Outcomes of whole breast radiation therapy in Asian breast cancer patients with prior cosmetic implants

BACKGROUND

As breast augmentation has become more popular, an increasing number of women with augmented breasts require treatment for breast cancer. This study aimed to assess the outcomes of postoperative whole breast radiation therapy (WB-RT) in Asian patients with breast cancer who underwent prior cosmetic breast implantation.

METHODS

We retrospectively reviewed the medical records of 61 patients with breast cancer who had prior cosmetic breast implants (prior-CBI) and underwent breast-conserving surgery (BCS) and WB-RT between 2015 and 2020. The median implant volume was 238.8 cc, with a median interval of 84.7 months between the prior-CBI and BCS. WB-RT was administered with either conventional fractionation (CF-RT) at 50 Gy in 25 fractions (N = 36) or hypofractionation (HF-RT) at 42.6 Gy in 16 fractions (N = 25). The incidences of implant-related complications (IRC) and their contributing factors were analyzed.

RESULTS

After a median follow-up of 43.5 months, the 3-year cumulative incidences of IRC and implant loss were 17.2% and 4.9%, respectively. Among the four (6.6%) patients who opted for implant removal after RT, three were potentially related to RT-related capsular contracture. There was no difference in the 3-year cumulative IRC rates following CF-RT and HF-RT (12.2% and 26.7%, respectively; p = 0.120). The risk factors for IRC included a larger implant size (> 260 cc) and a higher ratio of breast tissue to implant volume.

CONCLUSIONS

This study demonstrated a favorable safety profile of WB-RT for treatment of breast cancer in Asian women with prior-CBI. The integration of HF-RT following BCS was thought to be a feasible approach.

Role of dynamic contrast-enhanced MRI in predicting severe acute radiation-induced rectal injury in patients with rectal cancer

OBJECTIVES

To explore the potential of dynamic contrast-enhanced MRI (DCE-MRI) quantitative parameters in predicting severe acute radiation-induced rectal injury (RRI) in rectal cancer.

METHODS

This retrospective study enrolled 49 patients with rectal cancer who underwent neoadjuvant chemoradiotherapy and rectal MRI including a DCE-MRI sequence from November 2014 to March 2021. Two radiologists independently measured DCE-MRI quantitative parameters, including the forward volume transfer constant (Ktrans), rate constant (kep), fractional extravascular extracellular space volume (ve), and the thickness of the rectal wall farthest away from the tumor. These parameters were compared between mild and severe acute RRI groups based on histopathological assessment. Receiver operating characteristic curve analysis was performed to analyze statistically significant parameters.

RESULTS

Forty-nine patients (mean age, 54 years ± 12 [standard deviation]; 37 men) were enrolled, including 25 patients with severe acute RRI. Ktrans was lower in severe acute RRI group than mild acute RRI group (0.032 min-1 vs 0.054 min-1; p = 0.008), but difference of other parameters (kep, ve and rectal wall thickness) was not significant between these two groups (all p > 0.05). The area under the receiver operating characteristic curve of Ktrans was 0.72 (95% confidence interval: 0.57, 0.84). With a Ktrans cutoff value of 0.047 min-1, the sensitivity and specificity for severe acute RRI prediction were 80% and 54%, respectively.

CONCLUSION

Ktrans demonstrated moderate diagnostic performance in predicting severe acute RRI.

CLINICAL RELEVANCE STATEMENT

Dynamic contrast-enhanced MRI can provide non-invasive and objective evidence for perioperative management and treatment strategies in rectal cancer patients with acute radiation-induced rectal injury.

KEY POINTS

• To our knowledge, this study is the first to evaluate the predictive value of contrast-enhanced MRI (DCE-MRI) quantitative parameters for severe acute radiation-induced rectal injury (RRI) in patients with rectal cancer. • Forward volume transfer constant (Ktrans), derived from DCE-MRI, exhibited moderate diagnostic performance (AUC = 0.72) in predicting severe acute RRI of rectal cancer, with a sensitivity of 80% and specificity of 54%. • DCE-MRI is a promising imaging marker for distinguishing the severity of acute RRI in patients with rectal cancer.

Treatment of Fanconi anemia patient with synchronous esophageal and tongue cancer in COVID-19 era: a case report

Although Fanconi anemia patients accompany a high risk of multiple cancers, radiation therapy on these patients has been carried out only in limited cases due to the concern for radiation toxicity that stems from their susceptibility to radiation. We report a case of a 28-year-old female patient diagnosed as synchronous esophageal and tongue cancer, and underwent two cycles of radiation therapy, inevitably in the condition of coronavirus disease 2019 infection. She received radiation therapy of 30 Gy to esophageal mass with neoadjuvant aim in her first-round radiation therapy, and later received 27 Gy to tongue cancer surgical bed with adjuvant aim in her second-round radiation therapy. With no further treatment, she has been maintaining no evidence of disease state for 7 months. Managing Fanconi anemia patients with multiple cancers using radiation therapy is feasible, in which cases a dose de-escalation may be important considering the radiation toxicity and possible future re-treatment.

Sole brachytherapy for inoperable, recurrent, and irradiated salivary gland cancer

BACKGROUND AND PURPOSE

Salivary gland cancers (SGCs) are hard to treat when inoperable, and sole brachytherapy appears to be a promising therapeutic strategy. This study aimed to evaluate the effectiveness, safety, and capability of pain palliation using sole brachytherapy for inoperable, recurrent, and irradiated SGCs.

MATERIALS AND METHODS

Patients with inoperable SGCs treated using sole brachytherapy at Peking University School and Hospital of Stomatology were retrospectively included. Patients were divided into primary and recurrent groups and irradiated and non-irradiated groups. Local control (LC), overall survival (OS), radiation-relevant toxicities, and Visual Analogue Scale (VAS) score for pain, were recorded and evaluated.

RESULTS

A total of 176 patients from 2006 to 2020 were included. The 5-year LC rate was 48.6 %; for the primary, recurrent, non-irradiated and irradiated groups, the rates were 72.6 %, 39.5 %, 56.8 %, and 34.5 %, respectively. The 5-year OS rates was 52.6 %; for the primary, recurrent, non-irradiated, and irradiated groups, the rates were 62.9 %, 48.6 %, 58.9 %, and 42.3 %, respectively. The mean ± standard deviation of posttreatment VAS score of pain was 2.154 ± 2.989, which was significantly decreased from the score of 6.923 ± 2.280 prior to brachytherapy. Skin hyperpigmentation, mucositis, and dysphagia were the most frequently reported adverse events.

CONCLUSIONS

Brachytherapy as a sole modality, was retrospectively proven effective and safe in the management of inoperable SGCs and was beneficial in multiple irradiation and pain control.

Comorbid Conditions in Persons Exposed to Ionizing Radiation and Veterans of the Soviet-Afghan War: A Cohort Study in Kazakhstan

OBJECTIVES

This study investigated the prevalence and characteristics of comorbid conditions in patients exposed to ionizing radiation and those who were involved in the Soviet-Afghan war.

METHODS

This study analyzed the frequency and spectrum of morbidity and comorbidity in patients over a long-term period (30-35 years) following exposure to ionizing radiation at the Semipalatinsk nuclear test site or the Chornobyl nuclear power plant, and among participants of the Soviet-Afghan war. A cohort study, both prospective and retrospective, was conducted on 675 patients who underwent comprehensive examinations.

RESULTS

Numerical data were analyzed using the Statistica 6 program. The results are presented as the mean±standard deviation, median, and interquartile range (25-75th percentiles). The statistical significance of between-group differences was assessed using the Student t-test and Pearson chi-square test. A p-value of less than 0.05 was considered statistically significant. We found a high prevalence of cardiovascular diseases, including hypertension (55.0%) and cardiac ischemia (32.9%); these rates exceeded the average for this age group in the general population.

CONCLUSIONS

The cumulative impact of causal occupational, environmental, and ultra-high stress factors in the combat zone in participants of the Soviet-Afghan war, along with common conventional factors, contributed to the formation of a specific comorbidity structure. This necessitates a rational approach to identifying early predictors of cardiovascular events and central nervous system disorders, as well as pathognomonic clinical symptoms in this patient cohort. It also underscores the importance of selecting suitable methods and strategies for implementing treatment and prevention measures.

Amomum subulatum fruits protect against radiation-induced esophagitis by regulating antioxidant status and inflammatory responses

Radiation esophagitis (RE) is an inimical event that requires proper management while carrying out radiotherapy for thoracic cancers. The present study investigates the protective effect of dry fruits of the culinary and folkloric spice Amomum subulatum against experimental thoracic radiation-induced esophagitis. C57BL/6 mice were subjected to 25 Gy whole thorax irradiation and administered with 250 mg/kg body weight of methanolic extract of A. subulatum dry fruits (MEAS) orally for four consecutive weeks. Changes in tissue antioxidant activities, oxidative stress parameters, expression of antioxidant, inflammation, and fibrosis-related genes were observed. Administration of MEAS boosted antioxidant status, thereby reducing radiation-induced oxidative stress in the esophagus. PCR (polymerase chain reaction) results showed decreased expression of apoptosis, inflammation, and fibrosis-associated genes as well as increased expression of vital cytoprotective and antioxidant genes in MEAS-treated mice, manifesting its protective effect against radiation-induced oxidative stress, inflammatory responses, and fibrosis in the esophagus. Further, histopathology, immunohistochemistry (Cyclooxygenase-2), and Masson's Trichrome staining ascertained the protective effect of MEAS in alleviating radiation-induced esophageal injury. The synergistic effect of bioactive phytochemicals in MEAS with potent antioxidant and anti-inflammatory efficacies might have contributed to its mitigating effect against RE. Taken together, our results ascertained the radioprotective potential of MEAS, suggesting its possible nutraceutical application as a radiation countermeasure.

Immune checkpoint inhibition and single fraction stereotactic radiosurgery in brain metastases from non-small cell lung cancer: an international multicenter study of 395 patients

PURPOSE

Approximately 80% of brain metastases originate from non-small cell lung cancer (NSCLC). Immune checkpoint inhibitors (ICI) and stereotactic radiosurgery (SRS) are frequently utilized in this setting. However, concerns remain regarding the risk of radiation necrosis (RN) when SRS and ICI are administered concurrently.

METHODS

A retrospective study was conducted through the International Radiosurgery Research Foundation. Logistic regression models and competing risks analyses were utilized to identify predictors of any grade RN and symptomatic RN (SRN).

RESULTS

The study included 395 patients with 2,540 brain metastases treated with single fraction SRS and ICI across 11 institutions in four countries with a median follow-up of 14.2 months. The median age was 67 years. The median margin SRS dose was 19 Gy; 36.5% of patients had a V12 Gy ≥ 10 cm3. On multivariable analysis, V12 Gy ≥ 10 cm3 was a significant predictor of developing any grade RN (OR: 2.18) and SRN (OR: 3.95). At 1-year, the cumulative incidence of any grade and SRN for all patients was 4.8% and 3.8%, respectively. For concurrent and non-concurrent groups, the cumulative incidence of any grade RN was 3.8% versus 5.3%, respectively (p = 0.35); and for SRN was 3.8% vs. 3.6%, respectively (p = 0.95).

CONCLUSION

The risk of any grade RN and symptomatic RN following single fraction SRS and ICI for NSCLC brain metastases increases as V12 Gy exceeds 10 cm3. Concurrent ICI and SRS do not appear to increase this risk. Radiosurgical planning techniques should aim to minimize V12 Gy.

Radiation Injuries

Radiation-related injuries are rare. Yet the consequences of an event involving a radiation source can be substantial. As with any clinical emergency that rarely occurs, we are typically less prepared to deal with the situation. Compounding the crisis will be the "worried well" population who may believe that they too are contaminated or suffering from radiation poisoning and report to the hospital for evaluation. Identifying and triaging those who are sick or injured, managing the surge of patients, and knowing where resources can be accessed are all essential.

Percutaneous Coronary Intervention-Related Radiation Ulcer: Diagnosis, Management, and Prevention Strategy

Background

Radiation ulcers after percutaneous coronary intervention (PCI) are increasingly common. However, their diagnosis, treatment, and prevention strategies have not been well studied.

Objectives

To present our experience in the diagnosis, treatment, and prevention of PCI-related radiation ulcers.

Methods

Patients diagnosed with PCI-related radiation ulcers were collected. Radiation fields of PCI were simulated using the Pinnacle treatment planning system to confirm the diagnosis. Surgical methods and outcomes were reviewed, and a prevention protocol was developed and evaluated for its effectiveness.

Results

Seven male patients with ten ulcers were included. Among the patients, the right coronary artery was the most common target vessel of PCI, and the left anterior oblique was the most commonly used PCI view. Nine ulcers had undergone radical debridement and reconstruction: four smaller ones with primary closure or local flaps, and five with thoracodorsal artery perforator flaps. No new cases were identified in a 3-year follow-up period after implementing the prevention protocol.

Conclusions

PCI-related ulcer diagnosis is more evident with radiation field simulation. The thoracodorsal artery perforator flap is an ideal option for back or upper arm radiation ulcer reconstruction. The proposed prevention protocol for PCI procedures was effective in lowering the incidence of radiation ulcers.

Cluster-Based Toxicity Estimation of Osteoradionecrosis via Unsupervised Machine Learning: Moving Beyond Single Dose-Parameter Normal Tissue Complication Probability by Using Whole Dose-Volume Histograms for Cohort Risk Stratification

Purpose

Given the limitations of extant models for normal tissue complication probability estimation for osteoradionecrosis (ORN) of the mandible, the purpose of this study was to enrich statistical inference by exploiting structural properties of data and provide a clinically reliable model for ORN risk evaluation through an unsupervised-learning analysis.

Materials and Methods

The analysis was conducted on retrospective data of 1,259 head and neck cancer (HNC) patients treated at the University of Texas MD Anderson Cancer Center between 2005 and 2015. The (structural) clusters of mandibular dose-volume histograms (DVHs) were identified through the K-means clustering method. A soft-margin support vector machine (SVM) was used to determine the cluster borders and partition the dose-volume space. The risk of ORN for each dose-volume region was calculated based on the clinical risk factors and incidence rates.

Results

The K-means clustering method identified six clusters among the DVHs. Based on the first five clusters, the dose-volume space was partitioned almost perfectly by the soft-margin SVM into distinct regions with different risk indices. The sixth cluster overlapped the others entirely; the region of this cluster was determined by its envelops. These regions and the associated risk indices provide a range of constraints for dose optimization under different risk levels.

Conclusion

This study presents an unsupervised-learning analysis of a large-scale data set to evaluate the risk of mandibular ORN among HNC patients. The results provide a visual risk-assessment tool (based on the whole DVH) and a spectrum of dose constraints for radiation planning.

[Research progress of irradiation injuries anti-agents]

Irradiation injuries anti-agents refer to drugs that can inhibit the initial stage of radiation injuries, or reduce the development of radiation injuries and promote the recovery of injuries when used early after irradiation exposure. According to the mechanism of action and the time of intervention, the irradiation injuries anti-agents are divided into four categories: radioprotectors, radiomitigators, radiation therapeutics for external radiation exposure, and anti-agents for internalized radionuclides. In this paper, the research progress of irradiation injuries anti-agents in recent years is reviewed.

Radiation-induced senescence: therapeutic opportunities

The limitation of cancer radiotherapy does not derive from an inability to ablate tumor, but rather to do so without excessively damaging critical tissues and organs and adversely affecting patient's quality of life. Although cellular senescence is a normal consequence of aging, there is increasing evidence showing that the radiation-induced senescence in both tumor and adjacent normal tissues contributes to tumor recurrence, metastasis, and resistance to therapy, while chronic senescent cells in the normal tissue and organ are a source of many late damaging effects. In this review, we discuss how to identify cellular senescence using various bio-markers and the role of the so-called senescence-associated secretory phenotype characteristics on the pathogenesis of the radiation-induced late effects. We also discuss therapeutic options to eliminate cellular senescence using either senolytics and/or senostatics. Finally, a discussion of cellular reprogramming is presented, another promising avenue to improve the therapeutic gain of radiotherapy.

Smoking and Radiation-induced Skin Injury: Analysis of a Multiracial, Multiethnic Prospective Clinical Trial

INTRODUCTION

Smoking during breast radiotherapy (RT) may be associated with radiation-induced skin injury (RISI). We aimed to determine if a urinary biomarker of tobacco smoke exposure is associated with increased rates of RISI during and after breast RT.

PATIENTS AND METHODS

Women with Stage 0-IIIA breast cancer treated with breast-conserving surgery or mastectomy followed by RT to the breast or chest wall with or without regional nodal irradiation were prospectively enrolled on a multicenter study assessing acute/late RISI. 980 patients with urinary cotinine (UCot) measurements (baseline and end-RT) were categorized into three groups. Acute and late RISI was assessed using the ONS Acute Skin Reaction scale and the LENT-SOMA Criteria.

RESULTS

Late Grade 2+ and Grade 3+ RISI occurred in 18.2% and 1.9% of patients, respectively-primarily fibrosis, pain, edema, and hyperpigmentation. Grade 2+ late RISI was associated with UCot group (P= 006). Multivariable analysis identified UCot-based light smoker/secondhand smoke exposure (HR 1.79, P= .10) and smoking (HR 1.60, p = .06) as non-significantly associated with an increased risk of late RISI. Hypofractionated breast RT was associated with decreased risk of late RISI (HR 0.51, P=.03). UCot was not associated with acute RISI, multivariable analysis identified race, obesity, RT site/fractionation, and bra size to be associated with acute RISI.

CONCLUSIONS

Tobacco exposure during breast RT may be associated with an increased risk of late RISI without an effect on acute toxicity. Smoking cessation should be encouraged prior to radiotherapy to minimize these and other ill effects of smoking.

On-line estimated peak skin dose during percutaneous coronary intervention for chronic total occlusion using new patient dose mapping technology

BACKGROUND

X-ray exposure during complex percutaneous coronary intervention is a very important issue.

AIM

To reduce patient peak skin dose during percutaneous coronary intervention procedures for chronic total occlusion using on-line estimated peak skin dose software (Dose Map).

METHODS

Throughout the procedure, Dose Map provided a map of local cumulative peak skin dose. This map was displayed in-room from 1Gy cumulative air kerma, and was updated every 0.5Gy. The operator's actions to minimize deterministic risks following map notification were collected. Skin reaction was evaluated 3 months after the procedure. A comparison with our historical X-ray exposure data (207 patients from January 2013 to July 2014) was performed.

RESULTS

From November 2015 to October 2016, 97 patients (Japanese chronic total occlusion score 2.1±1.1; 100 percutaneous coronary intervention procedures for chronic total occlusion) were prospectively enrolled. Fluoroscopy time was 40.8 (21.6-60.3) minutes, cumulative air kerma 1884 (1144-3231) mGy, estimated peak skin dose 962 (604-1474) mGy and kerma area product 115.8 (71.5-206.7) Gy.cm². Cumulative air kerma was>3Gy in 28% of cases, and>5Gy in 11% of cases. In 68% of cases, at least one action was taken by the operator after map notification to optimize skin dose distribution. Main changes included: gantry angulation (52%); field of view (25%); and collimation (13%). No skin injuries were observed at follow-up. In comparison with our chronic total occlusion historical radiation data, median cumulative air kerma and kerma area product were reduced by 31% and 33%, respectively (P<0.005.

CONCLUSION

Online skin dose mapping software allows the distribution of patient skin dose during complex percutaneous coronary intervention procedures, and may minimize X-ray exposure.

[Progress in health effects and measurement standards of ultraviolet radiation in the workplace]

Ultraviolet radiation affects human health. On the one hand, moderate amounts of UV radiation can promote human health and have the effect of promoting vitamin D production; but on the other hand, excessive UV radiation can also cause adverse effects on human skin and eyes, such as causing skin photoaging, skin cancer, electrophthalmia and cataracts to occur. Therefore, the measurement of ultraviolet radiation is extremely important. This paper mainly reviews the health effects of ultraviolet radiation and the progress of measurement standards in the workplace, and puts forward suggestions on the revision of the existing standards from five aspects including use new measuring instruments and methods, improve the existing measuring instruments, specify the number of measurements, expand the scope of application of the standards and consider the influence of the sun on the measurement of artificial ultraviolet radiation, so as to provide reference for the revision of new standards.

Sexual dimorphism in gut microbiota dictates therapeutic efficacy of intravenous immunoglobulin on radiotherapy complications

INTRODUCTION

With the mounting number of cancer survivors, the complications following cancer treatment become novel conundrums and starve for countermeasures. Intravenous immunoglobulin (IVIg) is a purified preparation for immune-deficient and autoimmune conditions.

OBJECTIVES

Here, we investigated whether IVIg could be employed to fight against radiation injuries and explored the underlying mechanism.

METHODS

Hematopoietic or gastrointestinal (GI) tract toxicity was induced by total body or abdominal local irradiation. High-throughput sequencing was performed to analyze the gut microbiota configurations and gene expression profile of small intestine. The untargeted metabolomics of gut microbiome was assessed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analyses. Hydrodynamic-based gene delivery was used to knockdown the target genes in vivo.

RESULTS

Intravenous injection of IVIg protected against radiation-induced hematopoietic and GI tract toxicity in female mice but not in males. IVIg structured sex-characteristic gut microbiota configurations in abdominal irradiated mice. The irradiation enriched gut Lachnospiraceae in female mice but reduced those in males. IVIg injection combined with oral gavage of Lachnospiraceae or its metabolite hypoxanthine, alleviated radiation toxicity in male mice however, Lachnospiraceae or hypoxanthine alone failed to ameliorate the injuries. Abdominal local irradiation drove sex-distinct gene expression signatures in small intestine. Mechanistic investigation showed that replenishment of Lachnospiraceae or hypoxanthine offset abdominal radiation-reduced PLD1 expression in male mice. In females, irradiation elevated PLD1 expression. Deletion of PLD1 in GI tract of female mice erased the radioprotective effects of IVIg.

CONCLUSION

IVIg battles against radiation injuries in a sex-specific, gut microbiome-dependent way through Lachnospiraceae/hypoxanthine/PLD1 axis. Our findings provide a sex-precise therapeutic avenue to improve the prognosis of cancer patients with radiotherapy in pre-clinical settings.

Clinical factors affecting the determination of radiotherapy-induced skin toxicity in breast cancer

Purpose

Radiotherapy is essential for the treatment of breast cancer (BC). However, adverse effects may occur in healthy tissue, during treatment and even after several months. Although it is known that this clinical radiosensitivity is multifactorial, the factors involved are unknown yet. In this study, we evaluated the effect of these factors on the development of radiodermatitis in patients undergoing radiotherapy.

Materials and Methods

Demographic and lifestyle data collected during face-to-face interviews of 122 BC patients and data from clinical records were investigated. Most patients underwent conventional three-dimensional radiotherapy treatment. A total dose of 50 Gy was administered (2 Gy/day), followed by a boost in a tumor bed with a total dose of 18 Gy (2 Gy/day). Radiotoxicity was evaluated weekly using the Radiation Therapy Oncology Group classification system (range, 0 to 4, according to the severity).

Results

In the present study, 75.4% of patients presented acute skin toxic effects with different degrees of severity. In 25% of cases, these effects manifested at the end of the fourth week at a cumulative dose of 40 Gy. The association of grade ≥2 acute skin reactions with body mass index (BMI) and breast size and between grade 3–4 and age was positive compared with controls. However, the role of the other factors could not be confirmed.

Conclusion

Analysis of the factors related to individual radiosensitivity suggests that age, BMI and breast size play an important role in the development of acute skin toxicity during treatment. Particular attention to patients who present these characteristics would help to control treatment effectiveness and therefore optimize their quality of life.

The Tumor Control According to Radiation Dose of Gamma Knife Radiosurgery for Small and Medium-Sized Brain Metastases from Non-Small Cell Lung Cancer

Objective

The effectiveness of gamma knife radiosurgery (GKR) in the treatment of brain metastases is well established. The aim of this study was to evaluate the efficacy and safety of maximizing the radiation dose in GKR and the factors influencing tumor control in cases of small and medium-sized brain metastases from non-small cell lung cancer (NSCLC).

Methods

We analyzed 230 metastatic brain tumors less than 5 mL in volume in 146 patients with NSCLC who underwent GKR. The patients had no previous radiation therapy for brain metastases. The pathologies of the tumors were adenocarcinoma (n=207), squamous cell carcinoma (n=18), and others (n=5). The radiation doses were classified as 18, 20, 22, and 24 Gy, and based on the tumor volume, the tumors were categorized as follows : small-sized (less than 1 mL) and medium-sized (1–3 and 3–5 mL). The progression-free survival (PFS) of the individual 230 tumors and 146 brain metastases was evaluated after GKR depending on the pathology, Eastern Cooperative Oncology Group (ECOG) performance score (PS), tumor volume, radiation dose, and anti-cancer regimens. The radiotoxicity after GKR was also evaluated.

Results

After GKR, the restricted mean PFS of individual 230 tumors at 24 months was 15.6 months (14.0–17.1). In small-sized tumors, as the dose of radiation increased, the tumor control rates tended to increase (p=0.072). In medium-sized tumors, there was no statistically difference in PFS with an increase of radiation dose (p=0.783). On univariate analyses, a statistically significant increase in PFS was associated with adenocarcinomas (p=0.001), tumors with ECOG PS 0 (p=0.005), small-sized tumors (p=0.003), radiation dose of 24 Gy (p=0.014), synchronous lesions (p=0.002), and targeted therapy (p=0.004). On multivariate analyses, an improved PFS was seen with targeted therapy (hazard ratio, 0.356; 95% confidence interval, 0.150–0.842; p=0.019). After GKR, the restricted mean PFS of brain at 24 months was 9.8 months (8.5–11.1) in 146 patients, and the pattern of recurrence was mostly distant within the brain (66.4%). The small and medium-sized tumors treated with GKR showed radiotoxicitiy in five out of 230 tumors (2.2%), which were controlled with medical treatment.

Conclusion

The small-sized tumors were effectively controlled without symptomatic radiation necrosis as the radiation dose was increased up to 24 Gy. The medium-sized tumors showed potential for symptomatic radiation necrosis without signifcant tumor control rate, when greater than 18 Gy. GKR combined targeted therapy improved the tumor control of GKR-treated tumors.

The centrally restricted diffusion sign on MRI for assessment of radiation necrosis in metastases treated with stereotactic radiosurgery

Purpose

Differentiation of radiation necrosis from tumor progression in brain metastases treated with stereotactic radiosurgery (SRS) is challenging. For this, we assessed the performance of the centrally restricted diffusion sign.

Methods

Patients with brain metastases treated with SRS who underwent a subsequent intervention (biopsy/resection) for a ring-enhancing lesion on preoperative MRI between 2000 and 2020 were included. Excluded were lesions containing increased susceptibility limiting assessment of DWI. Two neuroradiologists classified the location of the diffusion restriction with respect to the post-contrast T1 images as centrally within the ring-enhancement (the centrally restricted diffusion sign), peripherally correlating to the rim of contrast enhancement, both locations, or none. Measures of diagnostic accuracy and 95% CI were calculated for the centrally restricted diffusion sign. Cohen's kappa was calculated to identify the interobserver agreement.

Results

Fifty-nine patients (36 female; mean age 59, range 40 to 80) were included, 36 with tumor progression and 23 with radiation necrosis based on histopathology. Primary tumors included 34 lung, 12 breast, 5 melanoma, 3 colorectal, 2 esophagus, 1 head and neck, 1 endometrium, and 1 thyroid. The centrally restricted diffusion sign was seen in 19/23 radiation necrosis cases (sensitivity 83% (95% CI 63 to 93%), specificity 64% (95% CI 48 to 78%), PPV 59% (95% CI 42 to 74%), NPV 85% (95% CI 68 to 94%)) and 13/36 tumor progression cases (difference p < 0.001). Interobserver agreement was substantial, at 0.61 (95% CI 0.45 to 70.8).

Conclusion

We found a low probability of radiation necrosis in the absence of the centrally restricted diffusion sign.

Breast Radiation and the Heart: Cardiac Toxicity and Cardiac Avoidance

The purpose of this invited review is to discuss the most recent and relevant outcome studies assessing the risk of late cardiac toxicity in women treated with radiotherapy for breast cancer and to describe the evidence-based technical factors associated with late cardiac toxicity. This review will also discuss the common radiation techniques for reducing radiation dose to the heart, which will lead to better outcomes and lower rates of late toxicity that can cause morbidity and mortality in women who have been cured of their breast cancer.

Physical and Biological Characteristics of Particle Therapy for Oncologists

Particle therapy is a promising and evolving modality of radiotherapy that can be used to treat tumors that are radioresistant to conventional photon beam radiotherapy. It has unique biological and physical advantages compared with conventional radiotherapy. The characteristic feature of particle therapy is the "Bragg peak," a steep and localized peak of dose, that enables precise delivery of the radiation dose to the tumor while effectively sparing normal organs. Especially, the charged particles (e.g., proton, helium, carbon) cause a high rate of energy loss along the track, thereby leading to high biological effectiveness, which makes particle therapy attractive. Using this property, the particle beam induces more severe DNA double-strand breaks than the photon beam, which is less influenced by the oxygen level. This review describes the general biological and physical aspects of particle therapy for oncologists, including non-radiation oncologists and beginners in the field.

Surveillance ultrasonography for conservative treatment of femoral shaft fractures in young children

BACKGROUND

The treatment for femoral shaft fracture (FSF) depends on the age of the patient. While the Pavlik harness is the first choice for patients under 6 months of age, spica casting is preferred for patients over 6 months and under preschool age. Minimally-invasive surgery using elastic stable intramedullary nails is also used in some cases. Skin traction is another treatment choice for some patients who are not candidates for the above methods. This study aimed to evaluate the feasibility of surveillance ultrasonography (US) for the conservative treatment of FSFs in young children.

MATERIALS AND METHODS

This retrospective study included 92 children who were diagnosed with FSF in our hospital from April 2017 to May 2019. After applying the inclusion and exclusion criteria, they were divided into US surveillance (A) and control (B) groups. All patients received conservative treatment by skin traction. For group A, US was used to assess the femur fractures and adjust its reduction on days 1, 3, 5, 7, 10, and 14 until the fracture stabilized. For group B, the fractures were checked by radiographs on days 1, 3, 5, 7, 10, and 14 until the callus appeared. The FSF angle was measured using anteroposterior and lateral radiographs.

RESULTS

All patients were followed up for 18 months. The radiographic evaluation of both groups at the final follow-up showed a significant difference in the FSF angle. The radiograph times and accumulated radiation also showed significant differences between the two groups. However, there was no significant difference in the incidence of complications.

CONCLUSIONS

For FSF closed reduction, surveillance US is a better option compared to radiographs in children treated by skin traction. This approach can significantly decrease exposure to X-ray radiation and improve the reduction.

LEVEL OF EVIDENCE

III.

Rupture of carotid artery pseudoaneurysm in the modern era of definitive chemoradiation for head and neck cancer: Two case reports

BACKGROUND

Carotid blowout syndrome (CBS) is a rupture of the carotid artery and is mainly caused by radiation and resection of head and neck cancers or direct tumor invasion of the carotid artery wall. It is a life-threatening clinical situation. There is no established and effective mode of management of CBS. Furthermore, there is no established preceding sign or symptom; therefore, preventive efforts are not clinically meaningful.

CASE SUMMARY

We described two cases of CBS that occurred in patients with head and neck cancer after definitive chemoradiotherapy (CRT) using three-dimensional conformal intensity-modulated radiation therapy. Two men aged 61 and 56 years with locally advanced head and neck cancer were treated with definitive CRT. After completing CRT, both of them achieved complete remission. Subsequently, they had persistent severe pain in the oropharyngeal mucosal region and the irradiated neck despite the use of opioid analgesics and rehabilitation for relief of contracted skin. However, continuous follow-up imaging studies showed no evidence of cancer recurrence. Eleven to twelve months after completing CRT, the patients visited the emergency room complaining about massive oronasal bleeding. Angiograms showed rupture of carotid artery pseudoaneurysms on the irradiated side. Despite attempting to secure hemostasis with carotid arterial stent insertion and coil embolization, both patients died because of repeated bleeding from the pseudoaneurysms.

CONCLUSION

In patients with persistent pain in irradiated sites, clinicians should be suspicious of progressing or impending CBS, even in the three-dimensional conformal intensity-modulated radiation therapy era.

Hyperbaric oxygen for radiation-induced cystitis: A long-term follow-up

INTRODUCTION AND OBJECTIVES

Bladder complications may be seen in up to 12% of patients treated with pelvic irradiation. Hyperbaric oxygen therapy (HBOT) is an option for the management of radiation-induced hemorrhagic cystitis (RIHC). The aim of this study was to evaluate the efficacy of HBOT in radiation cystitis and to identify the predictive factors for a successful outcome.

MATERIAL AND METHODS

We retrospectively reviewed 105 patients diagnosed with RIHC which were treated with HBOT between 2007 and 2016 in our institution. Patients received 100% oxygen in a multiplace hyperbaric chamber at 2.4atm for 80minutes. All patients fulfilled a questionnaire documenting symptom severity pre-HBOT and at the end of the follow-up period.

RESULTS

After a median of 40 HBOT sessions, there was success rate of 92,4% in the control of hematuria. During our follow-up period (median of 63 months) 24,7% patients presented with recurrence of hematuria. The mean score of the questionnaire-assessed variables: dysuria, urinary frequency and hematuria, was significantly lower after the follow-up period (P<.05). Our data shows that the sooner HBOT is delivered after the first episode of hematuria, better response rates are achieved and lower recurrences concerning hematuria were registered (P<.05). No serious complications were observed.

CONCLUSIONS

Our results support the safety and long-term benefits of HBOT on RIHC and other distressful bladder symptoms, which represents an expected improvement of quality of life in our patients.

Dental Pulp Stem Cell-Derived Extracellular Vesicles Mitigate Haematopoietic Damage after Radiation

Radiation therapy can cause haematopoietic damage, and mesenchymal stem cells (MSCs) derived extracellular vesicles (EVs) have been shown to reverse this damage. Our previous research showed that dental pulp stem cells (DPSCs) have a strong proliferation capacity and can produce abundant amounts of EVs to meet the requirements for use in vitro and in vivo. DPSCs derived EVs (DPSCs-EVs) are evaluated for their effect on reducing haematopoietic damage. Haematopoietic stem cell (HSC) numbers and function were assessed by flow cytometry, peripheral blood cell counts, histology and bone marrow transplantation. Epidermal growth factor (EGF) was used as a reference for evaluating the efficiency of EVs. miRNA microarray was employed to find out the changes of miRNA expression after cells being irradiated in vivo and the role they may play in mitigation the radiation caused injury. We observed the effect of DPSCs-EVs on promoting proliferation and inhibiting apoptosis of human umbilical vein endothelial cells (HUVECs) and FDC-P1 cells in vitro. We found that DPSCs-EVs and EGF could comparably inhibit the decrease in WBC, CFU count and KSL cells in vivo. We also verified that EVs could accelerate the recovery of long-term HSCs. In summary, DPSCs-EVs showed an apoptosis resistant effect on HUVECs and FDC-P1 cells after radiation injury in vitro. EVs from DPSCs were comparable to EGF in their ability to regulate haematopoietic regeneration after radiation injury in vivo. Radiation could alter the expression of some miRNAs in bone marrow cells, and EVs could correct these changes to some extent.

Squamous cell carcinoma developed in a chronic radiation-induced chest wall ulcer that is difficult to undergo thorough preoperative histological examination

•

Squamous cell carcinoma (SCC) arose in a large chronic radiation-induced thoracic ulcer which exposing the lung and pericardium after flap surgery.

•

Preoperative histopathological examination point indicated Inflammation. But after flap surgery, squamous cell carcinoma was diagnosed from a fistula at the margin of the flap.

•

We should have asked a thoracic/cardiac surgeon to conduct a biopsy at the pericardium during the debridement operation before flap covering.

•

It is necessary to consider the best method for performing the most thorough histological examination possible, even in areas where histological examinations are difficult, as all ulcers can contain tumors.

Introduction

We report a case in which squamous cell carcinoma (SCC) developed in a large chronic radiation-induced thoracic ulcer after flap surgery in areas where preoperative histological examinations are difficult.

Presentation of case

The patient was a 75-year-old female. She had undergone resection and radiotherapy for left breast cancer 15 years earlier. Six years ago, the ulcer expanded from the subclavian to xiphoid levels, exposing the lung and pericardium. A histopathological examination, which avoided the lung and pericardium, was performed. Inflammation was diagnosed. We reconstructed the chest wall with a pedicled rectus abdominis flap. Eighteen months later, three verrucous tissue-lined fistulas formed. A histological examination revealed well-differentiated SCC. Six months later, the patient died of massive bleeding from a fistula.

Discussion

It is unclear exactly when the SCC occurred. As three fistulas formed at the margins of the flap around the pericardium, we suspect that the cancer developed within or near the pericardial region.

We need to reflect on the lack of a thorough biopsy. As no pericardial biopsy was performed, we should have asked a thoracic/cardiac surgeon to conduct a biopsy during the debridement operation. If the tumor had been localized to the pericardium, it could have been removed.

Conclusion

It is necessary to consider the best method for performing the most thorough histological examination possible, even in areas where histological examinations are difficult, as all ulcers can contain tumors.

Genome-wide association study identifies genetic susceptibility loci and pathways of radiation-induced acute oral mucositis

Background

Radiation-induced oral mucositis (OM) is one of the most common acute complications for head and neck cancer. Severe OM is associated with radiation treatment breaks, which harms successful tumor management. Radiogenomics studies have indicated that genetic variants are associated with adverse effects of radiotherapy.

Methods

A large-scale genome-wide scan was performed in 1467 nasopharyngeal carcinoma patients, including 753 treated with 2D-CRT from Genetic Architecture of the Radiotherapy Toxicity and Prognosis (GARTP) cohort and 714 treated with IMRT (192 from the GARTP and 522 newly recruited). Subgroup analysis by radiotherapy technique was further performed in the top associations. We also performed physical and regulatory mapping of the risk loci and gene set enrichment analysis of the candidate target genes.

Results

We identified 50 associated genomic loci and 64 genes via positional mapping, expression quantitative trait locus (eQTL) mapping, chromatin interaction mapping and gene-based analysis, and 36 of these loci were replicated in subgroup analysis. Interestingly, one of the top loci located in TNKS, a gene relevant to radiation toxicity, was associated with increased OM risk with OR = 3.72 of the lead SNP rs117157809 (95% CI 2.10–6.57; P = 6.33 × 10⁻⁶). Gene set analyses showed that the 64 candidate target genes were enriched in the biological processes of regulating telomere capping and maintenance and telomerase activity (Top P = 7.73 × 10⁻⁷).

Conclusions

These results enhance the biological understanding of radiotherapy toxicity. The association signals enriched in telomere function regulation implicate the potential underlying mechanism and warrant further functional investigation and potential individual radiotherapy applications.

Changes of lung parenchyma density following high dose radiation therapy for thoracic carcinomas - an automated analysis of follow up CT scans

Background

An objective way to qualify the effect of radiotherapy (RT) on lung tissue is the analysis of CT scans after RT. In this analysis we focused on the changes in Hounsfield units (ΔHU) and the correlation with the corresponding radiation dose after RT.

Methods

Pre- and post-RT CT scans were matched and ΔHU was calculated using customized research software. ΔHU was calculated in 5-Gy-intervals and the correlation between ΔHU and the corresponding dose was calculated as well as the regression coefficients. Additionally the mean ΔHU and ΔHU in 5-Gy-intervals were calculated for each tumor entity.

Results

The mean density changes at 12 weeks and 6 months post RT were 28,16 HU and 32,83 HU. The correlation coefficient between radiation dose and ΔHU at 12 weeks and 6 months were 0,166 (p = 0,000) and 0,158 (p = 0,000). The resulting regression coefficient were 1439 HU/Gy (p = 0,000) and 1612 HU/Gy (p = 0,000). The individual regression coefficients for each patient range from − 2,23 HU/Gy to 7,46 HU/Gy at 12 weeks and − 0,45 HU/Gy to 10,51 HU/Gy at 6 months. When looking at the three tumor entities individually the highest ΔHU at 12 weeks was seen in patients with SCLC (38,13 HU) and at 6 month in those with esophageal carcinomas (40,98 HU).

Conclusion

For most dose intervals there was an increase of ΔHU with an increased radiation dose. This is reflected by a statistically significant, although low correlation coefficient. The regression coefficients of all patients show large interindividual differences.

Application of a machine learning method to whole brain white matter injury after radiotherapy for nasopharyngeal carcinoma

Background

The purpose/aim of this study was to 1) use magnetic resonance diffusion tensor imaging (DTI), fibre bundle/tract-based spatial statistics (TBSS) and machine learning methods to study changes in the white matter (WM) structure and whole brain WM network in different periods of the nasopharyngeal carcinoma (NPC) patients after radiotherapy (RT), 2) identify the most discriminating WM regions and WM connections as biomarkers of radiation brain injury (RBI), and 3) supplement the understanding of the pathogenesis of RBI, which is useful for early diagnosis in the clinic.

Methods

A DTI scan was performed in 77 patients and 67 normal controls. A fractional anisotropy map was generated by DTIFit. TBSS was used to find the region where the FA differed between the case and control groups. Each resulting FA value image is registered with each other to create an average FA value skeleton. Each resultant FA skeleton image was connected to feature vectors, and features with significant differences were extracted and classified using a support vector machine (SVM). Next, brain segmentation was performed on each subject’s DTI image using automated anatomical labeling (AAL), and deterministic white matter fiber bundle tracking was performed to generate symmetrical brain matrix, select the upper triangular component as a classification feature. Two-sample t-test was used to extract the features with significant differences, then classified by SVM. Finally, we adopted a permutation test and ROC curves to evaluate the reliability of the classifier.

Results

For FA, the accuracy of classification between the 0–6, 6–12 and > 12 months post-RT groups and the control group was 84.5, 83.9 and 74.5%, respectively. In the case groups, the FA with discriminative ability was reduced, mainly in the bilateral cerebellum and bilateral temporal lobe, with prolonged time, the damage was aggravated. For WM connections, the SVM classifier classification recognition rates of the 0–6, 6–12 and > 12 months post-RT groups reached 82.5, 78.4 and 76.3%, respectively. The WM connections with discriminative ability were reduced.

Conclusions

RBI is a disease involving whole brain WM network anomalies. These brain discriminating WM regions and WM connection modes can supplement the understanding of RBI and be used as biomarkers for the early clinical diagnosis of RBI.

[Complications and status quo of plaque radiotherapy for uveal melanoma]

Radiation treatment, including episcleral plaque radiotherapy, stereotactic radiosurgery, proton beam therapy and so on, is the primary eye-conserving choice for uveal melanoma. But the complications resulted from radiotherapy's nonselective kill to tumor cells can be visual-threatening and eventually result in the enucleation of eyeball. This review summarizes current radiation strategies for uveal melanoma and how these complications occur, develop and present, in the hope that it could provide insights for the radiation interventions and diagnosis of radiative complications. (Chin J Ophthalmol, 2018, 54: 707-711).

Controversies in the management of vesicovaginal fistula

Achieving 100% closure and continence rate in the management of vesicovaginal fistulas remains a challenge. There is still debate about several aspects of the care including the following.

[Occurrence of radiation-induced injury in vagina after radical radiotherapy of cervical cancer and its affecting factors]

Objective: To investigate the occurrence and degree of radiation-induced injury in vagina after radical radiotherapy of cervical cancer. Methods: A total of 282 cases of patients with cervical cancer were collected from November 2016 to September 2017. All of the above patients underwent radical radiotherapy from 2008 to 2017 in the First Affiliated Hospital of Xi'an Jiaotong University. The patients' International Federation of Gynecology and Obstetrics (FIGO) staging (2009) , brachytherapy dose, whether receive synchronous chemotherapy or not, age and body mass index (BMI) for the occurrence and severity of vaginal radiation injury at different time periods were analyzed by cross-sectional survey method. The single factor would be analyzed by the method of Chi-square test and the multiple factors would be analyzed by logistic regression method to checkout. Results: Of the 282 patients, the incidence of radiation-injury in vaginal was 84.4% (238/282) , with the incidence rate of degree Ⅰ,Ⅱ and Ⅲ radiation injury were respectively 50.7% (143/282), 29.8% (84/282) and 3.9% (11/282; χ(2)=153.375, P<0.05) , and there was no degree Ⅳ. Until the end of the follow-up time, the incidence of radiation-induced injury in vaginal after completing the treatment within 1 year, 1-2 years,>2-<5 years and ≥5 years were respectively 80.0% (24/30) , 87.2% (102/117) , 88.2% (60/68) and 77.6% (52/67; χ(2)=4.231, P=0.238) . There were 30 cases be followed within 1 year after treatment, the incidence rate of degreeⅠ,Ⅱ and Ⅲ of radiation injury in vagina was 60.0% (18/30) , 20.0% (6/30) and 0, respectively (χ(2)=28.636, P<0.05). There were 117 cases be followed between 1-2 years after treatment, the incidence rate of degreeⅠ,Ⅱ and Ⅲ vaginal radiation-induced injury were 54.7% (64/117) , 29.9% (35/117) and 2.6% (3/117) , respectively (χ(2)=77.198, P<0.05) . There were 68 cases be followed between >2-<5 years after treatment, the incidence rate of degree Ⅰ,Ⅱ and Ⅲ vaginal radiation-induced injury were 51.5% (35/68) ,33.8% (23/68) and 2.9% (2/68) , respectively (χ(2)=39.525, P<0.05) . There were 67 cases be followed ≥5 years after treatment, the incidence rate of degree Ⅰ,Ⅱ and Ⅲ vaginal radiation injury were 38.8% (26/67) , 29.9% (20/67) and 9.0% (6/67) , respectively (χ(2)=16.395, P<0.05) . The single-factor analysis result indicated that the brachytherapy dose had an obvious effect on vaginal radiation-induced injury (χ(2)=5.344, P=0.021) ; however, other factors, such as age, BMI, FIGO stages and synchronous chemotherapy, had no obvious effect on vaginal radiation-induced injury (all P>0.05) . The multifactor analysis indicated that the brachytherapy dose was an independent factor affecting the occurrence of vaginal radiation-induced injury (P=0.043) . Conclusion: After the radical radiotherapy of cervical cancer, the vaginal radiation-induced injury is associated with the dose of brachytherapy.

Comparison of Patient Skin Dose Evaluated Using Radiochromic Film and Dose Calculation Software

PURPOSE

To compare, in an interventional radiology setting, peak skin doses (PSDs) delivered as calculated using a dedicated software tool and as measured using radiochromic film. To assess the utility of this dose calculation software tool in routine clinical practice.

MATERIALS AND METHODS

First, radiochromic films were positioned on the examination table in the back of an adult anthropomorphic phantom to measure PSD, and X-ray examinations were simulated. Then, films were again positioned in the patient's back for 59 thoracic or abdominopelvic endovascular interventions. The results obtained with the radiochromic films were taken as a reference and were statistically compared with those of the software.

RESULTS

With measured PSDs ranging from 100 to 7000 mGy, the median software-film difference was 8.5%. Lin's concordance coefficient was 0.98 [0.97; 0.99] (p < 0.001), meaning that concordance was excellent between the two methods. For the films where PSD exceeded 1000 mGy, the median difference in the measured value was 8.7% [- 1.3; 21.1], with a maximum discrepancy of 34%. Lin's concordance coefficient was 0.98 [0.96; 1] (p < 0.001), meaning that concordance was excellent between the two methods.

CONCLUSION

Comparison between radiochromic films and the software tool showed that the software is a suitable tool for a simple and reliable estimation of PSD. The software seems to be a good alternative to films, whose use remains complex.

[Adjuvant radiotherapy during anti-VEGF in neovascular age-related macular degeneration]

Single adjuvant radiotherapy during anti-VEGF therapy could be in certain indications an alternative to the gold standard of sole intravitreal anti-VEGF drug injection in neovascular age-related macular degeneration. First clinical trials showed efficacy due to reduction of anti-VEGF injection numbers by 100 kV collimated beam radiotherapy. After consideration and performance of adjuvant radiotherapy, results of the course should be centrally registered in order to carry out further analysis.

[Attach importance to standardized treatment of chronic radiation proctopathy]

Radiation proctopathy represents the feared injury of rectum resulting from radiotherapy to pelvic malignancy. Interstitial fibrosis is the major histopathologic feature of chronic radiation proctopathy, whose symptoms may improve over time without any management. Treatment decisions should be based on the pattern and severity of symptoms and endoscopic findings. Non-surgical interventions are generally used to relieve major symptoms and prevent severe complications. Surgery is reserved for patients with refractory complications. Diverting stoma and restorative resection are suggested for selected patients to promote rehabilitation. Overall management should target on the improvement of patients' long-term quality-of-life.

[A randomized study of intensity-modulated radiation therapy versus three dimensional conformal radiation therapy for pelvic radiation in patients of post-operative treatment with gynecologic malignant tumor]

Objective: To study the difference between intensity-modulated radiation therapy (IMRT) and three dimensional conformal radiation therapy (3D-CRT) for pelvic radiation of post-operative treatment with gynecologic malignant tumor. Methods: A prospective investigation study was conducted on 183 patients of post-operative patients with whole pelvic radiation therapy of cervical cancer or endometrial cancer in Zhejiang Cancer Hospital [IMRT group (n=85) and 3D-CRT group (n=98)] from Oct. 2015 to Oct. 2016. The two groups received same dose (45 Gy in 25 fractions). Comparison of two groups with radiation dosimetry:the score according to the Radiation Therapy Oncology Group (RTOG) acute radiation injury grading standards before and after radiotherapy reaction, the score from functional assessment of cancer therapy scale-cervix (FACT-Cx) scale and expanded prostate cancer index composite for clinical practice (EPIC-CP) scale were also analyzed. Results: (1) There were no significant effect with age, culture level, family economic condition and ratio of radiochemotherapy between two groups (all P>0.05). (2) Dosimetric comparison for IMRT vs 3D-CRT: the average dose of planning target volume (PTV) decreased (46.1±0.4) vs (46.4±0.5) Gy, V(45) dose percentage increased (95.2±1.0) % vs (93.3±2.0) %, intestinal bag dose of V(4)0 decreased (24.4±6.8) % vs (36.5±15.9) %, rectal V(40) dose percentage decreased (73.9±12.3) % vs (85.4±8.4) %, and lower rectal V(45) dose percentage (32.8±13.4) % vs (71.5±13.7) %, bladder V(40) dose percentage decreased (55.5±13.0) % vs (84.4±13.0) %. Bone marrow V(20) lower: (67.9±5.4) % vs (79.5±6.6) %, V(1)0 lower: (82.1±6.0) % vs (86.3±6.6) %; there were significant differences (all P<0.05). There was no significant difference between the dose of V(45) in the intestinal pouch and bladder (P>0.05). (3) Acute radiation injury classification for IMRT vs 3D-CRT: big or small intestine: Ⅱ-Ⅲ reaction [13% (11/85) vs 24% (24/98); χ(2)=3.925, P=0.048], there was significant difference. Bladder: Ⅲ reaction [19% (16/85) vs 26% (25/98); χ(2)=1.171, P=0.279], there was no significant difference. Radiochemotherapy of bone marrow suppression: Ⅲ-Ⅳ reaction (14/20), the incidence rate [26% (14/54) vs 31% (20/65); χ(2)=0.339, P=0.562], the difference was not statistically significant. (4) Quality of life scale by FACT-Cx scale in IMRT vs 3D-CRT: there were no significant difference before radiotherapy (82±16 vs 85±16; t=1.279, P=0.203), while there was significant difference after radiotherapy (76±14 vs 71±18; t=-2.160, P=0.032). EPIC-CP scale score: before radiotherapy they were (16±7 vs 15±6; t=-0.174, P=0.862),but after radiotherapy (18±7 vs 22±7; t=3.158, P=0.002), there was significant difference between them. Before and after radiotherapy, the increased EPIC-CP scale of the IMRT group vs 3D-CRT group were 3±4 and 6±4, the 3D-CRT group was significantly higher, the difference was statistically significant (t=5.500, P=0.000). Conclusion: IMRT has shown that there are a significant benefit for the post-operative patients with cervical cancer and endometrial cancer compared to 3D-CRT.

Better compliance with hypofractionation vs. conventional fractionation in adjuvant breast cancer radiotherapy : Results of a single, institutional, retrospective study

BACKGROUND

The aim of the study was to identify factors significantly associated with the occurrence of unintended treatment interruptions in adjuvant breast cancer radiotherapy.

PATIENTS AND METHODS

Patients treated with postoperative radiotherapy of the breast or chest wall between March 2014 and August 2016 were evaluated. The radiotherapy regimens and techniques applied were either conventional fractionation (CF; 28 daily fractions of 1.8 Gy or 25 fractions of 2.0 Gy) or hypofractionation (HF; 15 daily fractions of 2.67 Gy) with inverse planned intensity-modulated radiotherapy (IMRT) or three-dimensional planned conformal radiotherapy (3DCRT). Logistic regression analysis was used to identify factors associated with noncompliance. Noncompliance was defined as the missing of at least one scheduled radiotherapy fraction.

RESULTS

In all, 19 of 140 (13.6%) patients treated with HF and 39 of 146 (26.7%) treated with CF experienced treatment interruptions. Of 23 factors tested, the fractionation regimen emerged as the only independent significant prognostic factor for noncompliance on multivariate analysis (CF; p = 0.007; odds ratio, 2.3; 95% confidence interval, 1.3-4.2). No statistically significant differences concerning the reasons for treatment interruptions could be detected between patients treated with CF or HF.

CONCLUSION

HF is significantly associated with a better patient compliance with the prescribed radiotherapy schedule compared with CF. The data suggest that this finding is basically related to the shorter overall treatment time of HF.

[Fistulas of the urogenital tract after radiotherapy]

BACKGROUND

Radiotherapy plays a substantial role in the treatment of malignancies. More than 2/3 of all oncologic patients undergo radiotherapy during their specific treatment. Besides manifold side effects of radiotherapy, radiogenic fistulas of the urogenital tract are a potential severe complication. These fistulas might affect the female genital tract and the urinary tract.

THERAPY

Potential manifold variety of radiogenic urogenital fistulas requires a specific therapy. Radiation tissue damage includes severely disturbed local blood supply. Consequently, in some cases extremely complex reconstructive techniques are necessary to restore the functionality of the urinary tract.

CONCLUSION

The treatment of radiogenic urogenital fistulas is challenging. A successful therapy can only be achieved by local improvement of the blood supply in the damaged area.

Changes in pulmonary function and influencing factors after high-dose intrathoracic radio(chemo)therapy

PURPOSE

Using prospectively collected patient-related, dose-related, and pulmonary function test (PFT) data before radiotherapy (RT) and at several follow-up visits after RT, the time course of PFT changes after high-dose radio(chemo)therapy and influencing factors were analyzed.

MATERIALS AND METHODS

From April 2012 to October 2015, 81 patients with non-small-cell lung carcinoma (NSCLC), small cell lung carcinoma (SCLC), or esophageal carcinoma where treated with high-dose radio(chemo)therapy. PFT data were collected before treatment and 6 weeks, 12 weeks, and 6 months after RT. The influence of patient- and treatment-related factors on PFT was analyzed.

RESULTS

Mean forced expiratory volume in 1 s (FEV1) constantly declined during follow-up (p = 0.001). In total, 68% of patients had a reduced FEV1 at 6 months. Mean vital capacity (VC) didn't change during follow-up (p > 0.05). Mean total lung capacity (TLC) showed a constant decline after RT (p = 0.026). At 6 months, 60% of patients showed a decline in VC and 73% in TLC. The mean diffusion capacity for carbon monoxide (DLCO) declined at 6 and 12 weeks, but recovered slightly at 6 months (p < 0.0005). At 6 months, 86% of patients had a reduced DLCO. After treatment, the partial pressure of CO₂ in the blood (pCO₂) was increased and pO₂ was decreased (p > 0.05). Only the pretreatment PFT classification had a significant influence on the post-RT FEV1.

CONCLUSION

DLCO seems to be the most reliable indicator for lung tissue damage after thoracic RT. Ventilation parameters appear to be less reliable. Concerning patient- or treatment-related factors, no reliable conclusion can be drawn regarding which factors may be relevant.

Impact of hypofractionation and tangential beam IMRT on the acute skin reaction in adjuvant breast cancer radiotherapy

Background

The purpose of the study was to evaluate the impact of multiple prognostic factors on the acute skin reaction in adjuvant breast cancer radiotherapy, in particular the impact of hypofractionation (HF) compared to conventional fractionation (CF) and tangential beam (TB) IMRT compared to three-dimensional conformal radiotherapy (3DCRT).

Methods

Two-hundred and sixty-six breast cancer patients with postoperative radiotherapy after breast conserving surgery or mastectomy were retrospectively evaluated. Patients were treated with HF (15 fractions of 2.67 Gy; n = 121) or CF (28 fractions of 1.8 Gy or 25 fractions of 2.0 Gy; n = 145) and TB-IMRT (n = 151) or 3DCRT (n = 115). The acute skin reactions were prospectively assessed using the CTCAE v4 grading scale. Ordinal regression analysis was used to assess the impact of possible prognostic factors on the maximal acute skin reaction.

Results

Grade 2 skin reactions were observed in 19 % of the patients treated with CF compared to 2 % treated with HF. On univariate analysis, the fractionation regimen, the PTV (breast versus chest wall), the volume of the PTV and the body mass index were significant prognostic factors for the maximum acute skin reaction. On multivariate analysis, the fractionation regimen (p < 0.00001) and the volume of the PTV (p = 0.0002) remained as independent significant factors.

Conclusions

Our data suggest that HF is associated with a significantly reduced maximal acute skin reaction compared to CF.

Safety of Radiographic Imaging in Pregnancy

There are many false assumptions, both in the general population and among physicians, regarding the influence of radiation on pregnant patients and the fetus during diagnostic procedures, in spite of scientific facts based on studies. These false assumptions are mostly based on the idea that every diagnostic procedure using ionizing radiation is a cause for serious concern and that artificial abortion as a possible solution might be considered. We analyzed data from counseling of pregnant patients exposed to ionizing radiation during diagnostic procedures in the Merkur University Hospital during a 4-year period. In this period, 26 patients presented for counseling after exposure to diagnostic ionizing radiation during pregnancy. Results showed most of these patients to have been exposed to radiation between the 2nd and 3rd week of gestation (36%), between the 4th and 5th week 32%, before the 2nd week 24%, and after the 6th week of gestation less than 8%. To provide reasonable estimate of fetal doses, Report No. 174 from the National Council on Radiation Protection and Measurements (NCRP) was used. Data from the Report include estimate of the fetal dose from direct and indirect exposures. Th e mean doses were up to 0.01 cGy in 46.2%, 0.01-0.15 cGy in 19.2%, 0.2-1 cGy in 26.9% and 1 cGy or more in 7.7% of patients. None of the counseled patients had medical indication for abortion, even though in a small percentage of patients abortion was a personal subjective decision. Considering that there are no Croatian guidelines for counseling patients exposed to ionizing radiation during pregnancy, it is recommended to use the International Commission on Radiological Protection guidelines in the management of pregnant patients exposed to ionizing radiation.

Eight decades of ICRP recommendations in medicine: a perspective

Medicine has been intimately associated with ionising radiation since the discovery of x rays in 1895; the first adverse effects of radiation were observed in persons working in research and on medical staff using x rays. Consequently, in 1925, the first International Congress of Radiology considered the need for a protection committee, which was established at its second congress in Stockholm in 1928 and is known today as the International Commission on Radiological Protection (ICRP). The first ICRP recommendations in 1928 were devoted to the protection of medical staff in the use of x rays for diagnosis and radiotherapy, and radium for radiotherapy. Later, ICRP devoted increased attention to the protection of patients, starting in 1970 with Publication 16 on protection of the patient in x-ray diagnosis, followed by three reports on the broad areas of radiation medicine: diagnostic radiology, radiation therapy, and nuclear medicine. A major change was made at the end of the 20(th) Century with the introduction of a series of short reports, focussed on specific problems and addressing specific medical practices. Since then, as many as 20 reports have been published on issues such as prevention of accidental exposure in radiotherapy, avoidance of radiation injuries from interventional procedures, managing radiation dose in digital radiology and computed tomography, protection in paediatric radiology, and many others.

Tissue-engineered conduit promotes sciatic nerve regeneration following radiation-induced injury as monitored by magnetic resonance imaging. Magn Reson Imaging. 2016;34:515-523. [PMID: 26686023 DOI: 10.1016/j.mri.2015.12.004]

PURPOSE

To observe the longitudinal changes in peripheral nerve repaired with chitosan conduits in a rat model of radiation-induced neuropathy.

MATERIALS AND METHODS

Four months after 40 Gy radiation to the right lower limbs, forty-two rats were divided randomly into three groups. Chitosan conduits were implanted with (group A, n=12) or without (group B, n=12) mesenchymal stem cells (MSCs), and untreated controls (group C, n=12). Following sciatic nerve MR imaging (including T2WI and Gd-DTPA enhanced T1WI), functional evaluation and electrophysiological exam were performed two-monthly, final histological assessments were done at the end of one year. The differences among the experimental and control groups were statistically analysed with Fisher's PLSD or t-test.

RESULTS

The compound muscle action potentials (CMAPs) and sciatic function index (SFI) had declined since 4 months after radiation injury. The focal nerve enlargement and hyperintensity, the perineurium and connecting muscle enhancement were demonstrated by MR neurography images. After chitosan tube implantation, the normalized signal intensities (SIs) in group A were declined more rapidly than SIs in other groups. The histological assessments indicated that group A had better remyelination, combined with higher CMAPs amplitude and SFI score than other groups.

CONCLUSION

A single fraction dose of 40 Gy can be used to establish a rat model of sciatic nerve injury. Longitudinal electrophysiological examination and MR neurography are useful to evaluate the post-irradiation sciatic neuropathy. The rats with tissue-engineered conduits implantation showed some improvement of lower limb function, accompanied by a normalization of (T1W/T2W) MR signal.

Feasibility of normal tissue dose reduction in radiotherapy using low strength magnetic field

Purpose

Toxicity of mucosa is one of the major concerns of radiotherapy (RT), when a target tumor is located near a mucosal lined organ. Energy of photon RT is transferred primarily by secondary electrons. If these secondary electrons could be removed in an internal cavity of mucosal lined organ, the mucosa will be spared without compromising the target tumor dose. The purpose of this study was to present a RT dose reduction in near target inner-surface (NTIS) of internal cavity, using Lorentz force of magnetic field.

Materials and Methods

Tissue equivalent phantoms, composed with a cylinder shaped internal cavity, and adjacent a target tumor part, were developed. The phantoms were irradiated using 6 MV photon beam, with or without 0.3 T of perpendicular magnetic field. Two experimental models were developed: single beam model (SBM) to analyze central axis dose distributions and multiple beam model (MBM) to simulate a clinical case of prostate cancer with rectum. RT dose of NTIS of internal cavity and target tumor area (TTA) were measured.

Results

With magnetic field applied, bending effect of dose distribution was visualized. The depth dose distribution of SBM showed 28.1% dose reduction of NTIS and little difference in dose of TTA with magnetic field. In MBM, cross-sectional dose of NTIS was reduced by 33.1% with magnetic field, while TTA dose were the same, irrespective of magnetic field.

Conclusion

RT dose of mucosal lined organ, located near treatment target, could be modulated by perpendicular magnetic field.

Protective efficacy of intravenous transplantation of adipose-derived stem cells for the prevention of radiation-induced salivary gland damage

OBJECTIVE

High-dose radiation therapy in the head and neck area can lead to irreversible damage to salivary glands (SGs) with consequent xerostomia. Adipose-derived stem cells (ADSCs) have been shown to repair or rescue damaged SGs. Thus, we investigated the protective efficacy of ADSCs in the prevention of SG damage induced by high dose radiation.

METHODS

Third-passage ADSCs (1×10(6)) were transplanted by intravenous infusion into the tail-vein of 8-week-old C57BL/6 mice, immediately after local irritation at a dose of 18Gy. The process was repeated twice a week during a period of six consecutive weeks. Eight weeks after radiation, functional evaluations were conducted by measuring salivary flow rate (SFR). Histological, immunohistochemical and transmission electron microscopic (TEM) examinations were performed to analyze microstructural and ultrastructural changes, microvessel density, amylase production, apoptosis, and proliferation activity.

RESULTS

Intravenously administrated ADSCs could home to irradiated SGs within 24h after infusion, significantly increasing SG weights, improving SFR, and preserving the microscopic morphologies of SGs eight weeks post-radiation. More functional acini, higher amylase production levels, and higher microvessel densities were observed in ADSC-treated SGs than in irradiated SGs. Additionally, enhanced cell proliferation activity and reduced radiation-induced SG apoptosis was observed in the ADSC-treated group when compared with the irradiated group.

CONCLUSION

Systemic administration of ADSCs immediately after radiation at a dose of 18Gy can protect both the morphology and function of SGs eight weeks after radiation in mice, and can be used as a protective measure for the prevention of SG damage induced by high-dose radiation.

Perception of radiation dose and potential risks of computed tomography in emergency department medical personnel

Objective

Use of computed tomography (CT) continues to increase, but the relatively high radiation doses associated with CT have raised health concerns such as future risk of cancer. We investigated the level of awareness regarding radiation doses and possible risks associated with CT in medical personnel (MP).

Methods

This study was conducted from April to May 2012 and included physicians and nurses who worked in the emergency department of 17 training hospitals. The questionnaire included measurement of the effect of CT or radiography on health using a 10-point numerical rating scale, estimation of the radiation dose of one abdominal CT scan compared with one chest radiograph, and perception of the increased lifetime risk of cancer associated with CT.

Results

A total of 354 MP participated in this study: 142 nurses, 87 interns, 86 residents, and 39 specialists. Interns were less aware of the effects of CT or radiography on health than other physicians or nurses (mean±SD of 4.8±2.7, 5.9±2.7, 6.1±2.7, and 6.0±2.2 for interns, residents, specialists, and nurses, respectively; P<0.05). There was a significant difference in knowledge about the relative radiation dose of one abdominal CT scan compared with one chest radiograph between physicians and nurses (48.6% vs. 28.9% for physicians vs. nurses, P<0.05). MP perceived an increased risk of cancer from radiation associated with CT.

Conclusion

MP perceive the risk of radiation associated with CT, but their level of knowledge seems to be insufficient.

A predictive model to guide management of the overlap region between target volume and organs at risk in prostate cancer volumetric modulated arc therapy

PURPOSE

The goal of this study is to determine whether the magnitude of overlap between planning target volume (PTV) and rectum (Rectumoverlap) or PTV and bladder (Bladderoverlap) in prostate cancer volumetric-modulated arc therapy (VMAT) is predictive of the dose-volume relationships achieved after optimization, and to identify predictive equations and cutoff values using these overlap volumes beyond which the Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC) dose-volume constraints are unlikely to be met.

MATERIALS AND METHODS

Fifty-seven patients with prostate cancer underwent VMAT planning using identical optimization conditions and normalization. The PTV (for the 50.4 Gy primary plan and 30.6 Gy boost plan) included 5 to 10 mm margins around the prostate and seminal vesicles. Pearson correlations, linear regression analyses, and receiver operating characteristic (ROC) curves were used to correlate the percentage overlap with dose-volume parameters.

RESULTS

The percentage Rectumoverlap and Bladderoverlap correlated with sparing of that organ but minimally impacted other dose-volume parameters, predicted the primary plan rectum V45 and bladder V50 with R(2) = 0.78 and R(2) = 0.83, respectively, and predicted the boost plan rectum V30 and bladder V30 with R(2) = 0.53 and R(2) = 0.81, respectively. The optimal cutoff value of boost Rectumoverlap to predict rectum V75 >15% was 3.5% (sensitivity 100%, specificity 94%, p < 0.01), and the optimal cutoff value of boost Bladderoverlap to predict bladder V80 >10% was 5.0% (sensitivity 83%, specificity 100%, p < 0.01).

CONCLUSION

The degree of overlap between PTV and bladder or rectum can be used to accurately guide physicians on the use of interventions to limit the extent of the overlap region prior to optimization.

Conjoined stent technique for radiation induced long segment carotid stenosis and pseudoaneurysm

Radiation induced carotid stenosis (RICS) is known but challenging complication of head and neck irradiation. Endovascular revascularization is preferred treatment modality than surgical revascularization. Sometimes endovascular treatment may be difficult in view of long segment of stenosis and associated pseudoaneurysm. We report a unique technique of carotid stenting named as "conjoined stent technique" in a challenging case of RICS with long segment of stenosis and pseudoaneurysm. In this technique we overlapped distal end of one stent with proximal end of second stent to occlude pseudoaneurysm. "Conjoined stent technique" may be viable option in case of long segment of RICS with associated pseudoaneurysm and alternative to flow diverters in extracranial carotid pseudoaneurysm.

Endoscopic findings of rectal mucosal damage after pelvic radiotherapy for cervical carcinoma: correlation of rectal mucosal damage with radiation dose and clinical symptoms

PURPOSE

To describe chronic rectal mucosal damage after pelvic radiotherapy (RT) for cervical cancer and correlate these findings with clinical symptoms and radiation dose.

MATERIALS AND METHODS

Thirty-two patients who underwent pelvic RT were diagnosed with radiation-induced proctitis based on endoscopy findings. The median follow-up period was 35 months after external beam radiotherapy (EBRT) and intracavitary radiotherapy (ICR). The Vienna Rectoscopy Score (VRS) was used to describe the endoscopic findings and compared to the European Organization for Research and Treatment of Cancer (EORTC)/Radiation Therapy Oncology Group (RTOG) morbidity score and the dosimetric parameters of RT (the ratio of rectal dose calculated at the rectal point [RP] to the prescribed dose, biologically effective dose [BED] at the RP in the ICR and EBRT plans, α/β = 3).

RESULTS

Rectal symptoms were noted in 28 patients (rectal bleeding in 21 patients, bowel habit changes in 6, mucosal stools in 1), and 4 patients had no symptoms. Endoscopic findings included telangiectasia in 18 patients, congested mucosa in 20, ulceration in 5, and stricture in 1. The RP ratio, BEDICR, BEDICR+EBRT was significantly associated with the VRS (RP ratio, median 76.5%; BEDICR, median 37.1 Gy3; BEDICR+EBRT, median 102.5 Gy3; p < 0.001). The VRS was significantly associated with the EORTC/RTOG score (p = 0.038).

CONCLUSION

The most prevalent endoscopic findings of RT-induced proctitis were telangiectasia and congested mucosa. The VRS was significantly associated with the EORTC/RTOG score and RP radiation dose.

Practical approaches to effective management of intestinal radiation injury: Benefit of resectional surgery

AIM: To study the outcome of patients undergoing surgical resection of the bowel for sustained radiation-induced damage intractable to conservative management.

METHODS: During a 7-year period we operated on 17 cases (5 male, 12 female) admitted to our surgical department with intestinal radiation injury (IRI). They were originally treated for a pelvic malignancy by surgical resection followed by postoperative radiotherapy. During follow-up, they developed radiation enteritis requiring surgical treatment due to failure of conservative management.

RESULTS: IRI was located in the terminal ileum in 12 patients, in the rectum in 2 patients, in the descending colon in 2 patients, and in the cecum in one patient. All patients had resection of the affected region(s). There were no postoperative deaths, while 3 cases presented with postoperative complications (17.7%). All patients remained free of symptoms without evidence of recurrence of IRI for a median follow-up period of 42 mo (range, 6-96 mo).

CONCLUSION: We report a favorable outcome without IRI recurrence of 17 patients treated by resection of the diseased bowel segment.