Radiation Oncology Archive Questions

Below are Dr. Anil Dhople’s answers to Radiation Oncology questions
received through the Ask the Expert feature.

This content is provided for informational purposes only, and is not intended
to be a substitute for individual medical advice in diagnosing or treating a
health problem. Please consult with your physician about your specific health
care concerns.



Now displaying records 1 to 9 of 9.

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Q : 1 10/31/2009	Regarding the RapidArc system, can you provide some information regarding the use of this procedure as opposed to surgery for bladder cancer? I have undergone BCG treatments that have not had positive results. I wonder what the success rates for this procedure are. RapidArc system is another piece of radiation technology in the aresenal of tools to treat cancer. Ultimately, the decision to use certain radiation technologies is made after the decision to use radiation is made. So, for patients with localized early stage bladder cancer that has not responded to BCG treatments, the next option is surgical resection. There have been numerous studies demonstrating the superiority of surgery in localized bladder cancer compared to radiation therapy. However, if you are not a surgical candidate, then radiation may need to be used. At this point, once the decision to use radiation has been made, RapidArc may allow for more rapid delivery of the radiation while sparing nearby critical structures such as the small bowel and rectum. There are no studies to date that have demonstrated any superiority of using RapidArc for bladder cancer compared to surgery.
Q : 2 10/07/2009	What is the need (if any) for radiosensitizers? That is, a drug that has no single agent effect but increases a tumor's response to radiation treatment. Radiosensitizers refers to a broad range of medications that essentially help make cancer cells more sensitive to the effects of radiation. Radiation oncologists would like to use radiosensitizers if there has been a proven benefit to the addition of a radiosensitizer for a particular cancer. However, not every radiosensitizer has been proven to be beneficial for every type of cancer, and therefore, radiosensitizers should be used only when clinically indicated.
Q : 3 08/04/2009	I am presently getting radiation treatments for breast cancer and have recently got a bad burn under my arm. What is the best prescription cream or ointment to use? My doctor gave me Mometasone cream and also Silvedene cream. They both burn when I put them on. I also tried bactroban ointment and that helps some. What do you recommend? Lidocaine topical cream can be effective in alleviating the burning sensation that accompanies skin breakdown from radiation treatments. Silvadene is a very good cream to help accelerate the healing process. Lidocaine topical cream will simply numb the area it is applied to. Be mindful to try and use gloves when applying it, as it can make your fingertips numb. Consult with your physician before applying lidocaine cream.
Q : 4 06/10/2009	Is this the department that provides the radioisotope embolization with Yttrium-90 spheres? I am trying to determine if my wife is eligible for this treatment. The University of Maryland does offer a wide array of liver-directed therapies, including radioisotope embolization with Ytrrium-90. This procedure is also known as Selective Internal Radiation Therapy (SIRT). There are numerous factors that must be taken into account when determining the best liver directed therapy for a specific patient. These factors include the size of the tumor in the liver, current liver function, the status of the cancer in other parts of the body, blood supply to the tumors in the liver, and any other medical conditions the patient may have.
Q : 5 05/14/2009	A family friend has recently undergone radiation and chemo for lung cancer. The radiation treatments damaged his throat so severely that he now suffers from an esophageal stricture. His doctor tried to dilate his throat but was unsuccessful. Do you know of any other procedures that may help? This is a common problem for patients who have completed radiation and chemotherapy for the treatment of their lung cancer. Dilation is the most common therapy, however, over time the stricture can come back. Strictures are due to severe inflammation of the tissue lining the esophagus. Only time will help heal the inflammation. Sometimes aggressive dilation, as frequently as every week, is necessary to give prolonged relief. If frequent dilation does not seem to help, then another option is to deploy a plastic stent in the area of the stricture. These are typically temporary stents that are left in place for a few weeks and then removed. The downside of these stents is that they can often be uncomfortable to the patient, and have a tendency to dislodge and then no longer function. Lastly, some patients are actually able to perform "self-dilation." This takes careful training by a specialist physician who has experience in this technique.
Q : 6 04/27/2009	I am a 46-year-old female Hodgkin's survivor. I am losing the use of my lower legs due to radiation damage from cobalt radiation treatment received at age 7. Can anything be done to stop or repair the nerve damage? Any advice is greatly appreciated. While the medical community has made Hodgkin's disease a curable cancer for most patients, long-term survivors are developing late side-effects from treatment. This is why patients with cancer diagnoses need to continue to follow-up with an oncologist to keep track of symptom development in long-term survivors. It is difficult to know exactly why you are having nerve damage this late after completion of therapy. It would be important to rule out other causes of nerve damage, and not just immediately attribute it to the history of radiation treatments. A physician who specializes in Neurology would be a good person to speak to. Other causes of nerve damage need to ruled out such as infections or inflammation. If nerve damage is attributed to the radiation, there have been some case reports of improvement of symptoms with hyperbaric oxygen therapy. While there is no strong evidence in the literature to suggest that this will work to reverse the damage, it may be worth looking into.
Q : 7 04/16/2009	I had an abdominal/pelvic CT scan for a diagnosis, but my doctor didnt warn me of the risks involved with ionizing radiation. Now that I know I probably received 10 mSv, I'm very worried about DNA damage to my cells that could cause cancer. Do our cells repair the DNA damage caused by the scan? All radiation exposure entails some risk of causing cancer. However, at doses less than 100mSv, this risk is very small. This is because experimental models have demonstrated cells can effectively repair damage at these doses. However, it is impossible to predict your exact risk as an individual. For further reading, I suggest reading the following reference: Lobrich, M., et al. "In vivo formation and repair of DNA double-strand breaks after computed tomography examinations", Proceedings of the National Academy of Science USA 2005, 102(25): pages 8984-8989.
Q : 8 04/07/2009	I am a 65 and was diagnosed in March, 09 following a lumpectory with grade 0, ductal carcinoma in situ. Margins were uninvolved, but the lateral margin was 2 mm from the specimen and the anterior margin was 1 mm from the specimen. The margins were trimmed with surgery on 4/6/09. Do you recommend Mammosite radiation, and is it offered anywhere in the greater Baltimore area? Would you suggest a second opinion before starting any therapy? MammoSite balloon radiation is currently considered investigational in the treatment of ductal carcinoma in situ. There is a large national study being conducted comparing partial breast radiation (i.e. Mammosite radiation) to the standard of care whole breast radiation. Certainly, it will be years before we know the results of this study. The issue with ductal carcinoma in situ is that there is a risk that there may be other pre-invasive or even invasive cancers in the same breast, which is why the current recommendation remains that women should undergo whole breast irradiation. Mammosite radiation is offered at the University of Maryland. If you would like a second opinion regarding your particular case, we would be happy to see you in consultation at the University of Maryland.
Q : 9 09/27/2008	How much time must elapse between radiation treatments on the esophagus? My husband had esophagus cancer. He had radiation and chemotherapy. If the cancer comes back, how soon can he have radiation again? Assuming your husband was treated with definitive chemoradiation, we generally would not repeat a course of radiation to the same areas of the esophagus due to normal tissue constraints (meaning that the normal anatomy near the tumor would be radiated beyond their tolerance if he were radiated again, which would convey risks of life-threatening toxicity). If he were to have a recurrence in an area not previously irradiated, then he could receive treatment there. In rare circumstances, when no other options exist, your radiation oncologist may consider re-irradiating an area of the esophagus, but this should be considered highly experimental, and in that case, the longer the time interval between the two treatment courses, the better.

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