MRI-guided Pelvic Radiation Therapy: A Primer for Radiologists.

Radiation therapy (RT) is a core pillar of oncologic treatment, and half of all patients with cancer receive this therapy as a curative or palliative treatment. The recent integration of MRI into the RT workflow has led to the advent of MRI-guided RT (MRIgRT). Using MRI rather than CT has clear advantages for guiding RT to pelvic tumors, including superior soft-tissue contrast, improved organ motion visualization, and the potential to image tumor phenotypic characteristics to identify the most aggressive or treatment-resistant areas, which can be targeted with a more focal higher radiation dose. Radiologists should be familiar with the potential uses of MRI in planning pelvic RT; the various RT techniques used, such as brachytherapy and external beam RT; and the impact of MRIgRT on treatment paradigms. Current clinical experience with and the evidence base for MRIgRT in the settings of prostate, cervical, and bladder cancer are discussed, and examples of treated cases are illustrated. In addition, the benefits of MRIgRT, such as real-time online adaptation of RT (during treatment) and interfraction and/or intrafraction adaptation to organ motion, as well as how MRIgRT can decrease toxic effects and improve oncologic outcomes, are highlighted. MRIgRT is particularly beneficial for treating mobile pelvic structures, and real-time adaptive RT for tumors can be achieved by using advanced MRI-guided linear accelerator systems to spare organs at risk. Future opportunities for development of biologically driven adapted RT with use of functional MRI sequences and radiogenomic approaches also are outlined. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Differentiation of patients with and without prostate cancer using urine 1 H NMR metabolomics.

Prostate cancer (PCa) is one of the most prevalent cancers in men worldwide. For its detection, serum prostate-specific antigen (PSA) screening is commonly used, despite its lack of specificity, high false positive rate, and inability to discriminate indolent from aggressive PCa. Following increases in serum PSA levels, clinicians often conduct prostate biopsies with or without advanced imaging. Nuclear magnetic resonance (NMR)-based metabolomics has proven to be promising for advancing early-detection and elucidation of disease progression, through the discovery and characterization of novel biomarkers. This retrospective study of urine-NMR samples, from prostate biopsy patients with and without PCa, identified several metabolites involved in energy metabolism, amino acid metabolism, and the hippuric acid pathway. Of note, lactate and hippurate-key metabolites involved in cellular proliferation and microbiome effects, respectively-were significantly altered, unveiling widespread metabolomic modifications associated with PCa development. These findings support urine metabolomics profiling as a promising strategy to identify new clinical biomarkers for PCa detection and diagnosis.

Determinants of COVID-19 vaccine acceptance and access among people experiencing homelessness in Germany: A qualitative interview study.

Introduction: People experiencing homelessness face lower life expectancy, higher prevalence of somatic and mental diseases and a more difficult access to healthcare compared to people in secure living. During the COVID-19 pandemic transmission rates were higher among people experiencing homelessness and preventive public health measures were not properly adapted to the specific needs of people experiencing homelessness. Thus, goal of our study was understanding the determinants of acceptability and access of the COVID-19 vaccine. Materials and methods: We conducted a qualitative interview study with twenty guideline interviews with adult people currently experiencing homelessness in Berlin, Germany (August 2021 - April 2022). Participants were approached in a purposive sampling strategy. The interviews were analyzed with qualitative content analysis according to Mayring. Results: Acceptance and attitude toward the COVID-19 vaccine is influenced by confidence in the vaccine as well as in the political and healthcare system, the individual COVID-19 risk perception and sense of collective responsibility. Overall, the acceptance of the vaccine was high among our participants. Facilities offering low threshold COVID-19 vaccines for people experiencing homelessness were perceived as helpful. Language barriers and the need for identity documents were major barriers to access the COVID 19 vaccine. Discussion: People experiencing homelessness are a marginalized and vulnerable group often underrepresented in the public and scientific discourse. During the COVID-19 pandemic, preventive public health measures, including the COVID-19 vaccine, failed to consider specific needs of people experiencing homelessness. Multidimensional strategy to enhance inclusive healthcare are needed to improve access and to reduce discrimination and stigmatization.

Corrigendum: Determinants of COVID-19 vaccine acceptance and access among people experiencing homelessness in Germany: a qualitative interview study.

[This corrects the article DOI: 10.3389/fpubh.2023.1148029.].

Patterns of Failure in High-Grade Soft Tissue Sarcomas of the Extremities and Trunk Wall After Pre- or Postoperative Radiation Therapy.

Purpose: Radiotherapy (RT) is a mainstay of treatment for high-grade soft tissue sarcomas (STS). We sought to examine the pattern of local recurrence (LR) with regard to target volume, clinical course, and tumor characteristics in extremity and trunk wall STS patients receiving pre- or postoperative RT. Methods and Materials: In this retrospective study, LR rates and patterns in 91 adult patients with a primary diagnosis of localized high-grade STS of the extremities and trunk wall treated with pre- or postoperative RT at our institution between 2004 and 2021 were analyzed. Radiation treatment plans and imaging data sets at diagnosis and LR were compared. Results: Seventeen out of 91 (18.7 %) patients developed a LR after a median time of 12.7 months. In 10 out of 13 LRs (76.9%) with available treatment plans and radiographic imaging data at the time of recurrence, the LR occurred within the planned target volume (PTV), 2 LRs were marginal (15.4%, at the edge of the PTV volume), and one relapsed out-of-field (7.7%, outside the PTV volume). Positive surgical margins (microscopic or macroscopic) were found in 5 out of 91 patients (5.5%), 1 of which was found in the 17 patients with LRs (5.9%). Eleven of 13 LR patients (84.6%) with available treatment plans and radiographic imaging data received postoperative RT; the median total RT dose was 60 Gy. Volumetric-modulated arc therapy was used in 10 (76.9%), intensity-modulated RT in 2 (15.4%), and 3-dimensional conformal radiation therapy in 1 (7.7%) of 13 LRs. Conclusions: The majority of LRs occurred within the PTV suggesting that LR is most likely not a consequence of inadequate target volume definition, but rather of radioresistant tumor biology. To further improve local tumor control, future research on the potential of dose escalation with normal tissue sparing, STS subtype-specific tumor biology, radiosensitivity, and surgical technique is indicated.

Preoperative hypofractionated radiotherapy for soft tissue sarcomas: a systematic review.

BACKGROUND: Soft tissue sarcomas (STS) represent a diverse group of rare malignant tumors. Currently, five to six weeks of preoperative radiotherapy (RT) combined with surgery constitute the mainstay of therapy for localized high-grade sarcomas (G2-G3). Growing evidence suggests that shortening preoperative RT courses by hypofractionation neither increases toxicity rates nor impairs oncological outcomes. Instead, shortening RT courses may improve therapy adherence, raise cost-effectiveness, and provide more treatment opportunities for a wider range of patients. Presumed higher rates of adverse effects and worse outcomes are concerns about hypofractionated RT (HFRT) for STS. This systematic review summarizes the current evidence on preoperative HFRT for the treatment of STS and discusses toxicity and oncological outcomes compared to normofractionated RT. METHODS: We conducted a systematic review of clinical trials describing outcomes for preoperative HFRT in the management of STS using PubMed, the Cochrane library, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, Embase, and Ovid Medline. We followed the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Trials on retroperitoneal sarcomas, postoperative RT, and hyperthermia were excluded. Articles published until November 30th, 2021, were included. RESULTS: Initial search yielded 94 articles. After removal of duplicate and ineligible articles, 13 articles qualified for analysis. Eight phase II trials and five retrospective analyses were reviewed. Most trials applied 5 × 5 Gy preoperatively in patients with high-grade STS. HFRT courses did not show increased rates of adverse events compared to historical trials of normofractionated RT. Toxicity rates were mostly comparable or lower than in trials of normofractionated RT. Moreover, HFRT achieved comparable local control rates with shorter duration of therapy. Currently, more than 15 prospective studies on HFRT + / - chemotherapy are ongoing. CONCLUSIONS: Retrospective data and phase II trials suggest preoperative HFRT to be a reasonable treatment modality for STS. Oncological outcomes and toxicity profiles were favorable. To date, our knowledge is mostly derived from phase II data. No randomized phase III trial comparing normofractionated and HFRT in STS has been published yet. Multiple ongoing phase II trials applying HFRT to investigate acute and late toxicity will hopefully bring forth valuable findings.

The role of neoadjuvant radiochemotherapy in the management of localized high-grade soft tissue sarcoma.

BACKGROUND: Standard treatment of soft tissue sarcoma (STS) of the extremities includes limb-sparing surgery combined with pre- or postoperative radiotherapy (RT). The role of perioperative chemotherapy (CTX) remains uncertain. STS patients with high-risk features for local recurrence, distant metastases, and increased mortality may require additional systemic therapy. The objective of this study was to evaluate predictors of outcome regarding local control (LC), overall survival (OS), and freedom from distant metastases (FFDM) in a large single-center cohort of patients suffering from localized high-grade STS (grade 2/3, G2/G3). Special emphasis was put on a subgroup of patients who received combined neoadjuvant radiochemotherapy (RCT). METHODS: Overall, 115 adult STS patients were included in this retrospective study. The median follow-up was 34 months. Twenty-three patients (20.0%) were treated with neoadjuvant RCT, 92 (80.0%) received other therapies (adjuvant RT alone (n = 58); neoadjuvant CTX + adjuvant RT (n = 17); adjuvant RCT (n = 10), neoadjuvant RT alone (n = 7)). To assess potential prognostic factors on LC, OS, and FFDM, univariate (UVA) and multivariable (MVA) Cox proportional hazards models were applied. RESULTS: UVA showed significantly better LC rates in the neoadjuvant RCT group (p = 0.025), with trends in MVA (p = 0.057). The 3-year LC rate was 89.7% in the neoadjuvant RCT group vs. 75.6% in the "other therapies" group. UVA also showed significantly better OS rates in the neoadjuvant RCT group (p = 0.049), however, this was not confirmed in MVA (p = 0.205), the 3-year OS rate was 85.8% for patients treated with neoadjuvant RCT compared to 73.5% in the "other therapies" group. UVA showed significantly better FFDM rates in (p = 0.018) and a trend towards better FFDM rates in MVA (p = 0.059). The 3-year FFDM rate was 89.7% for patients treated with neoadjuvant RCT compared to 65.9% in the "other therapies" group. In the subgroup of patients with G3 STS, neoadjuvant RCT was a significant positive predictor of LC and FFDM in MVA (p = 0.047, p = 0.027) but not for OS. Overall grade 3 and 4 toxicities were significantly higher (p = 0.019) in the neoadjuvant RCT group and occurred in 73.9% vs. 38.0% in patients receiving other therapies. CONCLUSIONS: The results suggest that neoadjuvant RCT might improve LC and FFDM in patients with localized G3 STS while also being associated with increased acute complication rates. Further prospective research is warranted to confirm these findings.