Cancer screening of healthy volunteers using whole-body 18F-FDG-PET scans: The Nishidai clinic study

Applicability and performance of 18F-FDG PET-based modalities for whole-body cancer screening: a systematic review and meta-analysis

PURPOSE

Screening tests are the cornerstone for early detection and optimal management of cancers. Most of the present cancer-screening tests are intrusive, time-consuming, and specifically target a particular anatomical site or cancer type. Only a few studies have reported the objective measures of 18F-FDG PET-based cancer screening in asymptomatic individuals. This review and meta-analysis is an attempt to assess the applicability and performance of 18F-FDG PET-based modalities for whole-body cancer screening.

MATERIALS AND METHODS

The systematic review and meta-analysis were performed following PRISMA guidelines. Literature searches in PubMed, Scopus, and Embase were conducted using relevant MeSH terms and keywords, for articles published in the last 2 decades (2000-2022). Pooled estimates of diagnostic test accuracy-including sensitivity, specificity, positive-likelihood ratio, negative-likelihood ratio, and hierarchical summary ROC (HSROC) curve were generated using bivariate random-effects meta-analysis.

RESULTS

Seventeen studies were included in the systematic review and 13 studies were deemed eligible for meta-analysis. The mean estimates of pooled sensitivity, specificity, positive-likelihood ratio, negative-likelihood ratio, and Odds ratio using 18F-FDG PET with a 95% confidence interval were 0.47 (0.25-0.69), 0.97 (0.95-0.98), 18.8 (6.8-51.5), 0.45 (0.27-0.76), 41.0 (7.9-211.8) and for 18F-FDG PET/CT were 0.83 (0.75-0.88), 0.98 (0.97-0.99), 49.7 (29.2-84.5), 0.15 (0.8-0.28), 329.9 (125.0-870.8), respectively. Among screening modalities, 18F-FDG PET/CT had a higher accuracy i.e., the area under the HSROC curve (AUC): 0.91 (0.87-0.95) compared to 18F-FDG PET: 0.72 (0.61-0.82).

CONCLUSION

This study demonstrates that currently 18F-FDG PET-based screening has limited applicability for population-based cancer-screening programs. However, it has a promising role as a combined screening strategy for at-risk individuals and allows for comprehensive diagnostic and prognostic evaluation in high-resource settings.

[18F]FDG PET/MRI combined with chest HRCT in early cancer detection: a retrospective study of 3020 asymptomatic subjects

PURPOSE

PET/MRI has become an important medical imaging approach in clinical practice. In this study, we retrospectively investigated the detectability of fluorine-18 (18F)-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging ([18F]FDG PET/MRI) combined with chest computerized tomography (CT) for early cancer in a large cohort of asymptomatic subjects.

METHODS

This study included a total of 3020 asymptomatic subjects who underwent whole-body [18F]FDG PET/MRI and chest HRCT examinations. All subjects received a 2-4-year follow-up for cancer development. Cancer detection rate, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the [18F]FDG PET/MRI with or without chest HRCT were calculated and analyzed.

RESULTS

Sixty-one subjects were pathologically diagnosed with cancers, among which 59 were correctly detected by [18F]FDG PET/MRI combined with chest HRCT. Of the 59 patients (32 with lung cancer, 9 with breast cancer, 6 with thyroid cancer, 5 with colon cancer, 3 with renal cancer, 1 with prostate cancer, 1 with gastric cancer, 1 with endometrial cancer, and 1 with lymphoma), 54 (91.5%) were at stage 0 or stage I (according to the 8th edition of the tumor-node-metastasis [TNM] staging system), 33 (55.9%) were detected by PET/MRI alone (27 with non-lung cancers and 6 with lung cancer). Cancer detection rate, sensitivity, specificity, PPV, and NPV for PET/MRI combined with chest CT were 2.0%, 96.7%, 99.6%, 83.1%, and 99.9%, respectively. For PET/MRI alone, the metrics were 1.1%, 54.1%, 99.6%, 73.3%, and 99.1%, respectively, and for PET/MRI in non-lung cancers, the metrics were 0.9%, 93.1%, 99.6%, 69.2%, and 99.9%, respectively.

CONCLUSIONS

[18F]FDG PET/MRI holds great promise for the early detection of non-lung cancers, while it seems insufficient for detecting early-stage lung cancers. Chest HRCT can be complementary to whole-body PET/MRI for early cancer detection.

TRIAL REGISTRATION

ChiCTR2200060041. Registered 16 May 2022. Public site: https://www.chictr.org.cn/index.html.

Performance of dedicated breast PET in breast cancer screening: comparison with digital mammography plus digital breast tomosynthesis and ultrasound

OBJECTIVE

To compare the diagnostic performance of dedicated breast positron emission tomography (dbPET) in breast cancer screening with digital mammography plus digital breast tomosynthesis (DM-DBT) and breast ultrasound (US).

METHODS

Women who participated in opportunistic whole-body PET/computed tomography cancer screening programs with breast examinations using dbPET, DM-DBT, and US between 2016-2020, whose results were determined pathologically or by follow-up for at least 1 year, were included. DbPET, DM-DBT, and US assessments were classified into four diagnostic categories: A (no abnormality), B (mild abnormality), C (need for follow-up), and D (recommend further examination). Category D was defined as screening positive. Each modality's recall rate, sensitivity, specificity, and positive predictive value (PPV) were calculated per examination to evaluate their diagnostic performance for breast cancer.

RESULTS

Out of 2156 screenings, 18 breast cancer cases were diagnosed during the follow-up period (10 invasive cancers and eight ductal carcinomas in situ [DCIS]). The recall rates for dbPET, DM-DBT, and US were 17.8%, 19.2%, and 9.4%, respectively. The recall rate of dbPET was highest in the first year and subsequently decreased to 11.4%. dbPET, DM-DBT, and US had sensitivities of 72.2%, 88.9%, and 83.3%; specificities of 82.6%, 81.4%, and 91.2%; and PPVs of 3.4%, 3.9%, and 7.4%, respectively. The sensitivities of dbPET, DM-DBT, and US for invasive cancers were 90%, 100%, and 90%, respectively. There were no significant differences between the modalities. One case of dbPET-false-negative invasive cancer was identified in retrospect. DbPET had 50% sensitivity for DCIS, while that of both DM-DBT and US was 75%. Furthermore, the specificity of dbPET in the first year was the lowest among all periods, and modalities increased over the years to 88.7%. The specificity of dbPET was significantly higher than that of DM-DBT (p < 0.01) in the last 3 years.

CONCLUSIONS

DbPET had a compatible sensitivity to DM-DBT and breast US for invasive breast cancer. The specificity of dbPET was improved and became higher than that of DM-DBT. DbPET may be a feasible screening modality.

Extra-articular findings with FDG-PET/CT in rheumatoid arthritis patients: more harm than benefit

Objective

Whole-body Positron Emission Tomography with CT-scanning using fluorine-18 fluorodeoxyglucose (18F-FDG) is occasionally used in rheumatoid arthritis (RA) patients to detect arthritis. FDG-PET/CT might also detect malignancies, but the amount of incidental findings and the number of relevant malignant disease that could be missed are currently unknown. We aimed to study the malignancy screening performance of whole-body FDG-PET/CT in longstanding RA patients with low disease activity.

Methods

FDG-PET/CT-scanning was done in the intervention arm of the Dose REduction Strategy of Subcutaneous TNF-inhibitors (DRESS) study, a randomized controlled trial on dose-tapering of biological Disease Modifying Anti-Rheumatic Drugs (bDMARDs). The reference standard was clinical diagnosis of malignancy during the 3 year follow-up of the study. Prevalence of extra-articular abnormalities, follow-up, and treatments were summarized post-hoc.

Results

121 scans were made in 79 patients. Extra-articular abnormalities were found in 59/121 (49%) scans, resulting in additional diagnostic procedures in 21/79 (26.6%) patients. Nine patients (7.4%) were suspected of malignancy, none turned out to be malignant. Six clinical malignancies that developed during follow-up were all negative on baseline FDG-PET/CT.

Conclusion

Whole-body FDG-PET/CT-scanning used in RA patients for imaging of arthritis results in frequent incidental extra-articular findings, while some who apparently had normal scans also developed malignancies.

Trial registration

Netherlands Trial Register, www.trialregister.nl, NL6771

Prospective Employer-Initiated Whole-Body Cancer Screening-Costs and Outcomes of a Cancer Screening Program in Japan

PURPOSES

To determine cancer detection and mortality and its costs associated with employee-initiated, prospective whole-body cancer screening program in an engineering company in Hamamatsu, Japan.

MATERIALS AND METHODS

The program includes whole-body fluorine-18-2-fluoro-2-deoxy-D-glucose PET/CT, brain and pelvis MR, and abdominal ultrasound, offered every 2 years five consecutive times. Employees are free to opt in or opt out anytime. The subjects were divided into the full (five consecutive screenings), partial (more than once and less than five), and no participation groups. The rate ratio of cancer detection rate and cancer-related mortality and cancer-related costs of care were measured. All employees also received other annual health screenings, including chest radiograph or upper gastrointestinal study.

RESULTS

Among 1,213 subjects, 543 employees were under full participation, 318 were under partial participation, and 352 were under no participation. In all, 26, 9, and 19 cancers were detected from the full participation, partial participation, and nonparticipation groups, respectively. No statistical significance was observed in the cancer detection rate ratio. The rate ratio of cancer-related deaths was 0.11 (0.01-0.90) for the full participation group compared with the nonparticipation group, and the difference was statistically significant. The cost of cancer-related care was highest among the nonparticipation group; however, the difference was not statistically significant (P = .108).

CONCLUSION

Whole-body cancer screening can successfully reduce cancer-related mortality and costs of cancer-related care. The cancer detection rate was not significantly improved because of broad implementation of additional annual health screenings offered to all employees at no cost, resulting in the high baseline cancer detection rate.

Relationship between Standard Uptake Values of Positron Emission Tomography/Computed Tomography and Salivary Metabolites in Oral Cancer: A Pilot Study

¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT) is usually used for staging or evaluation of treatment response rather than for cancer screening. However, ¹⁸F-FDG PET/CT has also been used in Japan for cancer screening in people with no cancer symptoms, and accumulating evidence supports this application of ¹⁸F-FDG PET/CT. Previously, we have observed a correlation between the saliva and tumor metabolomic profiles in patients with oral cancer. Hence, if salivary metabolites demonstrate a significant correlation with PET parameters such as the maximum standardized uptake value (SUV_max), they may have the potential to be used as a screening tool before PET/CT to identify patients with high SUV_max. Hence, in this study, we aimed to explore the relationship between salivary metabolites and SUV_max of ¹⁸F-FDG PET/CT using previously collected data. ¹⁸F-FDG PET/CT was performed for staging 26 patients with oral cancer. The collected data were integrated and analyzed along with quantified salivary hydrophilic metabolites obtained from the same patients with oral cancer and controls (n = 44). In total, 11 metabolites showed significant correlations with SUV_max in the delayed phases. A multiple logistic regression model of the two metabolites showed the ability to discriminate between patients with oral cancer and controls, with an area under the receiver operating characteristic curve of 0.738 (p = 0.001). This study uniquely confirmed a relationship between salivary metabolites and SUV_max of PET/CT in patients with oral cancer; salivary metabolites were significantly correlated with SUV_max. These salivary metabolites can be used as a screening tool before PET/CT to identify patients with high SUV_max, i.e., to detect the presence of oral cancer.

Ten-year prospective evaluation of whole-body cancer screening with multiple modalities including [18F]fluorodeoxyglucose positron emission tomography in a healthy population

PURPOSE

To prospectively evaluate the value of whole-body cancer screening with multiple modalities including FDG-PET in a healthy population.

METHODS

The study was conducted in 1197 healthy individuals aged ≥ 35 years at enrollment between August 2003 and July 2004. All participants were scheduled to receive annual whole-body cancer screening five times (screening period) with subsequent long-term follow-up (follow-up period). The endpoints of the study were definitive cancer diagnosis, cancer-related death, and all-cause death.

RESULTS

The follow-up rate was 99.8% for the screening period and 96.2% for the follow-up period. Forty-five cancers were confirmed during the screening period (August 2003 to July 2009), and 37 of the 45 were detected by the screening. Fourteen of the 45 were PET positive. Sixteen, 5, 4, 9 and 11 cancers were confirmed after the first, the second, the third, the fourth, and the fifth (took 2 years) screening, respectively. Eight participants died, of whom five died of cancer. The rate of cancer incidence (per 100,000) of 628.7 (95% confidence interval [CI] 445.0-812.4) was significantly high, and the rates of cancer mortality and all-cause mortality of 69.9 (95% CI 8.6-131.1) and 111.8 (95% CI 34.3-189.2), respectively, were significantly low, compared with the corresponding rates of 379.3, 138.2 and 354.2, respectively, in the age-rank- and sex-matched general population. During the follow-up period (August 2009 to July 2013), 37 cancers were confirmed and 30 of the 37 were detected. Seven participants died, of whom three died of cancer. The rate of cancer incidence was 809.6 (95% CI 548.7-1070.5). The rates of cancer mortality and all-cause mortality of 65.6 (95% CI 0-139.9) and 153.2 (95% CI 39.7-266.6), respectively, were significantly low compared with 190.1 and 462.3, respectively, in the general population.

CONCLUSION

Cancer detection by PET alone was limited. While the high cancer incidence was attributed to the extensive screening, the low cancer and all-cause mortality may indicate the potential value of this type of cancer screening. Cancer incidence increases with aging and it has been shown that continuous screening may reduce the risk caused by the cancer progression.

Comparison of FDG-PET/CT for Cancer Detection in Populations With Different Risks of Underlying Malignancy

Background/Aim: Whole-body positron-emission tomography/computed tomography with the glucose analog 2-[ 18 F]fluoro-2-deoxy-D-glucose (FDG-PET/CT) has been used to screen examinees for underlying malignancy in many countries. The aim of this study was to compare the potential value of FDG-PET/CT application in asymptomatic individuals with those with suspected malignancy. Patients and Methods: A total of 9,408 examinees underwent whole-body FDG-PET/CT at our hospital from July 2006 to August 2013. Three thousand and seven hundred asymptomatic individuals and 848 individuals with laboratory and clinical/radiologicaI suspicion of malignancy who had undergone FDG-PET/CT for cancer screening were recruited. The final confirmation of cancer and outcomes were based on a pathological report and continuous follow-up. Results: Forty-five out of 3,700 asymptomatic individuals (1.2%) had proven malignancy, and 42 of them (93.3%) were found by FDG-PET/CT. Two hundred and twelve out of 848 with suspected malignancy (25%) had proven malignancy, and 196 of them (92.5%) were detected by FDG-PET/CT. Most of these cancers in asymptomatic individuals were clinically at an early stage. The discovery rate in asymptomatic individuals and those with suspected malignancy was 1.1% and 23.1%, respectively. The overall survival of patients with cancer diagnosed with PET/CT was higher than those with suspected malignancy (78.6% vs. 48.5%, p<0.001). Patients with a resectable lesion, early-stage disease, and lower maximal standardized uptake value had significantly better survival than those without. Conclusion: FDG-PET/CT is useful in the early diagnosis of cancer and thus might improve the survival rates of these patients. Considering the costs and risk of radiation exposure, it would be better used as a priority in patients with laboratory and clinical/radiologic suspicion of malignancy.

Usefulness of both PET/CT with F18-FDG and whole-body diffusion-weighted imaging in cancer screening: a preliminary report

OBJECTIVE

Positron emission tomography/computed tomography (PET/CT) with fluorodeoxyglucose (F18-FDG) is useful for the detection of malignant lesions, including metastatic lesions, and this technique is widely used in cancer screening. However, this approach may occasionally yield false-positive and false-negative findings. At our PET center, to increase the accuracy of PET/CT, we use PET/CT and whole-body diffusion-weighted imaging (WB-DWI) together. This study aimed to assess the usefulness of this combination.

METHODS

We examined 29 subjects with confirmed diagnosis. All of them had undergone PET/CT and WB-DWI on the same day. Twenty-seven of them also underwent ultrasonography, blood testing, and upper gastrointestinal series on the same day and two fecal occult blood tests on another day. WB-DWI was performed on a 1.5-T MRI unit with a b value of 0 and 800 or 1000 s/mm². For all 29 cases, PET/CT and WB-DWI were classified to be positive or negative, and the diagnostic ability was calculated for each modality.

RESULTS

Among the 29 subjects, 17 had malignant tumors and 12 had benign tumors or no abnormalities. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET/CT were 65%, 25%, 55%, 33%, and 48%, respectively; while the corresponding values for WB-DWI were 59%, 100%, 100%, 63%, and 76%, respectively. By considering the result to be negative when PET/CT findings were positive but WB-DWI findings were negative, specificity increased from 25 to 100%, and accuracy increased from 48 to 76%. On the other hand, by considering the result to be positive when the findings of either PET/CT or WB-DWI were positive, sensitivity increased from 65 to 76%, and accuracy increased from 48 to 55%.

CONCLUSIONS

Our results suggest that using both PET/CT and WB-DWI together can increase accuracy in cancer screening. However, this approach was not able to detect malignant lesions in some cases, indicating that there were limitations with imaging certain organs. Therefore, it is important to further understand the features of PET/CT and WB-DWI and use them appropriately for each organ. Additionally, given that the study sample was relatively small, further research is needed to validate these findings.

[Systematic errors in clinical studies : A comprehensive survey]

Systematic errors and related phenomena represent an intrinsic challenge to the quality of clinical research. As a consequence even otherwise methodologically demanding studies may produce results that systematically differ from the true values. Systematic errors relating to investigative medicine are divided into six groups according to their affiliation with the consecutive chronological sections of the study. Bias can occur in preliminary literature research in the field, specifying the study design and selecting the study sample, measuring exposure and outcome, analyzing the data, interpreting the analyses and publishing the results. The most important systematic errors that concern diagnostic and interventional studies are created by access to the data of previous tests, calculated study design, preselection of the participants, comparison with non-contemporaneous controls, antedating the time of diagnosis and overdiagnosis of slowly progressive forms of diseases examined. Checking the measured values often leads to a mosaic of several biases with one being more or less dominant. Even by exercising due care in the preparation and performance of the study, the majority of distortions cannot be eliminated but only diminished. It is essential to consider each detected bias as a potential full or partial argument in support of an observed correlation. The control of systematic errors and related phenomena is both a significant element of the discussion of the study report and a key element for assessment of its scientific value.

[Systematic errors in clinical studies : A comprehensive survey]

Systematic errors and related phenomena represent an intrinsic challenge to the quality of clinical research. As a consequence even otherwise methodologically demanding studies may produce results that systematically differ from the true values. Systematic errors relating to investigative medicine are divided into six groups according to their affiliation with the consecutive chronological sections of the study. Bias can occur in preliminary literature research in the field, specifying the study design and selecting the study sample, measuring exposure and outcome, analyzing the data, interpreting the analyses and publishing the results. The most important systematic errors that concern diagnostic and interventional studies are created by access to the data of previous tests, calculated study design, preselection of the participants, comparison with non-contemporaneous controls, antedating the time of diagnosis and overdiagnosis of slowly progressive forms of diseases examined. Checking the measured values often leads to a mosaic of several biases with one being more or less dominant. Even by exercising due care in the preparation and performance of the study, the majority of distortions cannot be eliminated but only diminished. It is essential to consider each detected bias as a potential full or partial argument in support of an observed correlation. The control of systematic errors and related phenomena is both a significant element of the discussion of the study report and a key element for assessment of its scientific value.

Application of whole-body FDG-PET for cancer screening in a cohort of hospital employees

Whole-body positron emission tomography/computed tomography with the glucose analog 2-[F]fluoro-2-deoxy-D-glucose (FDG-PET/CT) has been extensively used to screen for underlying malignancies in asymptomatic individuals. We were able to survey a cohort of hospital employees using FDG-PET/CT and to report the results herein.A total of 116 hospital employees older than 55 years old were offered whole-body FDG-PET in our hospital. Ninety-seven employees (83.6%) completed the assessment from February 2014 to August 2014 in our PET center. The final confirmation of cancer was based on pathologic examination and follow-up after more than 1 year.Among the 97 participants, 92 were asymptomatic and 5 presented with previously diagnosed cancers. Six of the 92 asymptomatic participants (6.6%) with significant nodular lesions were referred for histological or cytological evaluation of the possibility of malignancy, and 1 case was considered clinically important and required surgical resection. The cancer discovery rate was 3.3% (3/92) with positive predictive value of 50% (3/6). In the 5 participants with previously identified cancers, no recurrence or metastasis was detected.The offer of whole-body FDG-PET for cancer screening was welcomed with enthusiasm by most of the hospital employees. PET/CT combines the merits of PET and CT and can be administered to and provide benefits to a select group of hospital employees.

A preliminary report of breast cancer screening by positron emission mammography

OBJECTIVE

Fluorine-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET) and PET/computed tomography (PET/CT) have had a considerable impact on the detection of various malignancies. PET and PET/CT are minimally invasive methods that can provide whole-body imaging at one time. Therefore, an FDG-PET cancer screening program has been widely used in Japan. However, the breast cancer detection rate of FDG-PET cancer screening is relatively low. Therefore, FDG-PET screening is not recommended for breast cancer screening. Positron emission mammography (PEM) is a high-resolution molecular breast imaging technology. PEM can detect small breast cancers that cannot be detected on PET or PET/CT images due to limited spatial resolution. We have performed opportunistic breast cancer screening using PEM since 2011. To the best of our knowledge, this is the first report regarding PEM breast cancer screening.

METHODS

This study enrolled 265 women. PEM images were analyzed by agreement of 2 experienced nuclear medicine physicians. The readers were given information from medical interview sheet. US findings were interpreted holistically. The number of participants, patient recall rate, further examination rate, and cancer detection rate by year were calculated.

RESULTS

The overall recall rate was 8.3%; the work-up examination rate was 77.3%, and cancer detection rate was 2.3%. The positive predictive value of PEM was 27.3%. Six cancers were found by PEM screening. Five were invasive cancers and one was ductal carcinoma in situ. Histological tumor sizes were reported in three cases: 0.7, 1.2, and 2 cm.

CONCLUSION

PEM screening appears to have potential for breast cancer screening.

Prevalence and risk of cancer of incidental uptake in prostate identified by fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography

OBJECTIVE

The objective was to investigate the prevalence of incidental fluorine-18 fluorodeoxyglucose (FDG) uptake in positron emission tomography/computed tomography.

METHODS

A total of 11,239 male nonprostate disease patients were included retrospectively.

RESULTS

The prevalence of incidental prostate FDG uptake was approximately 1.8%. Among 198 incidental lesions, 100 patients had further examinations; 20 lesions were confirmed to be malignant, while 80 lesions were benign. After logistic regression analysis, age, site, and the maximum standard uptake value were the potent predictors for differentiation of malignant prostate lesions.

CONCLUSION

When focal FDG uptake in the peripheral zone of prostate is detected, especially in elderly men, further clinical evaluation is recommended.

Diagnostic accuracy of FDG-PET cancer screening in asymptomatic individuals: use of record linkage from the Osaka Cancer Registry

BACKGROUND

Whole-body cancer screening with multimodalities including [(18)F]-fluorodeoxyglucose positron emission tomography (FDG-PET) detects a wide range of tumors. This program has been recognized as an option for opportunistic screening, particularly in Japan. However, reports on diagnostic accuracy have been limited. We aimed to evaluate the detectability and related properties of this screening program among asymptomatic individuals in a community setting.

METHODS

The study participants were 1,762 residents of Osaka Prefecture, Japan, who underwent opportunistic cancer screening at Higashitemma Clinic for the first time between November 2004 and December 2005. FDG-PET cancer screening was performed with several imaging modalities (e.g., FDG-PET, computed tomography, magnetic resonance imaging and ultrasonography) and fecal occult blood test. Screening records were linked to the Osaka cancer registry within 1 year after the screening to determine sensitivity, specificity and positive predictive values.

RESULTS

After excluding 12 participants with cancer detected before the screening, 33 were identified by the cancer registry to have primary cancers. Of these, the present screening program found that 28 were positive (6 prostate, 5 lung, 5 colorectal, 5 thyroid, 3 liver and 4 others). Sensitivity, specificity and positive predictive values were 84.8 % (28/33, 95 % confidence interval 69.1-93.3), 86.8 % (1,491/1,718, 85.1-88.3) and 10.1 % (28/277, 6.4-12.9), respectively.

CONCLUSIONS

FDG-PET cancer screening with multimodalities reasonably and accurately detects existing asymptomatic cancer. However, the numbers of false negatives and false positives were not insignificant. Facilities that provide the screening should inform participants of relevant information, including the limitations of this program.

What Is the Clinical Significance of FDG Unexpected Uptake in the Prostate in Patients Undergoing PET/CT for Other Malignancies?

Purpose. To determine the clinical significance of unexpected, abnormal FDG uptake in the prostate in patients undergoing FDG-PET/CT for staging of other primary malignancies without a prior history of prostate carcinoma. Methods. Retrospective search of FDG-PET/CT studies to identify patients with unexpected, abnormal FDG uptake in the prostate gland, who underwent subsequent biopsy, was performed. 26 patients were identified. Images were reviewed to determine the pattern of uptake within the prostate (focal or diffuse) and maximum standardized uptake value (SUVmax). PSA and Gleason scores were recorded. Results. 15/26 (58%) patients were found to have prostate carcinoma. Gleason scores ranged from 6 to 9.9. There was no statistical difference in the pattern of uptake (focal versus diffuse) or the SUVmax. Serum PSA levels with cancer (range, 2–26.8 ng; mean, 10.2 ng) and those without cancer (range, 2–10.5 ng; mean, 2.2 ng) were statistically significant (P < 0.007, Wilcoxon rank sum test). Conclusions. Patients with abnormal uptake in the prostate have a 58% likelihood of occult prostate cancer. In the setting of elevated serum PSA levels, abnormal prostate uptake should therefore be viewed with suspicion and a urology consult should be obtained; however, it is irrelevant in patients with underlying aggressive malignancies.

Detection of colorectal cancer and adenomas by FDG-PET cancer screening program: results based on a nationwide Japanese survey

PURPOSE

The aim of this study was to analyze the detection rate for CRC and adenomas for asymptomatic subjects in Japan by FDG-PET cancer screening program carried out between 2006 and 2009.

METHODS

The "FDG-PET cancer screening program" included both PET and positron emission tomography with computed tomography (PET/CT) with or without other screening tests. A total of 154,783 asymptomatic subjects underwent FDG-PET cancer screening program; we analyzed the 1,808 cases with findings from any detection method that indicated suspected CRC.

RESULTS

Among the 1,808 cases, the number of cases verified as CRC and adenoma was 394 and 679, respectively. The sensitivity and positive predictive value (PPV) of FDG-PET were 86.0 and 31.7% for CRC, and 63.6 and 63.8% for CRC and adenoma. The sensitivity and PPV of fecal occult blood test (FOBT) for CRC were lower than those of FDG-PET, but higher for adenoma. Therefore, FDG-PET and FOBT were complementary for screening for CRC, and CRC and adenoma. The majority of CRC detected by the FDG-PET imaging was UICC stage 0 or I, however, detection of smaller or less invasive cancer was limited.

CONCLUSION

The FDG-PET screening program in Japan has detected CRC at an early stage and adenomas as premalignant lesions. A combination of FDG-PET and FOBT yields the best results if the intent is to detect either CRC or adenoma. However, it is absolutely clear that an FDG-PET cancer screening program cannot detect all colon lesions.

The current status of an FDG-PET cancer screening program in Japan, based on a 4-year (2006-2009) nationwide survey

Objective

The aim of this study was to survey the 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) cancer screening program conducted in Japan.

Methods

The “FDG-PET cancer screening program” included both FDG-PET and positron emission tomography with computed tomography (PET/CT) with or without other combined screening tests that were performed for cancer screening in asymptomatic subjects. A total of 155,456 subjects who underwent the FDG-PET cancer screening program during 2006–2009 were analyzed.

Results

Of the 155,456 subjects, positive findings suggesting possible cancer were noted in 16,955 (10.9 %). The number of cases with detected cancer was 1,912 (1.23 % of the total screened cases, annual range 1.14–1.30 %). Of the 1,912 cases of detected cancer, positive findings on FDG-PET were present in 1,491 cases (0.96 % of the total number of screened cases). According to the results of further examinations, the true positive rate for subjects with suggested possible cancer (positive predictive value) was 32.3 % with FDG-PET. Cancers of the colon/rectum, thyroid, lung, and breast were most frequently found (396, 353, 319, and 163 cases, respectively) with high PET sensitivity (85.9, 90.7, 86.8, 84.0 %, respectively). Prostate cancer and gastric cancer (165 and 124 cases, respectively) had low PET sensitivity (37.0 and 37.9 %, respectively). The Union for International Cancer Control (UICC) clinical stage of cancer found with the FDG-PET cancer screening program was mainly Stage I.

Conclusions

The FDG-PET screening program in Japan has detected a variety of cancers at an early stage. However, several cancers were found in repeated FDG-PET cancer screening program, indicating the limitation of a one-time FDG-PET cancer screening program. The value of the FDG-PET cancer screening program is left to the judgment of individuals with regard to its potentials and limitations.

Is further evaluation needed for incidental focal uptake in the prostate in 18-fluoro-2-deoxyglucose positron emission tomography-computed tomography images?

OBJECTIVE

The aim of this study was to investigate the frequency of secondary evaluation to detect prostate cancer that was primarily manifested as abnormal hypermetabolism detected by 18-fluoro-2-deoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT). We also evaluated the association of maximum standardized uptake values (SUVmax) on PET/CT with clinicopathologic results.

MATERIALS AND METHODS

We evaluated PET/CT reports from a total of 12,037 patients to find cases with abnormal prostate hypermetabolism. Patients with known prostate cancer or a recent prostate procedure were excluded. We analyzed the frequency of secondary evaluations such as digital rectal exams (DRE), levels of serum prostate-specific antigen (PSA), and/or biopsy to confirm prostate cancer. Biopsied patients were categorized into benign and cancer groups. Clinicopathologic characteristics were compared between the groups.

RESULTS

Among 12,037 PET/CT images, 184 (1.5%) showed abnormal hypermetabolism in the prostate. Secondary evaluation was carried out in 120 patients. Biopsy was performed in 38 patients and prostate cancer was confirmed in 23 patients. The median serum PSA level was 3.2 and 49.7 ng/mL in the benign group and cancer group, respectively. The SUVmax was higher in the cancer group (5.7 ± 5.1) than in the benign group (4.8 ± 2.7), but the difference was not statistically significant (p = 0.37). In the cancer group, a high serum PSA level (≥ 20 ng/mL) was detected in 78.3% of the patients. The Gleason score was 7 in 34.7% and 8-10 in 56.5% of prostate cancer patients.

CONCLUSIONS

Hypermetabolism in the prostate was incidentally detected in 1.5% of patients, and only 65.2% of these patients underwent further evaluation (DRE and/or serum PSA levels). Among cases of incidentally detected hypermetabolism in the prostate, patients with abnormal findings (DRE and/or PSA levels) showed high positivity by biopsy, and more than two-thirds of the positive biopsies showed significant prostate cancer. Therefore, patients with hypermetabolism in the prostate should not be ignored and should be secondarily evaluated by DRE and PSA level.

Positron emission tomography and colorectal cancer

Colorectal cancer (CRC) is a major cause of cancer-related morbidity and mortality. Molecular imaging using positron emission tomography (PET) is now an integral part of multidisciplinary cancer care. In this review, we discuss the role of PET in CRC including well established indications in the assessment of recurrent disease and emerging applications such as initial staging, monitoring therapy efficacy and using PET for radiotherapy planning. With rapid advancement in imaging technology, we also discuss the future potential of combining PET and magnetic resonance imaging and the use of novel radiotracers.

Significance of incidental focal uptake in prostate on 18-fluoro-2-deoxyglucose positron emission tomography CT images

To evaluate the clinical significance of incidental focal prostate fluorodeoxyglucose (FDG) uptake, we reviewed 18-F-FDG positron emission tomography (PET)/CT scans from 2003 to 2007 and selected cases with focal FDG uptake in prostate. Cases of known prostate cancer were excluded. The maximum standardised uptake value (SUV(max)), site (central or peripheral) and pattern (discrete or ill-defined) of FDG uptake, calcification (present or absent) and prostate volume (<30 or ≥30 cc) were recorded. The PET/CT findings were correlated with serum prostate-specific antigen (PSA) levels, imaging studies, clinical follow-up and biopsy. Of a total of 5119 cases, 63 (1.2%) demonstrated focal FDG uptake in prostate. Eight cases were lost to follow-up. Among the 55 cases with follow-up, malignancy was confirmed by biopsy in 3 (5.4%). The three malignant cases had SUV(max) values of 3.3, 3.6 and 2.3, and all were noted in the peripheral portion of prostate; two of these cases had a discrete FDG uptake pattern, none had calcification corresponding to the FDG uptake area and one had a prostatic volume greater than 30 cc. The mean SUV(max) of 52 benign cases was 3.2 ± 1.7 and focal FDG uptake was noted in the peripheral portion in 34 (65%), 20 (38%) cases showed a discrete FDG uptake pattern, 35 (67%) were accompanied by calcification and 32 (62%) had a prostatic volume greater than 30 cc. The majority of cases demonstrating focal FDG uptake in prostate were benign and no PET/CT finding could reliably differentiate benign from malignant lesions; however, when discrete focal FDG uptake without coincidental calcification is seen, particularly in the peripheral zone of the prostate, further clinical evaluation is recommended.

Incidental fleurodeoxyglucose uptake in the prostate

This commentary confirms the rarity of prostatic cancer associated with incidental prostatic fleurodeoxyglucose (FDG) uptake. The study adds to the literature by showing that even if a prostate lesion is FDG avid it is unlikely to be due to cancer. The commentary considers the management of incidental prostate FDG uptake on the basis of the available evidence.

Analysis of various malignant neoplasms detected by FDG-PET cancer screening program: based on a Japanese Nationwide Survey

OBJECTIVE

The most distinctive feature of FDG-PET cancer screening program is the ability to find various kinds of malignant neoplasms in a single test. The aim of this survey is to clarify the range and frequency of various malignant neoplasms detected by FDG-PET cancer screening performed in Japan.

METHODS

"FDG-PET cancer screening" was defined as FDG-PET or positron emission tomography and computed tomography (PET/CT) scan with or without other tests performed for cancer screening of healthy subjects. This survey was based on a questionnaire regarding FDG-PET cancer screening. We analyzed the situation of 9 less frequently found malignant neoplasms including malignant lymphoma, malignancy of head and neck, esophagus, hepatobiliary and gallbladder, pancreas, kidney, cervical and uterine, ovary, and bladder.

RESULTS

The detailed information of subjects with the suspected 9 kinds of malignant neoplasms mentioned above in the FDG-PET cancer screening program was studied in a total of 1,219 cases from 212 facilities. A statistical significance between PET/CT and PET was found in relative sensitivity and PPV for renal cell cancer. Malignant lymphoma was frequently of indolent type, suspected head and neck cancers had many false-positive results, and pancreatic cancer detected in this program was often in the advanced stage even in asymptomatic subjects. The recommendation of combined screening modality to PET or PET/CT was as follows: gastric endoscopy for assessing early esophageal cancer; abdominal ultrasound for screening hepatobiliary and gallbladder cancer; pelvic magnetic resonance imaging for assessing gynecological and pelvic cancers; and the CA125 blood test for screening ovarian cancer. Delayed image was helpful depending on the type of suspected malignant neoplasm.

CONCLUSION

We analyzed various types of malignant neoplasms detected by the FDG-PET cancer screening program and presented recommended combination of examinations to cover FDG-PET and PET/CT.

Management of an incidental liver mass

The increased use of sensitive imaging modalities has led to increased identification of the incidental liver mass (ILM). A combination of careful consideration of patient factors and imaging characteristics of the ILM enables clinicians to recommend a safe and efficient course of action. Using an algorithmic approach, this article includes pertinent clinical factors and the specific radiologic criteria of ILMs and discusses the indications for potential procedures. It is the aim of this article to assist with the development of an individualized strategy for each patient with an ILM.

Detection of relevant colonic neoplasms with PET/CT: promising accuracy with minimal CT dose and a standardised PET cut-off

Objective:

To determine the performance of FDG-PET/CT in the detection of relevant colorectal neoplasms (adenomas ≥10 mm, with high-grade dysplasia, cancer) in relation to CT dose and contrast administration and to find a PET cut-off.

Methods:

84 patients, who underwent PET/CT and colonoscopy (n = 79)/sigmoidoscopy (n = 5) for \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\left( {{\hbox{79}} \times {\hbox{6}} + {\hbox{5}} \times {\hbox{2}}} \right)} = {\hbox{484}}$$\end{document} colonic segments, were included in a retrospective study. The accuracy of low-dose PET/CT in detecting mass-positive segments was evaluated by ROC analysis by two blinded independent reviewers relative to contrast-enhanced PET/CT. On a per-lesion basis characteristic PET values were tested as cut-offs.

Results:

Low-dose PET/CT and contrast-enhanced PET/CT provide similar accuracies (area under the curve for the average ROC ratings 0.925 vs. 0.929, respectively). PET demonstrated all carcinomas (n = 23) and 83% (30/36) of relevant adenomas. In all carcinomas and adenomas with high-grade dysplasia (n = 10) the SUV_max was ≥5. This cut-off resulted in a better per-segment sensitivity and negative predictive value (NPV) than the average PET/CT reviews (sensitivity: 89% vs. 82%; NPV: 99% vs. 98%). All other tested cut-offs were inferior to the SUV_max.

Conclusion:

FDG-PET/CT provides promising accuracy for colorectal mass detection. Low dose and lack of iodine contrast in the CT component do not impact the accuracy. The PET cut-off SUV_max ≥ 5 improves the accuracy.

Cancer screening using 18F-FDG PET/CT in Korean asymptomatic volunteers: a preliminary report

OBJECTIVE

This study was performed to evaluate the clinical value of (18)F-fluorodeoxyglucose (FDG) positron-emission tomography (PET)/computed tomography (CT) for cancer screening in Korean asymptomatic people.

METHODS

Between February 2004 and December 2006, 1,587 asymptomatic individuals underwent FDG PET/CT as part of a cancer screening program with some other diagnostic tests at the healthcare center of our hospital. After excluding patients with a history of malignant tumor, 1,336 subjects were enrolled. All PET/CT images were visually analyzed. In subjects showing positive findings for PET/CT or other screening tests, further diagnostic tests and pathological confirmation were performed.

RESULTS

Of the 1,336 subjects, malignant tumors were found in 16 participants (1.2%, thyroid cancer: 9, lung cancer: 2, stomach cancer: 2, and others: 4). There were 47 cases (3.6%) of positive PET/CT findings--11 cases were true positive (thyroid cancer: 8, lung cancer: 1, renal cancer: 1, and invasive thymoma), and 36 false positive, and five cases were false negative. The overall detection rate of PET/CT was 0.8%, and the sensitivity, specificity, positive-predictive value, and negative-predictive value of PET/CT were 68.8, 97.2, 23.4, and 99.6%, respectively.

CONCLUSIONS

Fluorodeoxyglucose positron-emission tomography has the potential to detect various kinds of malignant tumors in cancer screening test, and the overall detection rate of PET/CT was 0.8%. FDG PET/CT can be a useful cancer screening modality with the selection of high-risk group and appropriate combination with other screening modalities.

Early detection of adrenocortical carcinoma in a child with Li-Fraumeni syndrome

We report an early detection of cancer in a child with Li-Fraumeni syndrome. The proband was a 3-year-old male with a primitive mesenchymal tumor. Genetic analysis showed a germline TP53 mutation in codon 220 exon 6, which changed TAT --> TGT and resulted in a tyrosine-to-cysteine amino acid substitution (Tyr220Cys). The younger sister at risk was followed, and an asymptomatic adrenal cortical carcinoma was detected 3 years later. The report highlights the importance of genetic counseling and provides an example of early detection of cancers in childhood LFS carriers.

Prospective evaluation of whole-body cancer screening with multiple modalities including [18F]fluorodeoxyglucose positron emission tomography in a healthy population: a preliminary report

PURPOSE

To prospectively evaluate the utility of whole-body cancer screening with multiple modalities including [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) in a healthy population. This report summarizes the results of the first three annual screenings.

PARTICIPANTS AND METHODS

A total of 1,197 healthy volunteers > or = 35 years old were enrolled between August 2003 and July 2004 and offered annual cancer screening for 5 years with subsequent long-term follow-up. Screening modalities included were whole-body FDG-PET, chest and abdominal computed tomography (CT), brain and pelvic magnetic resonance imaging, several tumor markers, and fecal occult blood testing.

RESULTS

As of the end of 2006, 22 primary cancers were pathologically confirmed. Nineteen of 22 were detected by the screening; 18 in the initial, one in the second, and none in the third. Three were diagnosed after development of symptoms. Of the 18 detected in the initial screening (six thyroid, four lung, three prostate, three breast, one endometrial, and one thymic), 12 were at stage I and 11 were PET positive. PET-negative cancers were detected by CT or the prostate-specific antigen (PSA) test. Sensitivity and specificity were 50.0% (11 of 22) and 93.2% (1,095 of 1,175), respectively, for FDG-PET alone and 81.8% (18 of 22) and 82.0% (963 of 1,175), respectively, for the combination of imaging modalities and PSA.

CONCLUSION

While FDG-PET alone is insufficient, whole-body cancer screening with selected modalities including FDG-PET has initial performance supporting possible utility by detecting a wide variety of early-stage cancers with reasonable sensitivity. However, the detection of many indolent cancers and false positives necessitate continuing study for appropriate evaluation.