Publications (19) View all
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Article: Emerging role of stereotactic body radiotherapy in the treatment of pancreatic cancer.
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ABSTRACT: The management of pancreatic cancer continues to be challenging. Despite surgical, genetic and molecular advances, its overall prognosis remains poor. Surgical resection is the only modality that offers a chance for a cure, with an overall survival rate of 10-20% at 5 years. However, only 20% of the patients are surgical candidates because of locally advanced disease or systemic stage at presentation. Conventional radiotherapy, with or without chemotherapy, has been used to treat patients with advanced-stage pancreatic cancer, an approach with high rates of local recurrence. Stereotactic body radiation therapy, also known as stereotactic ablative radiotherapy has emerged as a treatment modality that allows the precise delivery of a large ablative radiation dose to a tumor volume while sparing surrounding organs and tissues. Phase I and II studies have shown good rates of local control of the disease but rates of distant metastasis remain significant. Strategies to combine novel systemic therapy and stereotactic body radiation therapy are to be explored.Expert Review of Anti-infective Therapy 04/2013; 13(4):481-7. · 2.65 Impact Factor -
Article: Four-year outcomes of hypofractionated high-dose-rate prostate brachytherapy and external beam radiotherapy.
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ABSTRACT: PURPOSE: High-dose-rate (HDR) brachytherapy boost in prostate cancer allows dose escalation and delivery of higher biologically effective dose (BED). We evaluated the outcomes of intensity-modulated radiation therapy (IMRT) and HDR boost in a community setting. METHODS AND MATERIALS: Between July 2003 and April 2008, 148 patients with prostate cancer were treated at Cancer Center of Irvine using two transperineal implants performed 1 week apart (22Gy delivered in four fractions divided between two insertions and delivered twice daily), followed by IMRT (50.4Gy). Hormonal therapy was given for 1 year to all patients with Gleason score of 8 or higher. RESULTS: Patient characteristics are as follows: median age at treatment, 71 years; American Joint Committee on Cancer Group IIB, 53%; Gleason score of 7, 41%; and Gleason score of 8 or higher, 14%. Median followup was 49 months, and median prostate-specific antigen (PSA) nadir was 0.15ng/mL. The 4-year actuarial biochemical disease-free survival (bDFS) was 96.8/81% by Phoenix/PSA lower than 0.5ng/mL criteria. According to National Comprehensive Cancer Center Clinical Practice Guidelines-defined recurrence risk groups, 4-year bDFS for low risk was 100/92.9%, intermediate risk was 100/86.7%, and high risk was 94/75.4% by Phoenix/PSA lower than 0.5ng/mL criteria. No statistically significant difference in bDFS was detected by either failure criteria based on risk group, lymph node risk, or initial PSA. Treatment was well tolerated. Subacute/late genitourinary and gastrointestinal toxicities were limited to 10% and 5%, respectively of all patients. CONCLUSIONS: Prostate IMRT plus HDR brachytherapy boost was well tolerated with appropriate PSA response and bDFS at 4 years, demonstrated in a community setting. This treatment schema provides a high BED, comparable with hypofractionated prostate regimens previously reported in the literature. Higher BED delivery should be explored in further dose escalation studies.Brachytherapy 02/2013; · 1.47 Impact Factor -
Article: Stereotactic body radiation therapy for metastasis to the adrenal glands.
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ABSTRACT: Many primary cancers can metastasize to the adrenal glands. Adrenalectomy via an open or laparoscopic approach is the current definitive treatment, but not all patients are eligible or wish to undergo surgery. There are only limited studies on the use of conventional radiation therapy for palliation of symptoms from adrenal metastasis. However, the advent of stereotactic body radiation therapy (SBRT) - also named stereotactic ablative radiotherapy for primary lung cancer, metastases to the lung, and metastases to the liver - have prompted some investigators to consider the use of SBRT for metastases to the adrenal glands. This review focuses on the emerging data on SBRT of metastasis to the adrenal glands, while also providing a brief discussion of the overall management of adrenal metastasis.Expert Review of Anti-infective Therapy 12/2012; 12(12):1613-20. · 2.65 Impact Factor -
Article: Radioactive seed migration after transperineal interstitial prostate brachytherapy and associated development of small-cell lung cancer.
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ABSTRACT: We report a case of lung carcinoma developing in the location of a migrated prostate brachytherapy seed. A 57-year-old male nonsmoker was originally diagnosed with prostate adenocarcinoma Group IIB in October 1999. Treatment was completed at an outside local hospital and consisted of hormone suppression, pelvic external beam radiation, and transperineal interstitial permanent prostate brachytherapy with loose iodine-125 seeds. The treatment was unremarkable for any complications, and immediate postimplant evaluation did not reveal any loose seeds. The patient remained clinically without evidence of disease and was asymptomatic until an isolated episode of hematuria in December 2009. Radiographic evaluation noted an incidental right lower lobe lung mass with a 4-mm hyperdensity slightly off-center. Biopsy confirmed Stage IB limited-stage small-cell lung cancer, and he underwent thoracic radiation with concurrent systemic chemotherapy. The mass remained mildly avid on a positron emission tomographic scan after treatment, and he underwent surgical evaluation with final pathology demonstrating no residual tumor but a metal rod-like implant consistent with a migrated radioactive brachytherapy seed. To our knowledge, this is the first case of a long-term adverse sequela seen in the location of a migrated brachytherapy seed. Although reported incidence of pulmonary seed emboli remains low with little measurable consequence on pulmonary function, we must appreciate that a theoretical risk for secondary malignancy remains not only locally within the periprostatic region but also at any site of seed migration.Brachytherapy 01/2012; 11(5):354-8. · 1.47 Impact Factor -
Article: Stereotactic body radiation therapy for prostate cancer.
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ABSTRACT: Stereotactic body radiation therapy (SBRT) is a promising treatment option for prostate cancer. Hypofractionation regimens, such as SBRT, may be more advantageous compared with conventional regimens because low α:β ratio of prostate cancer has high sensitivity to dose per fraction. In addition, a smaller and tighter margin with SBRT is expected to provide a low toxicity rate without reducing tumor control. The purpose of this article is to examine radiobiological, technical and clinical aspects of SBRT for prostate cancer.Future Oncology 09/2011; 7(9):1077-86. · 3.16 Impact Factor
