Challenges in using ¹?F-fluorodeoxyglucose-PET-CT to define a biological radiotherapy boost volume in locally advanced pancreatic cancer.
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PROVIDER: S-EPMC4078370 | BioStudies |
REPOSITORIES: biostudies
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Project description:Background and objectives: Induction chemotherapy (ICT) before definitive chemoradiation (CRT) gives high response rates in locally advanced squamous cell carcinoma of the head and neck (LA-SCCHN). However, pre-ICT gross tumor volume (GTV) for radiotherapy (RT) planning is still recommended. As 18F-FDG PET/CT has an advantage of biological tumor information comparing to standard imaging methods, we aimed to evaluate the feasibility of 18F-FDG PET/CT-based post-ICT GTV delineation for RT planning in LA-SCCHN and to assess the prognostic value of PET parameters: maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG). Methods: 47 LA-SCCHN patients were treated with 3 cycles of ICT (docetaxel, cisplatin, and 5-fluorouracil) followed by CRT (70 Gy in 35 fractions with weekly cisplatin). Pre- and post-ICT PET/CT examinations were acquired. Planning CT was co-registered with post-ICT PET/CT and RT target volumes were contoured according to post-ICT PET. Post-ICT percentage decrease of SUVmax, MTV and TLG in primary tumor and metastatic regional lymphnodes (LN) was counted. Loco-regional failure patterns, 3-year progression free (PFS) and overall survival (OS) were evaluated. Results: 3-year PFS and OS rates for study population were 67% and 61% respectively. 31.9% of patients progressed loco-regionally. All progress was localized in high-to-intermediate dose (60?70 Gy) RT volumes and none in low dose (50 Gy) volumes. Decrease of SUVmax ? 74% (p = 0.04), MTV ? 68% (p = 0.03), TLG ? 76% (p = 0.03) in primary tumor, and LN TLG decrease ? 74% (p = 0.03) were associated with PFS. Decrease of primary tumor SUVmax ? 74% (p = 0.04), MTV ? 69% (p = 0.03), TLG ? 74% (p = 0.02) and LN TLG ? 73% (p = 0.02) were prognostic factors for OS. Conclusions: According to our results, 18F-FDG PET/CT-based post-ICT GTV delineation is feasible strategy without negative impacts on loco-regional control and survival. Percentage decrease of metabolic PET parameters SUVmax, MTV and TLG has a prognostic value in LA-SCCHN.
| S-EPMC6306774 | BioStudies
Project description:We measured the repeatability of FDG PET/CT uptake metrics when acquiring scans in free breathing (FB) conditions compared with deep inspiration breath hold (DIBH) for locally advanced lung cancer. Twenty patients were enrolled in this prospective study. Two FDG PET/CT scans per patient were conducted few days apart and in two breathing conditions (FB and DIBH). This resulted in four scans per patient. Up to four FDG PET avid lesions per patient were contoured. The following FDG metrics were measured in all lesions and in all four scans: Standardized uptake value (SUV)peak, SUVmax, SUVmean, metabolic tumor volume (MTV) and total lesion glycolysis (TLG), based on an isocontur of 50% of SUVmax. FDG PET avid volumes were delineated by a nuclear medicine physician. The gross tumor volumes (GTV) were contoured on the corresponding CT scans. Nineteen patients were available for analysis. Test-retest standard deviations of FDG uptake metrics in FB and DIBH were: SUVpeak FB/DIBH: 16.2%/16.5%; SUVmax: 18.2%/22.1%; SUVmean: 18.3%/22.1%; TLG: 32.4%/40.5%. DIBH compared to FB resulted in higher values with mean differences in SUVmax of 12.6%, SUVpeak 4.4% and SUVmean 11.9%. MTV, TLG and GTV were all significantly smaller on day 1 in DIBH compared to FB. However, the differences between metrics under FB and DIBH were in all cases smaller than 1 SD of the day to day repeatability. FDG acquisition in DIBH does not have a clinically relevant impact on the uptake metrics and does not improve the test-retest repeatability of FDG uptake metrics in lung cancer patients.
2018-01-01 | S-EPMC5944828 | BioStudies
Project description:Background:This prospective study aims to determine the impact of PET/CT on radiotherapy planning and outcomes in patients with oesophageal cancer. Methods:All patients underwent PET/CT scanning in the radiotherapy treatment position, and received treatment planned using the PET/CT dataset. GTV was defined separately on PET/CT (GTV-PET) and CT (GTV-CT) datasets. A corresponding PTV was generated for each patient. Volumetric and spatial analysis quantified the proportion of FDG-avid disease not included in CT-based volumes. Clinical data was collected to determine locoregional control and overall survival rates. Results:13 (24.1%) of 57 accrued patients had metastatic disease detected on PET. Median follow up was 4 years. FDG-avid disease would have been excluded from GTV-CT in 29 of 38 patients (76%). In 5 patients, FDG-avid disease would have been completely excluded from the PTV-CT. GTV-CT underestimated the cranial and caudal extent of FDG-avid tumour in 14 (36%) and 10 (26%) patients. 4-Year overall survival and locoregional failure free survival were 37% and 65%. Conclusions:PET/CT altered the delineation of tumour volumes when compared to CT alone, and should be considered standard for treatment planning. Although clinical outcomes were not improved with PET/CT planning, it did allow the use of smaller radiotherapy volumes.
| S-EPMC5893524 | BioStudies
Project description:PURPOSE:The aim of the study was to evaluate the usefulness and accuracy of 18-fluorine-labeled fluorodeoxyglucose (PET) and magnetic resonance imaging (MRI) hybrid in gross tumor volume (GTV) delineation during radiotherapy planning in patients with carcinoma of the tongue. METHODS:Ten patients with squamous cell carcinoma (SCC) of the tongue underwent computed tomography (CT) and PET/MRI examination. The GTV for primary tumor and lymph nodes (nGTV) were defined on CT (GTV-CT) and compared to GTVs obtained from PET (GTV-PET) and MRI (GTV-MRI) images. Two methods of GTV determination were used: visual interpretation of CT, PET (GTV-PETvis) and MRI images and quantitative automatic method (Syngovia, Siemens) based on a chosen threshold value (20%, 30%, 40%, 50%) of standardized uptake values (SUVmax) from PET examination (GTV-PET20%, GTV-PET30%, etc.). Statistical analysis of differences in GTV values obtained from CT, PET and MRI studies was performed. GTV-CT was used as a reference. RESULTS:In all, 80% of GTV-MRI and 40% of GTV-PETvis were larger than GTV-CT. Respectively, 20% of GTV-MRI and 60% of GTV-PETvis were smaller than GTV-CT. Taking into account all threshold measurements, 70% of volumes were smaller than GTV-CT. GTV-PET30% were the most closely related volumes to GTV-CT from all threshold methods in 50% of patients. GTV-PETvis generated the most similar volumes in relation to GTV-CT from all PET measurements. Statistical analysis confirmed those results. Compared to nGTV-CT, 70% of nGTV-MRI and 20% of nGTV-PETvis were larger. The remaining nGTV-MRI and nGTV-PETvis measurements were smaller than nGTV-CT. Measurements of all thresholds nGTVs were smaller than nGTV-CTV in 52.5% of cases. nGTV-PET20% were the most closely related volumes to nGTV-CT in 40% of the cases. Statistical analysis showed that nGTV-PET20% (p?=?0.0468), nGTV-PETvis (p?=?0.0166), and nGTV-PET50% (p?=?0.0166) diverge significantly from nGTV-CT results. nGTV-MRI (p?=?0.1141), nGTV-PET30% (p?=?0.2845), and nGTV-PET40% (p?=?0.5076) were significantly related with nGTV-CT. CONCLUSION:Combination of PET/MRI provides more information during target tumor mass delineation in radiotherapy planning of patients with SCC of the tongue than other standard imaging methods. The most frequently matching threshold value was 30% of SUVmax for primary tumor delineation and 30-40% of SUVmax for nGTV determination.
| S-EPMC6704108 | BioStudies
Project description:PURPOSE:We evaluated that early metabolic response determined by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) during radiotherapy (RT), predicts outcomes in non-small cell lung cancer. MATERIAL AND METHODS:Twenty-eight patients evaluated using pretreatment 18F-FDG-PET/CT (PETpre) and interim 18F-FDG-PET/CT (PETinterim) after 11 fractions of RT were retrospectively reviewed. Maximum standardized uptake value (SUVmax) was calculated for primary lesion. Predictive value of gross tumor volume (?GTV) and SUVmax (?SUVmax) changes was evaluated for locoregional control (LRC), distant failure (DF), and overall survival (OS). Metabolic responders were patients with ?SUVmax >40%. RESULTS:Metabolic responders showed better trends in 1-year LRC (90.9%) than non-responders (47.1%) (p = 0.086). Patients with large GTVpre (?120 cc) demonstrated poor LRC (hazard ratio 4.14, p = 0.022), while metabolic non-responders with small GTVpre (<120 cc) and metabolic responders with large GTVpre both had 1-year LRC rates of 75.0%. Reduction of 25% in GTV was not associated with LRC; however, metabolic responders without a GTV response showed better 1-year LRC (83.3%) than metabolic non-responders with a reduction in GTV (42.9%). Metabolic responders showed lower 1-year DF (16.7%) than non-responders (50.0%) (p = 0.025). An ?SUVmax threshold of 40% yielded accuracy of 64% for predicting LRC, 75% for DF, and 54% for OS. However, ?GTV > 25% demonstrated inferior diagnostic values than metabolic response. CONCLUSIONS:Changes in tumor metabolism diagnosed using PETinterim during RT better predicted treatment responses, recurrences, and prognosis than other factors historically used.
| S-EPMC7371172 | BioStudies
Project description:<h4>Purpose</h4>Papillary renal cell carcinoma (RCC) is the second most common subtype of RCC, after clear cell RCC. This study aimed to investigate the usefulness of FDG PET/CT in primary and recurrent papillary RCC, and the role of staging FDG PET/CT in predicting survival.<h4>Methods</h4>A total of 66 patients with histopathologically confirmed papillary RCC who underwent either staging or restaging FDG PET/CT scans (30 had staging scans only, 28 had restaging scans only, 8 had both) were retrospectively included in this study. The sensitivity and specificity of restaging FDG PET/CT for detecting recurrence were assessed by histopathology and/or clinical follow-up as standard reference.<h4>Results</h4>Staging FDG PET/CT scans were performed in 38 patients, of which 31 (81.5%) showed FDG-positive primary renal lesions. The SUVmax of high-grade (WHO grade 3 and 4) papillary RCCs were significantly higher than that of low-grade (WHO grade 1 and 2) tumors (9.44?±?6.18 vs 4.83?±?3.19, P?=?0.008). The SUVmax was not significantly different between type 1 and type 2 papillary RCCs (5.71?±?2.88 vs. 6.99?±?5.57, P?=?0.563). Of the 38 patients, 12 developed disease progression during the follow-up period. Patients with primary tumor SUVmax>?5.85 were associated with significantly shorter progression-free survival (PFS) than those with tumor SUVmax?5.85 (P?=?0.005). Restaging FDG PET/CT scans were performed in 36 patients with suspected recurrent papillary RCCs. FDG PET/CT showed a sensitivity and specificity of 100 and 72.7% for detecting recurrent disease. Comparison of PET/CT scans with CT/MRI imaging was available in 23 patients. FDG PET/CT revealed additional findings in 11 patients, mainly including lymph node and bone metastases. FDG PET/CT findings led to change in management in 5.3% (2/38) of patients in the staging setting and 16.7 (6/36) of patients in the restaging setting.<h4>Conclusions</h4>FDG PET/CT had a sensitivity of 81.5% for detecting primary papillary RCC, and tumor SUVmax derived from staging FDG PET/CT was a predictor of PFS. In the restaging process of papillary RCC, FDG PET/CT was very effective for detecting recurrent disease.
| S-EPMC7908760 | BioStudies
Project description:Increased tumor metabolism and hypoxia are related to poor prognosis in solid tumors, including non-small cell lung cancer (NSCLC). PET imaging is a noninvasive technique that is frequently used to visualize and quantify tumor metabolism and hypoxia. The aim of this study was to perform an extensive comparison of tumor metabolism using 2[(18)F]fluoro-2-deoxy-d-glucose (FDG)-PET and hypoxia using HX4-PET imaging.FDG- and HX4-PET/CT images of 25 patients with NSCLC were coregistered. At a global tumor level, HX4 and FDG parameters were extracted from the gross tumor volume (GTV). The HX4 high-fraction (HX4-HF) and HX4 high-volume (HX4-HV) were defined using a tumor-to-blood ratio > 1.4. For FDG high-fraction (FDG-HF) and FDG high-volume (FDG-HV), a standardized uptake value (SUV) > 50% of SUVmax was used. We evaluated the spatial correlation between HX4 and FDG uptake within the tumor, to quantify the (mis)match between volumes with a high FDG and high HX4 uptake.At a tumor level, significant correlations were observed between FDG and HX4 parameters. For the primary GTV, the HX4-HF was three times smaller compared with the FDG-HF. In 53% of the primary lesions, less than 1 cm(3) of the HX4-HV was outside the FDG-HV; for 37%, this volume was 1.9 to 12 cm(3). Remarkably, a distinct uptake pattern was observed in 11%, with large hypoxic volumes localized outside the FDG-HV.Hypoxic tumor volumes are smaller than metabolic active volumes. Approximately half of the lesions showed a good spatial correlation between the PET tracers. In the other cases, a (partial) mismatch was observed. The addition of HX4-PET imaging has the potential to individualize patient treatment.
| S-EPMC5228298 | BioStudies
Project description:BACKGROUND:Hypoxic tumours exhibit increased resistance to radiation, chemical, and immune therapies. 18F-fluoromisonidazole (FMISO) positron emission tomography (PET) is a non-invasive, quantitative imaging technique used to evaluate the presence and spatial distribution of tumour hypoxia. To facilitate the use of FMISO PET for identification of individuals likely to benefit from hypoxia-targeted treatments, we investigated the reproducibility of FMISO PET spatiotemporal intratumour distribution in patients with non-small cell lung cancer (NSCLC). METHODS:Ten patients underwent 18F-fluorodeoxyglucose (FDG) PET/CT scans, followed by two FMISO PET/CT scans 1-2 days apart. Nineteen lesions in total were segmented from co-registered FDG PET image sets. Volumes of interest were also defined on normal contralateral lung and subscapularis muscle. The Pearson correlation coefficient r was calculated for mean standardized uptake values (SUV) within investigated volumes of interest and for voxels within tumour volumes (r TV). The reproducibility of FMISO voxelwise distribution, SUV- and tumour-to-blood ratio (TBR)-derived indices was assessed using correlation and Bland-Altman analyses. RESULTS:The SUVmax, SUVmean, TBRmax, and TBRmean were highly correlated (r???0.87, p?<?0.001) and were reproducible to within 10-15 %. The mean r TV was 0.84?±?0.10. 77 % of voxels identified as hypoxic on one FMISO scan were confirmed as such on the other FMISO scan. Mean voxelwise differences between TBR values as calculated from pooled data including all lesions were 0.9?±?10.8 %. CONCLUSIONS:High reproducibility of FMISO intratumour distribution in NSCLC patients was observed, facilitating its use in determining the topology of the hypoxic tumour sub-volumes for dose escalation, in patient stratification strategies for hypoxia-targeted therapies, and in monitoring response to therapeutic interventions. TRIAL REGISTRATION:Current Controlled Trials NCT02016872.
| S-EPMC5099292 | BioStudies
Project description:<h4>Background</h4>To assess the effect of radiochemotherapy (RCT) on proposed tumour hypoxia marker transverse relaxation time (T2*) and to analyse the relation between T2* and <sup>18</sup>F-misonidazole PET/CT (FMISO-PET) and <sup>18</sup>F-fluorodeoxyglucose PET/CT (FDG-PET).<h4>Methods</h4>Ten patients undergoing definitive RCT for squamous cell head-and-neck cancer (HNSCC) received repeat FMISO- and 3 Tesla T2*-weighted MRI at weeks 0, 2 and 5 during treatment and FDG-PET at baseline. Gross tumour volumes (GTV) of tumour (T), lymph nodes (LN) and hypoxic subvolumes (HSV, based on FMISO-PET) and complementary non-hypoxic subvolumes (nonHSV) were generated. Mean values for T2* and SUVmean FDG were determined.<h4>Results</h4>During RCT, marked reduction of tumour hypoxia on FMISO-PET was observed (T, LN), while mean T2* did not change significantly. At baseline, mean T2* values within HSV-T (15?±?5 ms) were smaller compared to nonHSV-T (18?±?3 ms; p =?0.051), whereas FDG SUVmean (12?±?6) was significantly higher for HSV-T (12?±?6) than for nonHSV-T (6?±?3; p =?0.026) and higher for HSV-LN (10?±?4) than for nonHSV-LN (5?±?2; p ??0.011). Correlation between FMISO PET and FDG PET was higher than between FMSIO PET and T2* (R<sup>2</sup> for GTV-T (FMISO/FDG)?=?0.81, R<sup>2</sup> for GTV-T (FMISO/T2*)?=?0.32).<h4>Conclusions</h4>Marked reduction of tumour hypoxia between week 0, 2 and 5 found on FMISO PET was not accompanied by a significant T2*change within GTVs over time. These results suggest a relation between tumour oxygenation status and T2* at baseline, but no simple correlation over time. Therefore, caution is warranted when using T2* as a substitute for FMISO-PET to monitor tumour hypoxia during RCT in HNSCC patients.<h4>Trial registration</h4>DRKS, DRKS00003830 . Registered 23.04.2012.
| S-EPMC6114038 | BioStudies
Project description:Non-small cell lung cancer (NSCLC) tumours are mostly heterogeneous. We hypothesized that areas within the tumour with a high pre-radiation (18)F-deoxyglucose (FDG) uptake, could identify residual metabolic-active areas, ultimately enabling selective-boosting of tumour sub-volumes.Fifty-five patients with inoperable stage I-III NSCLC treated with chemo-radiation or with radiotherapy alone were included. For each patient one pre-radiotherapy and one post-radiotherapy FDG-PET-CT scans were available. Twenty-two patients showing persistent FDG uptake in the primary tumour after radiotherapy were analyzed. Overlap fractions (OFs) were calculated between standardized uptake value (SUV) threshold-based auto-delineations on the pre- and post-radiotherapy scan.Patients with residual metabolic-active areas within the tumour had a significantly worse survival compared to individuals with a complete metabolic response (p=0.002). The residual metabolic-active areas within the tumour largely corresponded (OF>70%) with the 50%SUV high FDG uptake area of the pre-radiotherapy scan. The hotspot within the residual area (90%SUV) was completely within the GTV (OF=100%), and had a high overlap with the pre-radiotherapy 50%SUV threshold (OF>84%).The location of residual metabolic-active areas within the primary tumour after therapy corresponded with the original high FDG uptake areas pre-radiotherapy. Therefore, a single pre-treatment FDG-PET-CT scan allows for the identification of residual metabolic-active areas.
| S-EPMC4693609 | BioStudies