how often do you recommend that female patients use a vaginal dilator and for how long?
The need for a vaginal dilator is dependent on the degree of stenosis, and related to the total dose, dose per fraction for HDR brachy patients, and patients underlying tendency to form scar tissue. In general we suggest evaluation by the physician every 3 months. If it appears that scar tissue con...