Implications of standardized uptake value measurements of the primary lesions in proven cases of breast carcinoma with different degree of disease burden at diagnosis: does 2-deoxy-2-[F-18]fluoro-D-glucose-positron emission tomography predict tumor biology?

Understanding Breast Cancers through Spatial and High-Resolution Visualization Using Imaging Technologies

Breast cancer is the most common cancer affecting women worldwide. Although many analyses and treatments have traditionally targeted the breast cancer cells themselves, recent studies have focused on investigating entire cancer tissues, including breast cancer cells. To understand the structure of breast cancer tissues, including breast cancer cells, it is necessary to investigate the three-dimensional location of the cells and/or proteins comprising the tissues and to clarify the relationship between the three-dimensional structure and malignant transformation or metastasis of breast cancers. In this review, we aim to summarize the methods for analyzing the three-dimensional structure of breast cancer tissue, paying particular attention to the recent technological advances in the combination of the tissue-clearing method and optical three-dimensional imaging. We also aimed to identify the latest methods for exploring the relationship between the three-dimensional cell arrangement in breast cancer tissues and the gene expression of each cell. Finally, we aimed to describe the three-dimensional imaging features of breast cancer tissues using noninvasive photoacoustic imaging methods.

Quantification of FDG-PET/CT with delayed imaging in patients with newly diagnosed recurrent breast cancer

Background

Several studies have shown the advantage of delayed-time-point imaging with 18F-FDG-PET/CT to distinguish malignant from benign uptake. This may be relevant in cancer diseases with low metabolism, such as breast cancer. We aimed at examining the change in SUV from 1 h (1h) to 3 h (3h) time-point imaging in local and distant lesions in patients with recurrent breast cancer. Furthermore, we investigated the effect of partial volume correction in the different types of metastases, using semi-automatic quantitative software (ROVER™).

Methods

One-hundred and two patients with suspected breast cancer recurrence underwent whole-body PET/CT scans 1h and 3h after FDG injection. Semi-quantitative standardised uptake values (SUVmax, SUVmean) and partial volume corrected SUVmean (cSUVmean), were estimated in malignant lesions, and as reference in healthy liver tissue. The change in quantitative measures from 1h to 3h was calculated, and SUVmean was compared to cSUVmean. Metastases were verified by biopsy.

Results

Of the 102 included patients, 41 had verified recurrent disease with in median 15 lesions (range 1-70) amounting to a total of 337 malignant lesions included in the analysis. SUVmax of malignant lesions increased from 6.4 ± 3.4 [0.9-19.7] (mean ± SD, min and max) at 1h to 8.1 ± 4.4 [0.7-29.7] at 3h. SUVmax in breast, lung, lymph node and bone lesions increased significantly (p < 0.0001) between 1h and 3h by on average 25, 40, 33, and 27%, respectively. A similar pattern was observed with (uncorrected) SUVmean. Partial volume correction increased SUVmean significantly, by 63 and 71% at 1h and 3h imaging, respectively. The highest impact was in breast lesions at 3h, where cSUVmean increased by 87% compared to SUVmean.

Conclusion

SUVs increased from 1h to 3h in malignant lesions, SUVs of distant recurrence were in general about twice as high as those of local recurrence. Partial volume correction caused significant increases in these values. However, it is questionable, if these relatively modest quantitative advances of 3h imaging are sufficient to warrant delayed imaging in this patient group.

Trial registration

ClinicalTrails.gov NCT01552655. Registered 28 February 2012, partly retrospectively registered.

Electronic supplementary material

The online version of this article (10.1186/s12880-018-0254-8) contains supplementary material, which is available to authorized users.

Considering the Relationship between Quantitative Parameters and Prognostic Factors in Breast Cancer: Can Mean Standardized Uptake Value be an Alternative to Maximum Standardized Uptake Value?

It was aimed to investigate the correlation between maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), and retention index (RI), which represents the quantitative evaluation of the uptake of ¹⁸F-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) used in positron emission tomography (PET) and clinicopathologic as well as biologic prognostic factors. Forty-one women with breast cancer who were histopathologically diagnosed were included in this study. Neoadjuvant chemotherapy was applied to all patients before PET/computed tomography (CT). After FDG injection, PET/CT screening was applied within the 1^st h (PET-1) and in the 2^nd h (PET-2). SUVmax, SUVmean, SUVmax RI, and SUVmean RI of every image were calculated qualitatively and semiquantitatively. The correlation between quantitative and semiquantitative PET parameters and biologic as well as clinicopathologic prognosis factors was evaluated. Statistically, significant positive correlation was found between lymph nodes (LNs), which were evaluated by clinical picture, clinical stage as well as histopathologically and quantitative PET parameters (SUVmax1, SUVmax2,, RImax, SUVmean1, SUVmean2, RImean) (P < 0.05). While statistically significant correlation with RImax was detected only by LN (histopathological), correlations with RImean were detected by clinical picture, clinical stage, metabolic stage, and LN (histopathological). Statistically, significant correlation was found between RImax and estrogen receptor in patients who were histopathologically diagnosed with invasive ductal carcinoma (n = 34) (P < 0.05). We detected correlations between biologic and clinicopathologic prognostic factors and SUVmax as well as SUVmean values in breast carcinoma. SUVmean values may provide important knowledge when the correlation between prognostic factors and PET parameters is investigated even if they are not used routinely.

Pretreatment metabolic parameters measured by 18F-FDG-PET to predict the outcome of first-line chemotherapy in extensive-stage small-cell lung cancer

OBJECTIVE

Patients' pretreatment metabolic burden, as measured by radiotracer fluorine-18 fluorodeoxyglucose (F-FDG) PET/computed tomography (CT), has been shown to predict treatment outcome in various malignancies. However, its predictive role in extensive-stage small cell lung cancer (SCLC) has not been definitively determined. This retrospective study investigated the viability of using common pretreatment metabolic parameters, obtained through F-FDG-PET/CT, to predict outcomes of first-line chemotherapy in extensive-stage SCLC.

PARTICIPANTS AND METHODS

The study population comprised 154 consecutive patients with extensive-stage SCLC who underwent a pretreatment F-FDG-PET/CT scan and received standard first-line chemotherapy between January 2011 and December 2015.

RESULTS

Ten (6.5%) and 66 (42.9%) patients achieved a complete or a partial response, respectively (considered an objective response); 35 (22.7%) and 43 (27.9%) experienced stable or progressive disease. The metabolic tumor volume (MTV) was a significant factor for predicting an objective response. For predicting disease control (objective response or stable disease), MTV and total lesion glycolysis (TLG) were nonindependent factors.

CONCLUSION

Greater MTV and TLG could indicate a poorer response to first-line chemotherapy for patients with extensive-stage SCLC, but the predictive efficiency was not high enough for routine reliance. For patients who are not suitable to receive first-line chemotherapy, MTV and TLG may help guide clinical decisions.

Assessment of Aggressiveness of Breast Cancer Using Simultaneous 18F-FDG-PET and DCE-MRI: Preliminary Observation

PURPOSE

This study aims to investigate the feasibility of using simultaneous breast MRI and PET to assess the synergy of MR pharmacokinetic and fluorine-18 fluorodeoxyglucose (F-FDG) uptake data to characterize tumor aggressiveness in terms of metastatic burden and Ki67 status.

METHODS

Twelve consecutive patients underwent breast and whole-body PET/MRI. During the MR scan, PET events were simultaneously accumulated. MR contrast kinetic model parametric maps were computed using the extended Tofts model, including the volume transfer constant between blood plasma and the interstitial space (K), the transfer constant from the interstitial space to the blood plasma (kep), and the plasmatic volume fraction (Vp).

RESULTS

Patients with systemic metastases had a significantly lower kep compared to those with local disease (0.45 vs. 0.99 min, P = 0.011). Metastatic burden correlated positively with K and standardized uptake value (SUV), and negatively with kep. Ki67 positive tumors had a significantly greater K compared to Ki67 negative tumors (0.29 vs. 0.45 min, P = 0.03). A negative correlation was found between metabolic tumor volume and transfer constant (K or Kep).

CONCLUSION

These preliminary results suggest that MR pharmacokinetic parameters and FDG-PET may aid in the assessment of tumor aggressiveness and metastatic potential. Future studies are warranted with a larger cohort to further assess the role of pharmacokinetic modeling in simultaneous PET/MRI imaging.

Relation between primary tumor FDG avidity and site of first distant metastasis in patients with breast cancer

Identification of tumor imaging features associated with metastatic pattern may allow better understanding of cancer dissemination. Here, we investigated how primary tumor F-fluorodeoxyglucose (FDG) avidity influences the first site of breast cancer metastasis.Subjects were 264 patients with advanced breast cancer who underwent positron emission tomography/computed tomography at diagnosis and had metastasis at presentation (n = 193) or metastatic relapse after surgery (n = 71). Primary tumor FDG avidity (maximum SUV [SUVmax] ≥10.1) was compared with histology and first metastatic sites.The most common site of first metastasis was the bone, occurring in 62.7% of patients with metastasis at presentation and 38.0% of those with metastatic relapse. First metastasis to lung occurred in 30.1% and 35.2%, and to liver in 25.4% and 15.2% of respective groups. In patients with metastasis at presentation, primary tumors were FDG avid in 98/193 cases, and this was associated with more frequent first metastasis to lung (37.8% vs 22.1%; P = 0.018). In patients with metastasis relapse, primary tumors were FDG avid in 31/71 cases, and this was associated with more frequent first metastasis to lung (48.4% vs 25.0%; P = 0.041) and liver (29.0% vs 5.0%; P = 0.008). In patients with metastasis relapse, primary tumors that were FDG avid but hormone receptor negative had more first metastasis to lung (57.9% vs 26.9%; P = 0.016).FDG-avid primary breast tumors have favored first spread to the lung and liver, which suggests that tumor cells with heightened glycolytic activity better colonize these organs.

Exploring Tumor Biology with Fluorodeoxyglucose-Positron Emission Tomography Imaging in Breast Carcinoma

This article reviews the promising application of fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging in exploring tumor biology of breast carcinoma based upon the authors' experience and also reviews current literature on this topic. The interest in this novel aspect of breast PET imaging has gained momentum in recent years as more is understood about the molecular subtypes and heterogeneous behavior of breast cancer. With the development of newer targeted therapies, oncologists are realizing the need for a means of accurate prediction and assessment of treatment response early in the course of therapy. Hence the studies on FDG-PET imaging in exploring the tumor biology of breast carcinoma have focused on: tumor histologic subtypes, hormonal receptor expression, disease burden at diagnosis, tumor proliferation index, and other molecular parameters. The correlation of various PET tracer parameters (eg, 15O-water PET-derived blood flow measurements and 18F-FDG-PET derived glucose metabolism rate parameters) is also of considerable interest. To summarize, the utility of FDG-PET/CT imaging on this aspect of breast carcinoma imaging holds considerable promise in disease characterization, and it can be foreseen that it will soon aid in guiding and adapting newer therapeutic regimens.

18F-FDG PET/CT oncologic imaging at extended injection-to-scan acquisition time intervals derived from a single-institution 18F-FDG-directed surgery experience: feasibility and quantification of 18F-FDG accumulation within 18F-FDG-avid lesions and background tissues

Background

¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) is a well-established imaging modality for a wide variety of solid malignancies. Currently, only limited data exists regarding the utility of PET/CT imaging at very extended injection-to-scan acquisition times. The current retrospective data analysis assessed the feasibility and quantification of diagnostic ¹⁸F-FDG PET/CT oncologic imaging at extended injection-to-scan acquisition time intervals.

Methods

¹⁸F-FDG-avid lesions (not surgically manipulated or altered during ¹⁸F-FDG-directed surgery, and visualized both on preoperative and postoperative ¹⁸F-FDG PET/CT imaging) and corresponding background tissues were assessed for ¹⁸F-FDG accumulation on same-day preoperative and postoperative ¹⁸F-FDG PET/CT imaging. Multiple patient variables and ¹⁸F-FDG-avid lesion variables were examined.

Results

For the 32 ¹⁸F-FDG-avid lesions making up the final ¹⁸F-FDG-avid lesion data set (from among 7 patients), the mean injection-to-scan times of the preoperative and postoperative ¹⁸F-FDG PET/CT scans were 73 (±3, 70-78) and 530 (±79, 413-739) minutes, respectively (P < 0.001). The preoperative and postoperative mean ¹⁸F-FDG-avid lesion SUV_max values were 7.7 (±4.0, 3.6-19.5) and 11.3 (±6.0, 4.1-29.2), respectively (P < 0.001). The preoperative and postoperative mean background SUV_max values were 2.3 (±0.6, 1.0-3.2) and 2.1 (±0.6, 1.0-3.3), respectively (P = 0.017). The preoperative and postoperative mean lesion-to-background SUV_max ratios were 3.7 (±2.3, 1.5-9.8) and 5.8 (±3.6, 1.6-16.2), respectively, (P < 0.001).

Conclusions

¹⁸F-FDG PET/CT oncologic imaging can be successfully performed at extended injection-to-scan acquisition time intervals of up to approximately 5 half-lives for ¹⁸F-FDG while maintaining good/adequate diagnostic image quality. The resultant increase in the ¹⁸F-FDG-avid lesion SUV_max values, decreased background SUV_max values, and increased lesion-to-background SUV_max ratios seen from preoperative to postoperative ¹⁸F-FDG PET/CT imaging have great potential for allowing for the integrated, real-time use of ¹⁸F-FDG PET/CT imaging in conjunction with ¹⁸F-FDG-directed interventional radiology biopsy and ablation procedures and ¹⁸F-FDG-directed surgical procedures, as well as have far-reaching impact on potentially re-shaping future thinking regarding the “most optimal” injection-to-scan acquisition time interval for all routine diagnostic ¹⁸F-FDG PET/CT oncologic imaging.

Special Relevance of FDG-PET as an Upfront Diagnostic Modality at Initial Diagnosis and in Suspected Recurrence in Patients of Breast Carcinoma Hailing From Lower Socioeconomic Status Owing to Relative Late Presentation: A Pilot Study in a Medical College Hospital Setting in India

FDG-PET has found relatively limited use in routine management of breast carcinoma due to its limited utility in assessing the primary and axillary lymph node status. The aim of the study was to assess its role in a medical school and municipal hospital setting of Mumbai, where majority belongs to the lower socioeconomic status and presents relatively late and hence whole body FDG-PET could find important place for assessing whole body disease status that would justify being used upfront in this group of patients. Thus, the premise of this study was that FDG-PET will have special relevance in this particular setting for evaluation of patients of breast carcinoma with respect to initial staging, detection of locoregional recurrence and metastasis and assessing response to systemic treatment. A total of 52 patients proven to have breast carcinoma, who had undergone (18)F FDG-PET for disease staging at initial diagnosis and in in recurrent disease staging with a few cases as a baseline study for early treatment monitoring purposes over a study period of 3 years, were included in this analysis. 33.3 % of patients with pretreatment baseline FDG-PET were upstaged with diagnosis of additional lesions in the adrenal gland, liver, internal mammary, cervical lymph nodes and the mediastinum. On a lesion specific analysis, the percentage of increased lesion detection (including both lymph node with distant metastasis) by FDG-PET was 42.7 %. FDG-PET was found to be 100 % sensitive and specific for confirming recurrent breast cancer. Four out of 18 patients on chemotherapy underwent second FDG-PET after first cycle of chemotherapy, showed responsiveness to chemotherapy by decreased maximum standardized uptake value (SUVmax). FDG-PET showed 9 liver lesions in 6 patients, only 3 of them was reported in USG. In one patient USG abdomen was inconclusive between hemangioma and metastasis, FDG-PET ruled out liver metastasis in this patient. In the examined patient population belonging to lower socioeconomic status, where usual presentation is relatively late, upfront whole body survey with FDG-PET or PET/CT is of considerable value in view of higher probability of existence of metastatic disease, thus can be an important one-stop shop tool in assessing whole body disease status in a single examination. It also proved efficacious in diagnosing loco regional and distant recurrence, metabolic characterization of lump and early response to treatment in the examined few cases following one cycle of chemotherapy in locally advanced breast cancer.

When should we recommend use of dual time-point and delayed time-point imaging techniques in FDG PET?

FDG PET and PET/CT are now widely used in oncological imaging for tumor characterization, staging, restaging, and response evaluation. However, numerous benign etiologies may cause increased FDG uptake indistinguishable from that of malignancy. Multiple studies have shown that dual time-point imaging (DTPI) of FDG PET may be helpful in differentiating malignancy from benign processes. However, exceptions exist, and some studies have demonstrated significant overlap of FDG uptake patterns between benign and malignant lesions on delayed time-point images. In this review, we summarize our experience and opinions on the value of DTPI and delayed time-point imaging in oncology, with a review of the relevant literature. We believe that the major value of DTPI and delayed time-point imaging is the increased sensitivity due to continued clearance of background activity and continued FDG accumulation in malignant lesions, if the same diagnostic criteria (as in the initial standard single time-point imaging) are used. The specificity of DTPI and delayed time-point imaging depends on multiple factors, including the prevalence of malignancies, the patient population, and the cut-off values (either SUV or retention index) used to define a malignancy. Thus, DTPI and delayed time-point imaging would be more useful if performed for evaluation of lesions in regions with significant background activity clearance over time (such as the liver, the spleen, the mediastinum), and if used in the evaluation of the extent of tumor involvement rather than in the characterization of the nature of any specific lesion. Acute infectious and non-infectious inflammatory lesions remain as the major culprit for diminished diagnostic performance of these approaches (especially in tuberculosis-endemic regions). Tumor heterogeneity may also contribute to inconsistent performance of DTPI. The authors believe that selective use of DTPI and delayed time-point imaging will improve diagnostic accuracy and interpretation confidence in FDG PET imaging.

18F-FDG semi-quantitative parameters and biological prognostic factors in locally advanced breast cancer

AIM

To analyse the correlation between (18)F-FDG uptake assessed by PET/CT in locally advanced breast tumours and histopathological and immunohistochemical prognostic factors.

MATERIAL AND METHODS

Thirty-six women with breast cancer were prospectively evaluated. PET/CT was requested in the initial staging previous to adjuvant chemotherapy (multicentric study). All the patients underwent an (18)F-FDG PET/CT with a dual-time-point acquisition. Both examinations were evaluated qualitatively and semiquantitatively with calculation of SUVmax values in PET-1 (SUV-1) and in PET-2 (SUV-2) and the percentage variation of the standard uptake values (retention index) between PET-1 and PET-2. Clinical and metabolic stages were assessed according to TNM classification. The biological prognostic parameters, such as the steroid receptor status, p53 and c-erbB-2 expression, proliferation rate (Ki-67), and grading were determined from tissue of the primary tumour. Metabolic and biological parameters were correlated.

RESULTS

A positive relationship was found between semiquantitative metabolic parameters and biological parameters. SUV-1 and SUV-2 values did not show significant statistical correlation (p<.05) except for the clinical tumour size. About the biological parameters, retention index showed the best results with positive and significant relation (p<.05) with estrogen and progesterone receptor status and Ki-67. Isolated SUV values did not show significant relation to these parameters.

CONCLUSION

Retention index showed the best relation with biological parameters compared to isolated SUVmax values. These data suggest that SUV change over time is a prognostic marker.

Potential role of FDG PET imaging in predicting metastatic potential and assessment of therapeutic response to neoadjuvant chemotherapy in Ewing sarcoma family of tumors

AIMS AND OBJECTIVES

The aim of this study was to retrospectively correlate FDG uptake in primary Ewing sarcoma family of tumors (ESFT) with tumor behavior, and to evaluate whether FDG PET can be used to predict response to neoadjuvant chemotherapy (NACT) in this patient group.

METHODS

Out of the total 54 patients of recently diagnosed ESFT who underwent pretreatment FDG PET imaging, group I included patients without metastasis at presentation (n = 34) and group II included those with metastasis at presentation (n = 20). Fourteen of these patients had undergone FDG PET after 4 cycles of induction chemotherapy and surgical resection of primary tumor. In this subgroup of 14 patients, maximum standardized uptake value (SUVmax) of primary tumor was estimated before and after 4 cycles of induction chemotherapy and was correlated with the histopathological response in terms of necrosis in the tumor specimen.

RESULTS

Mean SUVmax in the primary tumor in group I patients was 6.84 and in group II patients, it was 11.31. The difference between mean SUVmax of these 2 groups was significant by Wilcoxon test analysis, with P < 0.01. In group II patients, SUVmax in metastasis with maximum FDG uptake was consistently lower as compared with that of primary tumor. In subgroup of 14 patients, Pearson correlation analysis showed that percentage change in SUVmax of primary tumor correlated well with percentage necrosis on histopathological examination (P < 0.01).

CONCLUSION

FDG uptake in primary ESFT reflected its metastatic potential and hence the aggressive behavior. The significant correlation between change in metabolic activity of the primary tumor and histopathological response after neoadjuvant chemotherapy suggests that FDG PET may be an ideal noninvasive method to assess tumor behavior and response to therapy in ESFT.

Personalized versus evidence-based medicine with PET-based imaging

In this Perspective the feasibility, scope and impact of integrating PET-based personalized medicine into the evidence-based clinical practice of oncology is discussed. The basic concepts of 'evidence-based medicine' and 'personalized medicine' at times seem contradictory; however, I will discuss, with specific clinical situations as examples, a synergistic and probably incremental link between the two and propose that the result of such integration will ultimately improve patient management. Tailoring therapeutic approaches and regimens by molecular imaging, with PET at its forefront, would enable disease management at the individual level and this modification would hopefully further strengthen the evidence-based approach in oncology.

18F-FDG uptake in lung, breast, and colon cancers: molecular biology correlates and disease characterization

It is hoped that in the not too distant future, noninvasive imaging-based molecular interrogation and characterization of tumors can improve our fundamental understanding of the dynamic biologic behavior of cancer. For example, the new dimension of diagnostic information that is provided by (18)F-FDG PET has led to improved clinical decision making and management changes in a substantial number of patients with cancer. In this context, the aim of this review is to bring together and summarize the current data on the correlation between the underlying molecular biology and the clinical observations of tumor (18)F-FDG accumulation in 3 major human cancers: lung, breast, and colon.

FDG-PET Dynamic Contrast-Enhanced CT in the Management of Breast Cancer

Breast cancer is a complex disease and molecular imaging may contribute to better management through providing new insight for early detection. Fluorodeoxyglucose (FDG)-PET/CT has made great strides as a functional anatomic technique and recently gained attention in the diagnosis, staging, and follow-up of breast cancer. FDG-PET and CT complement each other's strengths in integrated FDGPET/CT. One-stop-shop whole-body FDG-PET/CT coupled with integrated FDG-PET/CT mammography has also been advocated.

The Role of PET and PET/CT in the Surgical Management of Breast Cancer: A Review

The role of PET and PET/CT in the management of patients with breast cancer is in evolution. Recent investigations suggest dual time point imaging increases sensitivity of detection of smaller breast cancers even DCIS suggesting PET imaging may offer some value in patients where mammography is typically not particularly sensitive. PET/CT may have its greatest role in staging, especially for patients with locally advanced breast cancer and can even predict response to neoadjuvant therapy. PET/CT may be particularly useful in predicting the biology of higher risk triple-negative and HER-2/neupositive tumors. PET/CT will continue to play a major role in the management of patients with breast cancer.