Definition and validation of a radiomics signature for loco-regional tumour control in patients with locally advanced head and neck squamous cell carcinoma

Purpose: To develop and validate a CT-based radiomics signature for the prognosis of loco-regional tumour control (LRC) in patients with locally advanced head and neck squamous cell carcinoma (HNSCC) treated by primary radiochemotherapy (RCTx) based on retrospective data from 6 partner sites of the German Cancer Consortium - Radiation Oncology Group (DKTK-ROG). Material and methods: Pre-treatment CT images of 318 patients with locally advanced HNSCC were col-lected. Four-hundred forty-six features were extracted from each primary tumour volume and then fil-tered through stability analysis and clustering. First, a baseline signature was developed from demographic and tumour-associated clinical parameters. This signature was then supplemented by CT imaging features. A final signature was derived using repeated 3-fold cross-validation on the discovery cohort. Performance in external validation was assessed by the concordance index (C-Index). Furthermore, calibration and patient stratification in groups with low and high risk for loco-regional recurrence were analysed. Results: For the clinical baseline signature, only the primary tumour volume was selected. The final sig-nature combined the tumour volume with two independent radiomics features. It achieved moderatel

Thoughts on “Estimation of radiation exposure of children undergoing superselective, intra-arterial chemotherapy for retinoblastoma treatment: Assessment of Local Diagnostic Reference Levels as a function of age, sex and interventional success”

<jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>Many techniques for the surgical treatment of gynaecomastia have been reported to be effective with reasonable limited scar formation. The aim of this study was to develop a grade adopted algorithm for effective and scar sparing techniques in reconstruction of the male breast dependent on aetiology and grading.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Operative techniques, results, rates of revisions and complications were recorded between 2006 and 2018 and results of 164 male patients were analysed, retrospectively. Skin resecting methods have been used in the earlier stage but were later replaced by minimal periareolar incisions and subcutaneous mastectomy. Resections were combined with ultrasound-assisted liposuction up to grade 2b and inferior pedicled breast reduction in 3rd degree gynaecomastias resulting in reduction of scars and effective removal of breast tissue.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Retrospective analysis showed that a periareolar mastopexy was used in 24% of patients with gynaecomastia grade I, IIa and IIb to reshape the breast after subcutaneous mastectomy in the early stage of this study from 2006 to 2010. With the established standardised use of ultrasound-assisted liposuction, only 2% of patients required a mastopexy in the following years. In grade 3 gynaecomastia, the classical approach resulting in an inverted t-scar was later abandoned for an approach with a periareolar and submammary scar and inferior dermoglandular flap. The rate of secondary surgery with the used techniques did not increase.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>When using standardised techniques in reshaping the male breast, an aesthetically pleasing and safe result can be achieved by scar sparing techniques in a safe single-stage procedure.</jats:p></jats:sec><jats:sec><jats:title>Level of evidence</jats:title><jats:p>Level IV, therapeutic study.</jats:p></jats:sec&gt

Design and first results of a phantom study on the suitability of iterative reconstruction for lung-cancer screening with low-dose computer tomography

In this research computer tomography (CT) iterative reconstruction (IR) algorithms are investigated, specifically the impact of their statistical and model-based strength on image quality in low-dose lung screening CT protocols in comparison to filtered back projection (FBP). It has been probed whether statistical, model-based IR in conjunction with low-dose, and ultra-low-dose protocols are suitable for lungcancer screening. To this end, artificial lung nodules shaped as spheres and spicules made from material with calibrated Hounsfield units (HU) were attached on marked positions in the lung structure of an anthropomorphic phantom. Nodule positions were selected by distinguished radiologists. The phantom with nodules was scanned on a CT Scanner using standard high contrast (SHC), low-dose (LD) and ultra low-dose (ULD) protocol. For reconstruction FBP and the IR algorithm ADMIRE at three different strength levels were used. Volume CT dose index (CTDIvol) and dose-length product were recorded. Radiologists assessed subjective image quality using a six-point Likert scale by reading all image series in terms detectability of lung nodules. As a measurable objective image quality parameter signal-to-noise ratios (SNR) were investigated. The CTDIvol decreases by more than 70% for all protocols and nodules compared to diagnostic reference value for chest CT (p<0.00001). The evaluation of image quality parameters, i.e. SNR, indicates that LD and ULD protocols in conjunction with IR assert high quality lung-nodule detection. The results reveal that IR algorithm with moderate to high strength is an indispensable alternative to FBP in low-dose scanning, thus, potentially suitable for lung-tumour screening

Combined radiation- and immune checkpoint-inhibitor-induced pneumonitis – The challenge to predict and detect overlapping immune-related adverse effects from evolving laboratory biomarkers and clinical imaging

The risk of overlapping pulmonary toxicity induced by thoracic radio(chemo)therapy and immune checkpoint inhibitor therapy in the treatment of patients suffering from non-small cell lung cancer (NSCLC) is one important challenge in successful radioimmunotherapy. In the present opinion we highlight factors that we find important to be considered before treatment initiation, during the treatment sequence, and after treatment completion combined or sequential application of radio(chemo)therapy and immune checkpoint inhibitor therapy. A major aim is to optimize the therapeutic index and to avoid immune related adverse effects. The goals in the future will be focused not only on identifying patients already in the pretreatment phase who could benefit from this complex treatment, but also in identifying patients, who are most likely to have higher grade toxicity. In this respect, proper assessment of clinical performance status, monitoring for the presence of certain comorbidities, evaluation of laboratory parameters such as TGF-α and IL-6 levels, human leukocyte antigens (HLA), and consideration of other potential biomarkers which will evolve in near future are essential. Likewise, the critical parameters must be monitored during the treatment phase and follow-up care to detect potential side effects in time. With the help of high-end imaging which is already used on a daily basis in image guided radiotherapy (IGRT) for intensity modulated radiotherapy (IMRT), its advanced form volumetric modulated arc therapy (VMAT), and adaptive radiation therapy (ART), clinically relevant changes in lung tissue can be detected at an early stage of disease. Concurrent radiotherapy and immunotherapy requires a special focus on adverse events, particularly of the lung, but, when properly approached and applied, it may offer new perspectives for patients with locally advanced NSCLC to be seriously considered as a curative option

Single- and Dual-Source CT Myelography: Comparison of Radiation Exposure and Establishment of Diagnostic Reference Levels

CT myelography (CTM) is a diagnostic technique for the evaluation of various spinal pathologies, and plays an important role in diagnosis of different diseases such as spontaneous intracranial hypotension and postoperative cerebrospinal fluid leaks. The aims of this study were to examine radiation exposure, establish diagnostic reference levels (DRLs) and compare radiation doses of single- and dual-source examinations and different CTM protocols. In this retrospective study, 183 CTMs comprising 155 single-source and 28 dual-source examinations, performed between May 2015 and December 2020, were analyzed. Dose data included 31 whole spine (A), 23 cervical (B), 10 thoracic (C), and 119 lumbar (D) CTMs. Radiation exposure was reported for volume-weighted CT dose index (CTDIvol) and dose-length product (DLP). Radiation doses for CTDIvol and DLP were distributed as follows (median, IQR): A: 7.44 mGy (6.01–11.17 mGy)/509.7 mGy·cm (382.4–682.9 mGy·cm), B: 9.31 mGy (7.20–14.64 mGy)/214.5 mGy·cm (153.7–308.2 mGy·cm), C: 6.80 mGy (6.14–8.26 mGy)/365.4 mGy·cm (222.8–432.4 mGy·cm), D: 11.02 mGy (7.97–14.89 mGy)/308.0 mGy·cm (224.7–413.7 mGy·cm). Local DRLs could be depicted as follows (CTDIvol/DLP): A: 11 mGy/683 mGy·cm, B: 15 mGy/308 mGy·cm, C: 8 mGy/432 mGy·cm, D: 15 mGy/414 mGy·cm. High image quality was achieved for all anatomical regions. Basically, radiation exposure of CTM differs according to anatomical location

Adaptation Time as a Determinant of the Dosimetric Effectiveness of Online Adaptive Radiotherapy for Bladder Cancer

Interfraction anatomic deformations decrease the precision of radiotherapy, which can be improved by online adaptive radiation therapy (oART). However, oART takes time, allowing intrafractional deformations. In this study on focal radiotherapy for bladder cancer, we analyzed the time effect of oART on the equivalent uniform dose in the CTV (EUDCTV) per fraction and for the accumulated dose distribution over a treatment series as measure of effectiveness. A time-dependent digital CTV model was built from deformable image registration (DIR) between pre- and post-adaptation imaging. The model was highly dose fraction-specific. Planning target volume (PTV) margins were varied by shrinking the clinical PTV to obtain the margin-specific CTV. The EUDCTV per fraction decreased by—4.4 ± 0.9% of prescribed dose per min in treatment series with a steeper than average time dependency of EUDCTV. The EUDCTV for DIR-based accumulated dose distributions over a treatment series was significantly dependent on adaptation time and PTV margin (p CTV for a treatment series. Adaptation time is an important determinant of the precision of oART for one half of the bladder cancer patients, and it should be aimed at to be minimized

Radiation exposure of computed tomography imaging for the assessment of acute stroke

Purpose!#!To assess suspected acute stroke, the computed tomography (CT) protocol contains a non-contrast CT (NCCT), a CT angiography (CTA), and a CT perfusion (CTP). Due to assumably high radiation doses of the complete protocol, the aim of this study is to examine radiation exposure and to establish diagnostic reference levels (DRLs).!##!Methods!#!In this retrospective study, dose data of 921 patients with initial CT imaging for suspected acute stroke and dose monitoring with a DICOM header-based tracking and monitoring software were analyzed. Between June 2017 and January 2020, 1655 CT scans were included, which were performed on three different modern multi-slice CT scanners, including 921 NCCT, 465 CTA, and 269 CTP scans. Radiation exposure was reported for CT dose index (CTDI!##!Results!#!DRLs were assessed for each step (CTDI!##!Conclusion!#!Performing complementary CT techniques such as CTA and CTP for the assessment of acute stroke increases total radiation exposure. Hence, the revised DRLs for the complete protocol are required, where our local DRLs may help as benchmarks

Long-term survival of patients with central or > 7 cm T4 N0/1 M0 non-small-cell lung cancer treated with definitive concurrent radiochemotherapy in comparison to trimodality treatment

Abstarct Background To examine long-term-survival of cT4 cN0/1 cM0 non-small-cell lung carcinoma (NSCLC) patients undergoing definitive radiochemotherapy (ccRTx/CTx) in comparison to the trimodality treatment, neoadjuvant radiochemotherapy followed by surgery, at a high volume lung cancer center. Methods All consecutive patients with histopathologically confirmed NSCLC (cT4 cN0/1 cM0) with a curative-intent-to-treat ccRTx/CTx were included between 01.01.2001 and 01.07.2019. Mediastinal involvement was excluded by systematic EBUS-TBNA or mediastinoscopy. Following updated T4-stage-defining-criteria initial staging was reassessed by an expert-radiologist according to UICC-guidelines [8th edition]. Outcomes were compared with previously reported results from patients of the same institution with identical inclusion criteria, who had been treated with neoadjuvant radiochemotherapy and resection. Factors for treatment selection were documented. Endpoints were overall-survival (OS), progression-free-survival (PFS), and cumulative incidences of isolated loco-regional failures, distant metastases, secondary tumors as well as non-cancer deaths within the first year. Results Altogether 46 consecutive patients with histopathologically confirmed NSCLC cT4 cN0/1 cM0 [cN0 in 34 and cN1 in 12 cases] underwent ccRTx/CTx after induction chemotherapy (iCTx). Median follow-up was 133 months. OS-rates at 3-, 5-, and 7-years were 74.9%, 57.4%, and 57.4%, respectively. Absolute OS-rate of ccRTx/CTx at 5 years were within 10% of the trimodality treatment reference group (Log-Rank p = 0.184). The cumulative incidence of loco-regional relapse was higher after iCTx + ccRT/CTx (15.2% vs. 0% at 3 years, p = 0.0012, Gray’s test) while non-cancer deaths in the first year were lower than in the trimodality reference group (0% vs 9.1%, p = 0.0360, Gray’s test). None of the multiple recorded prognostic parameters were significantly associated with survival after iCTx + ccRT/CTx: Propensity score weighting for adjustment of prognostic factors between iCTx + ccRT/CTx and trimodality treatment did not change the results of the comparisons. Conclusions Patients with cT4 N0/1 M0 NSCLC have comparable OS with ccRTx/CTx and trimodality treatment. Loco-regional relapses were higher and non-cancer related deaths lower with ccRTx/CTx. Definitive radiochemotherapy is an adequate alternative for patients with an increased risk of surgery-related morbidity

Breast Radiation Exposure of 3D Digital Breast Tomosynthesis Compared to Full-Field Digital Mammography in a Clinical Follow-Up Setting

According to a position paper of the European Commission Initiative on Breast Cancer (ECIBC), DBT is close to being introduced in European breast cancer screening programmes. Our study aimed to examine radiation dose delivered by digital breast tomosynthesis (DBT) and digital mammography (FFDM) in comparison to sole FFDM in a clinical follow-up setting and in an identical patient cohort. Retrospectively, 768 breast examinations of 96 patients were included. Patients received both DBT and FFDM between May 2015 and July 2019: (I) FFDM in cranio-caudal (CC) and DBT in mediolateral oblique (MLO) view, as well as a (II) follow-up examination with FFDM in CC and MLO view. The mean glandular dose (MGD) was determined by the mammography system according to Dance&rsquo;s model. The MGD (standard deviation (SD), interquartile range (IQR)) was distributed as follows: (I) (CCFFDM+MLODBT) (a) left FFDMCC 1.40 mGy (0.36 mGy, 1.13&ndash;1.59 mGy), left DBTMLO 1.62 mGy (0.51 mGy, 1.27&ndash;1.82 mGy); (b) right FFDMCC 1.36 mGy (0.34 mGy, 1.14&ndash;1.51 mGy), right DBTMLO 1.59 mGy (0.52 mGy, 1.27&ndash;1.62 mGy). (II) (CCFFDM+MLOFFDM) (a) left FFDMCC 1.35 mGy (0.35 mGy, 1.10&ndash;1.60 mGy), left FFDMMLO 1.40 mGy (0.39 mGy, 1.12&ndash;1.59 mGy), (b) right FFDMCC 1.35 mGy (0.33 mGy, 1.12&ndash;1.48 mGy), right FFDMMLO 1.40 mGy (0.36 mGy, 1.14&ndash;1.58 mGy). MGD was significantly higher for DBT mlo views compared to FFDM (p &lt; 0.001). Radiation dose was significantly higher for DBT in MLO views compared to FFDM. However, the MGD of DBT MLO lies below the national diagnostic reference level of 2 mGy for an FFDM view. Hence, our results support the use of either DBT or FFDM as suggested in the ECIBC&rsquo;s Guidelines

Differences in Radiation Exposure of CT-Guided Percutaneous Manual and Powered Drill Bone Biopsy

Purpose!#!Apart from the commonly applied manual needle biopsy, CT-guided percutaneous biopsies of bone lesions can be performed with battery-powered drill biopsy systems. Due to assumably different radiation doses and procedural durations, the aim of this study is to examine radiation exposure and establish local diagnostic reference levels (DRLs) of CT-guided bone biopsies of different anatomical regions.!##!Methods!#!In this retrospective study, dose data of 187 patients who underwent CT-guided bone biopsy with a manual or powered drill biopsy system performed at one of three different multi-slice CT were analyzed. Between January 2012 and November 2019, a total of 27 femur (A), 74 ilium (B), 27 sacrum (C), 28 thoracic vertebrae (D) and 31 lumbar vertebrae (E) biopsies were included. Radiation exposure was reported for volume-weighted CT dose index (CTDI!##!Results!#!CTDI!##!Conclusion!#!Use of powered drill bone biopsy systems for CT-guided percutaneous bone biopsies can significantly reduce the radiation burden compared to manual biopsy for specific anatomical locations such as ilium and sacrum and does not increase radiation dose or procedural duration for any of the investigated locations.!##!Level of evidence!#!Level 3