Gamma Imaging Bests Ultrasound for Dense Breasts

Above Picture:  Tubulolobular Carcinoma (1 x 0.8 x 0.8 cm), detected by gamma imaging, negative mammo reading

Breast-specific gamma imaging (BSGI) shows greater accuracy than ultrasound in detecting potentially cancerous tumors in complex breast imaging cases and should therefore improve the management of such cases, according to research presented here at the Society of Nuclear Medicine (SNM) 2011 Annual Meeting.

     Conventional mammography often falls short in providing acceptable, clear images of malignancies in dense breast tissue. It typically detects about 85% of breast cancers in women with normal breast tissue, but only about 60% of cancers in women with dense breast tissue, according to the American Cancer Society.

     In such cases, clinicians commonly turn to ultrasound to investigate unanswered diagnostic questions. However, BSGI is emerging as another valuable tool for imaging dense breast tissue, illuminating the metabolic activity of breast lesions, said lead author Douglas Kieper, BSNMT, professor and nuclear medicine research supervisor at Hampton University in Virginia.

     "When other tests are needed [after mammography], ultrasound is the most frequently used," he explained. "However, since ultrasound and mammography are both anatomical imaging procedures, the things that make a mammogram hard to read can also affect ultrasound."

    "BSGI is a metabolic imaging procedure that can detect cancers not seen with mammography or ultrasound, especially in women with dense breast tissue," noted Mr. Kieper, who is also vice president of science and technology for Dilon Technologies, which develops BSGI products.

     In an effort to determine how BSGI can improve the management of such cases, Mr. Kieper and his colleagues evaluated 119 patients, from 4 medical centers, who were included in a patient registry and routinely scheduled for BSGI examination because of clinical or radiologic findings.

     Biopsies were conducted as considered clinically necessary and were used as the gold standard.

     The routine BSGI and ultrasound results were analyzed for their ability to provide additional information on the case and to alter the course of management.

     Among the 119 patients, 102 benign, 15 malignant, and 2 high-risk breast lesions were discovered.

     The use of BSGI resulted in a change in diagnosis in 109 of the 119 patients; the use of ultrasound resulted in a change in diagnosis in 71 patients.

     BSGI offered greater sensitivity for detecting breast cancer than ultrasound (100% vs 77%) and greater specificity in identifying benign cases as negative (82% vs 52%).

     "BSGI significantly improved the detection of breast cancer when mammography and ultrasound combined were not able to provide a confident diagnosis," Mr. Kieper said.

     One concern about BSGI is its use of an injected nuclear radiotracer. The radiotracer is absorbed at a higher rate by cancerous cells, allowing for improved detection, but it also increases radiation exposure.

     A recent report comparing imaging systems showed that a single BSGI exam involves a lifetime risk for fatal cancer that is as much as 20 to 30 times greater than that of digital mammography in women 40 years of age, according to the Radiological Society of North America.

     In addition, whereas the risk for breast cancer is only slightly increased with the use of mammography, BSGI, along with positron emission mammography, might increase the risk for cancers in other organs of the body, including the intestines, kidneys, bladder, gallbladder, uterus, ovaries, and colon.

     Researchers are working to adjust radiation doses, and some studies have shown encouraging signs of BSGI efficacy in imaging, even with much lower doses, noted Maroun Karam, MD, director of nuclear medicine and a professor of radiology at Albany Medical College in New York

     "The radiation level is a valid concern because the current guidelines from SNM [allow] a dose that is relatively high. However, recent studies from researchers at the Mayo Clinic and elsewhere have shown that this can be done with less radiation," he said.

      Meanwhile, the technology represents an important addition to breast imaging tools, he added.

      "I think this is a great breakthrough innovation in nuclear medicine and the diagnosis of breast cancer," Dr. Karam said. "There is a big gap for people with dense breasts, because the sensitivity of mammography in these women is quite low, so there is a need for imaging to resolve this issue." 

     The radiation levels are still a concern, but if the dose can be reduced to a relatively low level, BSGI could even be used as a screening method. At this point, it represents a valuable next step after mammogram for the imaging of dense breast tissue, and it's significantly less expensive than magnetic resonance imaging."

--Medscape Medical News (Society of Nuclear Medicine 2011 Annual Meeting: Abstract 246. Presented June 6, 2011. 

Wide Beam Reconstruction (WBR), an innovative software program for the reconstruction of nuclear medicine images, reduces the required radiopharmaceutical dose and image acquisition time by 50 percent for diagnostic quality myocardial perfusion SPECT (MPI), compared to conventional techniques, according to a new study published in the March-April 2011 issue of the Journal of Nuclear Cardiology.  Researchers found that with either half the dose of Tc-99m sestamibi or half the acquisition time, WBR resulted in image quality superior to processing with today's widely used OSEM (Ordered Subset Expectation Maximization) software. The study was conducted at St. Luke's-Roosevelt Hospital and Columbia University College of Physicians and Surgeons in New York City.

       "The escalating radiation levels of today's advanced imaging exams is causing growing concern among the medical community and the public at large," said Gordon DePuey, lead researcher and MD, Director of Nuclear Medicine at St. Luke's-Roosevelt Hospital and Professor of Radiology at Columbia University. "There is significant pressure to minimize radiation dose, particular for MPI nuclear SPECT exams." In addition, the ongoing shortages of radiopharmaceuticals due to nuclear reactor downtime compound the need to minimize dosage.

      Developed by UltraSPECT (Haifa, Israel) to address just these concerns, WBR is an innovative reconstruction algorithm incorporating depth-dependent resolution recovery and image noise modeling to deliver a higher quality image with lower count density data.

     In the new MPI study, researchers evaluated images from 156 patients undergoing myocardial perfusion SPECT with a standard full-time acquisition protocol processed with routine OSEM methods. The same 156 patients underwent half-time acquisition, and the data were processed with the WBR algorithm. The images were acquired both at rest and following exercise or pharmacologic stress. A second study group of 160 patients received half of the standard radiopharmaceutical dose, with images acquired for the full standard acquisition time. These were processed using WBR only.

All images were rated for quality by two observers unaware of the acquisition and processing methods. For both the lower dose and abbreviated acquisition time images, grading parameters included myocardial count density and uniformity, endocardial and epicardial edge definition, visualization and definition of the right ventricle, and background noise. For the abbreviated acquisition time images only, SPECT perfusion defects also were examined.

      Overall, WBR half-time and half-dose image quality was judged as superior to OSEM image quality in both arms of the study. There was no statistically significant difference between the two SPECT protocols in identifying the extent or severity of perfusion defects.

     According to Dr. DePuey, "The results of this study demonstrate that WBR is a powerful means of reducing dose without sacrificing image quality and diagnostic accuracy. I would recommend that all nuclear medicine laboratories adopt some strategy for reducing patient radiation exposure incorporating WBR or others techniques that have proven effective."

     Dr. DePuey notes that new SPECT cameras with multiple focused detectors are another effective dose-reduction solution. "Wide beam reconstruction technology, however, is a software-only solution," he says. "For sites unable to budget for a major hardware acquisition, WBR provides an equally effective, more affordable answer."

Sulfur Colloid vs. Blue Dye Method 

 Pharmalucence, Inc. (www.pharmalucence.com) has received FDA approval expanding the route of administration and use of its Sulfur Colloid Injection (SCI) to include location of lymph nodes in breast cancer patients.

     To gain FDA approval for the new drug indication, Pharmalucence conducted a systematic literature review of published scientific articles that describe the efficacy and safety of SCI versus a blue dye used in lymph node localization. All cancer types were evaluated in the study. 

     In all, 9,213 procedures were evaluated. SCI was present in at least one lymph node in 94.1% of procedures versus blue dye being present in at least one lymph node in 85.1% of procedures. Pharmalucence statistical analysis determined that SCI is superior to blue dye when used alone.  In addition, SCI in conjunction with blue dye is also shown to be superior to blue dye alone.  Go to article 

In Related News

Neoprobe® said it is on schedule with its plan to apply for FDA approval of its radiopharmaceutical Lymphoseek® in the third quarter. An FDA decision on the drug would then be likely to be handed down in the middle of next year, CEO Mark Pykett said.  Lymphoseek® is a proprietary radioactive diagnostic tracing agent being developed for use in connection with gamma detection devices in a surgical procedure known as Intraoperative Lymphatic Mapping.

Neoprobe® website 

     With the January 1, 2012, Centers for Medicare and Medicaid Services (CMS) accreditation mandate quickly approaching, the Intersocietal Accreditation Commission (ICAVL, ICAEL, ICANL, ICAMRL, ICACTL, and ICACSF) and the Society of Nuclear Medicine cosponsored a webinar in mid May to address the multitude of questions related to the upcoming deadline. At this time, the requirements of the Medicare Improvements for Patients and Providers Act (MIPPA) apply only to freestanding imaging centers. All nonhospital suppliers of the technical component of advanced diagnostic imaging services, inclusive of nuclear medicine, MRI, CT, and PET, must obtain accreditation as a condition for reimbursement.

     Because accreditation is granted for a period of 3 years, facilities already accredited by the ICANL, ICACTL, or ICAMRL are advised to ensure that their accreditation status will not expire before the 2012 deadline. (Check the status of your facility's accreditation in the online Directory of IAC Accredited Labs at www.intersocietal.org/iac/learnmore/lab_list.htm). Those due to apply for reaccreditation should do so in a timely manner; the facility must be fully accredited by January 1, 2012.

     In addition, facilities must be in compliance with the following newly mandated requirements that apply to CMS reimbursements after January 1, 2012:

• Facilities must be prepared to undergo a random site visit or audit at some time during their 3-year accreditation period.
• Facilities must have policies on patient record retention, consumer complaints, staff, and patient safety.
• Facilities must have a policy identifying the process for verifying the medical education and training of all physicians, as well as the certification and training of all technical staff members and any other direct patient care providers.
• CMS will not recognize an "under review" or "provisional" status.

     Although the IAC recommends that facilities striving to meet the CMS mandate on accreditation submit applications by summer 2011 to ensure that a decision is rendered in time, the IAC's online accreditation applications and review processes have made the processing of applications and rendering of decisions an efficient process. Applications are accepted at any time throughout the year.

Intersocietal Accreditation Commission  

Live Webinars 

Call Radiopharmacy Inc. for Accreditation Assistance

FDA DRUG SAFETY COMMUNICATION:  CARDIOGEN-82 

 The U.S. Food and Drug Administration (FDA) is alerting the public; in particular, the medical imaging community; about the potential for inadvertent, increased radiation exposure in patients who underwent or will be undergoing cardiac positron emission tomography (PET) scans with rubidium (Rb)-82 chloride injection from CardioGen-82 (manufactured by Bracco Diagnostics, Inc.).  A CardioGen-82 PET scan is one of a variety of nuclear medicine scans that use radioactive drugs to evaluate the heart.

     FDA has received reports of two patients who received more radiation than expected from CardioGen-82; the excess radiation was due to strontium isotopes which may have been inadvertently injected into the patients due to a "strontium breakthrough" problem with CardioGen-82.   

     At this time, FDA believes that the risk of harm from this exposure is minimal, although any unnecessary exposure to radiation is undesirable.  The estimated amount of excess radiation the two patients received is similar to that other patients may receive with cumulative exposure to certain other types of heart scans; it would take much more radiation to cause any severe adverse health effects in patients.

     FDA is actively investigating the root cause of this failure with CardioGen-82 and will promptly notify the public with updates.

     Healthcare professionals should closely follow the required testing and quality control procedures essential to help detect strontium breakthrough from CardioGen-82. Other types of heart scans provide information very similar to CardioGen-82 and professionals are encouraged to consider these alternatives while FDA completes its investigation of the reported cases of excess radiation exposure.   

     Patients who have recently had heart scans should talk to their healthcare professional if they have any questions.  Many heart scans do not involve use of CardioGen-82.  Patients who are planning to undergo a heart scan should talk to the healthcare professional if they are unsure of the type of planned heart scan and the radiation risks associated with the scan.  If a Cardio-Gen-82 scan is planned, patients may wish to delay this scan or use alternatives until the radiation issue is resolved.

Data Summary  

     FDA has received reports of two patients who underwent PET myocardial perfusion imaging scans with CardioGen-82 and had detectable levels of radiation several months after their PET scans. Both patients were crossing the border to/from the United States when radiation detectors identified radiation originating from the patients. The radiation was found to originate from strontium (Sr-82 and Sr-85). A PET scan had been performed in each patient approximately 2 and 4 months earlier, respectively. Since Rb-82 has a half-life of 75 seconds and both patients reported that they had no other exposure to radioactive substances, the residual radiation is likely due to undetected strontium breakthrough. The total number of patients who have received doses from CardioGen-82 generators with strontium breakthrough is currently unknown.

     The radiation exposure that a patient would typically receive from an injection of Rubidium-82 chloride (approximately 2.8 mSv) is generally less than that associated with other radionuclide cardiac diagnostic scans.  The radiation exposure that the two patients received due to strontium isotope exposure appears to substantially exceed that typically associated with CardioGen-82.  This assessment is based upon modeling performed by the Los Alamos National Laboratory.  This modeling suggests that the excessive radiation exposure (approximately 90 mSv) associated with the strontium isotopes appears similar to the amount of cumulative radiation exposure some patients receive during cardiac diagnostic evaluations with other radionuclides.  Multiple assumptions are involved in estimating the extent of this radiation exposure and efforts are ongoing to refine these estimates, including discussion with the Nuclear Regulatory Commission.   

     At this time, it is unknown whether this safety issue is due to a product problem involving generator failure or due to user error, or a combination of both factors. FDA is actively investigating the root cause of this issue and will take appropriate regulatory actions as warranted. FDA will promptly notify the public when a conclusion is made.

SNM CardioGen-82 Recall Information 

 14C - Urea Breath Test 

14C -urea breath test is a common test used to determine if an individual has an active infection caused by Helicobacter pylori.  H. pylori was discovered by Dr. Barry Marshall in 1982, and is associated with stomach and duodenal ulcers.  Although H. pylori may not always manifest in ulcers, but is believed to cause inflammation in the stomach lining leading to symptoms such as nausea, bloating, and a burning sensation in the stomach between meals or at night.

Diagnosing H. Pylori

Antigen/Antibody Testing:    A stool is collected from a patient and tested for H. pylori antigens. Another test using this method is conducted by obtaining a serum sample from the patient and testing it for antibodies that fight off H. pylori. These tests do not determine if the patient has an active H. pylori infection, only that H. pylori was recently in their system. The American College of Gastroenterology stated in the 2007 guidelines, "...a positive test is no better than a coin toss in predicting the presence of active infection."   Through meta-analysis this method of testing has sensitivity and specificity of 85% and 79% respectively.

Biopsy: This invasive method is utilized to rule out other stomach infections and determines H. pylori through a process of elimination utilizing other testing methods. The test is performed by inserting an endoscope into the mouth and snaked down the esophagus into the stomach to closely observe the esophagus, stomach, and duodenum. Using this instrument, a sample of tissue can also be removed from these locations. This sample is then tested using the CLOtest™ for the presence of urease, an enzyme produced by H. pylori. This test is requires special training and equipment and is invasive which increases the cost and can cause discomfort to the patient. Additionally invasive methods have been shown to have 100% sensitivity and 99% specificity. However, it should be noted the sensitivity of this method is highly dependent on the skill of the person collecting the sample because sampling from a location of a small population of bacteria could lead to false positives

¹⁴C -Urea Breath Test: A patient swallows a capsule containing Urea labeled with Carbon-14. After three minutes the capsule is dissolved in the stomach. If the ¹⁴C -urea comes into contact with H. pylori, it will be immediately broken down to ¹⁴Carbon-dioxide and ammonia by urease. ¹⁴Carbon-dioxide then enters the blood stream and is exhaled in exchange for oxygen. Peak levels of ¹⁴Carbon-dioxide can be measured in a person's breath 10-15 minutes following capsule ingestion. Therefore ten minutes following ingestion of the capsule a patient will exhale into a mylar balloon and again at twenty minutes. The two samples will then be analyzed. If the 15 min sample contains less than 50 DPM then it the patient is negative for H. pylori. If 50-100 DPM then intermediate, due to chemiluminescence or a cofounding factor such as medication. If greater than 100 DPM then the patient is positive for H. pylori. These results will be obtained 24 hours after the test is performed.

Of the three currently used methods to determine if H. pylori is present in an individual the ¹⁴C-urea breath test is very patient friendly, the most accurate, non-invasive, with a sensitivity and specificity of 95.9% and 97.7% respectively. Moreover, unlike other noninvasive methods it can be used to monitor an active infection and confirm eradication. It should be used after one month following triple therapy or antibiotic therapy to establish the presence or absence of H. pylori in patients that have been treated but remain symptomatic. However, some considerations must be taken into account.

1. The patient will receive a very small amount of radiation.
2. The patient cannot eat or drink anything for six hours prior to the exam.
3. Any proton pump inhibitors ( ie.Prilosec™ or Nexium™), sucralfate (ie. Carafate®) must be discontinued for at least 2 weeks prior to this test.
4. Bismusth (Pepto Bismol ®) and any antibiotic must be discontinued for at least one month prior to this test.
5. According to a case study conducted at Kuwait University in 2000, the incidence of false positives were significantly reduced by having the patient brush their teeth

Billing and Reimbursement

Medicaid and private insurance companies accept two CPT codes for the ¹⁴C-urea breath test reimbursement, 78268 for test analysis and 78267 for drug administration and sample collection.

Regulations:

Your site does not need a CLIA license to perform this test nor a radioactive materials license.

Go to article 

Delaying initial radioactive iodine-131 (I-131) therapy more than 180 days after total thyroidectomy may result in poor survival for thyroid carcinoma patients, according to a study published in the May issue of the Journal of Nuclear Medicine.

     Japanese researchers found that when initial radioactive iodine therapy was delayed more than 180 days, the risk of death was 4.22 times higher than among thyroid cancer patients who received initial therapy within 180 days. The lead author of the study is Dr. Tatsuya Higashi from Shiga Medical Center Research Institute (JNM, Vol. 52:5, pp. 683-689).

     The retrospective study initially reviewed 413 patients with thyroid carcinoma who received total thyroidectomy between January 1997 and June 2009. The researchers included patients with cases of thyroid carcinoma or other variants of thyroid carcinoma at the time of total thyroidectomy. In addition, patients were to have received at least one radioactive iodine treatment during the study's time frame.

     The study also required clinical follow-up for more than one year, and that the patient be younger than 45 years old with distant metastases at the time of thyroidectomy or older than 45 years with at least stage III thyroid carcinoma at the time of thyroidectomy.

     Patients were excluded from the study if they had pathologically confirmed anaplastic carcinoma, undifferentiated carcinoma, medullary carcinoma, or malignant lymphoma at the time of total thyroidectomy, or if their clinical follow-up had been less than one year, among other factors.

     The final cohort included 198 patients with an average interval between total thyroidectomy and initial radioactive iodine therapy of 2.59 years (range, 844-1,546 days). The researchers used patient records and clinical follow-up to confirm disease-specific survival, with the primary end point of survival as the date of death.

     Patient medical records showed that 124 patients received total thyroidectomy at the time of initial thyroid carcinoma detection, with 59 (47%) receiving hemithyroidectomy or subtotal thyroidectomy, and then total thyroidectomy later in their course of treatment (average interval, 6.3 years). The interval was unknown in 15 of those 59 patients.

     An average of three days after receiving I-131 orally, a standard whole-body exam was performed with a dual-head gamma camera.

     A total of 67 patients had observation periods without therapy of 180 days or less, 20 has periods between 180 days and 365 days, and 11 had periods between one and two years. In addition, 13 patients had observation periods without therapy of two to three years, and 73 patients had observation periods without therapy of three years or more.

Clinical follow-up

Based on clinical follow-up, 31 patients died during the observation periods. Two patients who died from cachexia and respiratory failure due to lung metastases were excluded from the present study. Five patients who died for nondisease-specific reasons, including esophageal, gallbladder, and gastric cancer, were also excluded from the study.

     The exclusions left 24 deceased patients (11 males and 13 females) for analysis. The reasons for death included 11 cases of respiratory failure due to lung metastases, six cases of uncontrollable brain metastases, three patients with massive hemoptysis from respiratory tract metastases, two cases of asphyxia related to a bulky neck mass, and one case each of cachexia due to multiple metastases and hemorrhagic cardiac tamponade due to direct invasion.

     The average cumulative number of radioactive iodine therapies (RITs) for deceased patients was four, ranging from one to 26 treatments. On average, deceased patients had an initial RIT at age 62.5 years, which was significantly older than for the survivors. There were no deceased patients younger than 45 years old, with solely local disease, or with lymph node metastases at the time of initial RIT.

     The average interval between total thyroidectomy and initial RIT in the deceased patients was 4.08 years, which was significantly longer than the 2.4-year interval in the survivors.

     In addition, the age at initial RIT of patients older than 45 years showed a significantly high prognostic value, while an interval between total thyroidectomy and initial RIT of 180 days or more also showed significant prognostic value.

Researchers' conclusion

     Based on the results, Higashi and colleagues concluded that the delay of initial RIT until more than 180 days after total thyroidectomy in thyroid carcinoma patients with metastases resulted in poor survival. "Performing initial RIT within 180 days after total thyroidectomy may improve survival in postoperative differentiated thyroid carcinoma patients with metastases," the authors wrote.

     The authors cited several limitations of the retrospective study. They noted that by including only thyroid carcinoma patients treated by RIT, the results may come from a biased patient group.

     In addition, the statistical analysis focused on clinical factors at the time of initial radioactive iodine therapy.

     "RIT is usually performed multiple times during long periods in most patients, and these cumulative therapeutic effects may have a great impact on prognosis," the authors wrote. "Further research evaluating the cumulative therapeutic effects of RIT on prognostic value in differentiated thyroid carcinoma patients is needed."

The American Society of Nuclear Cardiology is pleased to announce a new online education resource, Conference Highlights Meetings on Demand, a digital library of audio and slide presentations captured during ASNC2010, September 23 - 26, 2010 in Philadelphia.

Chaired by Brian G. Abbott, MD, FASNC, this online product features 10 sessions, 23 lectures, and more than 10 hours of audio recordings. Nuclear cardiology and cardiac imaging professionals will obtain the latest information in clinical practice as well as review cutting-edge scientific advances in the field. Sessions include Nuclear Cardiology in an Emerging CT World - Have the Clinical Paradigms Changed?, Basics of Interpretation and Reporting - A Case-Based Presentation, and Radiation Risk from Cardiac CT and Nuclear Cardiology -  Addressing Concerns with Innovative Solutions. To view the complete program content, please click here.

Both CME and ACE credits are available for Conference Highlights Meetings on Demand - order your online copy today!

CE Opportunity 

KSNMT Meeting Information   

Upcoming Webinars 

•  August 11, 2011: Radiation Risks in Clinical Research: Putting It in Perspective Speaker: John Sunderland, PhD

• October 13, 2011: Obtaining Vital Signs, ECG and Pharmacokinetic Sampling in Research Studies, Speaker: Marybeth Devine, CNMT

• December 8, 2011: FDG PET - Standardized Protocol/IND Status Speaker: Jeffrey Yap, PhD (to be confirmed)  

Go to SNM Webinar page