Common Questions we get

• After a mastectomy, what areas of the chest are radiated if radiation therapy is recommended?

  What would determine the target of radiation therapy after a mastectomy depends on the pathological findings at the time of mastectomy if patient has not received any chemotherapy prior to her mastectomy and the clinical findings prior to the mastectomy if patient has received chemotherapy prior to the mastectomy. The clinical findings prior to the mastectomy as well as the pathological findings in the surgical specimen would suggest what would be the areas at highest risk of a recurrence. This would be an educated guess based on natural history of the disease and years of research and therefore data and statistics. Generally speaking the most common sites of recurrence after a mastectomy are mastectomy scar, followed by supraclavicular nodes, followed by the axillary nodes. So the minimum area covered by radiation would be the chest wall including the mastectomy scar. Whether the regional lymph nodes including supraclavicular nodes and axillary nodes need to be irradiated or not depends on individual patient and subject to review of each patient’s clinical presentation and review of pathology and details of surgical procedure including whether the patient had undergone sentinel lymph node biopsy or a full axillary dissection and many other factors including biological markers defining level of aggression of the disease, etc. One size does not fit all and multidisciplinary conferences are where medical teams discuss the best approach for each patient and offer individualized care.

• For cervical cancer, what factors determine if radiation therapy after surgery is recommended?

  after a surgical resection. Studies have shown that addition of radiation therapy (and in some cases concurrent chemotherapy) would significantly reduce risk of recurrence. These high risk factors include positive surgical margins, parametrial involvement, deep stromal invasion, lymphovascular invasion, tumors larger than 4 centimeter, pelvic lymph node involvement, and periaortic lymph node involvement.

• How long after having a lumpectomy for breast cancer will radiation treatment begin?

  How long after a lumpectomy would radiation therapy begin depends on whether chemotherapy has been recommended or not. That is because generally speaking in the sequence of treatments, chemotherapy comes before radiation. But regardless of whether it is chemotherapy or radiation, the factor determining the beginning of next treatment is how well the incision of lumpectomy has healed and whether the infection site has become infected or not. Both chemotherapy and radiation therapy can delay the healing process and chemotherapy in particular can weaken the immune system and cause any infectious process to spread in the body. If no chemotherapy has been recommended, as a rule of thumb we would like to leave at least four weeks between surgical procedure and the beginning of radiation therapy but it is all right to delay it up to eight weeks for invasive cancer and up to twelve weeks for DCIS. But once the interval is increased more than that, one would be concerned that the efficacy of radiation would begin to decrease. Please bear in mind that the above is in regards to external beam radiation therapy because in APBI or Accelerated Partial Breast Irradiation using a variety of catheters such as The SAVI Applicator, MammoSite or Contura Balloon radiation can begin within a couple of days after insertion of these applicators and as soon as the pathology report is finalized.

• What are the external radiation techniques (delivery options) for treating cervical cancer?

  Traditionally external radiation for treating cervical cancer was given with four-field technique. That is radiation beams were directed from anterior, posterior, right and left lateral directions. This technique did not spare any of organs inside the pelvis. With the invention of CAT scans, three-dimensional radiation therapy was developed. This technology was a CT-based radiation planning system which allowed sparing of normal tissues to some extent. Later on a sophisticated form of 3D conformal radiation therapy, called Intensity Modulated Radiation Therapy or IMRT was developed. This form of radiation planning software is an inverse planning system which begins with a desired dose distribution and arrives at a specification of the required fluence modulation to create it. Obviously the more sophisticated these technologies get, the more successfully we can spare the normal tissues surrounding the target of radiation. Nowadays an even more sophisticated technology called RapidArc Therapy, not only improves dose conformity but also significantly shortens treatment times. Volumetric modulated arc therapy differs from existing techniques like IMRT because it delivers dose to the whole volume, rather than slice by slice and the treatment planning algorithm ensures the treatment precision, helping to spare normal healthy tissue.

• In what situations would radiation therapy be used to treat metastatic breast cancer?

  Lymph nodes in the armpit are the first location breast cancer would normally invade. Even though from staging standpoint, this is not technically considered metastatic or stage IV or M1 their involvement is an indication for radiation therapy. Technically speaking metastatic breast cancer suggests invasion of other organs by breast cancer. Organs commonly invaded by breast cancer include bone, lung, liver and brain but, also rare, breast cancer can metastasize to almost any other organ. Due to Blood Brain Barrier; most of chemotherapy agents are filtered out of brain, therefore treatment of choice for brain metastasis is radiation. Radiation for the metastatic breast cancer to bone is indicated if the lesion is either causing pain, or has caused fracture or is creating risk of a fracture. Otherwise we would not recommend radiation to every metastasis in the bone. Most of metastatic breast cancers to liver and lung respond very well to chemotherapy but after a while some of these lesions may become resistant to chemotherapy agents. In that case, radiation therapy would be indicated.

• What are typical long-term side effects of radiation for endometrial cancer that patients should watch for?

  Long-term side effects of radiation for endometrial cancer are generally due to radiation to the other organs inside the pelvis. These include the bowel, the bladder, and the vagina. Radiation to the bowel can cause chronic diarrhea, bowel obstruction and fistula formation. A fistula is an abnormal connection or passageway between two organs that normally do not connect and requires surgical repair. Radiation to the bowel may also cause thinning of the blood vessels in the bowel which may cause bleeding even with the normal passage of the stool. This may require laser ablation to stop the bleeding. Radiation to the bladder can cause stiffening of the bladder and therefore frequency of urination. Internal and/or external radiation to the vagina can cause narrowing of the vagina which would be progressive and would only be prevented by using a vaginal dilator. This is usually provided by the radiation oncologist after completion of radiation treatments. Even though statistically the risk is relatively small, radiation would increase the risk of a secondary malignancy in the irradiated field. Therefore the above mentioned organs are potentially at risk of developing another cancer. Particularly in case of endometrial cancer one has to be aware of HNPCC or Hereditary nonpolyposis colorectal cancer. This is a syndrome with increased risk of colorectal and endometrial cancer but unfortunately two major factors in this syndrome are overlooked even by medical professionals. One is the fact that individuals affected by this syndrome do not have increased number of polyps in their colon or rectum. The second one is the fact that women with HNPCC are at higher risk for endometrial cancer that they are for colorectal cancer. Therefore often when a woman is diagnosed with endometrial cancer nobody is alarmed about their risk of colorectal cancer regardless of whether they get radiation therapy or not and they should be!