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.

Staging of newly diagnosed Ewing sarcoma: Results of bone marrow aspiration and biopsy versus (18)FDG-PET/CT imaging for bone marrow involvement

BACKGROUND

Ewing sarcoma (ES) is an aggressive bone or extraosseous tumour with an unfavourable prognosis when bone marrow metastases are present at diagnosis. The gold standard diagnosis for bone marrow (BM) involvement is cytological and pathological analysis through bone marrow aspiration and biopsy (BMAB). Several recent studies suggest that these invasive and painful procedures could be replaced by 18F-fluorodeoxyglucose-positron emission tomography/computed tomography ((18)FDG-PET/CT), as this nuclear imaging technique is highly sensitive at detecting bone and extraosseous metastases of ES.

METHODS

In order to study the precision of (18)FDG-PET/CT in the evaluation of bone marrow metastases at diagnosis, we compared the imaging results with cytological/histological analyses performed on BM samples. We retrospectively studied 180 patients with ES recorded at the Léon Bérard Centre over the past 10 years, who were evaluated by (18)FDG-PET/CT and BMAB at diagnosis.

RESULTS

Of the 180 patients, 13 displayed marrow metastases by cytological/histological examination, and only one of these did not have (18)FDG-PET/CT signs of bone marrow involvement, whereas the 167 remaining patients without marrow metastasis all had a negative (18)FDG-PET/CT, except for one. Hence, the sensitivity and specificity of (18)FDG-PET/CT in these patients was 92.3% and 99.4%, respectively. The overall survival at five years of all patients was 67.4% but decrease to 38.5% in the group with bone marrow metastases.

CONCLUSION

Given the results presented herein the bone sarcoma group of the French Sarcoma Group suggests that invasive BMAB no longer be systematically performed for the staging at the diagnosis of ES.

Comparison of 68Ga-DOTA-FAPI and 18FDG PET/CT imaging modalities in the detection of liver metastases in patients with gastrointestinal system cancer

PURPOSE

We aimed to compare the diagnostic performance of PET/CT imaging performed with ⁶⁸Ga-DOTA-FAPI and ¹⁸FDG in detection of liver metastases in patients with gastrointestinal system (GIS) cancer.

METHODS

A total of 31 patients who underwent ⁶⁸Ga-DOTA-FAPI and ¹⁸F-FDG PET/CT examinations and diagnosed with GIS cancer (15 colorectal, 9 pancreas, 4 stomach and 3 other cancers) were included in the study. The presence of liver metastasis was decided based on histopathologic diagnosis, PET/CT, other radiologic examinations or tumor biomarker findings, and both PET/CT imaging findings were compared on the patient and lesion basis.

RESULTS

Of the 31 patients, 28 were found as true positive with ⁶⁸Ga-DOTA-FAPI-PET/CT and 17 with ¹⁸FDG-PET/CT. Of the 98 metastatic liver lesions determined according to our diagnostic criteria, 92 were found as true positive lesions with ⁶⁸Ga-DOTA-FAPI-PET/CT and 65 with ¹⁸FDG-PET/CT. There was a statistically significant difference between both imaging modalities in the patient and lesion based comparisons (p < 0.05). When semiquantitative values (SUVmax, mlr) obtained from the lesions were compared between the two imaging methods, mlr values showed statistically significant difference in all tumor subgroups (p < 0.05).

CONCLUSION

It was concluded that ⁶⁸Ga-DOTA-FAPI-PET/CT was superior over ¹⁸FDG-PET/CT in detection of liver metastases of GIS cancers and it can be a complementary method especially in negative cases with ¹⁸FDG-PET/CT.

Stereotactic Ablative Radiation Therapy for Lung Oligometastases: Predictive Parameters of Early Response by 18FDG-PET/CT

OBJECTIVES

The objective of this study was to investigate fludeoxyglucose F 18 positron emission tomography/computed tomography (¹⁸FDG-PET/CT) parameters as predictive of response after stereotactic ablative radiotherapy (SABR) for lung oligometastases.

METHODS

The inclusion criteria of the current retrospective study were as follows: (1) lung oligometastases treated by SABR, (2) presence of ¹⁸FDG-PET/CT before and after SABR for at least two subsequent evaluations, (3) Karnofsky performance status higher than 80, and (4) life expectancy longer than 6 months. All patients were treated with a biologically equivalent dose of at least 100 Gy with an alpha/beta ratio of 10. The following metabolic parameters were semiquantitatively defined: maximum standardized uptake value (SUV_max), mean standardized uptake value (SUV_mean), metabolic tumor volume, and total lesion glycolysis.

RESULTS

A total of 50 patients met the inclusion criteria, for a total of 70 lung metastases. The pre-SABR median SUV_max was 6.5 (range 4-17), the median SUV_mean was 3.7 (range 2.5-6.5), and the median metabolic tumor volume was 2.3 cm³ (0.2-31 cm³). The following metabolic parameters were significantly related to complete response at 6 months: SUV_max less than 5 (p < 0.001) and SUV_mean less than 3.5 (p = 0.03). ΔSUV_max at 3 to 6 months was +126% for lesions with in-field progression versus -26% for the remaining lesions (p = 0.002). ΔSUV_mean at 3 to 6 months was +15% for lesions with in-field progression versus -26% for the remaining metastases (p = 0.008).

CONCLUSIONS

In the current analysis, complete response from lung metastasis at 6 months after stereotactic body radiation therapy was significantly associated with both the maximum and mean values of pre-SABR ¹⁸FDG-PET/CT SUV. Longer-term trials are strongly advocated to improve the personalization of the monitoring of tumor response in patients with lung oligometastases and, consequently, monitoring of the cost-effectiveness of the health care.

Early assessment with 18F-fluorodeoxyglucose positron emission tomography/computed tomography can help predict the outcome of neoadjuvant chemotherapy in triple negative breast cancer

BACKGROUND

In patients with triple-negative breast cancer (TNBC), pathology complete response (pCR) to neoadjuvant chemotherapy (NAC) is associated with improved prognosis. This prospective study was designed and powered to investigate the ability of interim (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)FDG-PET/CT) to predict pathology outcomes to NAC early during treatment.

PATIENTS AND METHODS

Consecutive TNBC women underwent (18)FDG-PET/CT at baseline and after two courses of NAC. Maximum standardised uptake value (SUV(max)) in the primary tumour and lymph nodes at each examination and the evolution (ΔSUV(max)) between the two scans were measured. NAC was continued irrespective of PET results. Correlations between PET parameters and pathology response, and between PET parameters and event-free survival (EFS), were examined.

RESULTS

Fifty patients without distant metastases were enroled. At completion of NAC, surgery showed pCR in 19 patients, while 31 had residual tumour. Mean follow-up was 30.3 months. Thirteen patients, all with residual tumour, experienced relapse. Of all assessed clinical, biological and PET parameters, ΔSUV(max) in the primary tumour was the most predictive of pathology results (p<0.0001; Mann-Whitney-U test) and EFS (p=0.02; log rank test). A threshold of 42% decrease in SUV was identified because it offered the best accuracy in predicting EFS. There were 32 metabolic responders (⩾ 42% decrease in SUV(max)) and 18 non-responders. Within responders, the pCR rate was 59% and the 3-year EFS 77.5%. In non-responders, the pCR rate was 0% and the 3-year EFS 47.1%.

CONCLUSION

Interim (18)FDG can early predict the inefficacy of NAC in TNBC patients. It shows promise as a potential contributory biomarker in these patients.