The prognostic value of <Superscript>18</Superscript>F–FDG PET/CT prior to liver transplantation for nonresectable colorectal liver metastases

Purpose

The main objective of this study was to evaluate the prognostic value of volumetric and metabolic information derivied from F-18 fluorodeoxyglucose positron emission tomography (¹⁸F–FDG PET) in combination with computed tomography (CT) prior to liver transplantation (LT) in patients with nonresectable colorectal liver metastases (CLM). Due to scarcity of liver grafts, prognostic information enabling selection of candidates who will gain the highest survival after LT is of vital importance. ¹⁸F–FDG PET/CT was a part of the preoperative study protocol. Patients without evidence of extrahepatic malignant disease on ¹⁸F–FDG PET/CT who also fulfilled all the other inclusion criteria underwent LT.

Methods

The preoperative ¹⁸F–FDG PET/CT examinations of all patients included in the SECA (secondary cancer) study were retrospectively assessed. Maximum, mean and peak standardized uptake values (SUV_max, SUV_mean and SUV_peak), tumor to background (T/B) ratio, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were measured and calculated for all liver metastases. Total MTV and TLG were calculated for each patient. Cut-off values were determined for each of these parameters by using receiver operating characteristic (ROC) analysis dividing the patients into two groups. One, three and five-year overall survival (OS) and disease free survival (DFS) for patients over and under the cut-off value were compared by using the Kaplan–Meier method and log rank test.

Results

Twenty-three patients underwent LT in the SECA study. Total MTV and TLG under the cut-off values were significantly correlated to improved OS at three and five years (p = 0.027 and 0.026) and DFS (p = 0.01). One, three and five-year OS and DFS were not significantly related to SUV_max, SUV_mean, SUV_peak or T/B-ratio.

Conclusion

Total MTV and TLG from ¹⁸F FDG PET/CT prior to LT for nonresectable CLM were significantly correlated to improved three and five-year OS and DFS and can potentially improve the patient selection for LT.

     

Application of Quantitative Indexes of FDG PET to Treatment Response Evaluation in Indolent Lymphoma

Purpose

Although ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is a standard imaging modality for response evaluation in FDG-avid lymphoma, there is a controversy using FDG PET in indolent lymphoma. The purpose of this study was to investigate the effectiveness of quantitative indexes on FDG PET in response evaluation of the indolent lymphoma.

Methods

Fifty-seven indolent lymphoma patients who completed chemotherapy were retrospectively enrolled. FDG PET/computed tomography (CT) scans were performed at baseline, interim, and end of treatment (EOT). Response was determined by Lugano classification, and progression-free survival (PFS) by follow-up data. Maximum standardized uptake value (SUV_max), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured in the single hottest lesion (target A) or five hottest lesions (target B). Their efficacies regarding response evaluation and PFS prediction were evaluated.

Results

On EOT PET, SUV_max, and MTV of both targets were well associated with visual analysis. Changes between initial and EOT PET were not significantly different between CR and non-CR groups. On interim PET, SUV_max, and %ΔSUV_max in both targets were significantly different between CR and non-CR groups. For prediction of PFS, most tested indexes were significant on EOT and interim PET, with SUV_max being the most significant prognostic factor.

Conclusion

Quantitative indexes of FDG PET are well associated with Lugano classification in indolent lymphoma. SUV_max measured in the single hottest lesion can be effective in response evaluation and prognosis prediction on interim and EOT PET.

     

FDG PET/CT for assessing the resectability of NSCLC patients with N2 disease after neoadjuvant therapy

Objective

Neoadjuvant chemoradiotherapy (CMRT) is the most effective treatment of stage III non-small-cell lung cancer (NSCLC). The present study aimed at assessing FDG PET/CT for defining the response of N2 disease to neoadjuvant CMRT, as surgical resection after such therapy significantly improves 5-year survival in responding N2 disease.

Methods

Forty-five patients with locally advanced NSCLC underwent both pre-neoadjuvant therapy FDG PET/CT and post-neoadjuvant therapy FDG PET/CT followed by anatomical resection of lung and ipsilateral mediastinal lymph nodes (LN). Seventeen of these patients who had PET/CT studies in our institution and were operated after CMRT were retrospectively included in the study group (12 males, ages 43–78 years; stage IIIA: 14 patients, stage IIIB: 3 patients). PET/CT response in N2 was visually scored per-lymph node station and per patient. Quantitative N2 response was evaluated by SUV_max and total lesion glycolysis (TLG) measurements after therapy alone and in comparison with pre-therapy values. PET/CT N2 response was confirmed at surgery.

Results

Seventeen NSCLC patients with 29 metastatic N2 lymph nodes (LN) were assessed. Histopathology confirmed 14 responders and 3 non-responders, and was available in 20/29 metastatic LN, showing complete response in 17 and residual disease in 3 LN. LN-based visual analysis of N2 response on PET/CT defined 3 TP, 16 TN and 1 FP, for sensitivity, specificity, accuracy, negative and positive predictive values (NPV and PPV) of 100, 94, 95, 100 and 75 %, respectively. Patient-based visual analysis defined 3 TP, 13 TN and 1 FP study, for sensitivity, specificity, accuracy, NPV and PPV of 100, 93, 94, 100 and 75 %, respectively. Nodal-based quantitative analysis of FDG uptake in N2 nodes revealed a significant difference between responding and non-responding LN only of SUV_max post-therapy (2.5 ± 1.21 vs. 3.5 ± 2.36, P = 0.04).

Conclusion

FDG PET/CT after neoadjuvant therapy accurately defined response in metastatic N2 nodes of NSCLC patients, presenting very high sensitivity and NPV for detecting responding nodes. PET/CT may enable selection of candidates for curative resection of stage III NSCLC. Mediastinoscopy may not be mandatory in patients with a negative PET/CT after neoadjuvant therapy.

     

<Superscript>18</Superscript>F-FDG and <Superscript>18</Superscript>F-FLT PET/CT imaging in the characterization of mediastinal lymph nodes

Purpose

There is currently no single modality for accurate characterization of enlarged mediastinal lymph nodes into benign or malignant. Recently ¹⁸F-fluorothymidine (FLT) has been used as a proliferation marker. In this prospective study, we examined the role of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) and ¹⁸F-FLT PET/CT in categorizing mediastinal lymph nodes as benign or malignant.

Materials and methods

A total of 70 consecutive patients with mediastinal lymphadenopathy detected on computed tomography (CT) or chest radiograph underwent whole body ¹⁸F-FLT PET/CT and ¹⁸F-FDG PET/CT (within 1 week of each other). Lymph nodal tracer uptake was determined by calculation of standardized uptake value (SUV) with both the tracers. Results of PET/CT were compared with histopathology of the lymph nodes.

Results

Histopathology results showed thirty-seven patients with sarcoidosis, seven patients with tuberculosis, nine patients with non-small cell lung cancer, five patients with Hodgkin’s lymphoma and twelve patients with non-Hodgkin’s lymphoma. The mean FDG SUV_max of sarcoidosis, tuberculosis, Hodgkin’s and non-Hodgkin’s lymphoma was 12.7, 13.4, 8.2, and 8.8, respectively, and the mean FLT SUV_max was 6.0, 5.4, 4.4, and 3.8, respectively. It was not possible to characterize mediastinal lymphadenopathy as benign or malignant solely based on FDG SUV_max values (p > 0.05) or FLT SUV_max values (p > 0.05). There was no significant difference in FDG uptake (p > 0.9) or FLT uptake (p > 0.9) between sarcoidosis and tuberculosis. In lung cancer patients, the FDG SUV_max and FLT SUV_max of those lymph nodes with tumor infiltration on biopsy was 6.7 and 3.9, respectively, and those without nodal infiltration was 6.4 and 3.7, respectively, and both the tracers were not able to characterize the nodal status as malignant or benign (p > 0.05).

Conclusion

Though ¹⁸F-FLT PET/CT and ¹⁸F-FDG PET/CT reflect different aspects of biology, i.e., proliferation and metabolism, respectively, neither tracer could provide satisfactory categorization of benign and malignant lymph nodes. The results of this study clearly suggest that differentiation of mediastinal nodes into benign and malignant solely based on SUV_max values cannot be relied upon, especially in settings where tuberculosis and sarcoidosis are common.

     

Prediction of tumor differentiation using sequential PET/CT and MRI in patients with breast cancer

Objective

The aim of this study is to assess tumor differentiation using parameters from sequential positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) in patients with breast cancer.

Methods

This retrospective study included 78 patients with breast cancer. All patients underwent sequential PET/CT and MRI. For fluorodeoxyglucose (FDG)-PET image analysis, the maximum standardized uptake value (SUV_max) of FDG was assessed at both 1 and 2 h and metabolic tumor volume (MTV) and total lesion glycolysis (TLG). The kinetic analysis of dynamic contrast-enhanced MRI parameters was performed using dynamic enhancement curves. We assessed diffusion-weighted imaging (DWI)–MRI parameters regarding apparent diffusion coefficient (ADC) values. Histologic grades 1 and 2 were classified as low-grade, and grade 3 as high-grade tumor.

Results

Forty-five lesions of 78 patients were classified as histologic grade 3, while 26 and 7 lesions were grade 2 and grade 1, respectively. Patients with high-grade tumors showed significantly lower ADC-mean values than patients with low-grade tumors (0.99?±?0.19 vs.1.12?±?0.32, p?=?0.007). With respect to SUV_max1, MTV2.5, and TLG2.5, patients with high-grade tumors showed higher values than patients with low-grade tumors: SUV_max1 (7.92?±?4.5 vs.6.19?±?3.05, p?=?0.099), MTV2.5 (7.90?±?9.32 vs.4.38?±?5.10, p?=?0.095), and TLG2.5 (40.83?±?59.17 vs.19.66?±?26.08, p?=?0.082). However, other parameters did not reveal significant differences between low-grade and high-grade malignancies. In receiver-operating characteristic (ROC) curve analysis, ADC-mean values showed the highest area under the curve of 0.681 (95%CI 0.566–0.782) for assessing high-grade malignancy.

Conclusions

Lower ADC-mean values may predict the poor differentiation of breast cancer among diverse PET–MRI functional parameters.

     

Prognostic value of <Superscript>18</Superscript>F-fluorodeoxyglucose positron emission tomography in patients with gastric neuroendocrine carcinoma and mixed adenoneuroendocrine carcinoma

Objective

Gastric neuroendocrine carcinomas (NEC) and mixed adenoneuroendocrine carcinoma (MANEC) are very rare, aggressive tumors of the stomach. We aimed to examine predictive role of pretreatment ¹⁸F-FDG PET/CT-assessed metabolic parameter of primary tumors and metastases in patients with gastric NEC and MANEC.

Methods

We conducted a review of the 27 patients with histopathologically confirmed NECs (n = 10) and MANEC (n = 17) of the stomach at our institution between January 2005 and December 2012. All patients underwent ¹⁸F-FDG-PET examination at diagnosis. Metabolic parameters [SUV_max, SUV_mean, metabolic tumor volume (MTV) and total lesion glycolysis (TLG)] of the primary tumor and metastases on baseline PET/CT were analyzed.

Results

The median follow-up duration was 39.4 months (95 % CI 20.0–58.1 months) and the median overall survival (OS) was 25.7 months (95 % CI 14.1–37.2 months). All gastric lesions were well visualized (average SUV_max = 12.0, range 3.0–41.8). When subjects were divided into two groups by ROC cut-off value of 210.9 and 612, patients with high TLG in primary lesion and metastases showed poorer prognosis compared to low TLG patients (P = 0.09, P = 0.002, respectively). In the sub-analysis of patients with metastasis (n = 12), patients with high TLG in whole body tumor showed significantly shorter OS compared to those with low TLG (31.7 ± 11.4 vs. 7.2 ± 2.1 months, P = 0.006).

Conclusion

¹⁸F-FDG PET/CT is useful in evaluating prognosis of advanced gastric cancer with neuroendocrine carcinoma components. Baseline MTV of primary gastric cancer with metastatic disease, and MTV, TLG of metastases may be prognostic markers in patients with gastric NEC and MANEC.

     

Metabolic activity by <Superscript>18</Superscript>F–FDG-PET/CT is predictive of early response after nivolumab in previously treated NSCLC

Background

Nivolumab, an anti-programmed death-1 (PD-1) antibody, is administered in patients with previously treated non-small cell lung cancer. However, little is known about the established biomarker predicting the efficacy of nivolumab. Here, we conducted a preliminary study to investigate whether ¹⁸F–FDG-PET/CT could predict the therapeutic response of nivolumab at the early phase.

Methods

Twenty-four patients were enrolled in this study. ¹⁸F–FDG-PET/CT was carried out before and 1 month after nivolumab therapy. SUV_max, metabolic tumour volume (MTV), and total lesion glycolysis (TLG) were calculated. Immunohistochemical analysis of PD-L1 expression and tumour-infiltrating lymphocytes was conducted.

Results

Among all patients, a partial metabolic response to nivolumab was observed in 29% on SUV_max, 25% on MTV, and 33% on TLG, whereas seven (29%) patients achieved a partial response (PR) based on RECIST v1.1. The predictive probability of PR (100% vs. 29%, p = 0.021) and progressive disease (100% vs. 22.2%, p = 0.002) at 1 month after nivolumab initiation was significantly higher in ¹⁸F–FDG on PET/CT than in CT scans. Multivariate analysis confirmed that ¹⁸F–FDG uptake after administration of nivolumab was an independent prognostic factor. PD-L1 expression and nivolumab plasma concentration could not precisely predict the early therapeutic efficacy of nivolumab.

Conclusion

Metabolic response by ¹⁸F–FDG was effective in predicting efficacy and survival at 1 month after nivolumab treatment.

     

Prognostic importance of lymph node-to-primary tumor standardized uptake value ratio in invasive squamous cell carcinoma of uterine cervix

Purpose

Using integrated PET/CT, we evaluated the prognostic value of [¹⁸F]FDG uptake ratio between pelvic lymph node (LN) and primary tumor in invasive squamous cell carcinoma (SCCA) of the uterine cervix.

Methods

We retrospectively reviewed patients with International Federation of Gynecology and Obstetrics (FIGO) stages IB to IIA cervical SCCA who underwent preoperative [¹⁸F]FDG PET/CT scans. PET/CT parameters such as maximum standardized uptake value (SUV) of the primary cervical cancer (SUV_cervix) and LN (SUV_LN), and the LN-to-cervical cancer SUV ratio (SUV_LN/SUV_cervix) were assessed. Prognostic values of PET/CT-derived metabolic and volumetric variables and clinicopathology parameters were analyzed to predict progression-free survival (PFS) in regression analyses.

Results

Clinical data, treatment modalities, and results were reviewed for 103 eligible patients. Median post-surgical follow-up was 29 months (range, 6–89), and 19 (18.5%) patients experienced recurrence. Multivariate logistic regression analysis showed that SUV_LN / SUV_cervix > 0.1747(P = 0.048) was the independent risk factor of recurrence. Patient group categorized by SUV_LN/SUV_cervix showed significant difference in PFS (log-rank test, P < 0.001).

Conclusions

Preoperative SUV_LN/SUV_cervix measured by [¹⁸F]FDG PET/CT was significantly associated with recurrence, and has an incremental prognostic value for PFS in patients with cervical SCCA.

     

Prognostic value of volumetric FDG PET/CT parameters in patients with oral tongue squamous cell carcinoma who were treated by superselective intra-arterial chemoradiotherapy

Purpose

This study aimed to evaluate the predictive and prognostic value of FDG PET/CT-based volumetric parameters in patients with oral tongue squamous cell carcinoma (OTSCC) treated by superselective intra-arterial chemoradiotherapy (IA-CRT).

Methods

We conducted a retrospective study including 33 patients with biopsy-proven OTSCC between May 2007 and February 2016. All of the patients were treated by IA-CRT. Pretreatment SUV_max and metabolic tumor volume (MTV) of the primary tumor were measured. The SUV thresholds of 2.5 and 5.0 were used. Progression-free survival (PFS) and overall survival (OS) were chosen as endpoints to evaluate prognosis. Univariate and multivariate analyses were performed to assess the potential independent effect of FDG PET/CT parameters.

Results

The median follow-up for surviving patients was 40.7 months (range 6.0–107.5 months). In univariate and multivariate analyses, SUV_max and MTV (5.0) were independent prognostic factors for PFS. In univariate analysis, SUV_max failed to predict OS. MTV (5.0) was a significant prognostic factor for OS, but multivariate analysis failed to show statistical independence because it could not exclude the possibility of an artifact due to N stage.

Conclusions

FDG PET/CT-based volumetric parameters may be significant prognostic markers for survival of patients with OTSCC who are treated by IA-CRT.

     

Correlation of FDG PET/CT Findings with Long-Term Growth and Clinical Course of Abdominal Aortic Aneurysm

Purpose

Herein, we report characteristics of ¹⁸F–fluorodeoxyglucose (FDG) uptake in abdominal aortic aneurysms (AAAs) during a long-term follow-up. In addition, we investigated the association between FDG uptake and the physician decision to perform an intervention.

Methods

We performed a retrospective review of 42 patients with AAAs who underwent FDG positron emission tomography (PET)/computed tomography (CT). The size of the AAA was measured in serial CT or PET/CT images. The long-term growth rate of AAAs was calculated by linear regression of the size change. Maximal SUV of the AAA (SUV_AAA) and mean SUV of the blood pool (SUV_Blood) were measured in PET/CT fusion images. To assess the FDG uptake of AAAs, the target-to-background ratio (TBR) was defined as the ratio of SUV_AAA to SUV_Blood. We compared FDG uptake of AAAs with the long-term growth rate of AAAs and clinical data.

Results

TBR was not significantly different between patients with and without significant growth (1.55 ± 0.20 vs. 1.57 ± 0.14; P = 0.5599). However, in patients with significant growth, TBR exhibited a significant positive correlation with the growth rate (r ²  = 0.2601, P = 0.0306). TBR also exhibited a significant difference between patients with and without intervention (P = 0.0228).

Conclusion

FDG uptake of AAA is associated with long-term growth of AAAs in a specified group that exhibits growth. FDG PET/CT may only be effective in predicting the long-term growth of AAAs in specific subgroups of patients. It is also suggested that FDG PET is potentially related to the clinical conditions of AAA patients who need surgical or interventional treatment.

     

Radiomics analysis of pre-treatment [<Superscript>18</Superscript>F]FDG PET/CT for patients with metastatic colorectal cancer undergoing palliative systemic treatment

Background

The aim of this study was to assess radiomics features on pre-treatment [¹⁸F]FDG positron emission tomography (PET) as potential biomarkers for response and survival in patients with metastatic colorectal cancer (mCRC).

Methods

Patients with mCRC underwent [¹⁸F]FDG PET/computed tomography (CT) prior to first- or third-line palliative systemic treatment. Tumour lesions were semiautomatically delineated and standard uptake value (SUV), metabolically active tumour volume (MATV), total lesion glycolysis (TLG), entropy, area under the curve of the cumulative SUV-volume histogram (AUC-CSH), compactness and sphericity were obtained.

Results

Lesions of 47 patients receiving third-line systemic treatment had higher SUV_max, SUV_peak, SUV_mean, MATV and TLG, and lower AUC-CSH, compactness and sphericity compared to 52 patients receiving first-line systemic treatment. Therefore, first- and third-line groups were evaluated separately. In the first-line group, anatomical changes on CT correlated negatively with TLG (ρ?=?0.31) and MATV (ρ?=?0.36), and positively with compactness (ρ?=??0.27) and sphericity (ρ?=??0.27). Patients without benefit had higher mean entropy (p?=?0.021). Progression-free survival (PFS) and overall survival (OS) were worse with a decreased mean AUC [hazard ratio (HR) 0.86, HR 0.77] and increase in mean MATV (HR 1.15, HR 1.22), sum MATV (HR 1.14, HR 1.19), mean TLG (HR 1.16, HR 1.22) and sum TLG (HT1.12, HR1.18). In the third-line group, AUC-CSH correlated negatively with anatomical change (ρ?=?0.21). PFS and OS were worse with an increased mean MATV (HR 1.27, HR 1.68), sum MATV (HR 1.35, HR 2.04), mean TLG (HR 1.29, HR 1.52) and sum TLG (HT 1.27, HR 1.80). SUV_max and SUV_peak negatively correlated with OS (HR 1.19, HR 1.21). Cluster analysis of the 10 radiomics features demonstrated no complementary value in identifying aggressively growing lesions or patients with impaired survival.

Conclusion

We demonstrated an association between improved clinical outcome and pre-treatment low tumour volume and heterogeneity as well as high sphericity on [¹⁸F]FDG PET. Future PET imaging research should include radiomics features that incorporate tumour volume and heterogeneity when correlating PET data with clinical outcome.

     

[<Superscript>18</Superscript>F]FPRGD<Subscript>2</Subscript> PET/CT imaging of integrin α<Subscript>v</Subscript>β<Subscript>3</Subscript> levels in patients with locally advanced rectal carcinoma

Purpose

Our primary objective was to determine if [¹⁸F]FPRGD₂ PET/CT performed at baseline and/or after chemoradiotherapy (CRT) could predict tumour regression grade (TRG) in locally advanced rectal cancer (LARC). Secondary objectives were to compare baseline [¹⁸F]FPRGD₂ and [¹⁸F]FDG uptake, to evaluate the correlation between posttreatment [¹⁸F]FPRGD₂ uptake and tumour microvessel density (MVD) and to determine if [¹⁸F]FPRGD₂ and FDG PET/CT could predict disease-free survival.

Methods

Baseline [¹⁸F]FPRGD₂ and FDG PET/CT were performed in 32 consecutive patients (23 men, 9 women; mean age 63?±?8 years) with LARC before starting any therapy. A posttreatment [¹⁸F]FPRGD₂ PET/CT scan was performed in 24 patients after the end of CRT (median interval 7 weeks, range 3 – 15 weeks) and before surgery (median interval 4 days, range 1 – 15 days).

Results

All LARC showed uptake of both [¹⁸F]FPRGD₂ (SUV_max 5.4?±?1.5, range 2.7 – 9) and FDG (SUV_max 16.5?±?8, range 7.1 – 36.5). There was a moderate positive correlation between [¹⁸F]FPRGD₂ and FDG SUV_max (Pearson’s r?=?0.49, p?=?0.0026). There was a moderate negative correlation between baseline [¹⁸F]FPRGD₂ SUV_max and the TRG (Spearman’s r?=??0.37, p?=?0.037), and a [¹⁸F]FPRGD₂ SUV_max of >5.6 identified all patients with a complete response (TRG 0; AUC 0.84, 95 % CI 0.68 - 1, p?=?0.029). In the 24 patients who underwent a posttreatment [¹⁸F]FPRGD₂ PET/CT scan the response index, calculated as [(SUV_max1 ? SUV_max2)/SUV_max1] × 100 %, was not associated with TRG. Post-treatment [¹⁸F]FPRGD₂ uptake was not correlated with tumour MVD. Neither [¹⁸F]FPRGD₂ nor FDG uptake predicted disease-free survival.

Conclusion

Baseline [¹⁸F]FPRGD₂ uptake was correlated with the pathological response in patients with LARC treated with CRT. However, the specificity was too low to consider its clinical routine use.

     

Pretreatment tumor SUV<Subscript>max</Subscript> predicts disease-specific and overall survival in patients with head and neck soft tissue sarcoma

Purpose

Head and neck soft tissue sarcoma (HNSTS) is a rare type of tumor with various histological presentations and clinical behaviors. ¹⁸F-FDG PET/CT is being increasingly used for staging, grading, and predicting treatment outcomes in various types of human cancers, although this modality has been rarely studied in the survival prediction of HNSTS. Here we examined the prognostic value of tumor metabolic parameters measured using ¹⁸F-FDG PET/CT in patients with HNSTS.

Methods

This study included 36 consecutive patients with HNSTS who underwent ¹⁸F-FDG PET/CT scanning prior to treatment at our institution. Tumor gross total volume (GTV) was measured from pretreatment contrast-enhanced CT scans, and maximum standardized uptake value (SUV_max), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured using pretreatment ¹⁸F-FDG PET/CT scans. Univariate and multivariate Cox proportional hazard regression analyses were used to identify associations between imaging parameters and disease-specific survival (DSS) or overall survival (OS).

Results

Univariate analyses showed that SUV_max, MTV, and TLG, but not GTV, were significantly associated with DSS and OS (all P?<?0.05). After controlling for clinicopathological factors, SUV_max, MTV, and TLG were significantly associated with DSS and OS (all P?<?0.05). Patients with a tumor SUV_max value of >7.0 experienced an approximately fivefold increase in mortality in terms of DSS and OS relative to those with a tumor SUV_max <7.0.

Conclusion

Quantitative metabolic measurements on pretreatment ¹⁸F-FDG PET/CT can yield values that are significantly predictive of survival after treatment for HNSTS.

     

The value of 18F-FDG PET/CT in the management of malignant peripheral nerve sheath tumors

Purpose

Our objective was to determine how positron emission tomography (PET)/CT had been used in the clinical treatment of malignant peripheral nerve sheath tumor (MPNST) patients at The University of Texas MD Anderson Cancer Center.

Methods

We reviewed a database of MPNST patients referred to MD Anderson Cancer Center during 1995–2011. We enrolled 47 patients who underwent PET/CT imaging. Disease stage was based on conventional imaging and PET/CT findings using National Comprehensive Cancer Network (NCCN) guidelines. Treatment strategies based on PET/CT and conventional imaging were determined by chart review. The maximum and mean standardized uptake values (SUV_max, SUV_mean), metabolic tumor volume (MTV), total lesion glycolysis (TLG), change in SUV_max, change in MTV, and change in TLG were calculated from the PET/CT studies before and after treatment. Response prediction was based on imaging studies performed before and after therapy and categorized as positive or negative for residual tumor. Clinical outcome was determined from chart review.

Results

PET/CT was performed for staging in 16 patients, for restaging in 29 patients, and for surveillance in 2 patients. Of the patients, 88 % were correctly staged with PET/CT, whereas 75 % were correctly staged with conventional imaging. The sensitivity to detect local recurrence and distant metastasis at restaging was 100 and 100 % for PET/CT compared to 86 and 83 % for conventional imaging, respectively. PET/CT findings resulted in treatment changes in 31 % (5/16) and 14 % (4/29) of patients at staging and restaging, respectively. Recurrence, MTV, and TLG were prognostic factors for survival, whereas SUV_max and SUV_mean were not predictive. For 21 patients who had imaging studies performed both before and after treatment, PET/CT was better at predicting outcome (overall survival, progression-free survival) than conventional imaging. A decreasing SUV_max ≥ 30 % and decrease in TLG and MTV were significant predictors for overall and progression-free survival.

Conclusion

PET/CT is valuable in MPNST management because of its high accuracy in staging and high sensitivity and accuracy in restaging as well as improvements in treatment planning. MTV from baseline staging studies is predictive of survival. Additionally, change in SUV_max, TLG, and MTV accurately predicted outcomes after treatment.     

Predictive value of primary tumor parameters using <Superscript>18</Superscript>F-FDG PET/CT for occult lymph node metastasis in breast cancer with clinically negative axillary lymph node

Objective

This study aimed to demonstrate the clinical significance of total lesion glycolysis (TLG) of primary breast cancer using ¹⁸F-FDG PET/CT to predict axillary lymph node (ALN) metastasis in invasive ductal breast cancer (IDC) with a clinically negative axillary lymph node (cN-ALN).

Methods

135 patients, newly diagnosed with IDC with _CN-ALN between July 2016 and October 2017, were retrospectively enrolled. We estimated primary tumor PET/CT parameters including the maximum standard uptake value (SUV_max), metabolic tumor volume (MTV), and TLG, as well as clinicopathologic findings. All patients received breast surgery followed by pathologic axillary lymph node examination.

Results

Of the 135 patients, 31 (23.0%) were diagnosed with pathologically proven metastatic ALN. In univariate analysis, SUV_max, MTV, and TLG of the primary breast tumor were correlated with metastatic ALN along with tumor size, lymphovascular invasion, CD34, and D2-40. On multivariate analysis, TLG (>?5.74, p?=?0.009) had independent significance for predicting ALN metastasis in IDC with cN-ALN.

Conclusion

We demonstrated that TLG of primary tumors can be useful in predicting pathologic ALN metastasis in IDC patients with cN-ALN.

     

Comparison of Bayesian penalized likelihood reconstruction versus OS-EM for characterization of small pulmonary nodules in oncologic PET/CT

Objective

To determine whether the recently introduced Bayesian penalized likelihood PET reconstruction (Q.Clear) increases the visual conspicuity and SUV_max of small pulmonary nodules near the PET resolution limit, relative to ordered subset expectation maximization (OS-EM).

Methods

In this institutional review board-approved and HIPAA-compliant study, 29 FDG PET/CT scans performed on a five-ring GE Discovery IQ were retrospectively selected for pulmonary nodules described in the radiologist’s report as “too small to characterize”, or small lung nodules in patients at high risk for lung cancer. Thirty-two pulmonary nodules were assessed, with mean CT diameter of 8 mm (range 2–18). PET images were reconstructed with OS-EM and Q.Clear with noise penalty strength β values of 150, 250, and 350. Lesion visual conspicuity was scored by three readers on a 3-point scale, and lesion SUV_max and background liver and blood pool SUV_mean and SUV_stdev were recorded. Comparison was made by linear mixed model with modified Bonferroni post hoc testing; significance cutoff was p < 0.05.

Results

Q.Clear improved lesion visual conspicuity compared to OS-EM at β = 150 (p < 0.01), but not 250 or 350. Lesion SUV_max was increased compared to OS-EM at β = 150 and 250 (p < 0.01), but not 350.

Conclusion

In a cohort of small pulmonary nodules with size near an 8 mm PET full-width half maximum, Q.Clear significantly increased lesion visual conspicuity and SUV_max compared to our standard non- time-of-flight OS-EM reconstruction, but only with low noise penalization. Q.Clear with β = 150 may be advantageous when evaluation of small pulmonary nodules is of primary concern.

     

Increased evidence for the prognostic value of FDG uptake on late-treatment PET in non-tumour-affected oesophagus in irradiated patients with oesophageal carcinoma

Purpose

¹⁸F-FDG uptake in irradiated non-tumour-affected oesophagus (NTO) on restaging PET is a potential surrogate for the measurement of radiation-induced inflammation. Radiation-induced inflammation itself has been shown to be of high prognostic relevance in patients undergoing preoperative radiochemotherapy (RCT) for locally advanced oesophageal cancer. We assessed the prognostic relevance of FDG uptake in the NTO in an independent cohort of patients treated with definitive RCT.

Methods

This retrospective evaluation included 72 patients with oesophageal squamous cell carcinoma treated with definitive RCT with curative intent. All patients underwent pretreatment and restaging FDG PET after receiving a radiation dose of 40–50 Gy. Standardized uptake values (SUV_max/SUV_mean), metabolic tumour volume (MTV) and relative changes from pretreatment to restaging PET (?SUV_max/?SUV_mean) were determined within the tumour and NTO. Univariate Cox regression with respect to overall survival (OS), local control (LC), distant metastases (DM) and treatment failure (TF) was performed. Independence of parameters was tested by multivariate Cox regression.

Results

?SUV_max NTO and MTV were prognostic factors for all investigated clinical endpoints (OS, LC, DM, TF). Inclusion of clinical and PET tumour parameters in multivariate analysis showed that ?SUV_max NTO was an independent prognostic factor. Furthermore, multivariate analysis of ?SUV_max NTO using previously published cut-off values from preoperatively treated patients revealed that ?SUV_max NTO was independent prognostic factor for OS (HR?=?1.88, p =?0.038), TF (HR?=?2.11, p =?0.048) and DM (HR?=?3.02, p =?0.047).

Conclusion

NTO-related tracer uptake during the course of treatment in patients with oesophageal carcinoma was shown to be of high prognostic relevance. Thus, metabolically activity of NTO measured in terms of ?SUV_max NTO is a potential candidate for future treatment individualization (i.e. organ preservation).

     

FDG PET-derived parameters as prognostic tool in progressive malignant pleural mesothelioma treated patients

Purpose

The value of FDG PET-derived parameters in predicting overall survival (OS), local relapse-free survival (LRFS) and distant relapse-free survival (DRFS) in treated patients with malignant pleural mesothelioma (MPM) was evaluated.

Methods

This retrospective evaluation included 55 MPM patients treated between March 2006 and February 2015 with FDG PET/CT-guided salvage helical tomotherapy (HTT) after previous surgery plus chemotherapy. Univariate Cox regression analysis was performed to assess the impact of the following FDG PET-derived parameters: biological target volume (BTV), mean and maximum standardized uptake values (SUV_mean/max), metabolic tumour volume (MTV) and total lesion glycolysis (TLG), measured using different uptake thresholds (40%, 50% and 60%). Logistic regression was then performed to identify the best FDG PET-derived parameters for selecting patients with poorer survival.

Results

The median OS was 9.1 months (range 0.0 – 69.6 months) after the end of HTT; 54/55 patients were dead at the last follow-up. BTV and TLG40, TLG50 and TLG60 were the most significant predictors of OS (p <?0.005). The median OS was 4.8 months in patients with MTV60 >5 cm³ and TLG40 >334.4, compared with 13.8 months and 16.1 months in patients with smaller values, respectively. The median LRFS and DRFS were 6.2 months (range 1.2 – 39.4 months) and 6.5 months (0.0 – 66.4 months), respectively. TLG40, TLG50 and TLG60 were significantly correlated with LRFS (p <?0.015). Median DRFS was 6.4 months in patients with MTV40 >39.6 cm³ and 6.2 months in patients with TLG40 >334.4, compared with 17 months and 18.8 months in patients with smaller values. BTV, TLG40 and MTV40 were also found to be good predictors in patients with poor OS/LRFS/DRFS (median survival times less than the median values).

Conclusion

FDG PET-derived parameters effectively discriminated patients with a poor prognosis and may be helpful in the selection of MPM patients for salvage HTT.

     

Prognostic value of primary tumor SUV<Subscript>max</Subscript> on F-18 FDG PET/CT compared with semi-quantitative tumor uptake on Tc-99m sestamibi breast-specific gamma imaging in invasive ductal breast cancer

Objective

This study aimed to evaluate the prognostic value of F-18 FDG PET/CT in comparison with Tc-99m sestamibi breast-specific gamma imaging (BSGI) and previously established clinical prognostic parameters of invasive ductal breast carcinoma (IDC).

Methods

We retrospectively included 157 female IDC patients (mean age 49.2 years, range 29.9–78.9) who underwent PET/CT and BSGI. The maximum standardized uptake value (SUV_max) and tumor to normal background ratios (TNRs) of their primary tumors were measured on PET/CT and BSGI, respectively. Univariate and multivariate survival analyses were performed to evaluate the prognostic value of the measured parameters and other clinical prognostic factors: age, menopausal status, breast density, pathologic tumor size (pTS), axillary nodal status (ANS), nuclear grade, histologic grade, hormone receptor status of estrogen (ER) and progesterone receptors (PR) and HER-2 expression.

Results

Among 157 patients, recurrences occurred in 22 patients (14.0 %). In univariate analyses, pTS (p < 0.0001), ANS (p < 0.0001), nuclear grade (p = 0.0046), histologic grade (p = 0.0001), ER status (p < 0.0001), PR status (p = 0.0037), HER-2 status (p = 0.0007), primary tumor SUV_max (p < 0.0001) and TNR (p = 0.0001) were significant predictors of recurrence. Among them, pTS (p = 0.0172), ANS (p = 0.0416), ER status (p = 0.0375) and primary tumor SUV_max (p = 0.0239) were independent prognostic factors in multivariate regression analysis.

Conclusions

High primary tumor SUV_max of PET/CT and high TNR of BSGI were poor prognostic factors in IDC patients; in addition, primary tumor SUV_max was an independent prognostic factor along with pTS, ANS and ER status.

     

Predictive value of <Superscript>18</Superscript>F-FDG PET/CT in adults with T-cell lymphoblastic lymphoma: post hoc analysis of results from the GRAALL-LYSA LLO3 trial

Purpose

We examined whether FDG PET can be used to predict outcome in patients with lymphoblastic lymphoma (LL).

Methods

This was a retrospective post hoc analysis of data from the GRAAL-LYSA LL03 trial, in which the treatment of LL using an adapted paediatric-like acute lymphoblastic leukaemia protocol was evaluated. PET data acquired at baseline and after induction were analysed. Maximum standardized uptake values (SUV_max), total metabolic tumour volume and total lesion glycolysis were measured at baseline. The relative changes in SUV_max from baseline (ΔSUV_max) and the Deauville score were determined after induction.

Results

The population analysed comprised 36 patients with T-type LL. SUV_max using a cut-off value of ≤8.76 vs. >8.76 was predictive of 3-year event-free survival (31.6% vs. 80.4%; p = 0.013) and overall survival (35.0% vs. 83.7%; p = 0.028). ΔSUV_max using a cut-off value of ≤80% vs. >80% tended also to be predictive of 3-year event-free survival (40.0% vs. 76.0%; p = 0.054) and overall survival (49.2% vs. 85.6%; p = 0.085). Total metabolic tumour volume, baseline total lesion glycolysis and response according to the Deauville score were not predictive of outcome.

Conclusions

A low initial SUV_max was predictive of worse outcomes in our series of patients with T-type LL. Although relatively few patients were included, the study also suggested that ΔSUV_max may be useful for predicting therapeutic efficacy.