Time interval from diagnosis to treatment of brain metastases with stereotactic radiosurgery is not associated with radionecrosis or local failure
INTRODUCTION/UNASSIGNED:Brain metastases are the most common intracranial tumor diagnosed in adults. In patients treated with stereotactic radiosurgery, the incidence of post-treatment radionecrosis appears to be rising, which has been attributed to improved patient survival as well as novel systemic treatments. The impacts of concomitant immunotherapy and the interval between diagnosis and treatment on patient outcomes are unclear. METHODS/UNASSIGNED:This single institution, retrospective study consisted of patients who received single or multi-fraction stereotactic radiosurgery for intact brain metastases. Exclusion criteria included neurosurgical resection prior to treatment and treatment of non-malignant histologies or primary central nervous system malignancies. A univariate screen was implemented to determine which factors were associated with radionecrosis. The chi-square test or Fisher's exact test was used to compare the two groups for categorical variables, and the two-sample t-test or Mann-Whitney test was used for continuous data. Those factors that appeared to be associated with radionecrosis on univariate analyses were included in a multivariable model. Univariable and multivariable Cox proportional hazards models were used to assess potential predictors of time to local failure and time to regional failure. RESULTS/UNASSIGNED:A total of 107 evaluable patients with a total of 256 individual brain metastases were identified. The majority of metastases were non-small cell lung cancer (58.98%), followed by breast cancer (16.02%). Multivariable analyses demonstrated increased risk of radionecrosis with increasing MRI maximum axial dimension (OR 1.10, p=0.0123) and a history of previous whole brain radiation therapy (OR 3.48, p=0.0243). Receipt of stereotactic radiosurgery with concurrent immunotherapy was associated with a decreased risk of local failure (HR 0.31, p=0.0159). Time interval between diagnostic MRI and first treatment, time interval between CT simulation and first treatment, and concurrent immunotherapy had no impact on incidence of radionecrosis or regional failure. DISCUSSION/UNASSIGNED:An optimal time interval between diagnosis and treatment for intact brain metastases that minimizes radionecrosis and maximizes local and regional control could not be identified. Concurrent immunotherapy does not appear to increase the risk of radionecrosis and may improve local control. These data further support the safety and synergistic efficacy of stereotactic radiosurgery with concurrent immunotherapy.
Development of prostate cancer after pituitary dysfunction: a report of 8 patients
OBJECTIVES/OBJECTIVE:Eight patients with a history of pituitary dysfunction were seen in the Department of Radiation Oncology at the Hospital of the University of Pennsylvania for evaluation of their prostate carcinoma. Because prostate cancer is a hormonally responsive cancer, hormonal abnormalities from pituitary dysfunction may have played a role in its development. In addition, many patients with pituitary dysfunction receive exogenous hormonal replacement. The histories of these 8 patients were reviewed to look for any common underlying factor in the development of their prostate cancer. METHODS:The radiation oncology charts, hospital charts, and pathology reports were reviewed. The cause and treatment of the pituitary disorder were reviewed. Hormonal dysfunction, hormonal replacement, and treatment duration were recorded. The interval to the development of prostate cancer, stage at diagnosis, prostate-specific antigen level, Gleason score, treatment, and treatment outcome were also investigated. RESULTS:We found a variety of pituitary disorders and treatments. However, all patients received testosterone replacement therapy prior to the development of their prostate cancer (median of 30 months). The time to the development of the cancer ranged from 26 to 250 months (median 98). Patients had Stage T2 or T3 tumors at diagnosis. Patients were treated either with radical prostatectomy or radiation therapy. Six of the 8 patients were alive and doing well at their last follow-up examination. CONCLUSIONS:Prostate cancer has been shown to be androgen responsive. All the patients in this series were placed on physiologic testosterone replacement for pituitary dysfunction. The role of testosterone in the initiation of prostate cancer has been debated. However, at the present time, it seems appropriate to establish close monitoring for prostate cancer in patients receiving androgen therapy for pituitary dysfunction.