Prognostic value of metabolic volume measured by F-18 FDG PET-CT in patients with esophageal cancer

Prognostic value of baseline 18F-FDG PET/CT in patients with esophageal squamous cell carcinoma treated with definitive (chemo)radiotherapy

PURPOSE

To investigate the prognostic value of baseline ¹⁸F-FDG PET/CT in patients with esophageal squamous cell carcinoma (ESCC) treated with definitive (chemo)radiotherapy.

METHODS

A total of 98 ESCC patients with cTNM stage T1-4, N1-3, M0 who received definitive (chemo)radiotherapy after ¹⁸F-FDG PET/CT examination from December 2013 to December 2020 were retrospectively analyzed. Clinical factors included age, sex, histologic differentiation grade, tumor location, clinical stage, and treatment strategies. Parameters obtained by ¹⁸F-FDG PET/CT included SUV_max of primary tumor (SUV_Tumor), metabolic tumor volume (MTV), total lesion glycolysis (TLG), SUV_max of lymph node (SUV_LN), PET positive lymph nodes (PLNS) number, the shortest distance between the farthest PET positive lymph node and the primary tumor in three-dimensional space after the standardization of the patient BSA (SD_max(LN-T)). Univariate and multivariate analysis was conducted by Cox proportional hazard model to explore the significant factors affecting overall survival (OS) and progression-free survival (PFS) in ESCC patients.

RESULTS

Univariate analysis showed that tumor location, SUV_Tumor, MTV, TLG, PLNS number, SD_{max (LN-T)} were significant predictors of OS and tumor location, and clinical T stage, SUV_Tumor, MTV, TLG, SD_{max (LN-T)} were significant predictors of PFS (all p < 0.1). Multivariate analysis showed that MTV and SD_{max (LN-T)} were independent prognostic factors for OS (HR = 1.018, 95% CI 1.006-1.031; p = 0.005; HR = 6.988, 95% CI 2.119-23.042; p = 0.001) and PFS (HR = 1.019, 95% CI 1.005-1.034; p = 0.009; HR = 5.819, 95% CI 1.921-17.628; p = 0.002). Combined with independent prognostic factors MTV and SD_{max (LN-T)}, we can further stratify patient risk.

CONCLUSIONS

Before treatment, ¹⁸F-FDG PET/CT has important prognostic value for patients with ESCC treated with definitive (chemo)radiotherapy. The lower the value of MTV and SD_{max (LN-T)}, the better the prognosis of patients.

Volumetric Evaluation of Staging 18F-FDG PET/CT Images in Patients with Esophageal Cancer

Objectives:

The aim of this study was to evaluate the metastatic potential of primary tumor and survival in esophageal cancer (EC) patients by using metabolic tumor volume (MTV) and total lesion glycolysis (TLG) from the staging ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) images. Another aim is to determine a tumor volume-based cut-off value to predict long-term survival.

Methods:

Medical records of EC patients were retrospectively evaluated. Sixty-two patients with staging ¹⁸F-FDG PET/CT and at least five years of follow-up were included in the study. The region of interest to the primary tumor and all metastatic sites was created and MTV and TLG values of the primary tumor (MTVp, TLGp) and total tumor volume (MTVt and TLGt) values were obtained. The relationship between the obtained MTV and TLG values and short-time (one-year) and long time (five-year) survival was investigated.

Results:

Significant factors on survival were determined as lymph node or distant metastasis (p=0.024, 0.008, respectively) at the staging PET/CT. A significant relationship between volumetric parameters of the primary tumor and total tumor burden (MTVp, TLGp, MTVwb and TLGwb) between survivors and non-survivors for one-year and five-year was detected. In receiver operating characteristics analysis, the most significant volumetric parameter was MTVwb, with area under curve 0.771 in estimated five-year survival. The best cut-off value was detected as 36.1 mL with 78% sensitivity and 75% specificity for MTVwb in determining long-term survivors.

Conclusion:

Tumor burden in ¹⁸F-FDG PET/CT images at the time of staging of patients with EC will contribute to the prediction of long-term survivors.

18F-FDG PET/CT as predictive and prognostic factor in esophageal cancer treated with combined modality treatment

Purpose

[18F] fluorodeoxyglucose positron emission tomography/computed tomography ([18F] FDG-PET/CT) is used for diagnosis, staging, response assessment and prognosis prediction in different tumors, but its role in esophageal cancer is still debated. The aim of this study was to evaluate the role of semiquantitative baseline PET parameters as possible prognostic and predictive factors in a series of esophageal carcinomas treated with combined modalities.

Methods

43 patients with esophageal carcinoma were treated with chemoradiotherapy (CRT) followed by surgery in 20 cases and underwent pre-treatment 18F-FDG-PET/CT. Semiquantitative PET parameters were evaluated including Standardized Uptake Value (SUVmax e SUVmean), Metabolic Tumor Volume (MTV) and Total Lesion Glycolysis (TLG) with isocontour of 41 and 50%. Further variables analyzed were gender, primary tumor site, histological type, use of surgery, achievement of a radical resection and the type of chemotherapy regimen. The correlation of all variables with treatment response, loco-regional control (LR), Overall survival (OS) and Disease-Free Survival (DFS) was evaluated.

Results

SUVmax, SUVmean50 and SUVmean41 were significantly higher in node-positive cases and in squamous cell carcinomas. With respect to prognostic factors, MTV was found to be correlated with OS: patients with MTV41 < 11.32 cm³ and MTV50 < 8.07 cm³ (both p values = 0.04) showed better 3-year OS rates (33 vs. 20%). Further factors predicting a better prognosis were the use of surgery and radical resection (R0) (both p values < 0.01).

Conclusions

Pre-treatment MTV values were significant prognostic factors for OS, together with the use of surgery and R0 resection in esophageal cancers treated with multimodal therapies.

The prognostic value of total lesion glycolysis via 18F-fluorodeoxyglucose PET-CT in surgically treated esophageal squamous cell carcinoma

OBJECTIVE

In addition to staging, the identification of prognostic factors is important for predicting survival in patients with esophageal cancer after esophagectomy. The present study was performed to document the prognostic role of total lesion glycolysis (TLG) in postoperative patients.

METHODS

We retrospectively reviewed the records of 50 patients with esophageal squamous cell carcinoma who underwent surgical resection and complete lymph node dissection after positron emission tomography-computed tomography (PET-CT). A volume of interest was drawn on the primary lesion and suspected metastatic lymph nodes, and the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), TLG of the primary lesion (TLGp), and whole-body TLG (TLGwb) were measured using an SUV cutoff of 2.5.

RESULTS

The study population included 50 patients with a mean age of 63.14 ± 8.18 years: 12 (24%) were reported as stage I, 13 (26%) as stage II, and 25 (50%) as stage III. The median follow-up period was 20.46 months, and recurrences occurred in 17 patients. The mean SUVmax, MTV, TLGp, and TLGwb were 11.11 ± 6.40, 20.47 ± 22.88, 122.54 ± 180.98, and 129.37 ± 193.66, respectively. On the multivariate analysis, TLGp was a risk factor for disease-free survival (DFS) [hazard ratio (HR) = 1.002, p = 0.026], and TLGwb was a risk factor for DFS (HR = 1.002, p = 0.021) and overall survival (OS) (HR = 1.002, p = 0.044). The 3-year OS rates were 66.1% in patients with low TLGwb (≤ 41.45) and 33.3% in those with high TLGwb (>41.45; p = 0.004). The concordance index of the TLGwb was 0.752 (95% CI 0.659-0.845).

CONCLUSION

TLGwb is a significant prognostic factor for OS and DFS in patients with surgically treated esophageal squamous cell carcinoma.

Volumetric and dosimetric comparison of computerised radiotherapy treatment plan between using positron emission tomography/computed tomography (PET/CT) and CT images for target delineation in non-small cell lung cancer patients

Purpose

To compare intensity-modulated radiation therapy (IMRT) treatment planning between using positron emission tomography/computed tomography (PET/CT) and CT for target volume delineation in patients with non-small cell lung cancer (NSCLC).

Methods

Nine NSCLC patients with PET/CT images were enrolled into this study. Gross tumour volumes (GTVs) were delineated by the PET visual assessment (PETvis), the automated PET (PETauto), standardised uptake value (SUV)>2·5 (PET2·5) and threshold 40% SUVmax (PET40), and CT-based method. For each patient, two IMRT treatment plans based on CT and PET/CT delineation were performed. The target coverage and the dose–volume parameters for organs at risk were analysed.

Results

The PETauto referred to PET40 when SUVmax<7 and PET2·5 when SUVmax≥7. The mean GTVs were 15·04, 15·7 and 15·14 cc for PETauto, PETvis and CT based, respectively. The GTV of PETauto was not different from PETvis (p=0·441) and CT based (p=0·594). Based on CT delineation in IMRT planning, only 34% of the cases had sufficient PET/CT planning target volumes coverage, whereas the organs at risk dose parameters were not statistically significant (p>0·05).

Conclusions

PET/CT enables more accurate assessment of tumour delineation for NSCLC, therefore improve target coverage in IMRT plan.

Utilization of PET-CT in target volume delineation for three-dimensional conformal radiotherapy in patients with non-small cell lung cancer and atelectasis

Background

To investigate the utilization of PET-CT in target volume delineation for three-dimensional conformal radiotherapy in patients with non-small cell lung cancer (NSCLC) and atelectasis.

Methods

Thirty NSCLC patients who underwent radical radiotherapy from August 2010 to March 2012 were included in this study. All patients were pathologically confirmed to have atelectasis by imaging examination. PET-CT scanning was performed in these patients. According to the PET-CT scan results, the gross tumor volume (GTV) and organs at risk (OARs, including the lungs, heart, esophagus and spinal cord) were delineated separately both on CT and PET-CT images. The clinical target volume (CTV) was defined as the GTV plus a margin of 6-8 mm, and the planning target volume (PTV) as the GTV plus a margin of 10-15mm. An experienced physician was responsible for designing treatment plans Plan_CT and Plan_PET-CT on CT image sets. 95% of the PTV was encompassed by the 90% isodose curve, and the two treatment plans kept the same beam direction, beam number, gantry angle, and position of the multi-leaf collimator as much as possible. The GTV was compared using a target delineation system, and doses distributions to OARs were compared on the basis of dose-volume histogram (DVH) parameters.

Results

The GTV_CT and GTV_PET-CT had varying degrees of change in all 30 patients, and the changes in the GTV_CT and GTV_PET-CT exceeded 25% in 12 (40%) patients. The GTV_PET-CT decreased in varying degrees compared to the GTV_CT in 22 patients. Their median GTV_PET-CT and median GTV_PET-CT were 111.4 cm³ (range, 37.8 cm³-188.7 cm³) and 155.1 cm³ (range, 76.2 cm³-301.0 cm³), respectively, and the former was 43.7 cm³ (28.2%) less than the latter. The GTV_PET-CT increased in varying degrees compared to the GTV_CT in 8 patients. Their median GTV_PET-CT and median GTV_PET-CT were 144.7 cm³ (range, 125.4 cm³-178.7 cm³) and 125.8 cm³ (range, 105.6 cm³-153.5 cm³), respectively, and the former was 18.9 cm³ (15.0%) greater than the latter. Compared to Plan_CT parameters, Plan_PET-CT parameters showed varying degrees of changes. The changes in lung V₂₀, V₃₀, esophageal V₅₀ and V₅₅ were statistically significant (Ps< 0.05 for all), while the differences in mean lung dose, lung V₅, V₁₀, V₁₅, heart V₃₀, mean esophageal dose, esophagus Dmax, and spinal cord Dmax were not significant (Ps> 0.05 for all).

Conclusions

PET-CT allows a better distinction between the collapsed lung tissue and tumor tissue, improving the accuracy of radiotherapy target delineation, and reducing radiation damage to the surrounding OARs in NSCLC patients with atelectasis.