Dose analysis predicts non-Hodgkin lymphoma survival

June 11, 2013

Outcomes can be bleak for non-Hodgkin lymphoma (NHL), a cancer that develops in the white blood cells of the immune system. Accurate estimation of radiation absorbed dose in radioimmunotherapy (RIT) based on state-of-the-art 3D imaging could lead to more personalized and effective treatments to improve patients' chances of living longer without progression of their cancer, say researchers at the Society of Nuclear Medicine and Molecular Imaging's 2013 Annual Meeting.

"Typically, advanced low-grade NHL patients who undergo conventional treatment such as chemotherapy and external radiotherapy eventually relapse and die of their disease," said Yuni K. Dewaraja, PhD, associate professor in the division of nuclear medicine at the University of Michigan in Ann Arbor, Mich. "Improved tumor dosimetry calculations are an important first step in highly individualized planning for RIT, increasing the effectiveness of treatment and providing new options for a patient population in need."

Determining the appropriate dose of RIT—an intravenous drug therapy combining a radioactive particle and antibodies that seek specific cancer cell signaling—has been an area of investigation for some time. Now researchers are exploring whether the absorbed by the tumor—when it is determined accurately based on 3D —can predict the patient's response and length of response. This particular study focuses on the correlation between absorbed dose and outcome of RIT treatment with the radiopharmaceutical I-131 tositumomab.

"Therapy with radiolabeled , such as I-131 tositumomab, ordinarily involves limiting the administered radioactivity to a conservative dose of total-, but a more aggressive dosimetry-driven approach can be used to tailor the treatment to deliver an optimal therapeutic dose to the tumor while avoiding critical organ toxicity," said Dewaraja. "In addition to evaluating the response to I-131 RIT by and clinical response or non-response at follow-up, the present study examines progression-free survival, which is growing in use as the primary endpoint in oncology studies."

Progression free survival is the length of time patients survive without their cancer worsening. The new method of dose calculation in this study is highly personalized and based on 3D images using a molecular imaging technique called single photon emission computed tomography and computed tomography (SPECT/CT), a hybrid scanner that unites both functional and structural imaging of NHL and other tumors. In the study, data from patient imaging were fed through a specialized computer program called the Monte Carlo radiation transport algorithm to calculate the radiation dose absorbed by the tumor.

As part of a prospective study, researchers performed dose evaluations on a total of 39 patients who collectively had 130 tumors and applied their model of dose-response analysis. The key finding was that a much longer progression free survival was seen for those subjects who received a significantly higher radiation dose—more than 200 centigray, the standard measurement of ionizing radiation absorption. Those who received the greater dose had a median of 13.6 months without progression, whereas those who received less than 200 centigray had only about two months before their cancer progressed.

"This is the most important finding of the study, because the absorbed dose can be estimated from a diagnostic study performed prior to therapy, and future treatment protocols can be customized to deliver a dose exceeding 200 centigray to the tumor. This could potentially lead to marked improvements in overall patient survival," said Dewaraja. Additional studies are needed to assess the dose absorbed by the bone marrow to prevent any possible toxicity to this sensitive tissue.

Explore further: Researchers investigate a less toxic radiation treatment for HPV-Positive oropharynx cancer

Related Stories

Researchers investigate a less toxic radiation treatment for HPV-Positive oropharynx cancer

May 31, 2013
Researchers from Fox Chase Cancer Center and other institutions have completed a phase II clinical trial that may help identify those patients with HPV-positive oropharyngeal cancer who do not require the full radiation dose ...

Hepatic function testing can assist in treatment planning for liver cancer patients

February 8, 2013
Monitoring the hepatic function of unresectable liver cancer patients, measured by 99mTc-labeled iminodiacetic acid (HIDA) via single-photon emission computed tomography (SPECT) prior to and during radiation therapy, provides ...

Higher-dose RT results in inferior survival in patients with stage III lung cancer

May 29, 2013
In a randomized phase III clinical trial conducted by the Radiation Therapy Oncology Group (RTOG), high-dose (HD), compared with standard-dose (SD), radiotherapy (RT) with concurrent chemotherapy (CT) did not improve overall ...

Higher radiation dose does not help lung cancer patients live longer

October 3, 2011
A higher dose of radiation (74 Gy) does not improve overall survival for non-small cell lung cancer that has spread to the lymph nodes, compared to the standard radiation dose (60 Gy), according to an interim analysis of ...

Biodegradable implant may lessen side effects of radiation to treat prostate cancer

June 10, 2013
Several years ago, Virginia Commonwealth University Massey Cancer Center became the first center in the United States to test an Israeli-invented device designed to increase the space between the prostate and the rectum in ...

Recommended for you

New therapeutic approach for difficult-to-treat subtype of ovarian cancer identified

July 24, 2017
A potential new therapeutic strategy for a difficult-to-treat form of ovarian cancer has been discovered by Wistar scientists. The findings were published online in Nature Cell Biology.

Anti-cancer chemotherapeutic agent inhibits glioblastoma growth and radiation resistance

July 24, 2017
Glioblastoma is a primary brain tumor with dismal survival rates, even after treatment with surgery, chemotherapy and radiation. A small subpopulation of tumor cells—glioma stem cells—is responsible for glioblastoma's ...

Immune cells the missing ingredient in new bladder cancer treatment

July 24, 2017
New research offers a possible explanation for why a new type of cancer treatment hasn't been working as expected against bladder cancer.

Shooting the achilles heel of nervous system cancers

July 20, 2017
Virtually all cancer treatments used today also damage normal cells, causing the toxic side effects associated with cancer treatment. A cooperative research team led by researchers at Dartmouth's Norris Cotton Cancer Center ...

Molecular changes with age in normal breast tissue are linked to cancer-related changes

July 20, 2017
Several known factors are associated with a higher risk of breast cancer including increasing age, being overweight after menopause, alcohol intake, and family history. However, the underlying biologic mechanisms through ...

Immune-cell numbers predict response to combination immunotherapy in melanoma

July 20, 2017
Whether a melanoma patient will better respond to a single immunotherapy drug or two in combination depends on the abundance of certain white blood cells within their tumors, according to a new study conducted by UC San Francisco ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.