Ayca Muftuler Løndalen | Theragnostic Imaging

Mucosa-sparing dose painting of head and neck cancer

Tue, 01 Feb 2022 00:00:00 +0000

No abstract available

Assessment of Waldeyer's ring in pediatric and adolescent Hodgkin lymphoma patients-Importance of multimodality imaging: Results from the EuroNet-PHL-C1 trial

Thu, 01 Apr 2021 00:00:00 +0000

In the EuroNet Pediatric Hodgkin Lymphoma (EuroNet-PHL) trials, decision on Waldeyer’s ring (WR) involvement is usually based on clinical assessment, that is, physical examination and/or nasopharyngoscopy. However, clinical assessment only evaluates mucosal surface and is prone to interobserver variability. Modern cross-sectional imaging technology may provide valuable information beyond mucosal surface, which may lead to a more accurate WR staging. The EuroNet-PHL-C1 trial recruited 2102 patients, of which 1752 underwent central review including reference reading of their cross-sectional imaging data. In 14 of 1752 patients, WR was considered involved according to clinical assessment. In these 14 patients, the WR was re-assessed by applying an imaging-based algorithm considering information from ¹⁸ F-fluorodeoxyglucose positron emission tomography, contrast-enhanced computed tomography, and/or magnetic resonance imaging. For verification purposes, the imaging-based algorithm was applied to 100 consecutive patients whose WR was inconspicuous on clinical assessment. The imaging-based algorithm confirmed WR involvement only in four of the 14 patients. Of the remaining 10 patients, four had retropharyngeal lymph node involvement and six an inconspicuous WR. Applying the imaging-based algorithm to 100 consecutive patients with physiological appearance of their WR on clinical assessment, absence of WR involvement could be confirmed in 99. However, suspicion of WR involvement was raised in one patient. The imaging-based algorithm was feasible and easily applicable at initial staging of young patients with Hodgkin lymphoma. It increased the accuracy of WR staging, which may contribute to a more individualized treatment in the future.

Mapping Bone Marrow Response in the Vertebral Column by Positron Emission Tomography Following Radiotherapy and Erlotinib Therapy of Lung Cancer

Mon, 01 Apr 2019 00:00:00 +0000

To map functional bone marrow (BM) by 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG) positron emission tomography (PET) in the vertebral column of lung cancer patients prior to, during, and after treatment. Moreover, to identify radiation- and erlotinib-induced changes in the BM. Twenty-six patients with advanced non-small cell lung cancer, receiving radiotherapy (RT) alone or concomitantly with erlotinib, were examined by [¹⁸F]FDG PET before, during, and after treatment. A total of 61 [¹⁸F]FDG PET scans were analyzed. Vertebral column BM [¹⁸F]FDG standardized uptake value normalized to the liver (SUV_BMLR) was used as uptake measure. Wilcoxon signed-rank test was used to assess changes in BM uptake of [¹⁸F]FDG between sessions. Effects of erlotinib on the BM activity during and after treatment were assessed using Mann-Whitney U test. A homogeneous uptake of [¹⁸F]FDG was observed within the vertebral column prior to treatment. Mean SUV_BMLR (± S.E.M) in the body of thoracic vertebrae receiving a total RT dose of 10 Gy or higher was 0.64 ± 0.01, 0.56 ± 0.01, and 0.59 ± 0.01 at pre-, mid-, and post-therapy, respectively. A significant reduction in the mean SUV_BMLR was observed from pre- to both mid- and post-therapy (p < 0.05). Mean SUV_BMLR was significantly higher at post-therapy compared to mid-therapy for patients receiving erlotinib in addition to RT (p < 0.05). RT reduces BM [¹⁸F]FDG uptake in the vertebral column, especially in the high-dose region. Concomitant erlotinib may stimulate a recovery in BM [¹⁸F]FDG uptake from mid- to post-therapy. NCT02714530. Registered 10 September 2015.

A new method to assess pulmonary changes using 18F-fluoro-2-deoxyglucose positron emission tomography for lung cancer patients following radiotherapy

Wed, 01 Nov 2017 00:00:00 +0000

¹⁸F-fluoro-2-deoxyglucose positron emission tomography (¹⁸F-FDG-PET) may be used for assessing radiation induced alterations in the lung. However, there is a need to further develop methodologies to improve quantification. Using computed tomography (CT), a local structure method has been shown to be superior to conventional CT-based analysis. Here, we investigate whether the local structure method based on ¹⁸F-FDG-PET improves radiotherapy (RT) dose-response quantification for lung cancer patients. Sixteen patients with lung cancer undergoing fractionated RT were examined by ¹⁸F-FDG-PET/CT at three sessions (pre, mid, post) and the lung was delineated in the planning CT images. The RT dose matrix was co-registered with the PET images. For each PET image series, mean (μ) and standard deviation (σ) maps were calculated based on cubes in the lung (3 × 3 × 3 voxels), where the spread in pre-therapy μ and σ was characterized by a covariance ellipse in a sub-volume of 3 × 3 × 3 cubes. Mahalanobis distance was used to measure the distance of individual cube values to the origin of the ellipse and to further form local structure ‘S’ maps. The structural difference maps (ΔS) and mean difference maps (Δμ) were calculated by subtracting pre-therapy maps from maps at mid- and post-therapy. Corresponding maps based on CT images were also generated. ΔS identified new areas of interest in the lung compared to conventional Δμ maps. ΔS for PET and CT gave a significantly elevated lung signal compared to a control group during and post-RT (p < .05). Dose-response analyses by linear regression showed that ΔS between pre- and post-therapy for ¹⁸F-FDG-PET was the only parameter significantly associated with local lung dose (p = .04). The new method using local structures on ¹⁸F-FDG-PET provides a clearer uptake dose-response compared to conventional analysis and CT-based approaches and may be valuable in future studies addressing lung toxicity.

Assessment of pulmonary 18F-FDG-PET uptake and cytokine profiles in non-small cell lung cancer patients treated with radiotherapy and erlotinib

Thu, 15 Jun 2017 00:00:00 +0000

To investigate effects of radiotherapy (RT) and erlotinib on pulmonary glucose uptake using 2-deoxy-2-(18F)fluoro-D-glucose (¹⁸F-FDG) positron emission tomography (PET) during and after treatment of non-small cell lung cancer (NSCLC) and to identify associations between serum cytokine levels and lung glucose uptake. Twenty-seven patients with advanced NSCLC, receiving RT alone or concomitant RT and erlotinib therapy, were examined by ¹⁸F-FDG PET before, during, and after treatment. A total of 57 ¹⁸F-FDG PET scans were analyzed. Pulmonary ¹⁸F-FDG uptake and radiotherapy dose mapping were used to acquire dose-response curves for each patient, where subsequent linear regression gave a glucose uptake level in the un-irradiated parts of the lungs (SUV₀) and a response slope (ΔSUV). Serum cytokine levels at corresponding time points were assessed using a multiplex bioassay. Correlations between the most robust cytokines and lung ¹⁸F-FDG dose response parameters were further investigated. From the dose response analysis, SUV₀ at post-therapy was significantly higher (P < 0.001) than at mid- and pre-therapy (45% and 58%, respectively) for the group receiving RT + erlotinib. Also, SUV₀ at post-therapy was higher for patients receiving RT + erlotinib compared to RT alone (42%; P < 0.001). No differences in ΔSUV were seen with treatments or time. SUV₀ was positively associated (r = 0.47, P = 0.01) with serum levels of the chemokine C-C motif ligand 21 (CCL21) for patients receiving RT + erlotinib. Concomitant RT and erlotinib causes an elevation in pulmonary ¹⁸F-FDG uptake post treatment compared to RT alone. Pulmonary glucose uptake is associated with an upregulation of a chemokine (CCL21) involved in inflammatory reactions.