Bone metastasis in patients with non-small cell lung cancer: The diagnostic role of F-18 FDG PET/CT

Comparison of 18F-FDG and 68Ga-DOTA-IBA in detecting bone metastases: a lesion-basis study

Gallium 68 (68Ga)-labeled DOTA-conjugate ibandronic acid (DOTA-IBA) has been successfully synthesized and utilized for bone metastasis imaging. This study compares the diagnostic efficacy between 68Ga-DOTA-IBA and fluorine 18 (18F)-labeled fluorodeoxyglucose (FDG) in detecting bone metastases. This prospective study, conducted from October 2022 to September 2023, analyzed images from participants who underwent 68Ga-DOTA-IBA PET/CT and 18F-FDG PET/CT scans. Lesions were classified into five groups based on anatomical location (limbs, vertebrae, pelvis, ribs, and skull). Morphological bone changes were categorized as osteolytic, osteoblastic, or mixed. The semi-quantified radiotracer uptake, measured by the maximum standardized uptake value (SUVmax), was compared using a paired t-test. Detection rates between the two scans were analyzed using the McNemar test. A total of 46 participants (median age: 64 years [interquartile range: 53-68 years], 28 men) were evaluated. 68Ga-DOTA-IBA demonstrated higher diagnostic efficacy than 18F-FDG in detecting bone metastases in the limbs (73.2% vs. 64.1%), vertebras (78.1% vs. 67.4%), ribs (86.6% vs. 62.2%), pelvis (78.6% vs. 68.9%), and skulls (80.0% vs. 38%). For osteoblastic lesions, the detection rate for 68Ga-DOTA-IBA and 18F-FDG was 83.3% and 51.5% respectively (P < 0.001). The SUVmax of 68Ga-DOTA-IBA was 7.88 (95% CI 7.09-8.66), which was higher than that of 18F-FDG at 3.96 (95% CI 3.57-4.35) (P < 0.001). In participants with prostate cancer, the detection rate of 68Ga-DOTA-IBA and 18F-FDG was 84.7% and 55.0% respectively (P < 0.001). The SUVmax of 68Ga-DOTA-IBA was 10.44 (95% CI 8.57-12.30), which was higher than that of 18F-FDG 4.29 (95% CI 3.51-5.07) (P < 0.001). 68Ga-DOTA-IBA PET/CT demonstrates superior diagnostic performance over 18F-FDG PET/CT in detecting bone metastases, particularly in osteoblastic lesions and prostate cancer cases.

Imaging in Lung Cancer Staging

Lung cancer remains one of the leading causes of mortality worldwide, as well as in the United States. Clinical staging, primarily with imaging, is integral to stratify patients into groups that determine treatment options and predict survival. The eighth edition of the tumor, node, metastasis (TNM-8) staging system proposed in 2016 by the International Association for the Study of Lung Cancer remains the current standard for lung cancer staging. The system is used for all subtypes of lung cancer, including non-small cell lung cancer, small cell lung cancer, and bronchopulmonary carcinoid tumors.

Bone Metastases Are Measurable: The Role of Whole-Body MRI and Positron Emission Tomography

Metastatic tumor deposits in bone marrow elicit differential bone responses that vary with the type of malignancy. This results in either sclerotic, lytic, or mixed bone lesions, which can change in morphology due to treatment effects and/or secondary bone remodeling. Hence, morphological imaging is regarded unsuitable for response assessment of bone metastases and in the current Response Evaluation Criteria In Solid Tumors 1.1 (RECIST1.1) guideline bone metastases are deemed unmeasurable. Nevertheless, the advent of functional and molecular imaging modalities such as whole-body magnetic resonance imaging (WB-MRI) and positron emission tomography (PET) has improved the ability for follow-up of bone metastases, regardless of their morphology. Both these modalities not only have improved sensitivity for visual detection of bone lesions, but also allow for objective measurements of bone lesion characteristics. WB-MRI provides a global assessment of skeletal metastases and for a one-step "all-organ" approach of metastatic disease. Novel MRI techniques include diffusion-weighted imaging (DWI) targeting highly cellular lesions, dynamic contrast-enhanced MRI (DCE-MRI) for quantitative assessment of bone lesion vascularization, and multiparametric MRI (mpMRI) combining anatomical and functional sequences. Recommendations for a homogenization of MRI image acquisitions and generalizable response criteria have been developed. For PET, many metabolic and molecular radiotracers are available, some targeting tumor characteristics not confined to cancer type (e.g. 18F-FDG) while other targeted radiotracers target specific molecular characteristics, such as prostate specific membrane antigen (PSMA) ligands for prostate cancer. Supporting data on quantitative PET analysis regarding repeatability, reproducibility, and harmonization of PET/CT system performance is available. Bone metastases detected on PET and MRI can be quantitatively assessed using validated methodologies, both on a whole-body and individual lesion basis. Both have the advantage of covering not only bone lesions but visceral and nodal lesions as well. Hybrid imaging, combining PET with MRI, may provide complementary parameters on the morphologic, functional, metabolic and molecular level of bone metastases in one examination. For clinical implementation of measuring bone metastases in response assessment using WB-MRI and PET, current RECIST1.1 guidelines need to be adapted. This review summarizes available data and insights into imaging of bone metastases using MRI and PET.

Multimodal Imaging-Based Potential Visualization of the Tumor Microenvironment in Bone Metastasis

Bone metastasis (BM) is the most common malignant bone tumor and a significant cause of morbidity and mortality for patients with cancer. Compared to other metastatic organs, bone has unique characteristics in terms of the tumor microenvironment (TME). Precise assessments of the TME in BM could be an important step for developing an optimized management plan for patient care. Imaging approaches for BM have several advantages, such as biopsy not being required, multiple site evaluation, and serial assessment in the same sites. Owing to the developments of new imaging tracers or imaging modalities, bone TME could be visualized using multimodal imaging techniques. In this review, we describe the BM pathophysiology, diagnostic principles of major imaging modalities, and clinically available imaging modalities to visualize the TME in BM. We also discuss how the interactions between various factors affecting the TME could be visualized using multimodal imaging techniques.

Comparison of the Relative Diagnostic Performance of [68Ga]Ga-DOTA-FAPI-04 and [18F]FDG PET/CT for the Detection of Bone Metastasis in Patients With Different Cancers

Purpose

The present retrospective analysis sought to compare the relative diagnostic efficacy of [⁶⁸Ga]Ga-DOTA-FAPI-04 to that of [¹⁸F]FDG PET/CT as a means of detecting bone metastases in patients with a range of cancer types.

Materials

In total, 30 patients with bone metastases associated with different underlying malignancies were retrospectively enrolled. All patients had undergone [⁶⁸Ga]Ga-DOTA-FAPI-04 and [¹⁸F]FDG PET/CT, and the McNemar test was used to compare the relative diagnostic performance of these two imaging modalities. The maximum standard uptake value (SUVmax) was used to quantify radiotracer uptake by metastatic lesions, with the relative uptake associated with these two imaging strategies being compared via the Mann-Whitney U test. The cohort was further respectively divided into two (osteolytic and osteoblastic bone metastases) and three clinical subgroups (lung cancer, thyroid cancer, and liver cancer).

Results

[⁶⁸Ga]Ga-DOTA-FAPI-04 PET/CT was found to be significantly more sensitive as a means of diagnosing bone metastases relative to [¹⁸F]FDG PET/CT ([109/109] 100% vs [89/109] 81.7%; P< 0.01), consistent with the significantly increased uptake of [⁶⁸Ga]Ga-DOTA-FAPI-04 by these metastatic lesions relative to that of [¹⁸F]FDG (n=109, median SUVmax, 9.1 vs. 4.5; P< 0.01). [⁶⁸Ga]Ga-DOTA-FAPI-04 accumulation was significantly higher than that of [¹⁸F]FDG in both osteolytic (n=66, median SUVmax, 10.6 vs 6.1; P < 0.01), and osteoblastic metastases (n=43, median SUVmax, 7.7 vs 3.7; P < 0.01). [⁶⁸Ga]Ga-DOTA-FAPI-04 uptakes were significantly higher than that of [¹⁸F]FDG in bone metastases from lung cancer (n = 62, median SUVmax, 10.7 vs 5.2; P < 0.01), thyroid cancer (n = 18, median SUVmax, 5.65 vs 2.1; P < 0.01) and liver cancer (n = 12, median SUVmax, 5.65 vs 3.05; P < 0.01). However, [⁶⁸Ga]Ga-DOTA-FAPI-04 detected 10 false-positive lesions, while only 5 false-positive were visualized by [¹⁸F]FDG PET/CT.

Conclusion

[⁶⁸Ga]Ga-DOTA-FAPI-04 PET/CT exhibits excellent diagnostic performance as a means of detecting bone metastases, and is superior to [¹⁸F]FDG PET/CT in this diagnostic context. Furthermore, [⁶⁸Ga]Ga-DOTA-FAPI-04 tracer uptake levels are higher than those of [¹⁸F]FDG for most bone metastases. However, owing to the potential for false-positive bone lesions, it is critical that physicians interpret all CT findings with caution to ensure diagnostic accuracy.

Effect of the types of pretreatment imaging modalities on the treatment response to palliative radiation for painful bone metastases from solid cancer: a single-center retrospective analysis

Background

Determining the appropriate gross tumor volume is important for irradiation planning in addition to palliative radiation for bone metastases. While irradiation planning is commonly performed using simulation computed tomography (CT), magnetic resonance imaging (MRI), bone scintigraphy, and ¹⁸fluorodeoxyglucose-positron emission tomography-CT (¹⁸FDG-PET-CT) are more sensitive for detecting bone metastasis and invasion areas. Therefore, this study evaluated whether pretreatment imaging modalities influenced the response to palliative radiation therapy (i.e., the irradiation effect) for painful bone metastases from solid malignant carcinomas.

Methods

Consecutive patients with painful bone metastases treated with palliative radiation between January 2013 and December 2017 at our institution were included. We retrospectively investigated the pretreatment images from the different imaging modalities (CT, MRI, bone scintigraphy, and ¹⁸FDG-PET-CT) obtained between 1 month before and the initiation of palliative radiation and determined the primary site of carcinoma, histological type, metastatic lesion type (osteolytic, osteoblastic, or mixed), pathological fracture, and metastatic site (vertebral or not). We then evaluated the relationship between these factors and treatment response. We defined “response” as the condition in which patients achieved pain relief or reduced the use of painkiller medicines.

Results

In total, 131 patients (78 men and 53 women) were included; the median age was 66 years (range, 24–89 years). Prescribed doses were 8–50 Gy/1–25 fractions with 2–8 Gy/fraction. Among the 131 patients, 105 were responders (response rate, 80%). The imaging modalities performed before irradiation were CT in 131 patients, MRI in 54, bone scintigraphy in 56, and ¹⁸FDG-PET-CT in 14. The Welch t-test and chi-square test showed no significant association between treatment response and each factor. Multiple logistic regression analysis including the imaging modality, metastatic site, and pathological fracture also showed no significant association with each factor.

Conclusions

There was no significant relationship between the type of pretreatment imaging and treatment response for painful bone metastases. Thus, setting the appropriate radiation field according to CT images and clinical findings could help avoiding further image inspection before palliative radiation for painful bone metastases.

Strategies on Nanodiagnostics and Nanotherapies of the Three Common Cancers

The emergence of nanomedicine has enriched the knowledge and strategies of treating diseases, and especially some incurable diseases, such as cancers, acquired immune deficiency syndrome (AIDS), and neurodegenerative diseases. The application of nanoparticles in medicine is in the core of nanomedicine. Nanoparticles can be used in drug delivery for improving the uptake of poorly soluble drugs, targeted delivery to a specific site, and drug bioavailability. Early diagnosis of and targeted therapies for cancers can significantly improve patients' quality of life and extend patients' lives. The advantages of nanoparticles have given them a progressively important role in the nanodiagnosis and nanotherapy of common cancers. To provide a reference for the further application of nanoparticles, this review focuses on the recent development and application of nanoparticles in the early diagnosis and treatment of the three common cancers (lung cancer, liver cancer, and breast cancer) by using quantum dots, magnetic nanoparticles, and gold nanoparticles.

Staging Lung Cancer: Metastasis

The updated eighth edition of the tumor, node, metastasis (TNM) classification for lung cancer includes revisions to T and M descriptors. In terms of the M descriptor, the classification of intrathoracic metastatic disease as M1a is unchanged from TNM-7. Extrathoracic metastatic disease, which was classified as M1b in TNM-7, is now subdivided into M1b (single metastasis, single organ) and M1c (multiple metastases in one or multiple organs) descriptors. In this article, the rationale for changes in the M descriptors, the utility of preoperative staging with PET/computed tomography, and the treatment options available for patients with oligometastatic disease are discussed.

Update on F-18-fluoro-deoxy-glucose-PET/computed tomography in nonsmall cell lung cancer

PURPOSE OF REVIEW

The aim of this review is to provide an outline of current evidence for the use of F-18-fluoro-deoxy-glucose PET computed tomography (FDG-PET/CT) in nonsmall cell lung cancer (NSCLC) for diagnosis, staging, radiotherapy planning, response assessment and response monitoring.

RECENT FINDINGS

Management of patients with NSCLC requires a multimodality approach to accurately diagnose and stage patients. In this approach, FDG-PET/CT has become a standard staging instrument in lung cancer. FDG-PET/CT is, in addition to staging, also valuable for the characterization of the solitary pulmonary nodule. An increased uptake in the nodule as compared with mediastinal blood pool is suspected for malignancy. In radiotherapy planning, FDG-PET/CT can assist the radiation oncologist for optimal dose delivery to the tumour, while sparing healthy tissues. Evidence of the prognostic and predictive implications of FDG-PET/CT is accumulating. Volumetric parameters of PET, such as metabolic active tumour volume and total lesion glycolysis, are promising predictive and prognostic biomarkers. However, for implementation of metabolic response parameters in clinical practice, more randomized, PET-based, multicentre trials are necessary. The introduction of integrated PET and MRI scanners did not change the pivotal role of standard FDG-PET/CT yet, as with current technology, PET/MRI did not show superior performance in thoracic staging.

SUMMARY

The role of PET is described for diagnosis, staging and response assessment.

¹⁸F-FDG PET/CT in hepatocellular carcinoma: detection of bone metastasis and prediction of prognosis

OBJECTIVE

The purpose of this study was to assess the diagnostic accuracy and prognostic value of 18F-fluorodeoxyglucose PET/computed tomography (CT) in bone metastases from hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

Of 3912 consecutive HCC patients, 67 patients who had undergone both PET/CT and bone scintigraphy (BS) within a 3-month interval were evaluated.

RESULTS

Bone metastases were most frequently found in the pelvis (20%), followed by the lumbar spine (14%) and long bones (13%). PET/CT was significantly more sensitive than BS in region-based analyses, with 273 confirmed bone metastases (96.7 vs. 52.7%, respectively; P<0.001), and in patient-based analyses (99 vs. 85%; P=0.042). The median survival period was 5 (range, 0.4-18) months. On univariate analysis, poor prognostic factors included age (<60 years), multiple bone metastases, lymph node metastasis, high serum α-fetoprotein (≥400 IU/ml), Child-Pugh class B, and high maximum standardized uptake value (SUVmax) of bone metastasis (>5.0). Large metabolic volume (≥200 cm3) of bone metastasis was another poor prognostic factor. On Cox regression analysis, high α-fetoprotein was the only poor prognostic factor with statistical significance.

CONCLUSION

PET/CT was more sensitive than BS in bone metastasis from HCC by both patient-based and region-based analyses, and offered additional information on survival. PET/CT can be helpful in early diagnosis and opportune treatment of bone metastasis from HCC.

Staging of lung cancer

Primary lung cancer is the leading cause of cancer mortality in the world. Thorough clinical staging of patients with lung cancer is important, because therapeutic options and management are to a considerable degree dependent on stage at presentation. Radiologic imaging is an essential component of clinical staging, including chest radiography in some cases, computed tomography, MRI, and PET. Multiplanar imaging modalities allow assessment of features that are important for surgical, oncologic, and radiation therapy planning, including size of the primary tumor, location and relationship to normal anatomic structures in the thorax, and existence of nodal and/or metastatic disease.

Improved detection of bone metastases from lung cancer in the thoracic cage using 5- and 1-mm axial images versus a new CT software generating rib unfolding images: comparison with standard ¹⁸F-FDG-PET/CT

RATIONALE AND OBJECTIVES

To evaluate the performance of a dedicated computed tomography (CT) software called "bone reading" generating rib unfolded images for improved detection of rib metastases in patients with lung cancer in comparison to readings of 5- and 1-mm axial CT images and (18)F-Fluordeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT).

MATERIALS AND METHODS

Ninety consecutive patients who underwent (18)F-FDG-PET/CT and chest CT scanning between 2012 and 2014 at our institution were analyzed retrospectively. Chest CT scans with 5- and 1-mm slice thickness were interpreted blindly and separately focused on the detection of rib metastases (location, number, cortical vs. medullary, and osteoblastic vs. sclerotic). Subsequent image analysis of unfolded 1 mm-based CT rib images was performed. For all three data sets the reading time was registered. Finally, results were compared to those of FDG-PET. Validation was based on FDG-PET positivity for osteolytic and mixed osteolytic/osteoblastic focal rib lesions and follow-up for sclerotic PET-negative lesions.

RESULTS

A total of 47 metastatic rib lesions were found on FDG-PET/CT plus another 30 detected by CT bone reading and confirmed by follow-up CT. Twenty-nine lesions were osteolytic, 14 were mixed osteolytic/osteoblastic, and 34 were sclerotic. On a patient-based analysis, CT (5 mm), CT (1 mm), and CT (1-mm bone reading) yielded a sensitivity, specificity, and accuracy of 76.5/97.3/93, 81.3/97.3/94, and 88.2/95.9/92, respectively. On segment-based (unfolded rib) analysis, the sensitivity, specificity, and accuracy of the three evaluations were 47.7/95.7/67, 59.5/95.8/77, and 94.8/88.2/92, respectively. Reading time for 5 mm/1 mm axial images and unfolded images was 40.5/50.7/21.56 seconds, respectively.

CONCLUSIONS

The use of unfolded rib images in patients with lung cancer improves sensitivity and specificity of rib metastasis detection in comparison to 5- and 1-mm CT slice reading. Moreover, it may reduce the reading time.

FDG-PET Predicts Pain Response and Local Control in Palliative Radiotherapy With or Without Systemic Treatment in Patients With Bone Metastasis From Non-small-cell Lung Cancer

The purpose of the present study was to evaluate the prognostic value of the maximal standardized uptake value (SUVmax) from serial positron emission tomography scans in patients with bone metastases from non-small-cell lung cancer. The results showed that the pre-RT SUVmax predicted the initial pain severity and local control. Moreover, the change in the SUVmax after palliative radiotherapy predicted the pain response and local control rate.

INTRODUCTION

We sought to evaluate the value of fluorine-18 fluorodeoxyglucose positron emission tomography (PET) in predicting the pain severity, pain response, and in-field tumor control after palliative radiotherapy (RT) in patients with non-small-cell lung cancer (NSCLC) bone metastases.

MATERIALS AND METHODS

The present retrospective, institutional review board-approved study involved 74 patients with NSCLC and 185 bone metastatic lesions. All patients had undergone PET-computed tomography (CT) scans before and after RT. The pain scores were determined using a numerical rating scale, and the maximal standardized uptake value (SUVmax) at each location was recorded. The pain scores and responses to RT were compared using the pre-RT SUVmax and SUVmax changes after RT. Cox regression analyses were performed to identify the prognostic factors for in-field progression-free survival (PFS) and in-field event-free survival (EFS).

RESULTS

The pre-RT SUVmax correlated with the initial pain scores (r = 0.885, P < .001), and the decrease in the SUVmax after RT was associated with the pain response to RT (P = .001). During the follow-up period, 47.03% and 38.92% of the lesions showed in-field tumor radiographic progression and in-field events, respectively. The Cox regression analyses showed that a higher pre-RT SUVmax (≥ 8.2) was an independent prognostic factor of worse in-field PFS and worse in-field EFS (hazard ratio [HR] 1.42 and 1.46; P = .044 and P = .005, respectively) and that a greater SUVmax decrease (≥ 28.3%) after RT was an independent prognostic factor of better in-field PFS and better in-field EFS (HR 0.59 and 0.60, respectively; P < .001 for both).

CONCLUSION

In patients with NSCLC osseous metastasis treated with palliative RT, the pre-RT SUVmax predicted the initial pain severity and local control. Moreover, the change in the SUVmax after RT predicted the pain response and local control.

Comparison of choline-PET/CT, MRI, SPECT, and bone scintigraphy in the diagnosis of bone metastases in patients with prostate cancer: a meta-analysis

Published data on the diagnosis of bone metastases of prostate cancer are conflicting and heterogeneous. We performed a comprehensive meta-analysis to compare the diagnostic performance of choline-PET/CT, MRI, bone SPECT, and bone scintigraphy (BS) in detecting bone metastases in parents with prostate cancer. Pooled sensitivity, specificity, and diagnostic odds ratios (DOR) were calculated both on a per-patient basis and on a per-lesion basis. Summary receiver operating characteristic (SROC) curves were also drawn to obtain the area under curve (AUC) and Q* value. Sixteen articles consisting of 27 studies were included in the analysis. On a per-patient basis, the pooled sensitivities by using choline PET/CT, MRI, and BS were 0.91 [95% confidence interval (CI): 0.83-0.96], 0.97 (95% CI: 0.91-0.99), 0.79 (95% CI: 0.73-0.83), respectively. The pooled specificities for detection of bone metastases using choline PET/CT, MRI, and BS, were 0.99 (95% CI: 0.93-1.00), 0.95 (95% CI: 0.90-0.97), and 0.82 (95% CI: 0.78-0.85), respectively. On a per-lesion basis, the pooled sensitivities of choline PET/CT, bone SPECT, and BS were 0.84 (95% CI: 0.81-0.87), 0.90 (95% CI: 0.86-0.93), 0.59 (95% CI: 0.55-0.63), respectively. The pooled specificities were 0.93 (95% CI: 0.89-0.96) for choline PET/CT, 0.85 (95% CI: 0.80-0.90) for bone SPECT, and 0.75 (95% CI: 0.71-0.79) for BS. This meta-analysis indicated that MRI was better than choline PET/CT and BS on a per-patient basis. On a per-lesion analysis, choline PET/CT with the highest DOR and Q* was better than bone SPECT and BS for detecting bone metastases from prostate cancer.

Diagnostic value of 18F-FDG PET/CT in comparison to bone scintigraphy, CT and 18F-FDG PET for the detection of bone metastasis

PURPOSE

To evaluate the diagnostic value of 18F-FDG PET/CT for detection of bone metastasis in comparison with the efficacies of 18F-FDG PET/CT, CT, 18F-FDG PET and conventional planar bone scintigraphy in a series of cancer patients.

METHODS

Five hundred and thirty patients who underwent both 18F-FDG PET/CT and bone scintigraphy within 1 month were retrospectively analyzed. The skeletal system was classified into 10 anatomic segments and interpreted blindly and separately. For each modality, the sensitivity, specificity, accuracy, PPV and NPV were calculated and the results were statistically analyzed.

RESULTS

Bone metastases were confirmed in 117 patients with 459 positive segments. On patient-based analysis, the sensitivity, specificity, accuracy, PPV and NPV of 18F-FDG PET/CT were significantly higher than bone scintigraphy, CT and 18F-FDG PET (P<0.05). On segment-based analysis, the sensitivity of CT, bone scintigraphy, 18F-FDG PET and 18F-FDG PET/CT were 70.4%, 89.5%, 89.1% and 97.8%, respectively (P<0.05, compared with 18F-FDG PET/CT). The overall specificity and accuracy of the four modalities were 89.1%, 91.8%, 90.3%, 98.2% and 90.3%, 90.9%, 89.8%, 98.0%, respectively (P<0.05, compared with 18F-FDG PET/CT). The PPV and NPV were 89.8%, 87.6%, 85.6%, 97.2% and 85.6%, 93.2%, 92.8%, 98.6%, respectively. Three hundred and twelve lesions or segments were presented as lytic or sclerotic changes on CT images at the corresponding sites of increased 18F-FDG uptake. In lytic or mixed lesions, the sensitivity of 18F-FDG PET/CT and 18F-FDG PET were better than bone scintigraphy, while in osteoblastic lesions bone scintigraphy had a similar performance with 18F-FDG PET/CT but better than 18F-FDG PET alone.

CONCLUSION

Our data allow the conclusion that 18F-FDG PET/CT is superior to planar bone scintigraphy, CT or 18F-FDG PET in detecting bone metastasis. 18F-FDG PET/CT may enhance our diagnosis of tumor bone metastasis and provide more information for cancer treatment.

Role of FDG-PET scans in staging, response assessment, and follow-up care for non-small cell lung cancer

The integral role of positron-emission tomography (PET) using the glucose analog tracer fluorine-18 fluorodeoxyglucose (FDG) in the staging of non-small cell lung cancer (NSCLC) is well established. Evidence is emerging for the role of PET in response assessment to neoadjuvant therapy, combined-modality therapy, and early detection of recurrence. Here, we review the current literature on these aspects of PET in the management of NSCLC. FDG-PET, particularly integrated (18)F-FDG-PET/CT, scans have become a standard test in the staging of local tumor extent, mediastinal lymph node involvement, and distant metastatic disease in NSCLC. (18)F-FDG-PET sensitivity is generally superior to computed tomography (CT) scans alone. Local tumor extent and T stage can be more accurately determined with FDG-PET in certain cases, especially in areas of post-obstructive atelectasis or low CT density variation. FDG-PET sensitivity is decreased in tumors <1 cm, at least in part due to respiratory motion. False-negative results can occur in areas of low tumor burden, e.g., small lymph nodes or ground-glass opacities. (18)F-FDG-PET-CT nodal staging is more accurate than CT alone, as hilar and mediastinal involvement is often detected first on (18)F-FDG-PET scan when CT criteria for malignant involvement are not met. (18)F-FDG-PET scans have widely replaced bone scintography for assessing distant metastases, except for the brain, which still warrants dedicated brain imaging. (18)F-FDG uptake has also been shown to vary between histologies, with adenocarcinomas generally being less FDG avid than squamous cell carcinomas. (18)F-FDG-PET scans are useful to detect recurrences, but are currently not recommended for routine follow-up. Typically, patients are followed with chest CT scans every 3-6 months, using (18)F-FDG-PET to evaluate equivocal CT findings. As high (18)F-FDG uptake can occur in infectious, inflammatory, and other non-neoplastic conditions, (18)F-FDG-PET-positive findings require pathological confirmation in most cases. There is increased interest in the prognostic and predictive role of FDG-PET scans. Studies show that absence of metabolic response to neoadjuvant therapy correlates with poor pathologic response, and a favorable (18)F-FDG-PET response appears to be associated with improved survival. Further work is underway to identify subsets of patients that might benefit individualized management based on FDG-PET.

Diagnostic value of fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography for the detection of metastases in non-small-cell lung cancer patients

In the recent years, fluorine 18 fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET)/computed tomography (CT) has emerged as a new modality for staging non-small-cell lung cancer (NSCLC) patients. The aim of this meta-analysis was to assess the diagnostic value of (18)F-FDG PET/CT in detecting metastatic lesions in NSCLC patients. Meta-analysis methods were used to pool sensitivity, specificity, positive and negative likehood ratios, diagnostic odd ratios and to construct a summary receiver-operating characteristic curve. Data from included studies were pooled to compare the diagnostic accuracy between PET/CT and PET or CT alone in nodal staging. Totally, 56 studies involving 8,699 patients met the inclusion criteria. The pooled sensitivities and specificities of (18)F-FDG PET/CT were 0.72 [95% confidence interval (CI): 0.65-0.78] and 0.91 (95% CI: 0.86-0.94) in determining mediastinal nodal staging; 0.71 (95% CI: 0.60-0.80) and 0.83 (95% CI: 0.77-0.88) in intrathoracic staging; 0.78 (95% CI: 0.64-0.87) and 0.90 (95% CI: 0.84-0.94) in intrathoracic staging on a per-node basis. For detecting extrathoracic metastases, the pooled sensitivities and specificities of (18)F-FDG PET/CT were 0.77 (95% CI: 0.47-0.93) and 0.95 (95% CI: 0.92-0.97) for all extrathoracic metastases; 0.91 (95% CI: 0.80-0.97) and 0.98 (95% CI: 0.94-0.99) for bone metastases. (18)F-FDG PET/CT is beneficial in detecting lymph node metastases and extrathoracic metastases although PET/CT showed low sensitivity in detecting brain metastases. (18)F-FDG PET/CT confers significantly higher sensitivity and specificity than contrast-enhanced CT (both p < 0.01) and higher sensitivity than (18)F-FDG PET in staging NSCLC (p < 0.05).

Diagnosis of bone metastases: a meta-analysis comparing ¹⁸FDG PET, CT, MRI and bone scintigraphy

OBJECTIVE

To perform a meta-analysis to compare (18)FDG PET, CT, MRI and bone scintigraphy (BS) for the diagnosis of bone metastases.

METHODS

Databases including MEDLINE and EMBASE were searched for relevant original articles published from January 1995 to January 2010. Software was used to obtain pooled estimates of sensitivity, specificity and summary receiver operating characteristic curves (SROC).

RESULTS

67 articles consisting of 145 studies fulfilled all inclusion criteria. On per-patient basis, the pooled sensitivity estimates for PET, CT, MRI and BS were 89.7%, 72.9%, 90.6% and 86.0% respectively. PET=MRI>BS>CT. ("="indicated no significant difference, P > 0.05; ">" indicated significantly higher, P < 0.05). The pooled specificity estimates for PET, CT, MRI and BS were 96.8%, 94.8%, 95.4% and 81.4% respectively. PET = CT = MRI>BS. On per-lesion basis, the pooled sensitivity estimates for PET, CT, MRI and BS were 86.9%, 77.1%, 90.4% and 75.1% respectively. PET = MRI>BS>CT. The pooled specificity estimates for PET, CT, MRI and BS were 97.0%, 83.2%, 96.0% and 93.6% respectively. PET>MRI>BS>CT.

CONCLUSION

PET and MRI were found to be comparable and both significantly more accurate than CT and BS for the diagnosis of bone metastases.

A meta-analysis of 18FDG-PET, MRI and bone scintigraphy for diagnosis of bone metastases in patients with breast cancer

OBJECTIVE

To perform a meta-analysis comparing the diagnostic value of (18)FDG-PET, MRI, and bone scintigraphy (BS) in detecting bone metastases in patients with breast cancer.

MATERIALS AND METHODS

MEDLINE, EMBASE, Scopus, ScienceDirect, SpringerLink, Web of Knowledge, EBSCO, and the Cochrane Database of Systematic Review databases were searched for relevant original articles published from January 1995 to January 2010. Inclusion criteria was as follows: (18)FDG-PET, MRI or (99m)Tc-MDP BS was performed to detect bone metastases (the number of published CT studies was inadequate for meta-analysis and therefore could not be included in this study); sufficient data were presented to construct a 2 × 2 contingency table; histopathological analysis and/or close clinical and imaging follow-up for at least 6 months were used as the reference standard. Two reviewers independently assessed potentially eligible studies and extracted relevant data. A software program called "META-DiSc" was used to obtain the pooled estimates for sensitivity, specificity, diagnostic odds ratio (DOR), summary receiver operating characteristic (SROC) curves, and the *Q index for each modality.

RESULTS

Thirteen articles consisting of 23 studies fulfilled all inclusion criteria. On a per-patient basis, the pooled sensitivity estimates for MRI (97.1%) were significantly higher than those for PET (83.3%) and BS (87.0%; P <0.05). There was no significant difference between PET and BS (P <0.05). The pooled specificity estimates for PET (94.5%) and MRI (97.0%) were both significantly higher than those for BS (88.1%; P <0.05). There was no significant difference between PET and MRI (P >0.05). The pooled DOR estimates for MRI (298.5) were significantly higher than those for PET (82.1%) and BS (49.3%; P <0.05). There was no significant difference between PET and BS (P >0.05). The SROC curve for MRI showed better diagnostic accuracy than those for PET and BS. The SROC curve for PET was better than that for BS. The*Q index for MRI (0.935), PET (0.922), and BS (0.872) showed no significant difference (P ≥0.05). On a per-lesion basis, the pooled sensitivity estimates for BS (87.8%) were significantly higher than those for PET (52.7%; P <0.05). The pooled specificity estimates for PET (99.6%) were significantly higher than those for BS (96.1%; P <0.05).The pooled DOR estimates for PET (283.3) were significantly higher than those for BS (66.8%; P <0.05). The SROC curve for PET showed better diagnostic accuracy than that for BS. The*Q index for PET (0.941) was significantly higher than that for BS (0.893; P <0.05).

CONCLUSION

Magnetic resonance imaging was found to be better than (18)FDG-PET and BS for diagnosis of bone metastases in patients with breast cancer on a per-patient basis. On a per-lesion basis, (18)FDG-PET had lower sensitivity, higher specificity, a higher DOR, and a higher *Q index than BS.

A meta-analysis of ¹⁸FDG-PET-CT, ¹⁸FDG-PET, MRI and bone scintigraphy for diagnosis of bone metastases in patients with lung cancer

BACKGROUND AND PURPOSE

Lung cancer is the most common cause of cancer related death among both men and women worldwide. The skeleton is the most common site of cancer metastasis. Early detection is crucial for prognosis. To evaluate and compare the capability for bone metastasis assessment of [(18)F] fluoro-2-d-glucose positron emission tomography with computed tomography ((18)FDG-PET-CT), [(18)F] fluoro-2-d-glucose positron emission tomography ((18)FDG-PET), magnetic resonance imaging (MRI) and bone scintigraphy (BS) in lung cancer patients, a meta-analysis is preformed.

METHODS

We searched MEDLINE, OVID, EMBASE and the Cochrane Library for studies evaluating diagnosis validity of (18)FDG-PET-CT, (18)FDG-PET, MRI and BS between January 1990 and August 2010. Meta-analysis methods were used to pool sensitivity, specificity, diagnostic odd ratios (DORs) and to construct a summary receiver-operating characteristic curve (SROC).

RESULTS

A total of 17 articles (9 (18)FDG-PET-CT studies, 9 (18)FDG-PET studies, 6 MRI studies and 16 BS studies) that included 2940 patients who fulfilled all of the inclusion criteria were considered for inclusion in the analysis. The pooled sensitivity for the detection of bone metastasis in lung cancer using (18)FDG-PET-CT, (18)FDG-PET, MRI and BS were 0.92 (95% CI, 0.88-0.95), 0.87 (95% CI, 0.81-0.92), 0.77 (95% CI, 0.65-0.87) and 0.86 (95% CI, 0.82-0.89), respectively. The pooled specificity for the detection of bone metastasis from lung cancer using (18)FDG-PET-CT, (18)FDG-PET, MRI and BS were 0.98 (95% CI, 0.97-0.98), 0.94 (95% CI, 0.92-0.96), 0.92 (95% CI, 0.88-0.95), 0.88 (95% CI, 0.86-0.89), respectively. The pooled DORs estimates for (18)FDG-PET-CT 449.17 were significantly higher than for (18)FDG-PET (118.25, P<0.001), MRI (38.27, P<0.001) and BS (63.37, P<0.001). The pooled sensitivity of BS was not correlated with the prevalence of bone metastasis.

CONCLUSION

The results showed that both (18)FDG-PET-CT and (18)FDG-PET were better imaging methods for diagnosing bone metastasis from lung cancer than MRI and BS. (18)FDG-PET-CT has higher diagnostic value (sensitivity, specificity and DORs) for diagnosing bone metastasis from lung cancer than any other imaging methods.

Metabolic positron emission tomography imaging in cancer detection and therapy response

Positron emission tomography (PET) is a noninvasive imaging technique that provides a functional or metabolic assessment of normal tissue or disease conditions. Fluorine 18-fluorodeoxyglucose PET imaging (FDG-PET) is widely used clinically for tumor imaging due to increased glucose metabolism in most types of tumors, and has been shown to improve the diagnosis and subsequent treatment of cancers. We review its use in cancer diagnosis, staging, restaging, and assessment of response to treatment. In addition, other metabolic PET imaging agents in pre-clinical research or clinical trial stages of development are discussed, including amino acid analogs based on increased protein synthesis, and choline, which is based on increased membrane lipid synthesis. Amino acid analogs and choline are more specific to tumor cells than FDG, so they play an important role in differentiating cancers from benign conditions and in the diagnosis of cancers with low FDG uptake or high background FDG uptake. For decades, researchers have shown that tumors display altered metabolic profiles with elevated uptake of glucose, amino acids, and lipids. This can be used for cancer diagnosis and monitoring of the therapeutic response with excellent signal-to-noise ratios.

Surprise met in minor ops

The case of a woman who was initially diagnosed as having a sebaceous cyst but who died from metastatic lung carcinoma 2 weeks after her initial 'minor op' procedure. Minor surgical procedures are increasingly being performed by specialist nurses and by general practitioners in primary care. However, such non-experts may lack the resources to cope with surprises such as was found in this case. It is, therefore, imperative that adequate training and support is provided as the model of care changes.