Imaging Research
Pilot Study: Predicting response to radiation therapy by evaluating choline levels with MRS before and after radiotherapy
Specific aim: Determine whether choline levels (or other metabolites) predict sensitivity to radiation therapy.
Summary: Radiation therapy requires daily visits of the hospital with immobilization of the head at each session over a six-week period. Radiation therapy has also significant side effects, in particular in young children and should thus be avoided, when possible. For optimum patient management it is important to know which tumors are likely to respond to treatment. We hypothesize that high choline levels are associated with a higher likelihood for response to radiation therapy whereas low choline levels indicates tumors that are less likely to respond to this treatment. The availability of a predictor for response to treatment would have a direct impact on patient management. Patients with lesions with low choline levels may have little benefit from radiation therapy as their tumors are particularly resistant.
Rationale: Several groups have independently (adult gliomas) shown that higher levels of choline metabolites are associated with increased rates of membrane synthesis and cell proliferation - which may make these tumors also more sensitive to radiation therapy. It has also been shown that choline levels decrease (and lipid levels increase) in response to radiation therapy (biopsy confirmed studies in adult gliomas). We will thus specifically test whether among diffuse brain stem gliomas, tumors with relatively high levels of choline will show the largest absolute and relative changes after radiation therapy.
Status: Prospectively enrolling subjects for this study.
Note: Participants will need to undergo and MRS prior to and after radiation therapy. Sedation for imaging exclusively for research purposes is not allowed. All scanners are equipped with video goggles so participants can watch a movie during the scan. Scans may be accommodated on short notice.
Contact:
Stefan Bluml, PhD
Director, New Imaging Technology Lab.
Childrens Hospital Los Angeles, Dept. of Radiology
Associate Professor of Research Radiology
USC, Keck School of Medicine
SBluml@chla.usc.edu
Tel.: 323-361-5730
Jonathan L. Finlay, MD
Director Neural Tumors Program
Childrens Center for Cancer & Blood Diseases, Childrens Hospital Los Angels
Professor of Pediatrics, Neurology & Neurosurgery
USC, Keck School of Medicine
JFinlay@chla.usc.edu
Tel: 323-361-4629
Girish Dhall, MD
Attending Physician
Neural Tumors Program
Childrens Center for Cancer & Blood Diseases, Childrens Hospital Los Angels
Assistant Professor of Clinical Pediatrics
USC, Keck School of Medicine
GDhall@chla.usc.edu
Tel: 323-361-4629
Children’s of Los Angeles Imaging Study- Impact of steroids on metabolism of tumors (animal research)
Specific aim: Quantify the impact of steroids on tumor metabolism
Summary: Diffuse intrinsic brain stem glioma patients generally receive steroids starting at the time of diagnosis, with duration and dosage individually adjusted according to clinical needs. The impact of steroids on tumor metabolism is unknown and cannot be studied in patients who undergo treatment at the same time. It is hypothesized that steroids such as dexamethasone have a measurable impact on metabolism that needs to be taken into account when interpreting data. We will test the long term and short term impact of steroids on in vivo tumor metabolism in mouse models of human glioma.
Status: First set of animal experiments completed. New set of experiments in progress.
July 19, 2009