Seminars in radiation oncology
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The current clinical practice for cervical cancer intracavitary brachytherapy in most centers is to prescribe the dose to point A. However, this is an empirical point and does not necessarily reflect dose to the tumor. Although 3-dimensional image-based treatment planning is extensively used in prostate brachytherapy, only a few institutions have used it to shape the dose distribution in cervical brachytherapy. ⋯ The recommendations of the 2 groups are very similar and are discussed together in this article. Proposals are made for research in image-based brachytherapy for cervical cancer. At a recent transatlantic image-based cervical cancer brachytherapy workshop (Chicago, IL, July 28, 2005), it was suggested that because the recommendations are so similar and to prevent confusion, the nomenclature suggested by the European Group be adopted and future joint contouring workshops be organized to facilitate image-based cervical cancer brachytherapy.
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Standard-dose radiation therapy has limited capacity to cure bulky and locally advanced prostate cancer. Multiple randomized trials have shown a clinical benefit to adding androgen suppression therapy to external-beam radiation therapy in several subsets of prostate cancer. These studies have made combining hormonal therapy with radiation therapy the standard of care for men with locally advanced (T3-4) and unfavorable prostate cancers (Gleason score >or=8 and/or prostate-specific antigen >20 ng/mL). ⋯ Typically, shorter-term hormone therapy is defined as regimens of 4 to 6 months, with longer-term hormone therapy describing durations beyond 24 months. Historically, longer-term hormone therapy was thought to have a more profound systemic effect; however, with the emerging use of hormonal therapy for less-advanced disease, the overall impact of shorter-course hormone therapy is being seen. This review will summarize trials using hormonal therapy and radiation with an emphasis on phase III studies and describe the more recent integration of hormone therapy with radiation for prostate cancer.
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The use of conformal radiotherapy (RT) and the follow-up of patients for radiation liver toxicities has led to a quantitative understanding of partial liver RT tolerance. The most common toxicity is radiation-induced liver disease (RILD), a syndrome of anicteric ascites and hepatomegaly. Elevation of transaminases and reactivation of viral hepatitis have also been reported after liver RT. ⋯ Elevated transaminases are more common in the presence of poor liver function and hepatitis B infection. If the effective liver volume irradiated is less than 25%, very high RT doses may be delivered with little risk of liver toxicity. The mean liver doses associated with a 5% risk of classic RILD for primary and metastatic liver cancer are 28 Gy and 32 Gy, respectively, in 2 Gy per fraction.
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Central nervous system (CNS) failure in patients with locally advanced non-small cell; lung cancer (LA-NSCLC) is a common and debilitating problem. Standard follow-up after local regional therapy does not include routine radiologic evaluation of the brain. Imaging is performed at the onset of symptoms followed by palliative therapy for CNS failure. ⋯ The potential survival, quality of life, and neuropsychological advantage or disadvantage of these two approaches has not been systematically studied. This article will review the problem of CNS failures in patients with LA-NSCLC and the potential risks and benefits of close observation and PCI. The necessity of conducting an ambitious study evaluating the potential survival advantage of PCI will be discussed.
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With continued advances in strategies to detect cancer early and treat it effectively along with the aging of the population, the number of individuals living years beyond a cancer diagnosis can be expected to continue to increase. Although beneficial and often lifesaving against the diagnosed malignancy, most therapeutic modalities for cancer are associated with a spectrum of late complications ranging from minor and treatable to serious or, occasionally, potentially lethal. Taken as a whole, investigators conducting research among long-term cancer survivors (those 5 years or more beyond cancer diagnosis) are reporting that long-term adverse outcomes are more prevalent, serious, and persistent than expected in survivors of both pediatric and adult cancer. ⋯ Both length and quality of survival are important endpoints. Many cancer survivors are at risk for and develop physiologic and psychosocial late and long-term effects of cancer treatment that may lead to premature mortality and morbidity. Interventions-therapeutic and lifestyle-may carry the potential to treat or ameliorate these late effects and must be developed, examined, and disseminated if found effective.