Biomedical subjects

Dheerendra Prasad

Publications and source records attributed to Dheerendra Prasad.

4 recordsLinked to original sources

PubMed2006

Clinical results of conformal radiotherapy and radiosurgery for pituitary adenoma.

Radiation therapy provides a valuable adjunct to surgery as well as a viable management alternative to surgery for pituitary adenomas. The availability of conformal radiotherapy has dramatically reduced complication rates, and the advent of radiosurgery has reduced the latency of response in these patients. Although extended follow-up is needed to elucidate the long-term outcomes of these treatments, they are likely to be a permanent part of the therapeutic armamentarium for these patients for the near future.

Adenoma↗

PubMed2005

Malignant spinal-cord compression.

Malignant spinal-cord compression (MSCC) is a common complication of cancer and has a substantial negative effect on quality of life and survival. Despite widespread availability of good diagnostic technology, studies indicate that most patients are diagnosed only after they become unable to walk. We review the epidemiology, pathophysiology, and clinical features of MSCC. Clinical trials have informed the optimum management of MSCC, and we review the role of corticosteroids, radiotherapy, and surgery in the management of patients. We also emphasise advances in radiation delivery and the results of a randomised trial that supported aggressive debulking in patients with MSCC.

Combined Modality Therapy↗

PubMed2005

Gamma knife surgery for the treatment of intracranial metastases from breast cancer.

OBJECT: The goal of this study was to evaluate the effectiveness and limitations of gamma knife surgery (GKS) in the treatment of intracranial breast carcinoma lesions. METHODS: A retrospective analysis of the GKS database at the University of Virginia Health System identified 43 patients with a total of 84 lesions who were treated between 1989 and 2000. All patients who received treatment were included in this study. Imaging studies were available in 35 patients with 67 treated lesions. The overall duration of median survival was 13 months (95% confidence interval [CI] 7-16 months) after radiosurgery. A univariable Cox regression analysis revealed that a single lesion (p = 0.035), a high Karnofsky Performance Scale (KPS) score (p = 0.019), and a high Score Index for Radiosurgery (SIR) in Brain Metastases (p = 0.036) were associated with a significantly lengthened time to local treatment failure. The median duration of survival for patients grouped according to the SIR as low, middle, and high was 3, 8, and 21 months, respectively (p = 0.00033). A multivariable analysis showed that a high KPS score (p = 0.006), a high SIR (p = 0.014), and advanced age (0.038) were predictive of survival. The 1-, 2-, 3-, and 5-year survival rates were 49, 23, 12, and 2%, respectively. The overall median time to local treatment failure was 10 months (95% CI 6-14 months) after GKS. A univariable analysis demonstrated that a single lesion, higher KPS score, and a higher SIR were associated with a significantly longer time until local treatment failure. A multivariable analysis showed that a higher KPS score and SIR and patients who had received chemotherapy were associated with a significantly longer time to local treatment failure. Neuroimaging scores given for the enhancement pattern (ring-enhancing, heterogeneous, and homogeneous signal), amount of necrosis (none, < 50%, and > 50%), and mass effect (none, mild, moderate, and severe) of each treated lesion did not correlate with survival or local treatment failure. CONCLUSIONS: The SIR and the KPS score are prognostic factors in patients whose intracranial breast cancer metastases are treated with GKS. The SIR, which includes the KPS score, patient age, systemic disease status, largest lesion volume, and number of lesions, can be used to identify those patients with breast cancer metastasis who would benefit from GKS better than KPS score alone. The contribution of whole-brain radiation therapy to GKS with regard to local tumor control or survival could not be identified.

Adult↗

PubMed2002

Gamma surgery for melanoma metastases in the brain.

OBJECT: The aim of this study was to evaluate the usefulness and limitations of gamma surgery (GS) in the treatment of brain metastases from melanoma. METHODS: Imaging and clinical outcomes in 45 patients treated for 92 brain metastases from melanoma between October 1989 and October 1999 were retrospectively analyzed. Follow-up imaging studies were available in 35 patients with 66 treated lesions. Twenty-four percent of the lesions disappeared, 35% shrank, 23% remained unchanged, and 18% increased in size. No undue radiation-induced changes were observed in the surrounding brain. Clinical data were available in all patients. No deaths or neurological morbidity related to GS was observed. The median survival time, calculated using the Kaplan-Meier method, was 10.4 months from the time of GS. In both univariate and multivariate Cox regression analyses, a single brain lesion and lack of visceral metastases were statistically predictive of a better prognosis. Six of eight patients with solitary metastasis (that is, a single brain metastasis with no primary visceral tumor) were still alive at the close of the study, none of them with disease progression, with a follow-up period ranging between 14 and 82 months. Sixteen patients in this series received adjunctive whole-brain radiation therapy, which had no impact on their survival time or local and distant control of the brain disease. CONCLUSIONS: Gamma surgery is effective in treating melanoma metastases in the brain. It appears that the radiobiology of a single high dose overcomes the radioresistance barrier, yielding better results than fractionated radiation.

Brain↗