(Press-News.org) Vancouver, British Columbia – 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 radiation dose absorbed by the tumor—when it is determined accurately based on 3D molecular imaging—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 monoclonal antibodies, such as I-131 tositumomab, ordinarily involves limiting the administered radioactivity to a conservative dose of total-body radiation, 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 tumor shrinkage 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.
###
Scientific Paper 51: Yuni Dewaraja, Anca Avram, Peter Roberson, Lauren Smith, Scott Wilderman, Jincheng Shen, Hatice Savas, Ehab Youssef, Mark Kaminski, Matthew Schipper, University of Michigan, Ann Arbor, MI, "Tumor absorbed dose predicts progression free survival (PFS) following I-131 radioimmunotherapy (RIT)," SNMMI's 60th Annual Meeting, June 8, 2013, Vancouver, British Columbia.
Dose analysis predicts non-Hodgkin lymphoma survival
Comprehensive dosimetry based on 3-D medical images estimate best possible dose for targeted radioimmunotherapy in patients with invasive blood cancer
2013-06-11
ELSE PRESS RELEASES FROM THIS DATE:
Software toolkit shapes models for personalized radionuclide therapy
2013-06-11
Vancouver, British Columbia – External beam radiation treatment has long been manipulated into the unique shape of patients' tumors for personalized cancer care. Technology providing a means of patient-specific radionuclide drug therapies has not been standardized, as it has been limited to software that requires oncologists to manually define the areas of tumors. A new "phantom" model of the human form that can be deformed and reformed to match anatomy in a matter of hours using 3D graphic design software is being combined with a precision method for predicting how radionuclide ...
Pre-Alzheimer's: Metabolic disorder found in cognitively normal patients
2013-06-11
Vancouver, British Columbia – Alzheimer's disease has been linked in many studies to amyloid plaque buildup in the brain, but new research is finding a common thread between amyloid burden and lower energy levels, or metabolism, of neurons in certain areas of the brain associated with Alzheimer's disease—even for people with no sign of cognitive decline. This is a new development in the understanding of Alzheimer's pathology, say neuroscientists unveiling the research at the Society of Nuclear Medicine and Molecular Imaging's 2013 Annual Meeting.
"This study shows that ...
Molecular imaging finds hurdle for smokers' vaccine
2013-06-11
Vancouver, British Columbia – Researchers have yet again been sent back to the drawing board in the development of the much-sought-after vaccination for smokers, which would hypothetically inhibit the action of nicotine and its pleasure-producing chemical response in the brain. One of the newest studies of a proposed vaccine shows mixed results for patients after molecular imaging revealed no desirable effect and potentially allowed even more nicotine accumulation in the brain in some cases due to variations in immune response, say neuroscientists at the Society of Nuclear ...
High sugar intake linked to low dopamine release in insulin resistant patients
2013-06-11
Vancouver, British Columbia – Using positron emission tomography (PET) imaging of the brain, researchers have identified a sweet spot that operates in a disorderly way when simple sugars are introduced to people with insulin resistance, a precursor to type 2 diabetes. For those who have the metabolic syndrome, a sugar drink resulted in a lower-than-normal release of the chemical dopamine in a major pleasure center of the brain. This chemical response may be indicative of a deficient reward system, which could potentially be setting the stage for insulin resistance. This ...
Radiopeptide therapy improves survival outcomes for neuroendocrine cancer patients
2013-06-11
Vancouver, British Columbia – Peptide-receptor radionuclide therapy (PRRT) has been a subject of growing research on neuroendocrine tumors, which take up residence in a variety of organs replete with nerve cells that respond to hormone signaling. A countrywide study in Germany deemed PRRT treatment not only safe and effective but life-prolonging, according to a study unveiled during the Society of Nuclear Medicine and Molecular Imaging's 2013 Annual Meeting.
PRRT is a new and yet-to-be-approved treatment for patients with neuroendocrine tumors (NETs). These develop when ...
Molecular imaging enlists prostate enzyme to detect metastases
2013-06-11
Vancouver, British Columbia – No matter where they have hidden, metastatic prostate cancer cells still express some of the same signaling as normal prostate cells; in some cases even more so, as with the PSMA enzyme. Harnessing this enzyme could mean the beginning of a new platform for prostate cancer detection, staging, treatment and post-treatment monitoring, say researchers at the Society of Nuclear Medicine and Molecular Imaging's 2013 Annual Meeting.
"There are currently no ideal imaging techniques in clinical practice that are specific to prostate cancer," said ...
Radioimmunotherapy could extend lives of advanced lymphoma patients
2013-06-11
Vancouver, British Columbia – A new patient protocol for aggressive and recurrent lymphoma that combines intensive chemotherapy and radioimmunotherapy (RIT) may become the most powerful cancer-killing therapy available, with the hope that patients' lymphoma can be eradicated as they prepare for bone marrow transplant, say researchers at the 2013 Annual Meeting of the Society of Nuclear Medicine and Molecular Imaging. In a study presented at the meeting, survival rates without recurrence improved with the addition of RIT, with some having a 100 percent chance of survival ...
Breast cancer: PET and MR predict chemotherapy's ability to prolong life
2013-06-11
Vancouver, British Columbia – For patients with advanced breast cancer, positron emission tomography (PET) and magnetic resonance (MR) imaging can improve quality of life and survival by providing physicians with information on the effectiveness of chemotherapy prior to surgery, say researchers presenting at the 2013 Annual Meeting of the Society of Nuclear Medicine and Molecular Imaging.
Researchers combined separate imaging systems—PET, MR and CT—to map the course of chemotherapy before surgery, otherwise known as neoadjuvant chemotherapy. These different imaging systems ...
PET/MR effective for imaging recurrent prostate cancer
2013-06-11
Vancouver, British Columbia – When prostate cancer makes a comeback, it becomes increasingly important to have exceptional imaging available to find all possible regions where cancer has spread to other parts of the body, or metastasized, in order to plan the best possible treatment. A relatively new imaging system that simultaneously combines positron emission tomography and magnetic resonance (PET/MR) demonstrates a higher capacity for mapping recurrent prostate cancer than the already high standard of integrated PET and computed tomography (PET/CT), say researchers presenting ...
Hormonal treatment for endometrial cancer does not directly target the malignant cells
2013-06-11
Progesterone, a female hormone that can be used as a therapy for endometrial cancer, eliminates tumor cells indirectly by binding to its receptor in stromal or connective tissue cells residing in the tumor microenvironment, according to a study from the G.O. Discovery Lab team and collaborators at UCLA.
Like tumors of the breast and prostate, endometrial cancer is regulated by hormones. Unlike therapies for breast and prostate cancer, where drugs are given to block hormone signaling, in therapy for endometrial cancer progesterone is given to stimulate its hormone receptor. ...
LAST 30 PRESS RELEASES:
Largest phase 3 trial of novel treatment for hypertension shows promising results
European regulation needed to prevent the birth of children with inherited cancer-causing genetic mutation after sperm donation
Assembly instructions for enzymes
Rice geophysicist Ajo-Franklin wins Reginald Fessenden Award for pioneering work in fiber optic sensing
Research spotlight: New therapeutic approach stops glioblastoma from hijacking the immune system
‘Hopelessly attached’: Scientists discover new 2D material that sticks the landing
Flowers unfold with surprising precision, despite unruly genes
Research spotlight: Study provides a window into public perceptions about technological treatment options for brain conditions
Sound insulation tiles at school help calm crying children #ASA188
More young adults than ever take HIV-prevention medication, but gaps remain
Why are some rocks on the moon highly magnetic? MIT scientists may have an answer
Unique chemistry discovered in critical lithium deposits
Numerical simulations reveal the origin of barred olivine crystals in early solar system
Daytime boosts immunity, scientists find
How marine plankton adapts to a changing world
Charge radius of Helium-3 measured with unprecedented precision
Oral microbiota transmission partially mediates depression and anxiety in newlywed couples
First vascularized model of stem cell islet cells
US excess deaths continued to rise even after the COVID-19 pandemic
Excess US deaths before, during, and after the COVID-19 pandemic
Millions of HealthCare.gov participants face coverage loss due to burdensome reenrollment policies, according to new research
Study: DNA test detects three times more lung pathogens than traditional methods
Modulation of antiviral response in fungi via RNA editing
Global, regional, and national burden of nontraumatic subarachnoid hemorrhage
Earliest use of psychoactive and medicinal plant ‘harmal’ identified in Iron Age Arabia
Nano-scale biosensor lets scientists monitor molecules in real time
Study shows how El Niño and La Niña climate swings threaten mangroves worldwide
Quantum eyes on energy loss: diamond quantum imaging for next-gen power electronics
Kyoto conundrum: More hotels than households exist in ancient capital
Cluster-root secretions improve phosphorus availability in low-phosphorus soil
[Press-News.org] Dose analysis predicts non-Hodgkin lymphoma survivalComprehensive dosimetry based on 3-D medical images estimate best possible dose for targeted radioimmunotherapy in patients with invasive blood cancer