Curr Oncol
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In patients with multiple myeloma, Waldenström macroglobulinemia, or lymphoma, what is the efficacy of bortezomib alone or in combination as measured by survival, quality of life, disease control (for example, time to progression), response duration, or response rate?What is the toxicity associated with the use of bortezomib?Which patients are more or less likely to benefit from treatment with bortezomib? ⋯ Bortezomib 1.3,g/m(2) is given as a rapid intravenous bolus over 3-5 seconds on days 1, 4, 8, and 11 of a 21-day cycle; a minimum of 72 hours between doses is required to allow for recovery of normal proteasome function. Vital signs should be checked before and after each dose. A complete blood count is recommended before each dose, with blood chemistries (including electrolyte and creatinine levels) monitored at a minimum on days 1 and 8 of each cycle. The dose of bortezomib should be reduced or held immediately upon development of painful neuropathy, as described in the product monograph; dose modification may also be required for peripheral sensory neuropathy without pain or for other toxicities. Most toxicities are reversible if dose modification guidelines are followed. RESPONSE TO TREATMENT: Responses are usually apparent by 6 weeks (2 cycles). For patients achieving complete remission (determined by negative electrophoresis and immunofixation), bortezomib should be given for 2 additional cycles beyond the date of confirmed complete remission. In patients with progressive disease after 2 cycles or stable disease after 4 cycles, dexamethasone added to the bortezomib regimen (20 mg by mouth the day of and the day after each bortezomib dose) may produce an objective response. Bortezomib (with or without dexamethasone) should be continued in patients showing benefit from therapy (excluding those in complete remission) unless disease progression or significant toxicity is observed. Therapy should be discontinued in patients who do not respond to bortezomib alone if disease progression is seen within 2 cycles of the addition of dexamethasone. The Hematology dsg recognizes that thalidomide is an active agent in multiple myeloma patients who have relapsed after autologous stem-cell transplantation or who are refractory to alkylating agent-based chemotherapy. To date, no reported rcts have evaluated thalidomide in this role, and specifically, no trials have compared thalidomide with bortezomib. Given these limitations, the members of the Hematology dsg regard thalidomide or bortezomib as therapy alternatives to dexamethasone.
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We assessed the effect of geometric uncertainties on target coverage and on dose to the organs at risk (OARS) during intensity-modulated radiotherapy (IMRT) for head-and-neck cancer, and we estimated the required margins for the planning target volume (PTV) and the planning organ-at-risk volume (PRV). For eight head-and-neck cancer patients, we generated IMRT plans with localization uncertainty margins of 0 mm, 2.5 mm, and 5.0 mm. The beam intensities were then applied on repeat computed tomography (CT) scans obtained weekly during treatment, and dose distributions were recalculated. ⋯ Maximum dose to the spinal cord was above limit in 57.7%, 34.6%, and 15.4% of cases when 0-mm, 2.5-mm, and 5.0-mm margins (respectively) were used for prv. Significant deviations from the prescribed dose can occur during IMRT treatment delivery for head-and-neck cancer. The use of 2.5-mm to 5.0-mm margins for PTV and PRV greatly reduces the risk of underdosing targets and of overdosing the spinal cord.
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The Ottawa Rapid Palliative Radiotherapy Program (RPRP) was established in 1999 with the goal of facilitating access by family physicians to radiotherapy services for patients with advanced symptomatic cancer. Two years later, an audit revealed that of the 148 patients treated by the program, only 19 had been referred by family physicians. We therefore assessed awareness of the RPRP and perceptions of the effectiveness of palliative radiotherapy on the part of family physicians by surveying a random sample of family physicians in Eastern Ontario. ⋯ Among responders, 80% regularly provided palliative care, and these physicians were much more likely to be aware of and to refer patients for palliative radiotherapy. Our survey confirms the key role that family physicians play in providing care to patients with advanced cancer. However, significant deficits in family physician awareness of palliative radiotherapy programs and in knowledge of the effectiveness of palliative radiotherapy should be addressed to improve patient care.