diagnostic imaging

 

Cancer is a word that can inspire fear by its mere mention, and few people’s lives are untouched by cancer, whether they themselves experience it or someone important to them does. Fortunately, cancer survival rates are climbing, and one reason is that advances in diagnostic imaging have made diagnosing, treating, and monitoring cancer easier and more effective.

Different types of diagnostic imaging provide doctors with different information about the body, whether it shows the presence of disease or tracks progress of medical treatment. The contribution of medical imaging to medical practice is so vast that the New England Journal of Medicine ranked medical imaging as one of the top medical advances of the past millennium.

Regarding cancer, medical imaging helps doctors improve patient survival rates in three important ways: by allowing for earlier detection and diagnosis, by providing more accurate cancer staging and monitoring, and by allowing doctors to treat cancer more precisely. Here are just a few of the ways diagnostic imaging is helping in the battle against cancer.

Low Dose CT and Lung Cancer Screening

A recent report in the Annals of Internal Medicine found that low-dose computed tomography (LDCT) is beneficial in lung screening in healthy patients both under and over age 65. This information is particularly valuable because the Center for Medicare and Medicaid Services (CMS) is evaluating whether to cover LDCT screening for lung cancer to those on Medicare.

A meta-study of screening-related outcomes by age group of 19,210 participants under age 65 and 7,110 participants over age 65 found that in the older group there were higher rates of both positive and false-positive screens, but that the positive predictive value was actually higher in the older age group. This is believed to be due to the higher prevalence of lung cancer in older people. This was expected, since cancer incidence overall increases with age and in this case, since older participants were more likely to be former smokers and to have smoked more.

Cancers detected by screening were treated similarly in both age groups and the rate of surgical mortality was low in each group. Moreover, LDCT screening for lung cancer appeared to provide a similar benefit-harm tradeoff in older patients as in younger patients.

PET/CT in Breast Cancer Patients Under 40

In younger women with breast cancer, positron emission tomography/CT (PET/CT) imaging may reduce both morbidity and costs, by preventing unnecessary therapies. A recent article in the Journal of Nuclear Medicine by researchers from Memorial Sloan Kettering Cancer Center in New York detailed a retrospective study of women under 40 who had PET/CT for breast cancer staging after initial physical exam, mammography, ultrasound, and magnetic resonance imaging (MRI) before receiving treatment.

Specifically, PET/CT diagnostic imaging was evaluated in identifying unsuspected extra-axillary regional nodal as well as more distance metastases in patients with cancer from stages I to IIIC. As a result of PET/CT, 21% of patients were “upstaged” to stage III or IV, unsuspected extra-axillary regional nodes were found in 11% of patients, distant metastases were found in 15%, and both extra-axillary regional nodes and distant metastases were found in 5% of patients. All upstaging of patients to stage IV by PET/CT was confirmed with histological tests.

Researchers concluded that PET/CT in younger breast cancer patients, particularly those with stage IIB and III disease could be valuable in proper staging. This goes against current National Comprehensive Cancer Network guidelines recommending against systemic staging in patients with stage II disease, but researchers believe the study shows that PET/CT could potentially reduce morbidity and reduce unnecessary therapies in younger breast cancer patients.

Low Dose CT in Hodgkin Lymphoma Survivors

Survivors of Hodgkin lymphoma have a higher risk of treatment-related lung cancer, and LDCT shows promise in allowing detection of early stage, resectable cancers (cancers that can be removed surgically) in these patients. An article in the International Journal of Radiation Oncology details research that led to development of a decision-analytic and cost-effectiveness model for estimating the value of LDCT screening for lung cancer among Hodgkin lymphoma survivors.

From population databases and medical literature on Hodgkin lymphoma, researchers looked at lung cancer rates, stage distribution, and cause-specific survival estimates. They then assessed the type of radiation therapy that was used during treatment of Hodgkin lymphoma, patient smoking status, age at Hodgkin lymphoma diagnosis, time since treatment, and excess radiation dose from LDCT.

While the results did not show apparent cost-effectiveness among non-smokers, it did show cost-effectiveness among smokers. Researchers also found that the age at which patients were diagnosed with Hodgkin lymphoma affected findings, because earlier initiating of the LDCT screening improved patient outcomes. They concluded that because of increased risk for cancer later in life, Hodgkin lymphoma survivors may benefit from LDCT, particularly if they are smokers.

Future Uses of Medical Imaging in Cancer Patients

Diagnostic imaging is moving forward with technological advances that show promise in other types of cancer as well. Researchers at Cedars-Sinai Medical Center in Los Angeles, for example, are studying the use of diagnostic imaging with near-infrared light in conjunction with so-called “Tumor Paint” in the imaging and resection of brain tumors. Studies in mice of implanted human gliomas show that this technique is particularly useful in visualizing metastatic lesions that are separate from the main tumor.

The use of PET/MRI in bladder cancer staging is being studied by researchers at the University of North Carolina School of Medicine. One-quarter of bladder cancer patients have muscle-invasive cancer, and researchers are determining whether PET/MRI may be better for detecting lymph node involvement in these patients. Currently, conventional MRI and CT are used, but their accuracy is not good in these cases. Researchers hope that PET/MRI diagnostic imaging will offer better soft tissue characterization so that lymph node involvement will be easier to diagnose.

Conclusion

Diagnostic imaging is valuable in many areas of cancer detection, management, and treatment, and advances promise many more uses for diagnostic imaging in the future of cancer diagnosis and care. The board-certified radiologists who own and operate SteleRAD represent a broad range radiology sub-specialties, including those used in the diagnosis, staging, monitoring, and treatment of cancer. The radiologists of SteleRAD offer prompt and accurate interpretations for physician groups, hospitals, and imaging centers, delivery superb quality of services with optimum efficiency. To learn more, feel free to contact SteleRAD online or call 954-358-5250.