Radiation and chemotherapy

Brain metastasis is common in melanoma, and treatment options for brain metastasis include surgery, radiation, and chemotherapy. The choice of therapy depends on the number of metastatic lesions, accessibility of the lesions for surgery, the presence of neurologic symptoms, and the status of extracranial disease. 

Based on results on thousands of patients who underwent ECT for a variety of tumors, Xin32 has published extensive data in tabular from. Table 1 shows short-term (6 months) efficacy of ECT whereas Table 2 give the long-term cure rate of various cancers treated with ECT. The results, it is claimed,32 are equal to or better than those obtained by other techniques, i.e., surgery, radiation and chemotherapy. It is further claimed32 that ECT can also be applied to patients who cannot be treated by conventional techniques owing to their old age, general poor health, multiple ailments or advances cancers. 

Although the delivery of radiation and chemotherapy as sole modalities is definitely more complex than outlined above, there needs to be guiding principles that will allow for their successful integration in combined modality therapy. Peckham and Steele introduced several key concepts that govern the interactions of both radiation and chemotherapy when they are administered together in an attempt to improve the therapeutic effect of their separate administrations (27). 

Spatial cooperation is a term coined to describe a situation when disease in one particular anatomic site is missed by one modality but is treated adequately by another. The essence of this is that radiation is a local therapy that will not impact on metastatic disease beyond the planned field borders. Systemic cytotoxic chemotherapy is traditionally used to address the potential distant spread of cancer. In the original description of this mechanism there is no assumption of an interaction between the drugs and radiation with the idea being that the best radiation and best chemotherapy be administered independently of toxicities. The classic example used in several textbooks to illustrate this is the treatment of childhood leukemia with systemic chemotherapy, while their central nervous system, a potential sanctuary site where disease is not treated adequately by chemotherapy, is treated by radiation (28). The reality of the interaction between radiation and chemotherapy is that the dose and timing of radiation are adjusted accordingly to minimize their impact on the neural tissues. 

Kaiser MH, Ellenberg S S. Pancreatic cancer adj uvant combined radiation and chemotherapy following curative resection. Arch Surg 1985 120 899-903. 

In an excellent review of the literature on the interaction between radiation and the taxanes, especially looking at the effects of paclitaxel, Milas et al.(38) outline how they came to realize that reoxygenation played such a substantial role in the potentiation of tumor radioresponse. It has been well established for years that tumors contain areas of hypoxic cells that are normally 2.5 to 3 times less sensitive to radiation than normal cells (37). Both radiation and chemotherapies can cause reoxygenation through their preferential killing of those oxygenated cells that are located close to blood vessels. Milas et al. summarized observations that showed ... 

Within the multiple subsites of this tumor grouping, most work has been done in esophageal cancer. The large majority of these patients have been treated with paclitaxel in combination with radiation (Table 3). The experience with docetaxel is essentially limited to patients treated on phase I trials for thoracic malignancies that used radiation in combination with docetaxel (68,111). The situation is much the same for both pancreatic and gastric cancers as well. The rationale for looking at combination therapy that incorporates paclitaxel is much the same as in other disease sites, i.e., its activity in systemic disease (112), its potent preclinical radiosensitizing properties (38), and evidence from randomized trials that there is a benefit to combined modality therapy that includes at least radiation and chemotherapy (113-116). 

Green MR, Rocha Lima CM, Sherman CA. Radiation and chemotherapy forpatients with stage III non-small cell lung cancer. Sem Rad Oncol 2000 10 289-295. 

Concurrent schedule of chemotherapy and radiation therapy is defined as the delivery of radiation and chemotherapy simultaneously either early or late in the treatment schedule. The advantage of this schedule is that by giving the radiation and chemotherapy together early in the treatment course one can possibly prevent the development of resistant tumor cells. However, the disadvantages include increased toxicides and the decreased ability to deliver full dose chemotherapy (36). 

There are a number of advantages to combining both radiation and chemotherapy in the preoperative setting ... 

Macdonald JS, Smalley S, Benedetti J, et al. Postoperative Combined Radiation and Chemotherapy Improves Disease-free Survival (DFS) and overall Survival (OS) in Resected Adenocarcinoma of the Stomach and G.E. Junction. Am Soc Clin Oncol 2000 19 1a. 

GITSG, Further evidence of effective adjuvant combined radiation and chemotherapy following curative resection of pancreatic cancer. Gastrointestinal Tumor Study Group. Cancer 1987 59(12) 2006-2010. 

Jakse G, Frommhold H, Nedden DZ. Combined radiation and chemotherapy for locally advanced transitional cell carcinoma of the urinary bladder. Cancer 1985 55 1659-1664. 

Housset M, Maulard C, Chretien Y, et al. Combined radiation and chemotherapy for invasive transitional-cell carcinoma of the bladder a prospective study. J Clin Oncol 1993 11 2150-2157. 

Thomas G, Dembo A, DePetrillo A, et al. Concurrent radiation and chemotherapy in vulvar carcinoma. Gynecol Oncol 1989 34 263-267. 

Nevertheless, immunotoxins may be useful for purging cancer cells in bone marrow aspirate isolated from patients undergoing autologous bone marrow transplantation [29,30]. When no suitable bone marrow donor is available, the patients own marrow cells are collected for repopulation of immune cells after radiation and chemotherapy. The small fraction of leukemic cells in autologous bone marrow cells can be removed with immunotoxins before they are reintroduced to the patient for restoring their immune system. Because this procedure... 

CHEMOTHERAPEUTICS. ANTICANCER. Cancer is second only to cardiovascular disease as the principal cause of human mortality. As the median age of populations has risen, total deaths from cancer have increased. Treatment of cancer includes surgery, radiation, and chemotherapy, die last encompassing the use of both cytotoxic agents and relatively nnntoxic hormonal agents for the control of tumor growth. 

Thomas ED, Lochte HL Jr., Lu WC, Ferrebee JW. 1957. Intravenous infusion of bone marrow in patients receiving radiation and chemotherapy. NEJM. 257 491—496. 

ESAs have actually shown increase sensitivity of tumor cells to radiation and chemotherapy... 

Cancer patients given conventional treatment are not told that both radiation and chemotherapy can cause secondary cancer. 

Radiation and chemotherapy continue to be the workhorses of oncological treatment for surgically unapproachable tumors. By working on pathways that are related to loss of control of cell growth, one hopes to discover targets that may be as generic to different cancer types as radiation is. 

A 55-year-old man with chronic lymphocytic leukemia and rheumatoid arthritis took methotrexate for 4 years and developed a B cell non-Hodgkin s lymphoma in the shoulder and axillary lymph nodes he had Epstein-Barr viral antigens in the serum. After radiation and chemotherapy had failed, complete remission was achieved with a combination of rituximab and EPOCH (etoposide -I- prednisone -I- vincristine -I-cyclophosphamide + doxorubicin). 

A series of examples reveal that cell systems like these can be used in wide ranging studies of, for example, cancer sensitivity to radiation and chemotherapy and the analysis of penetration by cytotoxic drugs in targeted tumour therapies... 

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