XXXX : a problem with many open questions.

@entity1 @entity390 @entity15698 @entity5 @entity935 @entity391 @entity619 @entity750 @entity1209
@entity15698 ( @entity15698 ) is often considered to be less frequent and less severe than @entity1209 encountered in @entity1 receiving chemotherapy, although the issue has only been addressed in a few studies. It is possible that radiation oncologists undervalue the clinical relevance of @entity15698 . If untreated, sickness produces an adverse effect on the @entity1 's quality of life and may cause interruption of the treatment with possible unfavorable effects on @entity5 control. A prospective observational trial on @entity15698 has recently been published by the Italian Group for Antiemetic Research in Radiotherapy (IGARR). The study evidenced that the overall cumulative incidence of @entity391 and @entity390 occurred in about 40% of @entity1 undergoing radiotherapy, and that the irradiated site, radiation field size, and previous chemotherapy were significant risk factors. @entity1 submitted to abdominal radiotherapy were at major @entity391 and @entity390 (71%), followed by those treated on the thorax, brain, head and neck, and pelvis (49%, 40%, 40%%, and 39%, respectively). Few small randomized clinical trials have evaluated the efficacy of various antiemetic drugs in preventing @entity15698 . Generally, @entity1 who entered these trials were those submitted to total body irradiation, half body irradiation or upper abdomen irradiation because of the greater risk of developing @entity1209 . The few controlled trials published have shown that @entity935 receptor antagonists were effective in only about 50% of @entity1 , whereas @entity750 antagonists were more effective. Clinical practice guidelines for the use of antiemetics have recently been published by MASCC (Multinational Association of Supportive Care in Cancer) and ASCO (American Society of Clinical Oncology). Unfortunately, their recommendations were quite different, when classifying radiation emetogenic risk categories and when giving indications for the use of antiemetic drugs. However, MASCC and ASCO recommendations both suggested a prophylaxis with a @entity750 antagonist and a corticosteroid for @entity1 submitted to high emetogenic radiotherapy. There is evidence about the effectiveness of oral @entity619 alone in fractionated upper abdomen radiotherapy and the use of a rescue antiemetic treatment as a possible alternative to the prophylaxis. Many questions remain open, and other prospective controlled trials on @entity15698 are needed to answer them. Considering that radiotherapy to the abdomen, pelvis and thorax presents the most frequent problems in radiation oncology clinical practice, future trials on @entity15698 should deal with these irradiated sites. The IGARR is carrying out a double-blind randomized clinical trial comparing prophylactic ondansetron plus @entity619 versus ondansetron and @entity619 given as a rescue treatment in @entity1 undergoing fractionated radiotherapy to the upper abdomen.
