Radiotherapy-induced malignancies: review of clinical features, pathobiology, and evolving approaches for mitigating risk

Adjuvant Radiotherapy and Breast Cancer in Patients with Li-Fraumeni Syndrome: A Critical Review

Background/Objectives: Li-Fraumeni syndrome (LFS) is a disease caused by a germline mutation of the tp53 gene that predisposes the individual to various malignancies, including breast cancer. Its impact on treatment modalities in oncology remains poorly studied. In this critical review, we aimed to retrieve and analyze available data concerning adjuvant radiotherapy in early breast cancer for LFS patients, as well as the current guidelines. Methods: We reviewed articles with LFS patient cohorts that reported secondary malignancy rates after breast adjuvant radiotherapy. Rates of recurrence, when available, were also included. Furthermore, we discussed contemporary radiobiological evidence and guidelines on the subject. Results: Six retrospective studies were reviewed. Five reported much higher rates of secondary malignancies compared to the general population. Additionally, there was no clear trend toward increased locoregional control after adjuvant radiotherapy. Radiobiological data suggest increased radioresistance and radiosensitivity within p53-mutated cells. Guidelines recommend avoiding radiotherapy in LFS patients when possible. Conclusions: Currently, there is no standard treatment or cure for LFS or a germline variant of the TP53 gene. With few exceptions, cancers in people with LFS are treated the same way as cancers in other patients, but research continues into the best way to manage cancers involved in LFS.

Recent Progress in Developing Extracellular Vesicles as Nanovehicles to Deliver Carbohydrate-Based Therapeutics and Vaccines

Cell-derived, nanoscale extracellular vesicles (EVs) have emerged as promising tools in diagnostic, therapeutic, and vaccine applications. Their unique properties including the capability to encapsulate diverse molecular cargo as well as the versatility in surface functionalization make them ideal candidates for safe and effective vehicles to deliver a range of biomolecules including gene editing cassettes, therapeutic proteins, glycans, and glycoconjugate vaccines. In this review, we discuss recent advances in the development of EVs derived from mammalian and bacterial cells for use in a delivery of carbohydrate-based protein therapeutics and vaccines. We highlight key innovations in EVs' molecular design, characterization, and deployment for treating diseases including Alzheimer's disease, infectious diseases, and cancers. We discuss challenges for their clinical translation and provide perspectives for future development of EVs within biopharmaceutical research and the clinical translation landscape.

Navigating the Complexities of Radiation Injuries: Therapeutic Principles and Reconstructive Strategies

Radiation injuries, particularly those resulting from therapeutic or accidental exposure, present complex challenges for medical management. These injuries can manifest localized skin damage or extend to deeper tissues, presenting as various clinical entities that require treatment strategies, ranging from conservative management to complex surgical interventions. Radiation treatment constitutes a fundamental component of neoplastic management, with nearly two out of three oncological instances undergoing it as an element of their therapeutic strategy. The therapeutic approach to radiation injury consists of expanding prophylactic measures while maintaining the efficacy of treatment, such as conservative treatment or local debridement followed by reconstruction. The armamentarium of reconstructive methods available for plastic surgeons, from secondary healing to free tissue transfer, can be successfully applied to radiation injuries. However, the unique pathophysiological changes induced by radiation necessitate a careful and specialized approach for their application, considering the altered tissue characteristics and healing dynamics. The therapeutic strategy is guided by both the severity and progression of the injury, with the primary aim of restoring functionality and aesthetic aspects while simultaneously minimizing the risk of complications. This paper explores the various conditions encompassed by the term "radiation injury," reviews both non-surgical and surgical therapeutic strategies for managing these injuries, and highlights the unique challenges associated with treating irradiated tissues within specific oncological contexts.

CT Angiography-Guided Needle Insertion for Interstitial Brachytherapy in Locally Advanced Cervical Cancer

CT angiography might be a suitable procedure to avoid arterial puncture in combined intracavitary and interstitial brachytherapy for cervical cancer curatively treated with combined chemoradiation and brachytherapy boost. Data in the literature about this technique are scarce. We introduced this method and collected brachytherapy data from patients treated in our department between May 2021 and April 2024. We analyzed the applicator subtype, needle insertion (planned versus implanted), implanted depth and the role of CT angiography in selecting needle trajectories and insertion depths. None of the patients managed through this protocol experienced atrial puncture and consequent hemorrhage. Needle positions were accurately selected with the aid of CT angiography with proper coverage of brachytherapy targets and avoidance of organs at risk. CT angiography is a promising method for guiding needle insertion during interstitial brachytherapy.

Radiation Therapy Technology Advances and Mitigation of Subsequent Neoplasms in Childhood Cancer Survivors

PURPOSE

In this Pediatric Normal Tissue Effects in the Clinic (PENTEC) vision paper, challenges and opportunities in the assessment of subsequent neoplasms (SNs) from radiation therapy (RT) are presented and discussed in the context of technology advancement.

METHODS AND MATERIALS

The paper discusses the current knowledge of SN risks associated with historic, contemporary, and future RT technologies. Opportunities for research and SN mitigation strategies in pediatric patients with cancer are reviewed.

RESULTS

Present experience with radiation carcinogenesis is from populations exposed during widely different scenarios. Knowledge gaps exist within clinical cohorts and follow-up; dose-response and volume effects; dose-rate and fractionation effects; radiation quality and proton/particle therapy; age considerations; susceptibility of specific tissues; and risks related to genetic predisposition. The biological mechanisms associated with local and patient-level risks are largely unknown.

CONCLUSIONS

Future cancer care is expected to involve several available RT technologies, necessitating evidence and strategies to assess the performance of competing treatments. It is essential to maximize the utilization of existing follow-up while planning for prospective data collection, including standardized registration of individual treatment information with linkage across patient databases.

Evaluation of the Minimum Segment Width and Fluence Smoothing Tools for Intensity-modulated Techniques in Monaco Treatment Planning System

Purpose

This study aims to minimize monitor units (MUs) of intensity-modulated treatments in the Monaco treatment planning system while preserving plan quality by optimizing the "Minimum Segment Width" (MSW) and "Fluence Smoothing" parameters.

Materials and Methods

We retrospectively analyzed 30 prostate, 30 gynecological, 15 breast cancer, 10 head and neck tumor, 11 radiosurgery, and 10 hypo-fractionated plans. Original prostate plans employed "Fluence Smoothing" = Off and were reoptimized with Low, Medium, and High settings. The remaining pathologies initially used MSW = 0.5 cm and were reoptimized with MSW = 1.0 cm. Plan quality, including total MU, delivery time, and dosimetric constraints, was statistically analyzed with a paired t-test.

Results

Prostate plans exhibited the highest MU variation when changing "Fluence Smoothing" from Off to High (average ΔMU = -5.1%; P < 0.001). However, a High setting may increase overall MU when MSW = 0.5 cm. Gynecological plans changed substantially when MSW increased from 0.5 cm to 1.0 cm (average ΔMU = -29%; P < 0.001). Organs at risk sparing and planning target volumes remained within 1.2% differences. Replanning other pathologies with MSW = 1.0 cm affected breast and head and neck tumor plans (average ΔMU = -168.38, average Δt = -11.74 s, and average ΔMU = -256.56, average Δt = -15.05 s, respectively; all with P < 0.004). Radiosurgery and hypofractioned highly modulated plans did not yield statistically significant results.

Conclusions

In breast, pelvis, head and neck, and prostate plans, starting with MSW = 1.0 cm optimally reduces MU and treatment time without compromising plan quality. MSW has a greater impact on MU than the "Fluence Smoothing" parameter. Plans with high modulation might present divergent behavior, requiring a case-specific analysis with MSW values higher than 0.5 cm.

PTCOG Gastrointestinal Subcommittee Lower Gastrointestinal Tract Malignancies Consensus Statement

Purpose

Radiotherapy delivery in the definitive management of lower gastrointestinal (LGI) tract malignancies is associated with substantial risk of acute and late gastrointestinal (GI), genitourinary, dermatologic, and hematologic toxicities. Advanced radiation therapy techniques such as proton beam therapy (PBT) offer optimal dosimetric sparing of critical organs at risk, achieving a more favorable therapeutic ratio compared with photon therapy.

Materials and Methods

The international Particle Therapy Cooperative Group GI Subcommittee conducted a systematic literature review, from which consensus recommendations were developed on the application of PBT for LGI malignancies.

Results

Eleven recommendations on clinical indications for which PBT should be considered are presented with supporting literature, and each recommendation was assessed for level of evidence and strength of recommendation. Detailed technical guidelines pertaining to simulation, treatment planning and delivery, and image guidance are also provided.

Conclusion

PBT may be of significant value in select patients with LGI malignancies. Additional clinical data are needed to further elucidate the potential benefits of PBT for patients with anal cancer and rectal cancer.

Clinical Features of Li-Fraumeni Syndrome in Korea

PURPOSE

Li-Fraumeni syndrome (LFS) is a hereditary disorder caused by germline mutation in TP53. Owing to the rarity of LFS, data on its clinical features are limited. This study aimed to evaluate the clinical characteristics and prognosis of Korean patients with LFS.

MATERIALS AND METHODS

Patients who underwent genetic counseling and confirmed with germline TP53 mutation in the National Cancer Center in Korea between 2011 and 2022 were retrospectively reviewed. Data on family history with pedigree, types of mutation, clinical features, and prognosis were collected.

RESULTS

Fourteen patients with LFS were included in this study. The median age at diagnosis of the first tumor was 32 years. Missense and nonsense mutations were observed in 13 and one patients, respectively. The repeated mutations were p.Arg273His, p.Ala138Val, and pPro190Leu. The sister with breast cancer harbored the same mutation of p.Ala138Val. Seven patients had multiple primary cancers. Breast cancer was most frequently observed, and other types of tumor included sarcoma, thyroid cancer, pancreatic cancer, brain tumor, adrenocortical carcinoma, ovarian cancer, endometrial cancer, colon cancer, vaginal cancer, skin cancer, and leukemia. The median follow-up period was 51.5 months. Two and four patients showed local recurrence and distant metastasis, respectively. Two patients died of leukemia and pancreatic cancer 3 and 23 months after diagnosis, respectively.

CONCLUSION

This study provides information on different characteristics of patients with LFS, including types of mutation, types of cancer, and prognostic outcomes. For more appropriate management of these patients, proper genetic screening and multidisciplinary discussion are required.

Crosstalk between Oxidative Stress and Inflammation Induced by Ionizing Radiation in Healthy and Cancerous Cells

Radiotherapy (RT) is a unique modality in cancer treatment with no replacement in many cases and uses a tumoricidal dose of various ionizing radiation (IR) types to kill cancer cells. It causes oxidative stress through reactive oxygen species (ROS) production or the destruction of antioxidant systems. On the other hand, RT stimulates the immune system both directly and indirectly by releasing danger signals from stress-exposed and dying cells. Oxidative stress and inflammation are two reciprocal and closely related mechanisms, one induced and involved by the other. ROS regulates the intracellular signal transduction pathways, which participate in the activation and expression of pro-inflammatory genes. Reciprocally, inflammatory cells release ROS and immune system mediators during the inflammation process, which drive the induction of oxidative stress. Oxidative stress or inflammation-induced damages can result in cell death (CD) or survival mechanisms that may be destructive for normal cells or beneficial for cancerous cells. The present study has focused on the radioprotection of those agents with binary effects of antioxidant and anti-inflammatory mechanisms IR-induced CD.

Radiation-associated secondary malignancies: a novel opportunity for applying immunotherapies

Radiation is commonly used as a treatment intended to cure or palliate cancer patients. Despite remarkable advances in the precision of radiotherapy delivery, even the most advanced forms inevitably expose some healthy tissues surrounding the target site to radiation. On rare occasions, this results in the development of radiation-associated secondary malignancies (RASM). RASM are typically high-grade and carry a poorer prognosis than their non-radiated counterparts. RASM are characterized by a high mutation burden, increased T cell infiltration, and a microenvironment that bears unique inflammatory signatures of prior radiation, including increased expression of various cytokines (e.g., TGF-β, TNF-α, IL4, and IL10). Interestingly, these cytokines have been shown to up-regulate the expression of PD-1 and/or PD-L1-an immune checkpoint receptor/ligand pair that is commonly targeted by immune checkpoint blocking immunotherapies. Here, we review the current understanding of the tumor-immune interactions in RASM, highlight the distinct clinical and molecular characteristics of RASM that may render them immunologically "hot," and propose a rationale for the formal testing of immune checkpoint blockade as a treatment approach for patients with RASM.

Utility of PET-CT in Newly Diagnosed HPV-Associated Oropharyngeal Squamous Cell Carcinoma

OBJECTIVE

To compare the utility of positron emission tomography-computed tomography (PET-CT) versus contrasted CT neck combined with routine chest imaging for disease staging and treatment planning in human papillomavirus (HPV) associated oropharyngeal squamous cell carcinoma (OPSCC) with clinically evident sites of primary disease.

METHODS

All adult patients with primary HPV-associated OPSCC at a single quaternary care cancer center from 2018 to 2019 were reviewed, and those with images available for re-review were included. Primary outcomes included concordance in clinical staging between the 2 imaging modalities of interest (PET-CT vs CT), as well as independent agreement of each with pathologic staging. Analysis was performed via ordinal logistic regression. A secondary outcome was treatment selection after diagnostic imaging, analyzed via chi-squared testing.

RESULTS

In total, 100 patients were included for evaluation, of which 89% were male, 91% Caucasian, and mean age was 61.2 years (SD 9.6). Clinical disease staging agreed between imaging modalities in 95% of cases (54 of 57 patients). Pathologic staging agreed with clinical staging from CT neck in 93% of cases (25 of 27 patients; P = .004), and with PET-CT in 82% (14 of 17 patients; P =.003). No differences were observed between the 2 imaging modalities for subsequent treatment selection (P = .39).

CONCLUSION

In uncomplicated HPV-associated OPSCC, CT offers equivalent diagnostic accuracy to that of combined whole-body PET-CT for clinical staging, and has no appreciable impact on treatment selection. A reduced reliance on routine PET-CT during initial workup of HPV-associated OPSCC may be favorable for otherwise healthy patients with clinically evident sites of primary disease.

Performance of ACR TI-RADS and the Bethesda System in Predicting Risk of Malignancy in Thyroid Nodules at a Large Children's Hospital and a Comprehensive Review of the Pediatric Literature

While thyroid nodules are less common in children than in adults, they are more frequently malignant. However, pediatric data are scarce regarding the performance characteristics of imaging and cytopathology classification systems validated to predict the risk of malignancy (ROM) in adults and select those patients who require fine-needle aspiration (FNA) and possibly surgical resection. We retrospectively reviewed the electronic medical records of all patients 18 years of age or younger who underwent thyroid FNA at our institution from 1 July 2015 to 31 May 2022. Based on surgical follow-up from 74 of the 208 FNA cases, we determined the ROM for the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) ultrasound risk stratification system and The Bethesda System for Reporting Thyroid Cytopathology and added our results to those of pediatric cohorts from other institutions already published in the literature. We found the following ROMs for 1458 cases using ACR TI-RADS (TR): TR1. Benign: 2.2%, TR2. Not Suspicious: 9.3%, TR3. Mildly Suspicious: 16.6%, TR4. Moderately Suspicious: 27.0%, and TR5. Highly Suspicious 76.5%; and for 5911 cases using the Bethesda system: Bethesda I. Unsatisfactory: 16.8%, Bethesda II. Benign: 7.2%, Bethesda III: Atypia of Undetermined Significance: 29.6%, Bethesda IV. Follicular Neoplasm: 42.3%, Bethesda V. Suspicious for Malignancy: 90.8%, and Bethesda VI. Malignant: 98.8%. We conclude that ACR TI-RADS levels imply higher ROMs for the pediatric population than the corresponding suggested ROMs for adults, and, in order to avoid missing malignancies, we should consider modifying or altogether abandoning size cutoffs for recommending FNA in children and adolescents whose thyroid glands are smaller than those of adults. The Bethesda categories also imply higher ROMs for pediatric patients compared to adults.

Composite haemangioendothelioma in the heart: a case report

BACKGROUND

Primary cardiac neoplasm is rare and generally benign. Epithelioid haemangioendothelioma, a potentially malignant tumour of vascular origin, has been occasionally described in the heart. Composite haemangioendothelioma, characterized by a heterogeneous architecture of vascular components and usually located in soft tissue of the extremities, has only been reported twice in the heart. We herein report another case of this extremely uncommon cardiac tumour.

CASE SUMMARY

Comprehensive cardiac examination of a 59-year-old female patient with palpitations and personal history of Hodgkin's lymphoma and chest radiation revealed a mass in the left atrium. After surgical resection, histopathological and immunohistochemical analysis identified a composite haemangioendothelioma. After two years, repeated imaging revealed neither signs of local relapse nor metastasis.

CONCLUSIONS

Composite haemangioendothelioma, a very uncommon form of potentially malignant vascular tumour, can also be encountered in the heart. In this present case, the outcome was favourable two years after surgical resection without adjuvant therapy.

Comparison of Clinical Outcomes, Pathologic Characteristics, and Immune-Related Features of Postradiation vs Sporadic Oral Cavity Squamous Cell Carcinoma

Importance

Postradiation oral cavity squamous cell carcinoma (OCSCC) is a common secondary malignant neoplasm affecting survivors of head and neck cancer who underwent radiotherapy. The clinical, pathologic, and immune-related features of postradiation OCSCC are poorly characterized, and treatment options are limited because of surgical difficulty and high morbidity associated with reirradiation.

Objective

To determine whether postradiation OCSCC has distinctive clinical, pathologic, and immune-related features compared with demographic-matched sporadic OCSCC.

Design, Setting, and Participants

This retrospective matched cohort study was conducted at a single tertiary oncology center in Hong Kong. Participants included consecutive patients with OCSCC diagnosed between 2000 and 2020. Patients with postradiation OCSCC were matched with patients with sporadic OCSCC using age, year of diagnosis, sex, and anatomic subsites. Data analysis was performed from July to December 2022.

Exposure

Head and neck irradiation involving the oral cavity before the diagnosis of OCSCC.

Main Outcomes and Measures

The primary outcomes were relapse pattern, survival, and causes of death. Pathologic features; immunohistochemical staining for programmed death-ligand 1, PD-1, MSH6, PMS2, FOXP3, and Ki67; and mRNA expression of 31 immune-related genes were also analyzed.

Results

A total of 173 patients, 60 with postradiation OCSCC (median [IQR] age, 63.8 [53.0-71.7] years; 43 men [71.7%]) and 113 with sporadic OCSCC (median [IQR] age, 64.4 [52.8-70.6] years; 83 men [73.5%]), were included. Patients with postradiation OCSCC had a higher proportion of N0 disease than those with sporadic OCSCC (50 patients [83.3%] vs 56 patients [49.6%]). With a median (IQR) follow-up of 10.2 (1.2-20.5) years, the 10-year relapse-free survival rates were lower in patients with postradiation OCSCC than sporadic OCSCC (29.6% [95% CI, 17.1%-43.2%] vs 52.4% [95% CI, 41.8%-62.0%]; P = .04), and the same was true for overall survival (30.5% [95% CI, 17.6%-44.4%] vs 52.3% [95% CI, 41.4%-62.1%]; P = .03). All relapses in patients with postradiation OCSCC were locoregional, whereas 35.2% of relapses (12 of 34 patients) in patients with sporadic OCSCC were distant. Despite similar 10-year disease-specific survival rates between the 2 groups (68.8% [95% CI, 55.8%-81.0%] vs 67.1% [95% CI, 57.5%-76.5%]; P = .91), patients with postradiation OCSCC had excess mortality due to pneumonia and cerebrovascular events. Postradiation OCSCC exhibited more adverse pathologic features (perineural invasion, worse pattern of invasion, and tumor budding), higher PD-1 expression, and higher gene expression of CD4 and TGF-β compared with sporadic OCSCC.

Conclusions and Relevance

This retrospective matched cohort study found distinctive pathologic characteristics and relapse patterns of postradiation OCSCC compared with sporadic OCSCC, which may be attributable to the lack of adjuvant radiotherapy, aggressive biologic phenotype, and different host immune response. Further exploration of the role of immune checkpoint therapy may be justified.

Adult Cancer-Related Emergency Department Utilization: An Analysis of Trends and Outcomes From Emergency Departments in Maryland and New York

PURPOSE

To explore emergency department (ED) visits by adults with cancer and to estimate associations between inpatient admissions through the ED and mortality with sociodemographic and clinical factors within this cohort.

METHODS

We conducted a retrospective, pooled, cross-sectional analysis of the Healthcare Cost and Utilization State Emergency Department Databases and State Inpatient Databases for Maryland and New York from January 2013 to December 2017. We examined inpatient admissions through the ED and mortality using frequencies. Among patients with cancer, multivariable regressions were used to estimate sociodemographic and clinical factors associated with inpatient admissions and outpatient ED and inpatient mortality overall.

RESULTS

Among 22.7 million adult ED users, 1.3 million (5.7%) had at least one cancer-related diagnosis. ED visit rates per 100,000 population increased annually throughout the study period for patients with cancer and were 9.9% higher in 2017 compared with 2013 (2013: 303.5; 2017: 333.6). Having at least one inpatient admission (68.7% v 20.5%; P < .001) and inpatient or ED mortality (6.5% v 1.0%; P < .001) were higher among ED users with cancer compared with those without. Among patients with cancer, being uninsured (adjusted odds ratio, 0.52; 95% CI, 0.44 to 0.62) compared with having Medicare coverage and non-Hispanic Black (adjusted odds ratio, 0.86; 95% CI, 0.80 to 0.92) compared with non-Hispanic White were associated with decreased odds of inpatient admissions. In contrast, patients with cancer without health insurance, non-Hispanic Black patients, and residents of nonlarge metropolitan areas and of areas with lower household incomes had increased odds of mortality.

CONCLUSION

High inpatient admissions through the ED and mortality among adult patients with cancer, coupled with an increase in cancer-related ED visit rates and observed disparities in outcomes, highlight the need to improve access to oncologic services to contain ED use and improve care for patients with cancer.

Targeting miR-5088-5p attenuates radioresistance by suppressing Slug

Radiotherapy is widely used for cancer treatment, but paradoxically, it has been reported that surviving cancer cells can acquire resistance, leading to recurrence or metastasis. Efforts to reduce radioresistance are required to increase the effectiveness of radiotherapy. miRNAs are advantageous as therapeutic agents because it can simultaneously inhibit the expression of several target mRNAs. Therefore, this study discovered miRNA that regulated radioresistance and elucidated its signaling mechanism. Our previous study confirmed that miR-5088-5p was associated with malignancy and metastasis in breast cancer. As a study to clarify the relationship between radiation and miR-5088-5p identified as onco-miRNA, it was confirmed that radiation induced hypomethylation of the promoter of miR-5088-5p and its expression increased. On the other hand, miR-5088-5p inhibitors were confirmed to reduce radiation-induced epithelial-mesenchymal transition, stemness, and metastasis by reducing Slug. Therefore, this study showed the potential of miR-5088-5p inhibitors as therapeutic agents to suppress radioresistance.

Primary Cutaneous B-Cell Lymphoma Co-Existing with Mycosis Fungoides-A Case Report and Overview of the Literature

The existence of two sequential lymphomas, one localized and one systemic, either both with B or T lymphocytes, or one with B cells and one with T cells, with the same patient, is a known possibility. The second lymphoma is often induced by immunodepression or by the initial treatment. However, the existence of two cutaneous lymphomas with different cell lines, without systemic involvement, represents an uncommon situation. In this report, we describe the case of a 37-year-old man with an initial diagnosis of PMZBCL that over 10 months also developed a MF patch/plaque on the left leg.

A Dosimetric and Radiobiological Comparison of Intensity Modulated Radiotherapy, Volumetric Modulated Arc Therapy and Helical Tomotherapy Planning Techniques in Synchronous Bilateral Breast Cancer

OBJECTIVE

The present investigation intends to identify the optimal radiotherapy treatment plan for synchronous bilateral breast cancer (SBBC) using dosimetric and radiobiological indexes for three techniques, namely, helical tomotherapy (HT), volumetric modulated arc therapy (VMAT), and intensity-modulated radiotherapy (IMRT).

METHODS

Twenty SBBC treated female patients treatment planning data (average age of 52.5 years) were used as the sample for the present study. Three different plans were created using 50 Gy in a 25 fraction dose regime. Poisson, Niemierko, and LKB models were applied for calculating normal tissue complication probability (NTCP) and tumour control probability (TCP).

RESULT

The target average dose comparison between IMRT with HT and VMAT with HT was highly substantial (P=0.001). The percentage of TCP for IMRT, VMAT, and HT in the Poisson model were 93.70±0.28, 94.68±0.30, and 94.34±0.57, respectively (p<0.05). The dose maximum was lower for the whole lung in the HT plan, with an average dose of 49.31Gy±3.9 (p<0.009). The NTCP values of both Niemierko and LKB models were lower for the heart, lungs, and liver for the IMRT plan.

CONCLUSION

The sparing of organs at risk was higher in the HT plan dosimetrically, and the TCP was higher in the three techniques. The comparison between the three techniques shows that the IMRT and HT techniques could be considered for treating SBBC.

BCG Administration after Prior Radiation Treatment for Prostate Cancer

INTRODUCTION

Prostate radiotherapy is associated with worse oncologic outcomes in patients with bladder cancer. The underlying mechanism is incompletely understood but is thought to be related to an altered microenvironment promoting tumorigenesis. However, there is a gap in the literature regarding how the effect of BCG varies according to prior radiotherapy in patients with non-muscle invasive bladder cancer (NMIBC). In this context, we sought to evaluate oncologic outcomes in NMIBC patients who have previously undergone prostate radiotherapy compared to patients with no prior history of pelvic radiotherapy.

METHODS

This is a retrospective cohort study that includes all patients who received intravesical for NMIBC at our institution from 2001 to 2019. Patients were stratified into 3 cohorts: prior radiotherapy (RT), radical prostatectomy (RP), and no prostate cancer (No PCa). The outcomes of interest were recurrence at 1-year, progression to muscle-invasive bladder cancer (MIBC), and progression to metastatic disease. Comparisons were also made between cohorts with respect to elapsed time from radiation therapy. Wilcoxon rank-sum test was used for comparing continuous variables, while χ² and Fischer's exact tests were used to examine categorical variables.

RESULTS

In 199 total patients who underwent BCG for NMIBC, 23 had a prior history of prostate radiotherapy treatment, while 17 underwent prior radical prostatectomy. Overall, 41.2% of patients had recurrence at 1 year. There was no difference in the number of induction or maintenance BCG administrations received between the cohorts within the first year. There was no significant difference in recurrence at 1 year between the 3 cohorts (P = .56). There was also no difference in progression to MIBC or progression to metastatic disease with P = .50 and 0.89, respectively.

CONCLUSION

The risk of recurrence after induction BCG treatment for high-grade NMIBC does not vary according to prior radiation treatment for prostate cancer.

Considerations for carcinogenesis countermeasure development using mouse models

Activities in space will expose humans to profoundly new environments, challenging human performance and will require innovative supportive technologies. Among these environmental variables, exposure to ionizing radiation is a major concern for astronauts, as the long-term effects of exposure on diverse tissues are poorly understood. This need however creates opportunities for novel approaches, particularly in the development of countermeasures against the effects of ionizing radiation exposure. Carcinogenesis presents a unique challenge as a disease process, due to the inherent complexities of the process and the challenges of obtaining a large volume of clinical evidence. Thus, developing the countermeasures to address potential effects of ionizing radiation exposure will require understanding biological underpinnings to design countermeasures effectively in conjunction with highly robust modeling approaches to test and examine in vivo. This review will highlight specific considerations for accelerated development of space radiation countermeasures against carcinogenesis.

Colorectal cancer risk in association with colorectal cancer as a second malignancy in relatives: a nationwide cohort study

Background

Increasing number of individuals will have first-degree relatives (FDRs) diagnosed with colorectal cancer (CRC), as a second primary malignancy (CRCa-2) after a non-CRC cancer. We aimed to estimate whether and to what extent a family history of CRCa-2 is associated with an increased CRC risk.

Methods

In this Swedish nationwide cohort study, rate ratio (RR) and cumulative incidence of CRC were estimated among 172,531 individuals with a family history of CRC as a first primary malignancy (CRCa-1) and 17,830 with a family history of CRCa-2, respectively, using individuals without cancer family history as the reference group.

Results

A cumulative incidence of CRC by age 80 was 6.3 and 5.6% for individuals with a parental and a sibling family history of CRCa-2, respectively. RRs of CRC for one FDR diagnosed with CRCa-1 and CRCa-2 were respectively 1.72 (95% CI, 1.65–1.79) and 1.50 (1.32–1.70); the latter RR was lower than the former (P = 0.0356), but no difference was observed after adjusting age of diagnosis of CRC in FDR and family relationship (P = 0.6898). Increased RRs were found to be associated with a CRCa-2 diagnosis in FDR that occured after cancers in upper aerodigestive tract, breast, prostate, kidney and nervous system.

Conclusions

Individuals who have relatives with CRCa-2 have an increased risk of CRC, but the magnitude is lower than those having relatives with CRCa-1, which is related to different ages of diagnosis of CRC in FDR and family relationships.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10000-z.

“Low Dose MR” Dixon Technique for Imaging FDG PET-MR Lymphoma

Introduction  Hybrid PET-MR is a relatively new imaging modality with its major strength being the MR component offering superior soft tissue contrast. While PET/MRI offers the inherent advantage of reduced radiation dose, it has been shown to result in a markedly prolonged examination time becoming a challenge in children and sick patients. "Low dose MRI" is a term used in the nuclear medicine community to describe fast acquired PET-MR scan protocols that rely heavily on PET images for diagnosis. In this study, we sought to determine if the Dixon sequences obtained for attenuation correction could be used as a diagnostic sequence for interpreting PET-MRI lymphoma cases, potentially reducing scan time.

Materials and Methods  We retrospectively identified 40 patients who underwent ⁸⁸ FDG PET-MR body imaging studies for staging or restaging lymphoma. A radiologist and nuclear medicine physician initially reviewed top of the head to mid thigh PET images, attenuation correction coronal Dixon MRI sequences, and PET-MR fusion with Dixon sequence. The same physicians reviewed the PET images, multi-sequence MR including the attenuation correction Dixon, and multi-sequence PET-MR fusion images The lesions were further characterized based on their imaging characteristics, size, SUVmax, and malignant potency. A consensus read followed.

Results   All patients were adults with an average study age of 43.8 years. Our study consisted of 40 females and 48 males out of which 7 were for staging and 81 were for re-staging. All patients had systemic lymphoma. Thirty-seven of the studies had active lymph nodes on Dixon PET-MR that agreed with multi-sequence PET-MR which identified 33 positive cases (89.1%) having an average SUV 10.2 ± 7.74 SD. Four Dixon PET-MR cases did not detect lesions, with an average SUV 2.3 ± 0.55 SD, which was read as minimal residual activity. Multi-sequence MR identified 11 patients with enlarged lymph nodes without FDG uptake, which were not seen on Dixon MR. All 5 studies with bones lesions were detected by Dixon PET-MR as well as 2 soft tissue organ lesions. Multi-sequence MR identified 1 patient with non-active, healed bone lesion. Fifty-five of these studies were true negatives. Compared to multi-sequence PET-MR, Dixon PET-MR demonstrated 89.2% sensitivity, 100% specificity with no false positive studies.

Conclusion   The present study investigated the diagnostic potential of a fast protocol for integrated PET/MRI used for dedicated tumor staging of patients with lymphoma. In this retrospective study, Dixon PET-MR was shown to be sensitive and specific compared to multi-sequence PET-MR in the detection of lymphoma. The low number of these cases not detected had minimally active lymph nodes that resolved on subsequent imaging and probably were not clinically important.

High Prevalence of Gene Fusions and Copy Number Alterations in Pediatric Radiation Therapy-Induced Papillary and Follicular Thyroid Carcinomas

Background: Childhood cancer survivors and bone marrow transplant recipients treated with radiation therapy (RT) are at increased risk for subsequent thyroid cancer. However, the genetic landscape of pediatric thyroid cancer, both primary and RT-induced, remains poorly defined, as pediatric papillary thyroid carcinoma (PTC) has been understudied compared with adults and data on pediatric follicular thyroid carcinoma (FTC) are virtually nonexistent. The objective of this study was to characterize and compare the molecular profiles of pediatric RT-induced PTC and FTC cases with primary pediatric thyroid cancers. Methods: A total of 41 differentiated thyroid carcinomas (11 RT cases and 30 primary cases) from 37 patients seen at Phoenix Children's Hospital between January 1, 2010 and December 31, 2019 were evaluated by targeted next-generation sequencing and/or BRAF immunohistochemistry. Results: Eighty-six percent (6/7) of RT-PTC harbored a gene fusion (GF) compared with 56% (14/25) of primary PTC; 14% (1/7) of RT-PTC had a single-nucleotide variant (SNV; specifically, a point mutation in the DICER1 gene) compared with 44% (11/25) of primary PTC (all of the latter had the BRAF^V600E mutation). An exceedingly rare ROS1 fusion was identified in a child with RT-PTC. With respect to FTC, copy number alterations (CNAs) were seen in 75% (3/4) of RT cases compared with 40% (2/5) of primary cases. None of the RT-FTC had SNVs compared with 100% (5/5) of primary FTC. Conclusions: In children, the molecular profile of subsequent RT-induced thyroid cancers appears to differ from primary (sporadic and syndromic) cases, with a high prevalence of GFs in RT-PTC (similar to PTC occurring after the Chernobyl nuclear reactor accident) and CNAs in RT-FTC. A better understanding of the molecular mechanisms underlying these cancers may lead to more accurate diagnosis, prognosis, and treatment, as some of the genomic alterations are potentially targetable.

Risk of second primary neoplasms of the central nervous system

Purpose

Second primary (SP) neoplasms of the central nervous system (CNS) among cancer survivors are devastating but poorly understood processes. The absolute risk, or true incidence, of developing an SP CNS tumor among cancer survivors is not well characterized.

Methods and Materials

Patients diagnosed with cancer between 1975 and 2016 were queried using the Surveillance, Epidemiology, and End Results Program. Cumulative incidence rates (CIRs) were estimated using competitive risk analysis. The effects of covariates were assessed using multivariate competitive risk regression.

Results

More than 3.8 million patient records were extracted. The absolute risk of developing an SP CNS neoplasm at 25 years was highest among long-term survivors of CNS cancers (CIR, 6.6%). Cranial radiation increased the incidence of SP tumors in pediatric patients (25-year CIR, 5.7% vs 1.1%; P = .0012) but not adults (25-year CIR, 5.8% vs 5.0%; P = .66). Multivariate cumulative risk regression identified radiation among pediatric patients as the greatest risk for an increased CIR (subdistribution hazard ratio, 2.50; 95% CI, 1.86-3.38; P = 2e-9). Meningiomas (42.9% vs 24.1%; P = 2e-7) and glioblastomas (20.5% vs 14.5%; P = .046) represented a greater proportion of the SP CNS tumors in those who received cranial irradiation. The median age of an SP diagnosis was decreased among those who received prior radiation (41 years [interquartile range (IQR), 30-65 years] vs 49 years [IQR, 30-65 years]; P = 7e-5).

Conclusions

The risk of developing a second primary CNS neoplasm is elevated in patients with a prior CNS cancer independent of treatment history. The association between cranial radiation therapy and risk for subsequent cancers may be limited to the pediatric population.

Does Radioactive Iodine Therapy for Hyperthyroidism Cause Cancer?

Radioactive iodine has been considered a safe and effective therapeutic option for hyperthyroidism secondary to Graves disease and autonomously functioning thyroid nodules since the mid-20th century. The question of whether I-131 at the doses used for hyperthyroidism might increase the risk of cancer has been investigated in a number of observational cohort studies over the years, with the preponderance of evidence being reassuring as to its safety. In particular, the 1998 Cooperative Thyrotoxicosis Therapy Follow-up Study (CTTFUS) has been widely cited as compelling evidence that I-131 is safe in hyperthyroidism therapy with respect to carcinogenesis. However, in 2019, a study by Kitahara and colleagues re-analyzed the CTTFUS cohort, extending the follow-up time and applying a novel dosimetric model for estimating tissue absorbed doses of radiation. This new analysis concluded that radioactive iodine was associated with an increased risk for mortality from overall cancer, breast cancer, and non-breast solid cancers. Reaction to this study was vociferous and particularly negative in the nuclear medicine literature. This mini-review was inspired by the 2019 CTTFUS controversy, and it is intended to provide the necessary context for clinicians to provide nuanced advice to their patients on the subject. To that end, the pre-2019 literature is surveyed, the 2019 CTTFUS study and a 2020 follow-up are discussed, and lessons from the literature and critical commentaries are considered.

Defining the molecular features of radiation-induced glioma: A systematic review and meta-analysis

Background

Cranial radiation therapy is essential in treating many pediatric cancers, especially brain tumors; however, its use comes with the risk of developing second malignancies. Cranial radiation-induced gliomas (RIGs) are aggressive high-grade tumors with a dismal prognosis, for which no standard therapy exists. A definitive molecular signature for RIGs has not yet been established. We sought to address this gap by performing a systematic review and meta-analysis of the molecular features of cranial RIGs.

Methods

A systematic review of the literature was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Articles and case reports that described molecular analyses of cranial radiation-induced high-grade gliomas were identified and evaluated, and data extracted for collation.

Results

Of 1727 records identified, 31 were eligible, containing 102 unique RIGs with molecular data. The most frequent genetic alterations in RIGs included PDGFRA or TP53 mutations, PDGFRA or CDK4 amplifications, and CDKN2A deletion, along with 1q gain, 1p loss and 13q loss. Of note, mutations in ACVR1, EGFR, H3F3A, HIST1H3B, HIST1H3C, IDH2, SMARCB1 or the TERT promoter were not observed. A comparative analysis revealed that RIGs are molecularly distinct from most other astrocytomas and gliomas and instead align most closely with the pedGBM_RTK1 subgroup of pediatric glioblastoma.

Conclusions

This comprehensive analysis highlights the major molecular features of RIGs, demonstrates their molecular distinction from many other astrocytomas and gliomas, and reveals potential genetic drivers and therapeutic targets for this currently fatal disease.

Late Radiation-Related Toxicities in Patients Treated for Early-Stage Cervical Carcinoma by Surgery and Adjuvant Radiotherapy: A Retrospective Imaging Study

Surgical treatment is preferred therapy of early-stage cervical carcinoma. In the risk of cancer recurrence surgery is often followed by adjuvant radiotherapy. In our retrospective study we aimed at identifying late (≥6 months) and very late (≥5 years) radiation adverse effects on imaging scans as CT, PET/CT and MRI in patients who underwent successful treatment for cervical carcinoma by radical surgery combined with radiotherapy ± chemotherapy. We correlated imaging results with clinical manifestations. We selected young and middle-aged patients with long life expectancy, as late radiation-related toxicities may significantly affect their quality of life. Patients were selected from those who were primary diagnosed and treated between the years 1987–2011 and regularly visited our Oncology department in years 2011–2012. Following inclusion criteria were applied: age ≤55 years at diagnosis, clinical follow-up ≥5 years and at least one tomography scan ≥3 years after finished treatment. One hundred and three subjects were reviewed: 73 patients met all inclusion criteria, while 30 patients fulfilled the inclusion criteria except for available tomography scan ≥3 years after therapy. The mean imaging follow-up was 11.2 ± 7.6 years and the mean clinical follow-up was 15.0 ± 6.9 years. In 20 (27%) subjects 27 cases grade I radiation-related toxicities were found; 9 (33%) of those 27 cases were clinically silent. In 14 (19%) females only grade I toxicities were observed. Grade III-IV toxicities were found in 5 (6.8%) subjects. No grade V toxicities were observed. We concluded that severe late side effects caused by radiotherapy were exceedingly rare in females successfully treated for early-stage cervical carcinoma, only 1 bilateral osteonecrosis, 2 cases of ileus, and 2 potentially radiation-induced tumors were found. The majority of radiation-related comorbidities found on imaging scans were clinically silent.

Photodynamic therapy for facial skin cancer developed in the zone of previous radiotherapy (clinical case)

The results of a 13-year clinical observation of a patient after treatment for basal cell carcinoma of the skin of the right cheek Ist cT1N0M0 are presented. The history of the course of the disease is associated with the fact that the patient underwent radiation therapy in early childhood for hemangioma of the lower eyelid of the right eye and right cheek. In 2008, against the background of post-radiation changes in the area of the right cheek, basal cell carcinoma was diagnosed at the Moscow Oncological Research Institute. P.A. Herzen. At the Center for Laser and Photodynamic Diagnostics and Tumor Therapy, the patient underwent organ-preserving PDT treatment. A course of photodynamic therapy (PDT) with 5-aminolevulic acid was carried out. Subsequently, the patient was followed up until 2021 without relapse in the PDT area. In 2016, the patient was diagnosed with a relapse of the disease in the form of a new focus of basal cell carcinoma of the upper eyelid skin on the right Iast cT1N0M0. The patient underwent a course of PDT with a chlorin e6-based photosensitizer. Complete regression of the tumor was achieved, the period of relapse-free follow-up was 5 years.

Evaluating compliance of dental radiography for paediatric patient assessment in specialised tertiary care units: a United Kingdom multi-centre survey

Aim The aim of this survey was to determine compliance towards dental radiography selection criteria for paediatric patients undergoing new patient examinations in specialised tertiary care centres in the United Kingdom.Methods Five university-associated dental hospitals were included in this study. Retrospective data was collected reviewing all paediatric patients on the new patient assessment clinics, where dental imaging was requested or the patient had relevant previous imaging. Data was collected from 28 June 2018, continuing retrospectively for a maximum of six months or until 150 patients were reached. Patients referred solely for orthodontic assessment were excluded.Results Seven hundred and fifty patients were included with an average age of eight years - 95.5% of patients had a radiographic justification provided. All patients were grouped into 56 disease categories and a total range of one cross-sectional and nine planar radiographs were prescribed in this cohort. Each radiograph was assessed for compliance to the Faculty of General Dental Practice, European Association of Paediatric Dentistry and national Italian guidelines for dental diagnostic imaging. Additionally, selection criteria for CBCT scans were taken from SEDENTEXCT guidelines. Full panoramic radiographs were the most commonly prescribed at 34.8% (n = 261). However, this demonstrated the lowest compliance rate as per selection criteria at 75.9%. This was due to referrers requesting radiographs primarily for assessing dental development (18.8%; n = 49) and caries assessment (2.7%; n = 7). Other radiograph formats demonstrated varying levels of guideline compliance ranging from 93.5-100%.Conclusion This study identifies common radiograph request errors and can inform paediatric clinicians to improve compliance to guidelines and reduce radiation exposure to young patients.

Advanced cervical cancer in young women: imaging study of late and very late radiation-related side effects after successful treatment by combined radiotherapy

Background

Radical combined radiotherapy (RT) is a standard treatment for advanced cervical cancer. The aim of our study was to identify morphological late (≥6 months) and very late (≥5 years) radiation-related comorbidities on computed tomography (CT), positron emission tomography/computerized tomography (PET/CT) or magnetic resonance imaging (MRI) scans in young females who survived ≥5 years since RT and were considered as successfully treated. Secondly, we studied a rate of clinically silent radiation-related toxicities apparent on imaging scans that might influenced on future well-being of survived females. Thirdly, we analyzed reasons why patients underwent imaging scans.

Methods

We included 41 subjects aged under 50 years (mean 41.8±7.2 years, median 41 years), who survived ≥5 years since RT, with at least one available imaging scan ≥3 years since RT. The mean time between RT and the last available scan was 12.3±7.9 years (median 9 years); the mean time of clinical follow-up was 15.4±7.1 years (median 14 years).

Results

Fourteen (34.1%) females underwent the first imaging scan in emergency situation and 27 (65.9%) patients due to variable chronic complaints. Grade III-V radiation-related comorbidities occurred in 19 (46.3%) females including one case of death due to radiation-induced osteosarcoma. In 14 of 19 patients, comorbidities were multiple. Four (9.8%) females suffered from life-threatening complications (grade IV): one from an uretero-arterial fistula with massive hematuria and 3 from bowel perforations. Eleven (26.8%) subjects suffered from bowel strictures with ileus development, they underwent mean 1.7±0.8 surgery (median 1.5). The mean time since RT to the first surgery for intestinal complications was 5.4±6.0 years (median 3 years), to the second 12.0±9.6 years (median 11.5 years) and to the third surgery 9.0±4.2 years (median 9 years). Late fistulas formations (vesico-recto-vaginal) were seen in 6 (14.6%) patients. Bone complications were diagnosed in 9 (22.0%) of treated females, one case of osteosarcoma included, 4 of 9 bone complications were clinically silent. In 5 (12.2%) subjects, toxicities grade III-IV first time manifested >5 years since RT, majority of them were multiple. The bowel perforation and fistulas formations were the earliest manifested grade III-IV toxicities, with median time 3 years since RT, the bone complications were the latest manifested with median time 16 years since RT.

Conclusions

Our study is not able to bring information about the incidence of late and very late radiation related comorbidities, according to International Federation of Gynecology and Obstetrics (FIGO) recommendations patients are clinically followed only for 5 years and imaging cross-sectional scans are not recommended. However, our study shows that if females successfully treated for advanced cervical cancer report abdominal/pelvic clinical problems, it is highly probable their imaging scans will reveal late radiation related side-effects that may affect the rest of their life. It puts forward question whether females after radical RT should been regularly followed by cross-sectional imaging methods.

Replication stress and FOXM1 drive radiation induced genomic instability and cell transformation

In contrast to the vast majority of research that has focused on the immediate effects of ionizing radiation, this work concentrates on the molecular mechanism driving delayed effects that emerge in the progeny of the exposed cells. We employed functional protein arrays to identify molecular changes induced in a human bronchial epithelial cell line (HBEC3-KT) and osteosarcoma cell line (U2OS) and evaluated their impact on outcomes associated with radiation induced genomic instability (RIGI) at day 5 and 7 post-exposure to a 2Gy X-ray dose, which revealed replication stress in the context of increased FOXM1b expression. Irradiated cells had reduced DNA replication rate detected by the DNA fiber assay and increased DNA resection detected by RPA foci and phosphorylation. Irradiated cells increased utilization of homologous recombination-dependent repair detected by a gene conversion assay and DNA damage at mitosis reflected by RPA positive chromosomal bridges, micronuclei formation and 53BP1 positive bodies in G1, all known outcomes of replication stress. Interference with the function of FOXM1, a transcription factor widely expressed in cancer, employing an aptamer, decreased radiation-induced micronuclei formation and cell transformation while plasmid-driven overexpression of FOXM1b was sufficient to induce replication stress, micronuclei formation and cell transformation.

Pediatric craniospinal irradiation with a short partial-arc VMAT technique for medulloblastoma tumors in dosimetric comparison

Background

This study aimed to contrast four different irradiation methods for pediatric medulloblastoma tumors in a dosimetric comparison regarding planning target volume (PTV) coverage and sparing of organs at risk (OARs).

Methods

In sum 24 treatment plans for 6 pediatric patients were realized. Besides the clinical standard of a 3D-conformal radiotherapy (3D-CRT) treatment plan taken as a reference, volumetric modulated arc therapy (VMAT) treatment plans (“VMAT_AVD” vs. “noAVD” vs. “FullArc”) were optimized and calculated for each patient. For the thoracic and abdominal region, the short partial-arc VMAT_AVD technique uses an arc setup with reduced arc-length by 100°, using posterior and lateral beam entries. The noAVD uses a half 180° (posterior to lateral directions) and the FullArc uses a full 360° arc setup arrangement. The prescription dose was set to 35.2 Gy.

Results

We identified a more conformal dose coverage for PTVs and a better sparing of OARs with used VMAT methods. For VMAT_AVD mean dose reductions in organs at risk can be realized, from 16 to 6.6 Gy, from 27.1 to 8.7 Gy and from 8.0 to 1.9 Gy for the heart, the thyroid and the gonads respectively, compared to the 3D-CRT treatment method. In addition we have found out a superiority of VMAT_AVD compared to the noAVD and FullArc trials with lower exposure to low-dose radiation to the lungs and breasts.

Conclusions

With the short partial-arc VMAT_AVD technique, dose exposures to radiosensitive OARS like the heart, the thyroid or the gonads can be reduced and therefore, maybe the occurrence of late sequelae is less likely. Furthermore the PTV conformity is increased. The advantages of the VMAT_AVD have to be weighed against the potentially risks induced by an increased low dose exposure compared to the 3D-CRT method.

A Nordic-Baltic perspective on indications for proton therapy with strategies for identification of proper patients

The beneficial effects of protons are primarily based on reduction of low to intermediate radiation dose bath to normal tissue surrounding the radiotherapy target volume. Despite promise for reduced long-term toxicity, the percentage of cancer patients treated with proton therapy remains low. This is probably caused by technical improvements in planning and delivery of photon therapy, and by high cost, low availability and lack of high-level evidence on proton therapy. A number of proton treatment facilities are under construction or have recently opened; there are now two operational Scandinavian proton centres and two more are under construction, thereby eliminating the availability hurdle. Even with the advantageous physical properties of protons, there is still substantial ambiguity and no established criteria related to which patients should receive proton therapy. This topic was discussed in a session at the Nordic Collaborative Workshop on Particle Therapy, held in Uppsala 14-15 November 2019. This paper resumes the Nordic-Baltic perspective on proton therapy indications and discusses strategies to identify patients for proton therapy. As for indications, neoplastic entities, target volume localisation, size, internal motion, age, second cancer predisposition, dose escalation and treatment plan comparison based on the as low as reasonably achievable (ALARA) principle or normal tissue complication probability (NTCP) models were discussed. Importantly, the patient selection process should be integrated into the radiotherapy community and emphasis on collaboration across medical specialties, involvement of key decision makers and knowledge dissemination in general are important factors. An active Nordic-Baltic proton therapy organisation would also serve this purpose.

Germline MUTYH Mutation in a Pediatric Cancer Survivor Developing a Secondary Malignancy

Radiotherapy-induced second malignant neoplasms (SMNs) are a severe late complication in pediatric cancer survivors. Germline mutations in tumor suppressor genes contribute to SMNs; however, the most relevant germline variants mediating susceptibility are not fully defined. The authors performed matched whole-exome sequencing analyses of germline and tumor DNA from 4 pediatric solid tumor survivors who subsequently developed radiation-associated SMNs. Pathogenic and predicted deleterious germline variants were identified for each patient and validated with Sanger sequencing. These germline variants were compared with germline variants in a cohort of 59 pediatric patients diagnosed with primary sarcomas. Pathway analysis was performed to test for similarities in the germline variant profiles between individuals diagnosed with SMNs or primary sarcomas. One index patient was found to have a pathogenic germline monoallelic mutation in the MUTYH gene, which encodes the base excision repair enzyme adenine DNA glycosylase. This specific germline mutation is associated with a form of familial adenomatous polyposis, a new diagnosis in the patient. Germline-level genetic similarity exists between SMN-developing patients and patients developing primary sarcomas, with relevant genes involved in signal transduction and DNA repair mechanisms. The authors identify a germline MUTYH mutation in a pediatric cancer survivor developing an SMN. Germline mutations involving specific pathways such as base excision repair may identify individuals at risk for developing SMNs. The composition of germline variants in individual patients may enable estimates of patient-specific risk for developing SMNs. The authors anticipate that further analyses of germline genomes and epigenomes will reveal diverse genes and mechanisms influencing cancer risk.

Spontaneous and Radiation-Induced Chromosome Aberrations in Primary Fibroblasts of Patients With Pediatric First and Second Neoplasms

The purpose of the present study was to investigate whether former childhood cancer patients who developed a subsequent secondary primary neoplasm (SPN) are characterized by elevated spontaneous chromosomal instability or cellular and chromosomal radiation sensitivity as surrogate markers of compromised DNA repair compared to childhood cancer patients with a first primary neoplasm (FPN) only or tumor-free controls. Primary skin fibroblasts were obtained in a nested case-control study including 23 patients with a pediatric FPN, 22 matched patients with a pediatric FPN and an SPN, and 22 matched tumor-free donors. Clonogenic cell survival and cytogenetic aberrations in Giemsa-stained first metaphases were assessed after X-irradiation in G1 or on prematurely condensed chromosomes of cells irradiated and analyzed in G2. Fluorescence in situ hybridization was applied to investigate spontaneous transmissible aberrations in selected donors. No significant difference in clonogenic survival or the average yield of spontaneous or radiation-induced aberrations was found between the study populations. However, two donors with an SPN showed striking spontaneous chromosomal instability occurring as high rates of numerical and structural aberrations or non-clonal and clonal translocations. No correlation was found between radiation sensitivity and a susceptibility to a pediatric FPN or a treatment-associated SPN. Together, the results of this unique case-control study show genomic stability and normal radiation sensitivity in normal somatic cells of donors with an early and high intrinsic or therapy-associated tumor risk. These findings provide valuable information for future studies on the etiology of sporadic childhood cancer and therapy-related SPN as well as for the establishment of predictive biomarkers based on altered DNA repair processes.

The effect of chronic low-dose environmental radiation on organ mass of bank voles in the Chernobyl exclusion zone

PURPOSE

Animals are exposed to environmental ionizing radiation (IR) externally through proximity to contaminated soil and internally through ingestion and inhalation of radionuclides. Internal organs can respond to radioactive contamination through physiological stress. Chronic stress can compromise the size of physiologically active organs, but studies on wild mammal populations are scarce. The effects of environmental IR contamination on organ masses were studied by using a wild rodent inhabiting the Chernobyl exclusion zone (CEZ).

MATERIAL AND METHODS

The masses of brain, heart, kidney, spleen, liver and lung were assessed from bank voles (Myodes glareolus) captured from areas across radioactive contamination gradient within the CEZ. Relative organ masses were used to correct for the body mass of an individual.

RESULTS

Results showed a significant negative correlation between IR level in the environment and relative brain and kidney mass. A significant positive correlation between IR and relative heart mass was also found. Principal component analysis (PCA) also suggested positive relationship between IR and relative spleen mass; however, this relationship was not significant when spleen was analyzed separately. There was no apparent relationship between IR and relative liver or lung mass.

CONCLUSIONS

Results suggest that in the wild populations even low but chronic doses of IR can lead to changes in relative organ mass. The novelty of these result is showing that exposure to low doses can affect the organ masses in similar fashion as previously shown on high, acute, radiation doses. These data support the hypothesis that wildlife might be more sensitive to IR than animals used in laboratory studies. However, more research is needed to rule out the other indirect effects such as radiosensitivity of the food sources or possible combined stress effects from e.g. infections.

Secondary malignancy following stereotactic radiosurgery for benign neurologic disease: A cohort study and review of the literature

Radiation-associated malignancy and malignant transformation are risks associated with stereotactic radiosurgery (SRS); however, incidence is uncertain. The purpose of our study is to present the rate of radiation-associated malignancy and malignant transformation at our institution. After IRB approval, we undertook a retrospective cohort study evaluating patients treated with Gamma Knife® or linac-based SRS between 1990 and 2014 for benign CNS pathology with at least 5 years of clinical follow-up. Risk of transformation was calculated using the Kaplan-Meier method. A total of 273 patients met selection criteria. Median clinical follow-up after SRS was 11 years (range 5-27). Over 3,216 patient-years following SRS, we found zero cases of radiation-associated malignancy and two cases of radiation-associated malignant transformation for a crude rate of 0.73% or case rate of 0.62 per 1,000 patient-years. The Kaplan-Meier risk of malignant transformation at 5, 10, and 15 years was 0.4% (95% CI 0.05% 2.6%). These data support the continued use of SRS for benign intracranial pathology without significant concern for secondary malignancy.

Primary adenoid cystic carcinoma of the trachea: clinical outcome of 38 patients after interdisciplinary treatment in a single institution

Background

Primary adenoid cystic carcinomas (ACCs) of the trachea are rare tumors of the central bronchial system. In patients presenting with unresectable tumors, severe comorbidities, or incomplete surgical resection, definitive radiotherapy is currently the recommended treatment. Irradiation with carbon ions (C¹²) has shown promising local control (LC) and survival rates in cases of ACCs of the head and neck. No data on the therapeutic efficacy of C12 radiotherapy in treating tracheal ACC has been published.

Methods

All patients with histologically confirmed ACC of the trachea treated with surgery and/or radiation treatment at Heidelberg University Hospital between 1991 and 2017 were included in this analysis. Patient and treatment characteristics, short- and long-term toxicity after radiotherapy, overall survival (OS), freedom from local progression (FFLP), and freedom from distant progression (FFDP) were prospectively acquired and retrospectively analyzed.

Results

Thirty-eight patients (23 women and 15 men) with a median age of 51 were treated by surgery (n = 20) and/or radiotherapy with either C¹² (n = 7) or photons (n = 24). Of these patients, 61% presented with locally advanced (stage 4) ACC. The median follow-up for all patients was 74.5 months. The 5-year OS for all patients was 95% (10-year: 81%). The 5-year FFLP and FFDP were 96% (10-year: 83%) and 69% (10-year: 53%), respectively. In patients who underwent surgery alone, the 5-year OS was 100% (10-year: 80%). The 5-year FFLP and FFDP were 100% (10-year: 100%) and 80% (10-year: 60%), respectively. In patients who underwent radiotherapy alone, the 5-year OS was 100% (10-year: 83%). The 5-year FFLP and FFDP were 88% (10-year: 44%) and 67% (10-year: 34%), respectively. In patients who received multi-modal treatment including surgery and adjuvant radiotherapy, the 5-year OS was 84% (10-year: 84%). The 5-year FFLP was 100% (10-year: 100%) and the 5-year FFDP was 65% (10-year, 65%).

Conclusions

The long-term prognosis is favorable if surgery is performed. In cases of an incomplete resection, good OS can still be achieved following adjuvant radiotherapy. For radiotherapy, irradiation with C¹² shows promising first results. However, more data is needed to prove the long-term advantage of C¹² over photons.

Trial registration

The ethics committee of the Heidelberg University Hospital approved the retrospective data analysis (S-174/2019).

Integrating nanomedicine into clinical radiotherapy regimens

While the advancement of clinical radiotherapy was driven by technological innovations throughout the 20th century, continued improvement relies on rational combination therapies derived from biological insights. In this review, we highlight the importance of combination radiotherapy in the era of precision medicine. Specifically, we survey and summarize the areas of research where improved understanding in cancer biology will propel the field of radiotherapy forward by allowing integration of novel nanotechnology-based treatments.

The association between histological subtype of a first primary endometrial cancer and second cancer risk

OBJECTIVE

To evaluate the risk of a second primary cancer after endometrial cancer according to histological subtype.

METHODS

Using data from the 13 National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) registries we identified women diagnosed with a primary endometrial cancer between 1992 and 2014. We calculated standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) for second primary cancer risk (all anatomical sites combined and for individual anatomical sites) among patients with endometrial cancer compared with the general population, in the overall study population and according to histological subtype.

RESULTS

Among 96 256 women diagnosed with endometrial cancer, 8.4% (n=8083) developed a second primary cancer. The risk of second primary cancer was higher among patients with endometrial cancer than in the general population (SIR=1.05, 95% CI 1.03 to 1.07). We observed significantly higher second primary cancer risk among women with high grade endometrioid (SIR=1.12, 95% CI 1.05 to 1.19), serous (SIR=1.24, 95% CI 1.11 to 1.38), carcinosarcoma (SIR=1.18, 95% CI 1.02 to 1.35), mixed epithelial (SIR=1.22, 95% CI 1.06 to 1.40), and sarcoma (SIR=1.28, 95% CI 1.12 to 1.45) compared with the general population, but not for women with low grade endometrioid (SIR=1.01, 95% CI 0.98 to 1.03) or clear cell (SIR=1.09, 95% CI 0.88 to 1.33) endometrial cancer. Women with low grade endometrioid endometrial cancer had significantly lower second primary cancer risks in the gum and other mouth (SIR=0.57, 95% CI 0.30 to 0.97), lung and bronchus (SIR=0.72, 95% CI 0.66 to 0.77), and lymphocytic leukemia (SIR=0.71, 95% CI 0.54 to 0.93) while women with high risk endometrial cancer histological subtypes experienced significantly higher second primary cancer risk at several anatomical sites.

CONCLUSIONS

Risk of developing second primary cancersat all anatomic sites combined and at individual anatomical sites varied according to histological subtype. Clinicians should be aware that women with different histological subtypes carry different second primary cancer risks .

Tumor microenvironment modulation enhances immunologic benefit of chemoradiotherapy

BACKGROUND

Chemoradiotherapy (CRT) remains one of the most common cancer treatment modalities, and recent data suggest that CRT is maximally effective when there is generation of an anti-tumoral immune response. However, CRT has also been shown to promote immunosuppressive mechanisms which must be blocked or reversed to maximize its immune stimulating effects.

METHODS

Therefore, using a preclinical model of human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC), we developed a clinically relevant therapy combining CRT and two existing immunomodulatory drugs: cyclophosphamide (CTX) and the small molecule inducible nitric oxide synthase (iNOS) inhibitor L-n6-(1-iminoethyl)-lysine (L-NIL). In this model, we treated the syngeneic HPV-HNSCC mEER tumor-bearing mice with fractionated (10 fractions of 3 Gy) tumor-directed radiation and weekly cisplatin administration. We compared the immune responses induced by CRT and those induced by combinatory treatment (CRT + CTX/L-NIL) with flow cytometry, quantitative multiplex immunofluorescence and by profiling immune-related gene expression changes.

RESULTS

We show that combination treatment favorably remodels the tumor myeloid immune microenvironment including an increase in anti-tumor immune cell types (inflammatory monocytes and M1-like macrophages) and a decrease in immunosuppressive granulocytic myeloid-derived suppressor cells (MDSCs). Intratumoral T cell infiltration and tumor antigen specificity of T cells were also improved, including a 31.8-fold increase in the CD8+ T cell/ regulatory T cell ratio and a significant increase in tumor antigen-specific CD8+ T cells compared to CRT alone. CTX/LNIL immunomodulation was also shown to significantly improve CRT efficacy, leading to rejection of 21% established tumors in a CD8-dependent manner.

CONCLUSIONS

Overall, these data show that modulation of the tumor immune microenvironment with CTX/L-NIL enhances susceptibility of treatment-refractory tumors to CRT. The combination of tumor immune microenvironment modulation with CRT constitutes a translationally relevant approach to enhance CRT efficacy through enhanced immune activation.

Inhibition of Radiation-Induced Ccl2 Signaling Protects Lungs from Vascular Dysfunction and Endothelial Cell Loss

Aims: Radiation-induced normal tissue toxicity often precludes the application of curative radiation doses. Here we investigated the therapeutic potential of chemokine C-C motif ligand 2 (Ccl2) signaling inhibition to protect normal lung tissue from radiotherapy (RT)-induced injury. Results: RT-induced vascular dysfunction and associated adverse effects can be efficiently antagonized by inhibition of Ccl2 signaling using either the selective Ccl2 inhibitor bindarit (BIN) or mice deficient for the main Ccl2 receptor CCR2 (KO). BIN-treatment efficiently counteracted the RT-induced expression of Ccl2, normalized endothelial cell (EC) morphology and vascular function, and limited lung inflammation and metastasis early after irradiation (acute effects). A similar protection of the vascular compartment was detected by loss of Ccl2 signaling in lungs of CCR2-KO mice. Long-term Ccl2 signaling inhibition also significantly limited EC loss and accompanied fibrosis progression as adverse late effect. With respect to the human situation, we further confirmed that Ccl2 secreted by RT-induced senescent epithelial cells resulted in the activation of normally quiescent but DNA-damaged EC finally leading to EC loss in ex vivo cultured human normal lung tissue. Innovation: Abrogation of certain aspects of the secretome of irradiated resident lung cells, in particular signaling inhibition of the senescence-associated secretory phenotype-factor Ccl2 secreted predominantly by RT-induced senescent epithelial cells, resulted in protection of the endothelial compartment. Conclusions: Radioprotection of the normal tissue via Ccl2 signaling inhibition without simultaneous protection or preferable radiosensitization of tumor tissue might improve local tumor control and survival, because higher doses of radiation could be used.

Concurrent phyllodes tumor, eccrine carcinoma, and multinodular goiter 20 years after radiotherapy for Hodgkin lymphoma

This unusual case of concurrent eccrine adenocarcinoma, phyllodes tumor, and multinodular goiter serves to alert the oncologic community to the high prevalence of second cancers after childhood radiotherapy. Increased surveillance and index of suspicion are recommended to successfully diagnose and treat second primary cancers in this vulnerable population.

Second Primary Spindle Cell Carcinoma of Oral Cavity and Oropharynx: A Case Report and Literature Review

Spindle cell squamous cell carcinoma (SpCC) is a poorly differentiated subtype of squamous cell carcinoma (SqCC). We report a case with second primary oropharyngeal SpCC after seven years of complete treatment of SqCC. The patient underwent surgery and adjuvant chemoradiotherapy. Relevant literature about SpCC was reviewed.