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Radiation-induced nausea and vomiting is a common problem for cancer patients. The emetogenic potential of radiation depends greatly on the location of the radiation field, the size of the radiation field, and the fractionation scheme. Radiation fields can be categorized as having high, moderate, low, or minimal emetogenic risk, and treatment differs accordingly. The National Comprehensive Cancer Network, the Multinational Association of Supportive Care in Cancer, and the American Society of Clinical Oncology publish clinical practice guidelines addressing the issue of radiation-induced nausea and vomiting. This article reviews the treatment recommendations for each category of radiation-induced nausea and vomiting from these national and international guideline committees and provides the rationale for these recommendations.

A principal factor in determining the biologic consequences of photodynamic therapy (PDT) is the light fluence rate. Preclinical and, more recently, clinical studies have focused on low-irradiance schemes, suggesting that prolonged light exposure, better known as CLIPT (continuous low-irradiance PDT), may improve tumor control while reducing morbidity. After a brief look at the origin of light therapy and photosensitizers, this article turns to the promising animal research supporting the use of low- and ultra-low fluence rate PDT, which serves as the basis of the ongoing CLIPT dosimetry trials for patients with chest wall progression of breast cancer. The future of CLIPT seems to be a home-based therapy using a portable, self-contained energy delivery system.

Flow cytometry quantifies the gene product expression on hematopoietic cells, permitting the identification of all cells within a bone marrow aspirate and classifying them according to lineage and maturational stage. The relationships in the expression of multiple markers on myeloblasts, maturing monocytes, and myeloid cells suggests that development of these cells is a stepwise process in which genes are not only turned on or off, but are up- and down-regulated at the junctions between stages. In neoplastic processes, a loss of coordination of these steps is seen, resulting in the abnormal relationships identified by flow cytometry. In myelodysplastic syndromes, the abnormal patterns can be identified on both the immature myeloblasts and maturing myeloid cells and monocytes. The detection of these abnormalities is useful in diagnosing myelodysplasia but requires a detailed understanding of the expression of these gene products to discriminate neoplastic transformation from a stressed marrow. Although the patterns of antigen expression for normal hematopoiesis are precisely defined, each patient with a neoplastic transformation has a unique repertoire of abnormalities that may evolve as the disease progresses. Therefore, scoring systems, in which the abnormalities are counted, provide a means for determining the extent of dysregulation at all the maturational steps, thereby determining a “distance from normal” for a patient at a specific time in the disease course. This is useful, not only to facilitate diagnosis, but to provide prognostic information that may be complementary to the conventional classification schemes and scoring systems.