Late Sequelae of Radiotherapy

Spatially fractionated radiation therapy: a critical review on current status of clinical and preclinical studies and knowledge gaps

Spatially fractionated radiation therapy (SFRT) is a therapeutic approach with the potential to disrupt the classical paradigms of conventional radiation therapy. The high spatial dose modulation in SFRT activates distinct radiobiological mechanisms which lead to a remarkable increase in normal tissue tolerances. Several decades of clinical use and numerous preclinical experiments suggest that SFRT has the potential to increase the therapeutic index, especially in bulky and radioresistant tumors. To unleash the full potential of SFRT a deeper understanding of the underlying biology and its relationship with the complex dosimetry of SFRT is needed. This review provides a critical analysis of the field, discussing not only the main clinical and preclinical findings but also analyzing the main knowledge gaps in a holistic way.

Knowledge and competences in hematological malignancies amongst radiation oncology residents in Germany-results from a national survey

INTRODUCTION

Radiation oncology is a pivotal modality in the treatment of hematologic malignancies. To enable state-of-the-art patient care, structured education during residency is essential. However, given the lack of detailed data, the scope of educational opportunities available to trainees remains elusive. This prompted our group to perform a national survey amongst radiation oncology residents in Germany assessing the status quo of competences in the treatment of lymphoma and leukemia patients. Furthermore, areas of potential improvement were identified to further the goal of competence-based education for residents.

METHODS

A survey-based analysis was conducted to assess the knowledge and competence of radiation oncology residents in Germany regarding hematological malignancies. A decisive questionnaire covering demographics, self-assessment of competences, and areas for improvement was developed in adaption of a survey by the Association of Residents in Radiation Oncology and distributed amongst 1439 members of the German Society of Radiation Oncology. Responses were collected anonymously via an online survey tool and analyzed using descriptive statistics and chi-square tests.

RESULTS

A total of 59 complete and 22 partial responses were collected, yielding a 5.6% response rate. Participants' competence varied, with notable experience gaps in pediatric cases, proton therapy, and large-field techniques like total-skin irradiation or pediatric total body irradiation. While participants felt confident in treatment planning and patient counseling, they showed deficiencies in the definition of the planning target volume for modern involved site radiotherapy. Resources for education included national and international guidelines, scientific reviews, and textbooks. Board-certified radiation oncologists and physicians from specialized lymphoma centers demonstrated higher overall competence levels.

CONCLUSION

This survey highlights the diversity of resident education regarding hematological malignancies in German radiation oncology programs. Knowledge gaps exist in key areas, including pediatric cases and specialized techniques. Competence-based education, interactive teaching formats, and rotations to specialized centers are potential strategies to address these gaps. The study contributes to the understanding of the federal educational landscape, underscoring the need for standardized and comprehensive training to ensure optimal patient care in hematological malignancies within the context of radiation oncology. Further research and collaborations are warranted to enhance training and expertise in this critical domain.

Influence of demographic change on the demand for radiotherapy using forecasted predictions for prostate cancer in Germany

PURPOSE

Demographic change will lead to an increase in age-associated cancers. The demand for primary treatment, especially oncologic therapies, is difficult to predict. This work is an attempt to project the demand for radiation therapy (RT) in 2030, taking into account demographic changes using prostate cancer (PC) as an example.

MATERIALS AND METHODS

Using the GENESIS database of the Federal Statistical Office, we retrieved demographic population projections for 2030 and retrospective demographic surveys from 1999 to 2019. Additionally, we queried incidence rates for PC in the respective age groups of 50-54, 55-59, 60-64, 65-69, 70-74, 75-79, 80-84, and +85 years from 1999-2019 via the Federal Cancer Registry of the Robert Koch Institute. We used a regression method to determine the age-dependent correlation between the incidence of PC and the population size of the respective age group by combining the data from 1999 to 2019. This information was used to calculate the incidence rates in the age groups of the expected population for 2030 and the expected new cases of PC in 2030. Finally, we extrapolated the indications for the demand for RT based on data from the Report on Cancer Incidence in Germany from 2016.

RESULTS

Considering a population-dependent incidence rate, an increase in new cases of PC is expected. This increase is particularly evident in the age groups of 70-74 and 80-84 years. With regards to RT, the estimate indicates an overall increase of 27.4% in demand. There is also a shift in RT demands towards older patients, especially in the 80- to 84-year-old age group.

CONCLUSION

We observe an age-associated increase in primary cases of PC. This is likely to result in an increased demand for RT. The exact demand cannot be predicted. However, trends can be estimated to plan for the demand. This, though, requires a good database from cancer registries.

Palliative care on the radiation oncology ward-improvements in clinical care through interdisciplinary ward rounds

INTRODUCTION

Palliative care is essential for patients with terminal diseases and aims at effective symptom control. This may stand in opposition to radiation treatment as an oncological treatment modality. The hereby presented work demonstrates the successful integration of a palliative care service in the radiation oncology ward.

METHODS

Since 2015, 1018 patients were seen by the palliative care service on the radiation oncology ward and have been analyzed in this single center study. To assess teaching efficacy of the consultation service, a survey was conducted among 15 radiation oncology residents.

RESULTS

Cooperation between the two departments proved to be efficient with rising patient numbers. Palliative care was able to guide appropriate postdischarge care with the number of patients dying on the radiation oncology ward decreasing significantly (p = 0.009). The main topics for consultation were pain medication (92.3%), organization of postdischarge care (92.3%), and psycho-oncological support (84.6%). Most residents had a positive image of the palliative care service and consented on adjectives like "enriching", "empathic", "collegial", "professionally founded", and a "low threshold for consultation". All participants agreed that cooperation deepened their knowledge on palliative care.

CONCLUSION

A synergistic cooperation between a palliative care consultation service and a radiation oncology department addresses patient symptoms on an individual level. It confers advanced knowledge on palliative care which is essential for resident education and patient treatment.

Radiation doses to mediastinal organs at risk in early-stage unfavorable Hodgkin lymphoma- a risk stratified analysis of the GHSG HD17 trial

Introduction

The German Hodgkin Study Group (GHSG) HD17 trial established the omission of radiotherapy (RT) for patients with early-stage unfavorable Hodgkin lymphoma being PET-negative after 2 cycles of BEACOPP escalated plus 2 cycles of ABVD. This patient group reveals heterogeneity in characteristics and disease extent which prompted us to perform a decisive dosimetric analysis according to GHSG risk factors. This may help to tailor RT individually balancing risks and benefits.

Methods

For quality assurance, RT-plans were requested from the treating facilities (n= 141) and analyzed centrally. Dose-volume histograms were scanned either paper-based or digitally to obtain doses to mediastinal organs. These were registered and compared according to GHSG risk factors.

Results

Overall, RT plans of 176 patients were requested, 139 of which had dosimetric information on target volumes within the mediastinum. Most of these patients were stage II (92.8%), had no B-symptoms (79.1%) and were aged < 50 years (89.9%). Risk factors were present in 8.6% (extranodal involvement), 31.7% (bulky disease), 46.0% (elevated erythrocyte sedimentation rate) and 64.0% (three involved areas), respectively. The presence of bulky disease significantly affected the mean RT doses to the heart (p=0.005) and to the left lung (median: 11.3 Gy vs. 9.9 Gy; p=0.042) as well as V5 of the right and left lung, respectively (median right lung: 67.4% vs. 51.0%; p=0.011; median left lung: 65.9% vs. 54.2%; p=0.008). Significant differences in similar organs at risk parameters could be found between the sub-cohorts with the presence or absence of extranodal involvement, respectively. In contrast, an elevated erythrocyte sedimentation rate did not deteriorate dosimetry significantly. No association of any risk factor with radiation doses to the female breast was found.

Conclusion

Pre-chemotherapy risk factors may help to predict potential RT exposure to normal organs and to critically review treatment indication. Individualized risk-benefit evaluations for patients with HL in early-stage unfavorable disease are mandatory.

Strahlentherapeutische Behandlung von Leukämien

Hintergrund

Ziel der Arbeit

Material und Methoden

Ergebnisse

Schlussfolgerung

Synchronous/Metachronous Multiple Primary Malignancies: Review of Associated Risk Factors

The incidence of secondary primary malignancy (SPM) has been reported to range from 1.33% to 5.8%, according to the location of the primary cancer and the follow-up duration. The highest occurrence rate of SPM, of 36.6% within 6 months, has been reported in lung cancer. Genitourinary malignancies were reported to be the third-most-common SPM in several reports. However, the incidence of genitourinary malignancy as the first primary cancer associated with SPM has not been reported. Several risk factors are related to the occurrence of SPM, including viral infection chemotherapy, radiation, genetics, smoking, betel quid chewing, and environmental factors. An early survey for SPM is indicated in first primary malignancy patients with these associated factors. In this study, we summarize several risk factors related to the occurrence of SPMs and preventive tests, which may help in their early detection and, consequently, better survival.

Definition of an Normal Tissue Complication Probability Model for the Inner Ear in Definitive Radiochemotherapy of Nasopharynx Carcinoma

Background: Definitive radiochemotherapy is the treatment of choice for locally advanced nasopharyngeal carcinoma. Due to the vicinity of the nasopharynx to the inner ear and the use of ototoxic platinum-based chemotherapy, there is a risk for irreversible damage to the auditory system. To avoid or minimize these critical side effects, radiation exposure to each inner ear must be balanced between target volume coverage and toxicity. However, normal tissue complication probability (NTCP) models of the inner ear validated by clinical data are rare. Patients and Methods: This retrospective study investigates the inner ear toxicity of 46 patients who received radio(chemo-)therapy for nasopharyngeal carcinoma at our institution from 2004 to 2021 according to CTCAE 5.0 criteria. For each inner ear, the mean (Dmean) and maximum (Dmax) dose in Gray (Gy) was evaluated and correlated with clinical toxicity data. Based on the data, an NTCP model and a cutoff dose logistic regression model (CDLR) were created. Results: In 11 patients (23.9%) hearing impairment and/or tinnitus was observed as a possible therapy-associated toxicity. Dmean was between 15−60 Gy, whereas Dmax was between 30−75 Gy. There was a dose-dependent, sigmoidal relation between inner ear dose and toxicity. A Dmean of 44 Gy and 65 Gy was associated with inner ear damage in 25% and 50% of patients, respectively. The maximum curve slope (m) was found at 50% and is m=0.013. The Dmax values showed a 25% and 50% complication probability at 58 Gy and 69 Gy, respectively, and a maximum slope of the sigmoid curve at 50% with m=0.025. Conclusion: There is a sigmoidal relation between radiation dose and incidence of inner ear toxicities. Dose constraints for the inner ear of <44 Gy (Dmean) or <58 Gy (Dmax) are suggested to limit the probability of inner ear toxicity <25%.

Strahlentherapeutische Behandlung von Leukämien

Hintergrund

Lymphoide Zellen weisen eine hohe Strahlensensitivität auf, sodass die Strahlentherapie eine sinnvolle Ergänzung der Systemtherapie bei Leukämien darstellt. Vor allem als konditionierende Behandlung vor allogener Stammzelltransplantation ist die Radiotherapie in Form einer Ganzkörperbestrahlung etabliert.

Ziel der Arbeit

Die vorliegende Arbeit ermöglicht einen Überblick über Durchführung und Nebenwirkungen der strahlentherapeutischen Behandlung bei Leukämien. Hierbei werden insbesondere die (Langzeit‑)Nebenwirkungen nach Ganzkörperbestrahlung dargestellt.

Material und Methoden

Es erfolgte eine selektive Literaturrecherche über die Datenbank PubMed zur Radiotherapie von Leukämien und zu Ganzkörperbestrahlungen mit Fokus auf Nebenwirkungen sowie technische und konzeptionelle Neuerungen.

Ergebnisse

Die Ganzkörperbestrahlung ist eine effektive Therapie zur Konditionierung vor allogener Stammzelltransplantation und weist ein diverses, aber beherrschbares, Toxizitätsspektrum mit endokrinen, kardiopulmonalen, okulären, nephrologischen und neurologischen Langzeitnebenwirkungen sowie Sekundärneoplasien auf. Zusätzlich kann eine Radiotherapie in Niedrigdosis effektiv zur Behandlung myeloider Sarkome (Chlorome) angewendet werden.

Schlussfolgerung

Die Vielfalt der Nebenwirkungen nach Ganzkörperbestrahlung erfordert eine interdisziplinäre und langfristige Nachsorgebetreuung durch internistische Onkolog*innen/Transplantationsmediziner*innen und Radioonkolog*innen. Technische Entwicklungen der Strahlentherapie können in Zukunft eine selektive Adressierung des Knochenmarks sowie der lymphatischen Organe realisieren. Aktuell sind diese noch nicht in der klinischen Routine etabliert und werden im Rahmen klinischer Studien evaluiert.

The Burden of Survivorship on Hematological Patients-Long-Term Analysis of Toxicities after Total Body Irradiation and Allogeneic Stem Cell Transplantation

Simple Summary

Total body irradiation is an essential large-field technique enabling myeloablation before allogeneic stem cell transplantation. With its field encompassing all organs, a diverse spectrum of toxicities may arise. This work analyzes long-term pulmonary, cardiac, ocular, neurological and renal toxicities in a monocentric patient cohort and identifies possible risk factors. Both the number of patients and the duration of the follow-up period exceed those of many comparable studies in the literature.

Abstract

Total body irradiation is an effective conditioning modality before autologous or allogeneic stem cell transplantation. With the whole body being the radiation target volume, a diverse spectrum of toxicities has been reported. This fact prompted us to investigate the long-term sequelae of this treatment concept in a large patient cohort. Overall, 322 patients with acute leukemia or myelodysplastic syndrome with a minimum follow-up of one year were included (the median follow-up in this study was 68 months). Pulmonary, cardiac, ocular, neurological and renal toxicities were observed in 23.9%, 14.0%, 23.6%, 23.9% and 20.2% of all patients, respectively. The majority of these side effects were grades 1 and 2 (64.9–89.2% of all toxicities in the respective categories). The use of 12 Gray total body irradiation resulted in a significant increase in ocular toxicities (p = 0.013) and severe mucositis (p < 0.001). Renal toxicities were influenced by the age at transplantation (relative risk: 1.06, p < 0.001) and disease entity. In summary, total body irradiation triggers a multifaceted, but manageable, toxicity profile. Except for ocular toxicities and mucositis, a 12 Gray regimen did not lead to an increase in long-term side effects.

[Strategic approach to pathological fractures]

Pathological tumor-associated fractures are overall rare. They can occur in every age group and every bone. Although tumor-related fractures only form a small proportion of bone fractures, the early recognition of the cause of the fracture and treatment according to oncological guidelines are of enormous importance for affected patients. False treatment is frequently associated with far-reaching negative consequences with respect to the course of the disease. The great challenge is not the expeditious surgical treatment but much more the adequate diagnostics and the incorporation of local fracture treatment into an interdisciplinary overall oncological concept.

Pulmonary Toxicity after Total Body Irradiation-An Underrated Complication? Estimation of Risk via Normal Tissue Complication Probability Calculations and Correlation with Clinical Data

Simple Summary

Total body irradiation is an integral part of many conditioning regimens prior to allogeneic stem cell transplantation. It is a large-field technique affecting all organs at risk, of which the lungs are critical for patient survival. However, the precise rates of long-term pulmonary toxicities are unknown. This analysis provides a large patient cohort with long-term follow-up investigating TBI sequelae. Additionally, we present normal tissue complication probability calculations for acute and chronic lung toxicities to enable comparison between biophysical and real-world data. To our knowledge, this is the first adaption of this model to a total-body irradiation patient cohort, which will help to evaluate the feasibility and appropriateness of this approach.

Abstract

Total body irradiation (TBI) is an essential part of various conditioning regimens prior to allogeneic stem cell transplantation, but is accompanied by relevant (long-term) toxicities. In the lungs, a complex mechanism induces initial inflammation (pneumonitis) followed by chronic fibrosis. The hereby presented analysis investigates the occurrence of pulmonary toxicity in a large patient collective and correlates it with data derived from normal tissue complication probability (NTCP) calculations. The clinical data of 335 hemato-oncological patients undergoing TBI were analyzed with a follow-up of 85 months. Overall, 24.8% of all patients displayed lung toxicities, predominantly pneumonia and pulmonary obstructions (13.4% and 6.0%, respectively). NTCP calculations estimated median risks to be 20.3%, 0.6% and 20.4% for overall pneumonitis (both radiological and clinical), symptomatic pneumonitis and lung fibrosis, respectively. These numbers are consistent with real-world data from the literature and further specify radiological and clinical apparent toxicity rates. Overall, the estimated risk for clinical apparent pneumonitis is very low, corresponding to the probability of non-infectious acute respiratory distress syndrome, although the underlying pathophysiology is not identical. Radiological pneumonitis and lung fibrosis are expected to be more common but require a more precise documentation by the transplantation team, radiologists and radiation oncologists.