Increased FDG uptake on late-treatment PET in non-tumour-affected oesophagus is prognostic for pathological complete response and disease recurrence in patients undergoing neoadjuvant radiochemotherapy

Purpose

Early side effects including oesophagitis are potential prognostic factors in patients undergoing radiochemotherapy (RCT) for locally advanced oesophageal cancer (LAEC). We assessed the prognostic value of ¹⁸F-fluorodeoxyglucose (FDG) uptake within irradiated non-tumour-affected oesophagus (NTO) during restaging positron emission tomography (PET) as a surrogate for inflammation/oesophagitis.

Methods

This retrospective evaluation included 64 patients with LAEC who had completed neoadjuvant RCT and had successful oncological resection. All patients underwent FDG PET/CT before and after RCT. In the restaging PET scan maximum and mean standardized uptake values (SUV_max, SUV_mean) were determined in the tumour and NTO. Univariate Cox regression with respect to overall survival, local control, distant metastases and treatment failure was performed. Independence of clinically relevant parameters was tested in a multivariate Cox regression analysis.

Results

Increased FDG uptake, measured in terms of SUV_mean in NTO during restaging was significantly associated with complete pathological remission (p = 0.002) and did not show a high correlation with FDG response of the tumour (rho < 0.3). In the univariate analysis, increased SUV_max and SUV_mean in NTO was associated with improved overall survival (p = 0.011, p = 0.004), better local control (p = 0.051, p = 0.044), a lower rate of treatment failure (p < 0.001 for both) and development of distant metastases (p = 0.012, p = 0.001). In the multivariate analysis, SUV_max and SUV_mean in NTO remained a significant prognostic factor for treatment failure (p < 0.001, p = 0.004) and distant metastases (p = 0.040, p = 0.011).

Conclusions

FDG uptake in irradiated normal tissues measured on restaging PET has significant prognostic value in patients undergoing neoadjuvant RCT for LAEC. This effect may potentially be of use in treatment personalization.

     

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.

     

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.

     

Prognostic Value of Tumor-to-Blood Standardized Uptake Ratio in Patients with Resectable Non-Small-Cell Lung Cancer

Objectives

Previously published studies showed that the standard tumor-to-blood standardized uptake value (SUV) ratio (SUR) was a more accurate prognostic method than tumor maximum standardized uptake value (SUV_max). This study evaluated and compared prognostic value of positron emission tomography (PET) parameters and normalized value of PET parameters by blood pool SUV in non-small-cell lung cancer (NSCLC) patients who received curative surgery.

Methods

Seventy-seven patients who underwent curative resection for NSCLC between January 2010 to December 2013 were enrolled in this study. ¹⁸Fluorine-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) was performed before surgery. The mean standardized uptake value (SUV_mean), SUV_max, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of each lesion was measured, on the workstation. SUR_mean, SUR_max, and TLGSUR were calculated by dividing each of them by descending aorta SUV_mean. Cox proportional hazards regression was used to analyze the effect of age, sex, pathological parameters, and PET parameters on recurrence and death.

Results

In Cox regression analysis, N stage predicted for both recurrence (p?<?0.0001) and death (p?<?0.0001). SUR_max predicted recurrence (p?=?0.0014), not death. Area under the receiver operating characteristic curve of SUR_max was 0.759 with cutoff value 4.004. However, SUV_max, SUV_mean, MTV, TLG, SUR_mean, and TLGSUR predicted neither recurrence nor death.

Conclusions

Among PET parameters, SUR_max was the independent predictor of recurrence in NSCLC patients who received curative surgery. N stage was the independent prognostic factor for both recurrence and death. Both parameters could be used to stratify the risk of NSCLC patients.

     

The role of FDG PET/CT in therapy control of aortic graft infection

Purpose

¹⁸F-FDG PET/CT (PET/CT) is a useful tool for the diagnosis of aortic graft infection (AGI), but has rarely been used to influence therapeutic decisions during follow-up. We aimed to study the role of PET/CT in the long-term monitoring of patients.

Methods

Participants of the prospective Vascular Graft Infection Cohort Study (VASGRA) were included if they had microbiologically proven AGI. We quantified the metabolic activity in PET/CT by using maximum standardized uptake value (SUV_max) and further classified it as being focal or diffuse. Multivariable linear regression models were fit using generalized estimating equations to investigate factors associated with SUV_max over time.

Results

Sixty-eight participants with AGI contributed to 266 PET/CTs including 36 examinations performed after stop of antimicrobial therapy. Higher C-reactive protein (CRP) (adjusted coefficient per log₁₀ mg/L 0.05 [95% C.I. 0.02–0.08]) was associated with higher SUV_max. CRP, metabolic and clinical findings informed the decision to either start (medians of SUV_max 7.1 and CRP 31.5 mg/L; 100% focal uptake), escalate (SUV_max 9.5; CRP 31.5; 100% focal uptake), continue (SUV_max 6.0; CRP 9.95 mg/L; 90% focal uptake), or stop (SUV_max 4.3; CRP 3.5 mg/L; 61% focal uptake) antibiotic treatment. Of note, decisions to escalate or continue antibiotic treatment were taken despite normal CRP values in 12.5 and 35.7% of PET/CTs, respectively.

Conclusions

Consecutive PET/CTs could influence the clinical decision-making in patients with AGI in the near future. More studies on the use of PET/CT in case of aortic graft infection may offer the potential for individualized treatment approaches.

CLINICALTRIALS.GOV IDENTIFIER

NCT01821664.

     

Refining prognosis in patients with hepatocellular carcinoma through incorporation of metabolic imaging biomarkers

Purpose

¹⁸F-fluorodeoxyglucose positron emission tomopraphy/computed tomography (FDGPET/CT) has been proven to be useful for imaging many types of cancer; however, its role is not well defined in hepatocellular carcinoma (HCC). We assessed the prognostic value of metabolic imaging biomarkers as established by baseline pretreatment FDG PET/CT in patients with HCC.

Methods

We retrospectively analyzed the records of patients with HCC who underwent FDG PET/CT before initial treatment from May 2013 through May 2014. Four PET/CT parameters were measured: maximum standardized uptake value (SUV_max), total lesion glycolysis (TLG), metabolic tumor volume (MTV), and tumor-to-normal-liver SUV ratio (TNR). Optimal cut-off values for the PET/CT parameters to stratify patients in terms of overall survival (OS) were determined. Multivariate analysis was performed to determine whether the PET/CT parameters could add to the prognostic value of the Cancer of the Liver Italian Program (CLIP) scoring system and the Barcelona-Clinic Liver Cancer (BCLC) staging system.

Results

The analysis included 56 patients. Univariate analysis of the association between OS and continuous variables, including the PET/CT parameters SUV_max, TLG, tumor size, total bilirubin level, and alkaline phosphatase level were significant predictors of OS. SUV_max ≥ 11.7, TLG ≥ 1,341, MTV ≥ 230 mL, and TNR ≥ 4.8 were identified as cut-off values. Multivariate analysis revealed that SUV_max ≥ 11.7 and TNR ≥ 4.8 were independent factors predicting a poor prognosis in both the CLIP scoring system and the BCLC staging system, as was TLG in the BCLC staging system.

Conclusion

Pretreatment FDG PET/CT in patients with HCC can add to the prognostic value of standard clinical measures. Incorporation of imaging biomarkers derived from FDG PET/CT into HCC staging systems should be considered.

     

Role of <Superscript>18</Superscript>F-FDG PET/CT in patients affected by Langerhans cell histiocytosis

Purpose

Langerhans cell histiocytosis (LCH) is a rare hematological disorder for which the utility of¹⁸F-FDG PET/CT is unclear. Our aim was to explore the metabolic features of LCH and the possible role of¹⁸F-FDG PET/CT in LCH evaluation.

Materials and methods

We found 17 patients with histologically proven LCH who underwent 17¹⁸F-FDG PET/CT scans for staging and 42 scans for restaging/follow-up purposes. PET/CT results were compared with those obtained from other conventional imaging modalities (bone scintigraphy, plain radiogram, computed tomography, magnetic resonance).

Results

¹⁸F-FDG PET/CT was positive in 15/17 patients, and it detected 36/37 lesions; all bone and extraskeletal lesions, except for a cecal lesion, were¹⁸F-FDG-avid. Only 1/4 of the patients with lung LCH had hypermetabolic lesions. The average SUV_max of the FDG-avid lesions was 7.3 ± 6.7, the average lesion-to-liver SUV_max ratio was 3.4 ± 2.5, and the average lesion-to-blood pool SUV_max ratio was 4 ± 3.2. In comparison to other imaging methods,¹⁸F-FDG PET/CT detected additional lesions or was able to evaluate treatment response earlier in 33/74 cases; it was confirmatory in 38/74 and detected fewer lesions in 3/74 (all three with lung LCH).

Conclusions

¹⁸F-FDG PET/CT seems to be useful for evaluating LCH when compared to conventional imaging, except in pulmonary cases. It can be used both for staging and restaging purposes.

     

Inverse Prognostic Relationships of <Superscript>18</Superscript>F-FDG PET/CT Metabolic Parameters in Patients with Distal Bile Duct Cancer Undergoing Curative Surgery

Purpose

As there were few previous studies with a small number of subjects, the purpose of this was to evaluate the prognostic significance of ¹⁸F-FDG PET/CT in patients with distal bile duct cancer undergoing curative surgery.

Methods

The study included 40 patients (M/F?=?24:16; age 68.0?±?8.0 years) who underwent preoperative ¹⁸F-FDG PET/CT followed by curative surgical resection. The participant’s age, sex, Eastern Cooperative Oncology Group performance-status score, baseline serum CA 19-9 level, stage, pathologic T and N stages, tumor size, tumor grade, tumor growth pattern, R0 resection, and adjuvant therapy were included as clinicopathological variables for predicting overall survival. The PET variables were maximum standardized uptake value (SUV_max), average SUV (SUV_avg), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the tumor. The Kaplan-Meyer method and Cox proportional hazards model were used for the survival analysis.

Results

A total of 15 of 40 patients (37.5%) died during the follow-up period. In univariate analysis, low SUV_max (≤?2.7, p?=?0.0005) and low SUV_avg (≤?2.6, p?=?0.0034) were significant predictors of poor overall survival. In multivariate analyses, only low SUV_max (HR?=?6.7016, 95% CI 1.9961–22.4993, p?=?0.0047) was an independent prognostic factor associated with poor overall survival.

Conclusion

The SUV_max of the primary tumor measured by ¹⁸F-FDG PET/CT was an independent significant prognostic factor for overall survival in patients with distal bile duct cancer. However, different results from a previous study warrant further large sample-sized study.

     

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.

     

SUV<Subscript>max</Subscript> on FDG-PET is a predictor of prognosis in patients with maxillary sinus cancer

Purpose

Our aim was to determine whether the maximum standardized uptake value (SUV_max) of the primary lesion demonstrated by [¹⁸F]-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) is associated with the prognosis of maxillary sinus cancer.

Materials and methods

The relationships of clinicopathological factors including age, T stage, N stage, histologic type, treatment strategy, and primary tumor SUV_max with progression-free (PFS) and overall (OS) survival were evaluated using the log-rank test and Cox method in 31 patients with maxillary sinus cancer before combined superselective intra-arterial chemotherapy using high-dose cisplatin with concurrent radiotherapy, or radiotherapy alone.

Results

The median duration of follow-up was 55.4 (range 9.7–72.6) months. PFS and OS of patients exhibiting a high SUV_max (≥16 and ≥17, respectively) for the primary tumor were significantly lower than those of patients for whom the primary tumor SUV_max was low (p = 0.0010 and p = 0.033, respectively). Multivariate analyses showed that T stage (p = 0.0049) and primary tumor SUV_max (p = 0.026) were independently prognostic of poorer PFS and that only primary tumor SUV_max (p = 0.049) was independently prognostic of poorer OS.

Conclusion

SUV_max of the primary tumor determined by FDG-PET/CT before treatment could be a good surrogate marker for prognostication of maxillary sinus cancer.

     

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.

     

SUV navigator enables rapid [<Superscript>18</Superscript>F]-FDG PET/CT image interpretation compared with 2D ROI and 3D VOI evaluations

Purpose

Positron emission tomography (PET) and the maximum standardized uptake value (SUV_max) is a useful technique for assessing malignant tumors. Measurements of SUV_max in multiple lesions per patient frequently require many time-consuming procedures. To address this issue, we designed a novel interface named SUV Navigator (SUVnavi), and the purpose of this study was to investigate its utility.

Materials and methods

We measured SUV_max in 661 lesions from 100 patients with malignant tumors. Diagnoses and SUV_max measurements were made with SUVnavi, 2D, and 3D measurements. SUV measurement accuracy in each method were also evaluated.

Results

The average reduction in time with SUVnavi versus 2D was 53.8% and 3D was 37.5%; time required with SUVnavi was significantly shorter than with 2D and 3D (P < 0.001 and P < 0.001, respectively). The time reduction and lesion number had a positive correlation (P < 0.001 and P < 0.001, respectively). SUV_max agreed with precise SUV_max in all lesions measured with SUVnavi and 3D but in only 466 of 661 lesions (70.5%) measured with 2D.

Conclusion

SUVnavi may be useful for rapid [¹⁸F]-fluorodeoxyglucose positron emission tomography/computed tomography ([¹⁸F]-FDG PET/CT) image interpretation without reducing the accuracy of SUV_max measurement.

     

Differentiating the grades of thymic epithelial tumor malignancy using textural features of intratumoral heterogeneity via <Superscript>18</Superscript>F-FDG PET/CT

Objective

We aimed to explore the ability of textural heterogeneity indices determined by ¹⁸F-FDG PET/CT for grading the malignancy of thymic epithelial tumors (TETs).

Methods

We retrospectively enrolled 47 patients with pathologically proven TETs who underwent pre-treatment ¹⁸F-FDG PET/CT. TETs were classified by pathological results into three subgroups with increasing grades of malignancy: low-risk thymoma (LRT; WHO classification A, AB and B1), high-risk thymoma (B2 and B3), and thymic carcinoma (TC). Using ¹⁸F-FDG PET/CT, we obtained conventional imaging indices including SUV_max and 20 intratumoral heterogeneity indices: i.e., four local-scale indices derived from the neighborhood gray-tone difference matrix (NGTDM), eight regional-scale indices from the gray-level run-length matrix (GLRLM), and eight regional-scale indices from the gray-level size zone matrix (GLSZM). Area under the receiver operating characteristic curve (AUC) was used to demonstrate the abilities of the imaging indices for differentiating subgroups. Multivariable logistic regression analysis was performed to show the independent significance of the textural indices. Combined criteria using optimal cutoff values of the SUV_max and a best-performing heterogeneity index were applied to investigate whether they improved differentiation between the subgroups.

Results

Most of the GLRLM and GLSZM indices and the SUV_max showed good or fair discrimination (AUC >0.7) with best performance for some of the GLRLM indices and the SUV_max, whereas the NGTDM indices showed relatively inferior performance. The discriminative ability of some of the GLSZM indices was independent from that of SUV_max in multivariate analysis. Combined use of the SUV_max and a GLSZM index improved positive predictive values for LRT and TC.

Conclusions

Texture analysis of ¹⁸F-FDG PET/CT scans has the potential to differentiate between TET tumor grades; regional-scale indices from GLRLM and GLSZM perform better than local-scale indices from the NGTDM. The SUV_max and heterogeneity indices may have complementary value in differentiating TET subgroups.

     

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.

     

Predictive value of <Superscript>18</Superscript>F-FDG PET/CT in restaging patients affected by ovarian carcinoma: a multicentre study

Purpose

Ovarian cancer is the eighth most common malignancy among women and has a high mortality rate. Prognostic factors able to drive an effective therapy are essential. ¹⁸F-Fluoro-2-deoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) has been investigated in patients with epithelial ovarian cancer and showed promise in diagnosing, staging, detecting recurrent lesions and monitoring treatment response. Conversely, its prognostic role remains unclear. We aimed at assessing the prognostic value of ¹⁸F-FDG PET/CT performed in the restaging process in a multicentre study.

Methods

We evaluated 168 patients affected by ovarian carcinoma, who underwent a restaging ¹⁸F-FDG PET/CT. The presence of local recurrences, lymph node involvement and distant metastasis was recorded as well as lesion dimensions, maximum and mean standardized uptake values (SUV_max and SUV_mean, respectively). Progression-free survival (PFS) and overall survival (OS) at 3 and 4 years were computed by using Kaplan-Meier curves. Increased odds ratio was assessed using Cox regression analysis testing all lesion parameters measured by PET/CT.

Results

PFS was significantly longer in patients with a negative than a positive restaging PET/CT study (3- and 4-year PFS 64 and 53 % vs 23 and 12 %, respectively; p?<?0.001). Similarly, a negative study was associated with a significantly higher OS rate after 4 years of follow-up (67 vs 25 % in negative and positive groups, respectively; p?<?0.001). Lymph node or distant involvement were also independently associated with an increased risk of disease progression [hazard ratio (HR) 1.6 and 2.2, respectively; p?=?0.003]. Moreover, PET/CT showed an incremental prognostic value compared to the International Federation of Gynecology and Obstetrics (FIGO) staging system. In the analysis of patient subsets, individuals with the same FIGO stage I–II but with negative PET had a significantly better 4-year OS than patients with low FIGO stage but positive PET. This implies that patients with the same FIGO stage can be further prognostically stratified using PET (p?=?0.01). At receiver-operating characteristic (ROC) analysis, no thresholds for semiquantitative parameters were predictive of a worse outcome.

Conclusion

¹⁸F-FDG PET/CT has an important prognostic value in assessing the risk of disease progression and mortality rate. An efficacious therapy planning might therefore effectively rely on ¹⁸F-FDG PET/CT findings. Semiquantitative data were not proven to be an effective tool to predict disease progression.

     

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.

     

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.

     

Prospective evaluation of [<Superscript>11</Superscript>C]Choline PET/CT in therapy response assessment of standardized docetaxel first-line chemotherapy in patients with advanced castration refractory prostate cancer

Purpose

The aim of this study was to prospectively evaluate the value of [¹¹C] Choline PET/CT in monitoring early and late response to a standardized first-line docetaxel chemotherapy in castration refractory prostate cancer (mCRPC) patients.

Methods

Thirty-two patients were referred for [¹¹C] Choline PET/CT before the start of docetaxel chemotherapy, after one and ten chemotherapy cycles (or - in case of discontinuation - after the last administered cycle) for therapy response assessment. [¹¹C] Choline uptake (SUV_max, SUV_mean), CT derived Houndsfield units (HU_max, HU_mean), and volume of bone, lung, and nodal metastases and local recurrence were measured semi-automatically at these timepoints. Change in SUV_max, SUV_mean, HU_max, HU_mean, and volume was assessed between PET 2 and 1 (early response assessment, ERA) and PET 3 and 1 (late response assessment, LRA) on a patient and lesion basis. Results of PET/CT were compared to clinically used RECIST 1.1 and clinical criteria based therapy response assessment including PSA for defining progressive disease (PD) and non-progressive disease (nPD), respectively. Relationships between changes of SUV_max and SUV_mean (early and late) and changes of PSA_early and PSA_late were evaluated. Prognostic value of initial SUV_max and SUV_mean was assessed. Statistical analyses were performed using SPSS.

Results

In the patient-based ERA and LRA there were no statistically significant differences in change of choline uptake, HU, and volume between PD and nPD applying RECIST or clinical response criteria. In the lesion-based ERA, decrease in choline uptake of bone metastases was even higher in PD (applying RECIST criteria), whereas in LRA the decrease was higher in nPD (applying clinical criteria). There were only significant correlations between change in choline uptake and PSA in ERA in PD, in LRA no significant correlations were discovered. Initial SUV_max and SUV_mean were statistically significantly higher in nPD (applying clinical criteria).

Conclusion

There is no significant correlation between change in choline uptake in [¹¹C] Choline PET/CT and clinically routinely used objective response assessment during the early and late course of docetaxel chemotherapy. Therefore, [¹¹C] Choline PET/CT seems to be of limited use in therapy response assessment in standardized first-line chemotherapy in mCRPC patients.

     

Prognostic implication of the metastatic lesion-to-ovarian cancer standardised uptake value ratio in advanced serous epithelial ovarian cancer

Objectives

To evaluate the prognostic value of metabolic activity of metastatic lesions measured by ¹⁸F-flurodeoxyglucose (¹⁸F-FDG) uptake on preoperative positron emission tomography/computed tomography (PET/CT) in patients with advanced serous epithelial ovarian cancer (EOC).

Methods

Clinico-pathological variables and PET/CT parameters such as the maximum standardised uptake value of the ovarian cancer (SUV_ovary), metastatic lesions (SUV_meta), and the metastatic lesion-to-ovarian cancer standardised uptake value ratio (SUV_meta/SUV_ovary) were assessed in International Federation of Gynaecology and Obstetrics (FIGO) stage III, IV patients.

Results

Clinico-pathological data were retrospectively reviewed for 94 eligible patients. The median progression-free survival (PFS) was 18.5 months (range, 6-90 months), and 57 (60.6%) patients experienced recurrence. Older age [P = 0.017, hazard ratio (HR) 1.036, 95% CI 1.006–1.066], residual disease after surgery (P = 0.024, HR 1.907, 95% CI 1.087-3.346), and high SUV_meta/SUV_ovary (P = 0.019, HR 2.321, 95% CI 1.148-4.692) were independent risk factors of recurrence. Patients with high SUV_meta/SUV_ovary showed a significantly worse PFS than those with low SUV_meta/SUV_ovary (P = 0.007, log-rank test).

Conclusions

Preoperative SUV_meta/SUV_ovary was significantly associated with recurrence and has an incremental prognostic value for PFS in patients with advanced serous EOC.

Key Points

? The prognostic value of the metabolic activity of metastatic lesions was investigated. ? SUV_meta/SUV_ovary was significantly associated with recurrence of serous EOC. ? Preoperative SUV_meta/SUV_ovary can be a predicator of serous EOC recurrence.

     

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.