PubMed Health⌕ Search

Biomedical subjects

Revathy B Iyer

Publications and source records attributed to Revathy B Iyer.

12 recordsLinked to original sources
PubMed2006

Cytokines, GM-CSF and IFNgamma administered by priming and post-chemotherapy cycling in recurrent ovarian cancer patients receiving carboplatin.

BACKGROUND: Monocyte/macrophages (MO/MA), a polymorphic population of innate immune cells, have the potential to mediate antitumor effects, and may also contribute to protumor effects. A priming and post-chemotherapy schedule of the myeloid cell mobilizing and immune stimulatory growth factor, granulocyte monocyte stimulating factor (GM-CSF, Leukine) and the MO/MA activating cytokine recombinant interferon gamma 1b (rIFN-gamma1b, Actimmune) has been developed. The pre- and post-chemotherapy design is based upon known in vivo kinetics and immune modulatory effects of these molecules. Carboplatin (Paraplatin) was selected as the cornerstone of treatment of epithelial ovarian cancer (EOC). METHODS: We studied hematopoietic and immunologic effects of GM-CSF and rIFN-gamma1b before and after carboplatin in patients with recurrent EOC. Potentially chemotherapy-sensitive patients with recurrent measurable tumors received subcutaneous GM-CSF (starting at 400 mug/day) for 7 days plus subcutaneous rIFN-gamma1b (100 mug) on days 5 and 7, before and after intravenous carboplatin (area under the curve of 5). We performed standard hematologic assessment and monitored monocyte (MO), dendritic cell, major cell subset counts, and antibody-dependent cell-mediated cytotoxicity (ADCC) against a Her2neu+ tumor cell line, as well as selected plasma inflammatory cytokine, chemokine and growth factor levels. RESULTS: Our analysis comprised only the first 3 months of treatment in the initial 25 patients. Relative to pretreatment baseline values, white blood cell, neutrophil, MO, and eosinophil counts increased (P <or= .001 for each); the proportion of platelets increased 9 days after the second (P <or= .002) and third (P <or= .04) carboplatin treatments; and the number of cells in the activated MO subsets CD14+HLA-DR+, CD14+CD64+, and CD14+CXCR3+ increased (P <or= .04 for each); plasma levels of the proangiogenic interleukins 1alpha, 6, and 8 were lower (P <or= .03 for each); M-CSF, a product of activated MO/MA, was increased on day 9 (P = .007); and GM-CSF was increased in plasma after GM-CSF administration (P <or= .04). Quality of life measurements were reduced during the GM-CSF/IFN-gamma1b cycle while recovering at pre-chemotherapy baseline for FACT-G scores only. CONCLUSION: A novel regimen of GM-CSF plus IFN-gamma1b administered to 25 EOC patients receiving carboplatin increased myeloid cells, platelets and total activated MO populations during the initial 3 months; however, ADCC responses were not consistently enhanced during this period.

Journal Article↗
PubMed2006

Recurrent ovarian cancer: spectrum of imaging findings.

OBJECTIVE: The purpose of this article is to show the appearance of atypical sites of metastasis in patients with recurrent ovarian cancer. CONCLUSION: Metastatic disease from ovarian cancer outside of the peritoneal cavity is generally rare at presentation but is increasingly seen in patients who have recurrent disease, despite multiple therapies. It is important for radiologists to recognize atypical sites of metastasis in patients with recurrent ovarian cancer to facilitate earlier diagnosis and treatment.

Abdominal Neoplasms↗
PubMed2006

Spectrum of imaging findings in the abdomen after radiotherapy.

OBJECTIVE: The objective of this article is to describe the imaging appearances of radiation injury to normal tissues in the abdomen that may be seen during imaging surveillance of oncology patients. CONCLUSION: Therapeutic radiation is used to treat various malignant conditions in the abdomen. Radiation damages normal surrounding tissues as well as the intended tumor. Radiation changes vary based on the target organ and the time from completion of therapy. Familiarity with the spectrum of changes that may be seen on follow-up imaging studies should help in the differentiation of radiation injury from other causes such as recurrent malignancy.

Abdominal Neoplasms↗
PubMed2005

Feasibility of dose escalation using intensity-modulated radiotherapy in posthysterectomy cervical carcinoma.

PURPOSE: To evaluate retrospectively the utility of intensity-modulated radiotherapy (IMRT) in reducing the volume of normal tissues receiving radiation at varying dose levels when the female pelvis after hysterectomy is treated to doses of 50.4 Gy and 54 Gy. METHODS AND MATERIALS: Computed tomography scans from 10 patients who had previously undergone conventional postoperative RT were selected. The clinical tumor volume (vaginal apex and iliac nodes) and organs at risk were contoured. Margins were added to generate the planning tumor volume. The Pinnacle and Corvus planning systems were used to develop conventional and IMRT plans, respectively. Conventional four-field plans were prescribed to deliver 45 Gy (4F(45 Gy)) or 50.4 Gy; eight-field IMRT plans were prescribed to deliver 50.4 Gy (IMRT(50.4 Gy)) or 54 Gy (IMRT(54 Gy)) to the planning tumor volume. All plans were normalized so that > or =97% of the planning tumor volume received the prescribed dose. Student's t test was used to compare the volumes of organs at risk receiving the same doses with different plans. RESULTS: The mean volume of bowel receiving > or =45 Gy was lower with the IMRT(50.4 Gy) (33% lower) and IMRT(54 Gy) (18% lower) plans than with the 4F(45 Gy) plan. The mean volume of rectum receiving > or =45 Gy or > or =50 Gy was also significantly reduced with the IMRT plans despite an escalation of the prescribed dose from 45 Gy with the conventional plans to 54 Gy with IMRT. The mean volume of bladder treated to 45 Gy was the same or slightly lower with the IMRT(50.4 Gy) and IMRT(54 Gy) plans compared with the 4F(45 Gy) plan. Compared with the 4F(45 Gy) plan, the IMRT(50.4 Gy) plan resulted in a smaller volume of bowel receiving 35-45 Gy and a larger volume of bowel receiving 50-55 Gy. Compared with the 4F(45 Gy) plan, the IMRT(54 Gy) plan resulted in smaller volumes of bowel receiving 45-50 Gy; however, small volumes of bowel received 55-60 Gy with the IMRT plan. CONCLUSION: Intensity-modulated RT may permit an increase in the radiation dose that can safely be delivered to the central pelvis and pelvic lymph nodes after hysterectomy. However, dose-volume calculations using individual CT scans do not account for internal organ motion. Detailed data concerning the relationships among radiation dose, treatment volume, and treatment effects are lacking, and prospective studies of pelvic IMRT are needed to determine the safety and efficacy of this treatment.

Feasibility Studies↗
PubMed2004

Computed tomographic colonography (virtual colonoscopy): a multicenter comparison with standard colonoscopy for detection of colorectal neoplasia.

CONTEXT: Conventional colonoscopy is the best available method for detection of colorectal cancer; however, it is invasive and not without risk. Computed tomographic colonography (CTC), also known as virtual colonoscopy, has been reported to be reasonably accurate in the diagnosis of colorectal neoplasia in studies performed at expert centers. OBJECTIVE: To assess the accuracy of CTC in a large number of participants across multiple centers. DESIGN, SETTING, AND PARTICIPANTS: A nonrandomized, evaluator-blinded, noninferiority study design of 615 participants aged 50 years or older who were referred for routine, clinically indicated colonoscopy in 9 major hospital centers between April 17, 2000, and October 3, 2001. The CTC was performed by using multislice scanners immediately before standard colonoscopy; findings at colonoscopy were reported before and after segmental unblinding to the CTC results. MAIN OUTCOME MEASURES: The sensitivity and specificity of CTC and conventional colonoscopy in detecting participants with lesions sized at least 6 mm. Secondary outcomes included detection of all lesions, detection of advanced lesions, possible technical confounders, participant preferences, and evidence for increasing accuracy with experience. RESULTS: A total of 827 lesions were detected in 308 of 600 participants who underwent both procedures; 104 participants had lesions sized at least 6 mm. The sensitivity of CTC for detecting participants with 1 or more lesions sized at least 6 mm was 39.0% (95% confidence interval [CI], 29.6%-48.4%) and for lesions sized at least 10 mm, it was 55.0% (95% CI, 39.9%-70.0%). These results were significantly lower than those for conventional colonoscopy, with sensitivities of 99.0% (95% CI, 97.1%->99.9%) and 100%, respectively. A total of 496 participants were without any lesion sized at least 6 mm. The specificity of CTC and conventional colonoscopy for detecting participants without any lesion sized at least 6 mm was 90.5% (95% CI, 87.9%-93.1%) and 100%, respectively, and without lesions sized at least 10 mm, 96.0% (95% CI, 94.3%-97.6%) and 100%, respectively. Computed tomographic colonography missed 2 of 8 cancers. The accuracy of CTC varied considerably between centers and did not improve as the study progressed. Participants expressed no clear preference for either technique. CONCLUSIONS: Computed tomographic colonography by these methods is not yet ready for widespread clinical application. Techniques and training need to be improved.

Colonography, Computed Tomographic↗
PubMed2004

Hepatic adenoma.

Explore the source record for details and available documents.

Adenoma↗
PubMed2003

Imaging in cervical cancer.

Cervical cancer traditionally has been staged clinically. Advances in imaging could improve the staging of cervical cancer by facilitating the detection of lymph node metastases and micrometastases in distant organs. Such progress could lead to improvements in treatment selection and therefore increase overall survival rates. At the Second International Conference on Clinical Cancer (Houston, TX, April 11-14, 2002), a panel composed of gynecologic oncologists, radiation oncologists, and diagnostic radiologists reviewed relevant technologies. Advances in lymphangiography, ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), and lymphatic mapping were reviewed, along with the impact of these advances on the diagnosis, treatment, and survival of patients with cervical cancer. Few cancer centers still use lymphangiography, but the sensitivity of this method ranges from 28% to 83%, with specificity ranging from 47% to 100%. The roles of transabdominal and transvaginal ultrasonography in evaluating cervical cancer are expected to expand when new contrast agents increase the sensitivity of these techniques to parametrial invasion and lymph node metastases; meanwhile, ultrasonography's most significant contributions may involve the identification of uterine and cervical leiomyomas and the evaluation of urinary tract obstruction. Advances in CT have made it a rival technique to MRI, but limitations prevent CT from providing definitive information on certain parameters. MRI, which is valuable because of its superior soft tissue contrast resolution, multiplanar capabilities, and cost-effectiveness, is used to determine the size of the cervix and to detect certain types of invasion, characteristics of lymph nodes, and the presence of disease in the ureter, lung, and liver. PET with 2-[fluorine-18]fluoro-2-deoxy-D-glucose has been found to detect abnormal lymph node regions better than CT does but PET can also be used in conjunction with CT to measure tumor dimensions. PET also has become a method for identifying tumors that are unresponsive to chemoradiation. When used together with immunohistochemical and molecular techniques as well as conventional stains, sentinel lymph node mapping, an important development in the surgical management of solid tumors, is expected to improve gynecologic cancer management. Advances in imaging methods and in contrast agents, along with advances in the combined use of the two, are expected to make imaging technologies more valuable in cervical cancer assessment.

Diagnostic Imaging↗
PubMedDate not supplied

CT colonography: surveillance in patients with a history of colorectal cancer.

Colorectal cancer is a leading cause of morbidity and mortality in the United States. It is also a disease that is preventable if precursor adenomatous polys are removed. Once a diagnosis of colorectal cancer is made, surgical resection is the only means of cure. The ability to resect colorectal cancer for cure is largely dependent upon the stage of tumor at presentation. Once a patient has been treated for colorectal cancer with surgery and in some cases neo-adjuvant or adjuvant therapy, they will present for follow-up. Surveillance is performed on these patients in order to detect local recurrence that if detected early can be surgically resected for cure. Surveillance also allows detection of distant metastatic disease that may in some cases also be cured with resection. Finally, surveillance of the remaining colon is important to detect the development of new or metachronous adenomatoid polyps that if left in place could develop into new colon cancers. Imaging can play a part in patient surveillance to detect recurrent disease at extracolonic sites as well as the development of new colonic lesions. CT colonography is a promising tool for surveillance in patients with a history of colorectal cancer.

Colonic Polyps↗