First prospective clinical trial of adaptive radiotherapy for head and neck cancer patients

February 9, 2012

Researchers led by a senior investigator at Hofstra-North Shore LIJ School of Medicine and The Feinstein Institute for Medical Research have released initial findings from a first-of-a-kind clinical trial in adaptive radiotherapy (ART) for head and neck cancer. The trial, sponsored by the National Cancer Institute, provides evidence that ART may benefit patients with less technical difficulty than previously believed. The findings of this trial were released online in advance of publication in the International Journal of Radiation Oncology Biology Physics.

Physicians commonly use radiotherapy to treat of the oropharynx (back of throat). Current standard-of-care is called intensity-modulated radiotherapy, or IMRT. IMRT allows physicians to "sculpt" radiation to fit the anatomy of individual patients. Although appealing, this technique has a crucial Achilles' heel – it is based entirely on a CT or MRI scan taken before actual treatment begins. Since a typical course of radiation treatment for oropharynx cancer lasts 6-7 weeks, standard IMRT cannot compensate for common changes that take place in a patient's body during this time, such as weight loss, shrinkage of tumor, or gradual movement of normal tissues. Recent work suggests that the inability of standard IMRT to keep up with these changes may lead to unanticipated toxicity, or potentially worse, missing of tumor.

For this new trial, which was conducted at the University of Texas M.D. Anderson Cancer Center, investigators started patients on standard IMRT. They then took CT scans while patients were lying in the radiation treatment room each day so they could monitor changes in tumor and normal tissues during the entire course of treatment. Through computerized techniques, the investigators "adapted" (thus the name "adaptive radiotherapy") treatment if they noticed significant tumor or body changes that could affect quality of treatment. Most strikingly, the group found that most patients required only one, or at most two adaptions of IMRT to maintain treatment quality.

"This is the first prospective clinical trial of its kind to gauge how "refitting" of IMRT to a patient's body actually impacts care for a patient who has ," noted David Schwartz, MD, vice-chair of radiation medicine at the North Shore-LIJ Health System, associate professor at the Hofstra North Shore-LIJ School of Medicine, and a senior investigator at The Feinstein Institute for . "What most encouraged us was that ART appears effective with only 1 or 2 additional replans. This means that ART does not have to be overly burdensome or expensive to make a difference. This is something that is feasible, and could eventually make a real-world difference in many clinics."

"ART keeps radiation treatment tightly fitted to a patient's body, almost as if it were being shrink-wrapped," Schwartz added. "It is as individualized as our current treatment can realistically be."

Specifics of the Trial

Twenty-four patients enrolled onto this institutional review board approved trial; data for 22 of these patients were analyzed with at least 12 months follow-up. Treatment was initiated with a baseline IMRT plan, and computed tomography (CT) imaging was performed in the treatment room each day to map tumors and normal anatomy to assess need for ART replanning.

Primary site was base of tongue in 15 patients, tonsil in 6 patients, and glossopharyngeal sulcus in one patient. Twenty patients (91 percent) had American Joint Committee on Cancer (AJCC) Stage IV disease. T stage distribution was 2 T1, 12 T2, 3 T3, 5 T4. N stage distribution was 1 N0, 2 N1, 5 N2a, 12 N2b, and 2 N2c. Of the patients, 21 (95%) received systemic therapy.

All patients required at least one ART replan because of tumor and normal tissue changes; eight patients (36 percent) required a second ART replan. For the patients who required one adaptive replan, parotid salivary glands had shrunk by an average of 16 percent and tumors had shrunk by five percent by the time of the replan. For the who required a second adaptive replan, parotid glands and tumors had shrunk by 24 percent and 14 percent, respectively. Most ART replans were completed within one day.

With a 31-month median follow-up, there has been no primary site failure and one nodal relapse, yielding 100 percent local and 95 percent regional disease control at two years. Chronic toxicity and functional outcomes beyond one year remain favorable relative to published results for standard IMRT.

Explore further: Combining CT, FDG-PET provides more accurate treatments for head and neck cancer patients

Related Stories

Combining CT, FDG-PET provides more accurate treatments for head and neck cancer patients

April 29, 2011
Combining computerized tomography (CT) with fluorodeoxyglucose positron emission tomography (FDG-PET) images results in significantly more defined tumor outlines and potentially different treatment options in head and neck ...

Newer radiation technology improves head and neck cancer patients' long-term quality of life

January 26, 2012
Patients treated with IMRT for head and neck cancer report an increasingly better quality of life post-treatment when compared to patients receiving other forms of radiation therapy, according to a study presented at the ...

IMRT improves outcomes in patients with extranodal lymphoma of the head and neck

August 15, 2011
Lymphoma is a cancer that affects organs of the immune system, including the lymph nodes. In a subtype of the disease called extranodal lymphoma, tumors arise in non-lymphoid organs, such as the tongue and tonsils. Patients ...

IMRT has less harmful rectal side effects than 3D-CRT for prostate cancer patients

September 26, 2011
Men with localized prostate cancer treated with a newer technology, intensity modulated radiation therapy (IMRT), have more than a quarter (26 percent) fewer late bowel and rectal side effects and a statistically improved ...

Shorter radiation course for prostate cancer is effective in long-term follow-up

September 26, 2011
A shorter course of radiation treatment that delivers higher doses of radiation per day in fewer days (hypofractionation) is as effective in decreasing intermediate to high-risk prostate cancer from returning as conventional ...

Use of costly breast cancer therapy strongly influenced by reimbursement policy

April 28, 2011
What Medicare would pay for and where a radiation oncologist practiced were two factors that strongly influenced the choice of intensity-modulated radiation therapy (IMRT) for treating breast cancer, according to an article ...

Recommended for you

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 ...

Discovery could lead to better results for patients undergoing radiation

July 19, 2017
More than half of cancer patients undergo radiotherapy, in which high doses of radiation are aimed at diseased tissue to kill cancer cells. But due to a phenomenon known as radiation-induced bystander effect (RIBE), in which ...

Definitive genomic study reveals alterations driving most medulloblastoma brain tumors

July 19, 2017
The most comprehensive analysis yet of medulloblastoma has identified genomic changes responsible for more than 75 percent of the brain tumors, including two new suspected cancer genes that were found exclusively in the least ...

Novel CRISPR-Cas9 screening enables discovery of new targets to aid cancer immunotherapy

July 19, 2017
A novel screening method developed by a team at Dana-Farber/Boston Children's Cancer and Blood Disorders Center—using CRISPR-Cas9 genome editing technology to test the function of thousands of tumor genes in mice—has ...

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.