18F-fluorodeoxyglucose positron emission tomography immediately after chemoradiotherapy predicts prognosis in patients with locoregional postoperative recurrent esophageal cancer

18F-Fluorodeoxyglucose Positron Emission Tomography Parameters can Predict Long-Term Outcome Following Trimodality Treatment for Oesophageal Cancer

AIMS

¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸FDG-PET/CT) is routinely used for the pre-treatment staging of oesophageal or gastro-oesophageal junction cancers (EGEJC). The aim of this study was to identify objective ¹⁸FDG-PET/CT-derived parameters that can aid in predicting the patterns of recurrence and prognostication in patients with EGEJC.

PATIENTS AND METHODS

EGEJC patients referred for consideration of preoperative chemoradiation therapy were identified and clinicopathological data were collected. ¹⁸FDG-PET/CT imaging data were reviewed and correlated with treatment outcomes. Maximum standardised uptake value (SUV_max), metabolic tumour volume (MTV) and total lesion glycolysis were assessed and association with recurrence-free survival (RFS), locoregional recurrence-free survival (LR-RFS), oesophageal cancer-specific survival (ECSS) and overall survival were evaluated using receiver operating characteristic curves, as well as Cox regression and Kaplan-Meier models.

RESULTS

In total, 191 EGEJC patients completed trimodality treatment and 164 with ¹⁸FDG-PET/CT data were included in this analysis. At the time of analysis, 15 (9.1%), 70 (42.7%) and two (1.2%) patients were noted to have locoregional, distant and both locoregional and distant metastases, respectively. The median RFS was 30 months (9.6-50.4) and the 5-year RFS was 31.1%. The 5-year overall survival and ECSS were both noted to be 34.8%. Pre-treatment MTV₂₅ > 28.5 cm³ (P = 0.029), MTV₄₀ > 12.4 cm³ (P = 0.018) and MTV₅₀ > 10.2 cm³ (P = 0.005) predicted for worse LR-RFS, ECSS and overall survival for MTV definition of voxels ≥25%, 40% and 50% of SUV_max.

CONCLUSION

¹⁸FDG-PET/CT parameters MTV and total lesion glycolysis are useful prognostic tools to predict for LR-RFS, ECSS and overall survival in EGEJC. MTV had the highest accuracy in predicting clinical outcomes. The volume cut-off points we identified for different MTV thresholds predicted outcomes with significant accuracy and may potentially be used for decision making in clinical practice.

Positron Emission Tomography/Computed Tomography in Esophageal Carcinoma: Applications and Limitations

Squamous cell carcinoma and adenocarcinoma represent approximately 98% of esophageal malignant tumors. During the last 30 years, the incidence of adenocarcinoma has increased in Western countries (including the USA) where adenocarcinoma currently represents more than 60% of esophageal malignancies, although, worldwide, squamous cell carcinoma continues to be the predominant histologic type. Integrated positron emission tomography or computed tomography with 2-[fluorine18] fluro-2-deoxy-d-glucose is used in many institutions routinely as a tool in the initial staging and then repeated after therapy for the assessment of response to neoadjuvant therapy and detection of recurrent disease in patients with esophageal carcinoma. As with any other imaging modality, 2-[fluorine18] fluro-2-deoxy-d-glucose-positron emission tomography or computed tomography has strengths and limitations that should be understood in order to maximize its utility.

Molecular biological correlation of fluorine-18 fluorodeoxyglucose uptake in esophageal squamous cell carcinoma

OBJECTIVE

The aim of this study was to assess the relationship between fluorine-18 fluorodeoxyglucose (F-FDG) uptake and molecular biological markers in esophageal squamous cell carcinoma (ESCC) patients.

METHODS

Our patient population included 51 patients who underwent F-FDG PET/computed tomography before surgery. Excised tumor tissue was analyzed immunohistochemically using monoclonal antibodies for glucose transporter-1 (GLUT-1), GLUT-3, CD34 [microvessel density (MVD) marker], CD68 (macrophage marker), and CD163 (tumor-associated macrophage marker). The relationships among pathological factors [pathological T stage (p-T stage), pathological lymph node status (p-N status), pathological stage (p-stage), and pathological tumor length], the maximum standardized uptake value (SUVmax), and these molecular biological markers were evaluated using Spearman's rank test and the Kruskal-Wallis test.

RESULTS

GLUT-1, GLUT-3, CD34, and CD163 significantly correlated with SUVmax (r=0.547, P<0.001 for GLUT-1; r=0.569, P<0.001 for GLUT-3; r=0.463, P=0.001 for CD34, r=0.455, P=0.001 for CD163), whereas SUVmax, GLUT-1, GLUT-3, CD34, and CD163 significantly correlated with p-T stage (r=0.552, P<0.001 for SUVmax, r=0.307, P=0.03 for GLUT-1, r=0.349, P=0.013 for GLUT-3, r=0.313, P=0.027 for CD34, r=0.526 for CD163, P<0.001), but not with p-N status. CD68 levels showed no significant correlation with SUVmax, p-T stage, p-stage, or p-N status.

CONCLUSION

SUVmax, GLUT-1 expression, GLUT-3 expression, MVD, and TAMs show a relationship with the tumor stage and extent of ESCC. GLUT-1, GLUT-3, MVD, and TAMs are associated with the mechanism of F-FDG uptake in ESCC.

[18F]fluoro-2-deoxyglucose-positron emission tomography for the assessment of histopathological response after preoperative chemoradiotherapy in advanced oral squamous cell carcinoma

BACKGROUND

[(18)F]fluoro-2-deoxyglucose-positron emission tomography (FDG-PET) is widely used to evaluate tumor metabolic activity. The aim of this study was to evaluate the usefulness of FDG-PET in assessing the histopathological response to preoperative concurrent chemoradiotherapy (CRT) in patients with oral squamous cell carcinoma (OSCC).

METHODS

Forty-five patients with resectable advanced OSCC who had received preoperative CRT followed by tumor ablative surgery between January 2004 and December 2011 were included in the study. All patients underwent FDG-PET before and after preoperative CRT. The maximum standardized uptake value (SUVmax) before (pre-SUV) and after preoperative CRT (post-SUV) and the SUVmax reduction rate (ΔSUV %) were used to evaluate the response to preoperative CRT. Correlations among SUVmax, histopathological response, and expression of cancer antigen Ki-67 and hypoxia-inducible factor-1α (HIF-1α) were analyzed.

RESULTS

Preoperative CRT significantly reduced intratumoral FDG uptake (P < 0.001). The pre-SUV and post-SUV were significantly lower in patients with a pathological complete response (pCR) than in those with a non-pCR (pre-SUV P = 0.037; post-SUV P = 0.001). ΔSUV % was higher in patients with pCR than in those with non-pCR (P = 0.029). The pre-SUV was significantly correlated with Ki-67 and HIF-1α expression in pretreatment biopsy specimens (Ki-67 P = 0.046, R = 0.292; HIF-1α P = 0.007, R = 0.385). The expression of both Ki-67 and HIF-1α was significantly lower in patients with pCR than in those with non-pCR (Ki-67 P < 0.001; HIF-1α P < 0.001).

CONCLUSIONS

Low pre-SUV and post-SUV and high ΔSUV % may predict a good histopathological response to preoperative CRT. Ki-67 and HIF-1α expression in pretreatment biopsy specimens were predictors of histopathological response to preoperative CRT.

The relationship between GLUT-1 and vascular endothelial growth factor expression and 18F-FDG uptake in esophageal squamous cell cancer patients

PURPOSE

To examine the relationship between glucose transporter-1 (GLUT-1) and vascular endothelial growth factor (VEGF) expression and (18)F-FDG uptake in esophageal squamous cell cancer patients.

MATERIALS AND METHODS

Fifty-seven patients (52 male and 5 female) were included in this study. (18)F-FDG PET/CT was performed prior to the surgery. Immunohistochemistry was performed using postoperative histopathological specimens. The estimation of immunohistochemistry was conducted using scoring analysis. We investigated the correlations between maximum standardized uptake value (SUV(max)) and GLUT-1/VEGF expressions/pathologic tumor length (p-tumor length), and the relationships between pathologic T (p-T) stage and GLUT-1/VEGF expressions/SUV(max) and between lymph node metastasis (p-N) stage and GLUT-1/VEGF expressions/SUV(max).

RESULTS

SUV(max) significantly correlated with GLUT-1 expressions and p-tumor length (GLUT-1: r = 0.475, P < 0.001; p-tumor length: r = 0.475, P < 0.001). SUV(max) of the primary tumor had a significant relationship with p-T stage, p-N stage, and VEGF expression (p-T stage: P < 0.001; p-N stage: P = 0.037; VEGF expression: P = 0.009). There was a statistically significant difference between GLUT-1 expression and p-T stage/VEGF expression, but not p-N stage (p-T stage: P = 0.012; VEGF expression: P = 0.01; p-N stage: P = 0.572). VEGF expression had a significant relationship with p-T stage, but not with p-N stage (p-T stage: P = 0.032; p-N stage: P = 0.763).

CONCLUSION

(18)F-FDG uptake can be determined by GLUT-1 and VEGF. SUV(max) would have a connection with the tumor progression and lymph node metastasis.

Positron emission tomography (PET) evaluation after initial chemotherapy and radiation therapy predicts local control in rhabdomyosarcoma

PURPOSE

18-fluorodeoxyglucose positron emission tomography (PET) is already an integral part of staging in rhabdomyosarcoma. We investigated whether primary-site treatment response characterized by serial PET imaging at specific time points can be correlated with local control.

PATIENTS AND METHODS

We retrospectively examined 94 patients with rhabdomyosarcoma who received initial chemotherapy 15 weeks (median) before radiotherapy and underwent baseline, preradiation, and postradiation PET. Baseline PET standardized uptake values (SUVmax) and the presence or absence of abnormal uptake (termed PET-positive or PET-negative) both before and after radiation were examined for the primary site. Local relapse-free survival (LRFS) was calculated according to baseline SUVmax, PET-positive status, and PET-negative status by the Kaplan-Meier method, and comparisons were tested with the log-rank test.

RESULTS

The median patient age was 11 years. With 3-year median follow-up, LRFS was improved among postradiation PET-negative vs PET-positive patients: 94% vs 75%, P=.02. By contrast, on baseline PET, LRFS was not significantly different for primary-site SUVmax≤7 vs >7 (median), although the findings suggested a trend toward improved LRFS: 96% for SUVmax≤7 vs 79% for SUVmax>7, P=.08. Preradiation PET also suggested a statistically insignificant trend toward improved LRFS for PET-negative (97%) vs PET-positive (81%) patients (P=.06).

CONCLUSION

Negative postradiation PET predicted improved LRFS. Notably, 77% of patients with persistent postradiation uptake did not experience local failure, suggesting that these patients could be closely followed up rather than immediately referred for intervention. Negative baseline and preradiation PET findings suggested statistically insignificant trends toward improved LRFS. Additional study may further understanding of relationships between PET findings at these time points and outcome in rhabdomyosarcoma.

18F-FDG PET/CT predicts survival after radioembolization of hepatic metastases from breast cancer

(90)Y radioembolization (selective internal radiation therapy [SIRT]) has emerged as a valuable therapeutic option in unresectable, chemotherapy-refractory hepatic metastases from breast cancer. The objective of the present study was to evaluate (18)F-FDG PET/CT for predicting survival in these patients.

METHODS

Fifty-eight consecutive patients with hepatic metastases from breast cancer were treated with SIRT. Before therapy, all patients underwent MRI of the liver. (18)F-FDG PET/CT was performed at baseline and 3 mo after SIRT to calculate percentage changes in maximum (18)F-FDG standardized uptake value (SUV(max)) relative to baseline. A decrease of more than 30% in the follow-up scan, compared with the baseline examination, indicated therapy response. Treatment response at 3 mo was also assessed in 43 patients using contrast-enhanced MRI and CT on the basis of the Response Evaluation Criteria in Solid Tumors. All patients were followed to complete survival data.

RESULTS

Overall median survival after SIRT was 47 wk. Response as assessed with SUV(max) correlated significantly with survival after radioembolization, with responders having significantly longer survival (65 wk) than nonresponders (43 wk; P < 0.05). In multivariate analysis the change in SUV(max) was identified as the only independent predictor of survival (hazard ratio, 0.23; P < 0.005). Furthermore, a high pretherapeutic SUV(max) (>20) was associated with a significantly shorter median survival than was an SUV(max) of 20 or less (21 vs. 52 wk; P < 0.005). The presence of extrahepatic metastases (mean survival in both groups, 47 wk; P = 0.92), hormone receptor status (estrogen, P = 0.53; progesterone, P = 0.79; Her-2/neu, P = 0.49), and MRI/CT response (P = 0.91) did not predict survival.

CONCLUSION

The change in SUV(max) as assessed by (18)F-FDG PET/CT before and 3 mo after SIRT was identified as the only independent predictor of survival in patients with hepatic metastases of breast cancer.

The value of [18F]fluorodeoxyglucose-PET/CT in oesophageal cancer

[¹⁸F]Fluorodeoxyglucose-positron emission tomography/computed tomography (CT) is recognized as a useful adjunct to conventional imaging with CT and endoscopic ultrasonography for the staging of oesophageal cancer, for response assessment and identification of recurrent disease and it may provide prognostic information.

18F-FDG PET independently predicts survival in patients with cholangiocellular carcinoma treated with 90Y microspheres

PURPOSE

(90)Y radioembolization has emerged as a valuable therapy for intrahepatic cholangiocellular carcinomas (ICC). We aimed to evaluate the prognostic power of FDG PET/CT and that of pretherapeutic scintigraphy with (99m)Tc-labelled macroagglutinated albumin (MAA), an index of tumour vascularization.

METHODS

The study group comprised 26 consecutive patients suffering from nonresectable ICC. Before treatment with radioembolization, all patients underwent MRI of the liver, as well as MAA scintigraphy, which was followed immediately by SPECT(/CT) to quantify the liver-lung shunt fraction. Using image fusion, regions of interest were drawn around the tumours and the entire liver, and the tumour-to-liver quotient was calculated. In addition, FDG PET/CT was performed at baseline and 3 months after radioembolization, and the percentage changes in peak (ΔSUV(max)) and mean (ΔSUV(mean)) FDG uptake and in metabolic tumour volume (ΔVol(2SD)) relative to baseline were calculated. Treatment response at 3 months was also assessed using contrast-enhanced MRI and CT on the basis of standard criteria.

RESULTS

Of 23 patients in whom follow-up MRI was available, 5 (22%) showed a partial response, 15 (65%) stable disease and 3 (13%) progressive disease. The change in all FDG values significantly predicted survival by Kaplan-Meier analysis after radioembolization; ΔVol(2SD) responders had a median survival of 97 weeks versus 30 weeks in nonresponders (P = 0.02), whereas ΔSUV(max) and ΔSUV(mean) responders had a median survival of 114 weeks (responder) versus 19 weeks (nonresponder) and 69 weeks in patients with stable disease (P < 0.05). Pretherapeutic MAA scintigraphy or MRI did not predict survival, nor did the presence of extrahepatic metastases, or prior therapies. Only ΔVol(2SD) was significantly associated with survival by univariate analysis (hazard ratio 0.25; P = 0.04) and multivariate analysis (hazard ratio 0.20, P = 0.04).

CONCLUSION

FDG PET/CT was able to predict patient outcome after radioembolization treatment, with the change in metabolically active tumour volume at 3 months being the best independent predictor. High tumour vascularization, as indicated by MAA scintigraphy, was not a prerequisite for successful radioembolization and was even associated with a tendency towards shorter survival.

Strategies of assessing and quantifying radiation treatment metabolic tumor response using F18 FDG Positron Emission Tomography (PET)

The use of positron emission tomography (PET) using F18 labeled fluorodeoxyglucose (FDG) for both oncology disease staging and radiation therapy target volume delineation has steadily increased over the last decade, and FDG-PET is today readily available in all major medical centers. The goal of anti tumor treatment, including chemotherapy and/or radiation therapy is to diminish a tumor cell population, ideally to the state of total eradication. Reducing the number of viable tumor cells can lead to a reduction in anatomical tumor size, and may also be correlated with decreased FDG uptake. Efforts to assess tumor response to therapy have attempted to describe and quantify changes in glucose utilization, also referred to as metabolic tumor response. In this review, an attempt is made to present and discuss methodologies to assess and quantify tumor metabolic response to radiation therapy or chemoradiation treatment courses.