Radiation oncology investigations
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Radiat Oncol Investig · Jan 1999
Treatment outcome for patients with primary nonsmall-cell lung cancer and synchronous brain metastasis.
The purpose of this study was to evaluate the outcome of treatment for patients with newly diagnosed nonsmall-cell lung cancer (NSCLC) with an isolated, single, synchronous brain metastasis. A retrospective review was performed evaluating any patient diagnosed between 1982 and 1996 at the Cleveland Clinic Foundation with NSCLC metastatic only to the brain. Patients with multiple brain metastases or with systemic metastases to any other organ were excluded. ⋯ Two of the 4 patients with a local failure were salvaged, and ultimate local control of the original brain metastasis was achieved in 93.6% of cases. Survival remains poor for patients with Stage IV NSCLC even when metastatic disease is limited to a single site within the brain; however, aggressive therapy of both the lung primary and the brain metastasis may provide a survival advantage. Excellent local control of single brain metastases was achieved with a combination of WBRT with either surgical resection or SRS.
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Radiat Oncol Investig · Jan 1999
Comparative StudyExtent of margin positivity as a predictor for local recurrence after breast conserving irradiation.
The extent of positivity of the final excision margin in relationship to other relevant factors was evaluated as a predictor for local recurrence after breast conservation therapy (BCT). As part of an institutional practice policy for BCT in 509 stage I/II breast carcinomas, 105 cases had a final excision margin, which was positive. The median age for this cohort was 58 years and the median follow-up was 86 months. ⋯ A Kaplan-Meier plot of freedom from local failure showed a significant (P = 0.008) difference between cases grouped by EOP grade of focal/minimal as compared to moderate/extensive. A Cox proportional hazards regression model found that the only variable significantly related at the P < or = 0.05 level to local failure was an EOP grade of moderate/extensive. For breast excision specimens with a positive final margin, an EOP grade of moderate/extensive is a predictor for local recurrence after BCT, which may be independent of other variables such as age or histology.
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Radiat Oncol Investig · Jan 1999
Implantable polymers for tirapazamine treatments of experimental intracranial malignant glioma.
Malignant gliomas remain refractory to intensive radiotherapy and cellular hypoxia enhances clinical radioresistance. Under hypoxic conditions, the benzotriazine di-N-oxide (3-amino-1,2,4-benzotriazine 1,4-dioxide) (tirapazamine) is reduced to yield a free-radical intermediate that results in DNA damage and cellular death. For extracranial xenografts, tirapazamine treatments have shown promise. ⋯ The basis for potential toxicity is discussed. We conclude that implantable biodegradable polymers provide controlled intracranial release for treatment of experimental glioma. For treatment of malignant gliomas, the combination of continuous polymer-mediated delivery and fractionated systemic delivery of tirapazamine with external beam radiotherapy warrants further exploration.