My clinical research interests have been translational and practical, emphasizing combined modality therapy in cancer management, late effects of therapy including secondary malignancies, and the utilization of brachytherapy (implanted radiation sources) in both malignant and benign disease.
Extensive Research Description
During my first ten years on the Yale faculty, I participated in clinical trials evaluating the efficacy of bioreductive alkylating agents as an adjunct to radiotherapy in cervix cancer. A Phase III study comparing radiotherapy alone with radiotherapy plus Mitomycin C for cervix cancer has been completed in Venezuela with results showing a significant improvement in disease-free survival with the addition of Mitomycin C, which is a hypoxic cell cytotoxin.
For several years, I had been collaborating with Interventional Cardiology and Medical Physics in a clinical program utilizing coronary brachytherapy to manage in-stent restenosis. Some current or upcoming clinical research projects include:
1) modifying radiation dose and volume in advanced stage Hodgkin’s disease based on response to initial chemotherapy (a cooperative group trial);
2) the effects of prostate edema during brachytherapy on modulating radiation dose delivery;
3) the changes in second malignancies seen after Hodgkins Lymphoma therapy with shift away from primary extended field radiotherapy to combined chemotherapy and low dose involved field radiotherapy
4) an examination of the economic forces that drive the use and demand for radiotherapeutic modalities, often with poorly developed evidence.
Regarding this latter concept, in the management of localized prostate cancer, brachytherapy is in a decline while Intensity Modulated and Image Guided Radiotherapy is in ascendancy for complex reasons. In early stage breast cancer, there is an increasing trend toward partial breast irradiation using 3D conformal radiotherapy or brachytherapy. Coronary brachytherapy had experienced a several year surge in usage and interest amongst cardiologists, but now is less frequently needed due to the efficacy of drug eluting stents, a complementary albeit expensive technology. Palliative radiotherapy in terminally ill cancer patients has become less frequently used, due in part to the capitated reimbursement for hospice care and the relatively high expense and inconvenience of radiotherapy versus medical therapy.
- Smith B, Smith G, Roberts K, Buchholz T, “Baseline Utilization of Breast Radiotherapy Prior to Institution of the Medicare Practice Quality Reporting Initiative,” International Journal of Radiation Oncology, Biology, and Physics, 74(5):1506-1512, 2009.
- The Chemoradiation for Cervical Cancer Meta-analysis Collaboration (CCCMAC), “Reducing uncertainties about the effects of chemoradiation for cervical cancer: a systematic review and meta-analysis of individual patient data from 18 randomized trials,” Jou
- Chen ZJ, Deng J, Roberts K, Nath R, “On the need to compensate for edema-induced dose reductions in preplanned (131) Cs prostate brachytherapy,” International Journal of Radiation Oncology, Biology, and Physics 70(1):303-10, 2008.
- Chen Z, Deng J, Roberts K, Nath R, “Potential impact of prostate edema on the dosimetry of permanent seed implants using the new 131Cs (model CS-1) seeds,” Medical Physics 33(4):968-75, 2006.
- Dainiak N, Delli Carpini D, Bohan M, Werdmann M, Wilds E, Barlow A, Beck C, Cheng D, Daly N, Glazer P, Mas P, Nath R, Piontek G, Price K, Albanese J, Roberts K, Salner AL, Rockwell S, “Development of a statewide hospital plan for radiologic emergencies,”
- Roberts KB, Manus MP, Hicks RJ, Rischin D, Wirth A, Wright GM, Ball DL. PET imaging for suspected residual tumour or thoracic recurrence of non-small cell lung cancer after pneumonectomy. Lung Cancer. 2005 Jan47(1):49-57.
- Yue N, Roberts KB, Son H, Khosravi S, Pfau SE, Nath R. Optimization of dose distributions for bifurcated coronary vessels treated with catheter-based photon and beta emitters using the simulated annealing algorithm. Med Phys. 2004 Sep31(9):2610-22.
- Singh HS, Yue N, Azimi N, Nath R, Roberts KB, Pfau S. Relation of clinical success in coronary brachytherapy to dose. Am J Cardiol. 2004 Oct 194(7):847-52.
- Singh HS, Roberts KB, Yue N, Nath R, Song GH, Azimi N, Pfau S. Brachytherapy for in-stent restenosis in general interventional practice: a single institution's experience using four radiation devices. Cardiovasc Radiat Med. 2003 Jul-Sep4(3):126-32.
- Yue N, Roberts KB, Pfau SE, Nath R. Dose distributions in bifurcated coronary vessels treated with catheter-based photon and beta emitters in intravascular brachytherapy. Med Phys. 2003 Jul30(7):1628-36.