Prophylactic Cranial Irradiation PCI Long Term Effects
My sister has gone through 5 cycles of chemo (1 more cycle to go) and 25 chest radiation therapy treatments. The doctor is suggesting PCI (10 treatments) when her chemo is finished. She has asked questions regarding long-term effects and was told to surf the net to find out (I find that unacceptable). If you can offer any information or point me to a legitimate site, I would be very grateful. Thank you for anything you can offer.
Barbara Campling, MD, Medical Oncologist, responds:
From what you tell me about your sister's treatment, especially the fact that she had radiation to the chest along with her chemotherapy, I assume that she has "limited-stage" small cell lung cancer. This means that the cancer was confined to the chest at diagnosis, and that she was well enough to tolerate aggressive treatment that offers some hope of long-term survival. The fact that she is being offered radiation therapy to the brain at the completion of her chemotherapy is a good thing, and this implies that her cancer has responded well to therapy so far.
As you have discovered, prophylactic cranial irradiation (PCI) has been used for many years in this disease. Small cell lung cancer usually responds very well to chemotherapy. However, chemotherapy does not get into the brain very well. As a result, the chances of the cancer recurring in the brain after completion of therapy are as high as 50% in patients who live for two years after diagnosis. Many studies have shown that the chance of recurrence in the brain is greatly reduced by giving PCI after the completion of therapy. Furthermore, there is significant improvement in the long-term survival in patients who get PCI. For some time, we were just offering this treatment to patients with limited-stage small cell lung cancer who had already responded to treatment, because those patients were the ones expected to live long enough to benefit from PCI. However, a newer studies support the use of PCI even for patients with extensive-stage small cell lung cancer (that has spread outside of the chest and cannot be cured) who have responded well to chemotherapy. PCI can also prolong survival for these patients.
You are concerned about possible damage to the brain with this treatment. The dose of radiation that is given to prevent recurrence of cancer is lower than the dose used to treat brain metastases. Patients who get this treatment may experience headaches, nausea and fatigue during and for a short time after the treatment. If your sister decides to go through with this treatment, it may delay the recovery from the rigorous chemotherapy and chest radiation that she has been through. There have been some studies that have compared the cognitive functioning of patients who did and did not receive PCI. No differences were found. However, although the majority of patients function normally after PCI, radiation therapy to the brain can result in some cognitive decline that is most commonly experienced by patients as short-term memory loss. These possible side effects need to be balanced against the benefits, namely a reduced chance of recurrence in the brain and a significant improvement in overall survival.