Effects of radiation on normal tissue: consequences and mechanisms

Is immediate dental implant in fibula free flap beneficial for implant survival and osteoradionecrosis in jaw reconstruction?

OBJECTIVES

This study aimed to compare the risk of osteoradionecrosis and implant survival in oral cancer patients undergoing immediate dental implants during jaw reconstruction, termed "Jaw in a Day" (JIAD), with those receiving no implants or delayed implants (non-JIAD).

PATIENTS & METHODS

Clinicopathologic data were collected from prospectively enrolled JIAD patients (n = 10, 29 implants) and retrospectively from non-JIAD patients (n = 117, 86 implants). Survival analyses were performed to assess implant survival and osteoradionecrosis-free survival.

RESULTS

Osteoradionecrosis occurred in 0 % of JIAD cases compared to 19.3 % in non-JIAD cases without implants and 71.4 % in non-JIAD cases with delayed implants (p = 0.008). Osteoradionecrosis-free survival was significantly better in the JIAD group than the non-JIAD group (p = 0.0059). Implants in the JIAD group all survived regardless of radiation therapy (29/29, 100 %) and 95.1 % (58/61) of implants survived in delayed implants in non-irradiated fibula without radiotherapy. Meanwhile, only 11 of 25 implants placed in irradiated fibula flaps survived, even when the implants were placed after a median time interval of 624 days after radiotherapy, and none of them were earlier than 360 days. The survival analysis revealed a significant difference (p < 0.0001).

CONCLUSION

JIAD appears to offer superior outcomes in terms of implant survival and osteoradionecrosis prevention compared to delayed implant placement. Placing implants in irradiated fibula, even after years, significantly poses high risk of implant failure and osteoradionecrosis. JIAD represents a promising approach for optimal rehabilitation, particularly in oral cancer patients requiring postoperative radiotherapy. Proper positioning and orientation of implants and flaps are crucial for implant survival.

Pubic bone osteomyelitis and fistulas after radiation therapy of the pelvic region: patient-reported outcomes and urological management of a rare but serious complication

PURPOSE

This study investigated late urinary adverse events (UAEs) in patients who underwent pelvic radiation therapy, with a focus on occurrence, diagnostic characteristics and the impact of subsequent extirpative surgery with the need of urinary diversion on quality of life.

METHODS

A retrospective analysis of 20 patients after pelvic radiotherapy (2016-2022) was conducted. Data included demographics, perioperative details, oncological parameters, and patient-reported outcomes. Imaging (CT, MRI) was examined for early manifestations of late UAEs.

RESULTS

In the study cohort, prostate cancer was the primary malignancy in 85% with a mean radiation dose of 84 Gray over 35 days. Time to diagnosis of late UAEs was 4.0 years post-radiation. Radiological assessment demonstrated a progressive increase in typical CT and MRI features of pubic bone osteomyelitis over time. Surgical interventions, mainly cystectomy, were required with variable outcomes in patient-reported post-surgery quality of life.

CONCLUSION

Diagnosing and managing late UAEs after pelvic radiation necessitate an understanding of their occurrence, diagnostic features and appropriate management strategies. Early imaging, particularly MRI, is crucial for timely diagnosis and treatment planning. Variable post-surgery quality of life underscores the importance of a multidisciplinary approach in managing late UAEs. The study contributes to understanding these complications and emphasizes their consideration in post-radiation follow-up care.

Timing Considerations for Artificial Urinary Sphincter Implantation Post-Pelvic Radiotherapy

BACKGROUND

To explore the optimal timing for placing an artificial urinary sphincter (AUS) post-radiation therapy (RT).

METHODS

A bi-institutional retrospective review of all patients who underwent their first (virgin) AUS placement after pelvic RT between January 1st 2011 and July 1st 2023. To determine the optimal timeline for device implantation 2-5 years post-RT, we compared hazard ratios (HRs) for device revision/explantation (Rev/Exp) using Kaplan-Meier curves for each year (earlier vs. later than 2/3/4/5 years post-RT).The Pearson correlation coefficient identified trends in Rev/Exp reasons (erosion/infection vs. other).

RESULTS

Seventy-two patients met our inclusion criteria with a median age of 65.5 years (IQR 70-81.25). Fifteen (20.1%) had undergone one or more previous urethral or bladder neck interventions (urethroplasty in one [1.4%], internal urethrotomy in 7 [9.7%], and bladder neck incision in 9 [12.5%]). After a median follow-up of 57.5 months (IQR 13-107), a total of 36 (50%) devices were Rev/Exp, with mechanical failure in 14 (19.4%) and device erosion in 12 (16.7%) being the main reasons. Device survival analysis revealed no significant difference in the risk of device Rev/Exp when implanted earlier versus later than 2, 3, 4,or 5 years post-RT, with p-values of 0.3, 0.3, 0.4, and 0.4, respectively. A constant trend towards higher infection/erosion rates as indication for device Rev/Exp the later the insertion was noticed:R2 = 0.98.

CONCLUSIONS

Despite a small sample size, our study indicates that implanting an AUS within 5-years after RT shows comparable device lifespan. However, later insertions may have higher removal rates due to erosion/infection.

CLINICAL TRIAL REGISTRATION

Not applicable.

Low-dose radiation promotes high-fat diet-induced atherosclerosis by activating cGAS signal pathway

BACKGROUND

Atherosclerosis (AS) is the most prevalent cardiovascular disease, with an exceptionally high burden. High-fat diet (HFD) is a popular diet behavior, whereas low-dose radiation (LDR) is an environmental physical factor. There is evidence to suggest that an HFD may exacerbate the onset of atherosclerosis. Whether the combination effect of HFD and LDR would have potential on atherosclerosis development remains incompletely unclear.

METHODS

In this study, ApoE-/- mice were used as atherosclerosis model animals to investigate the combination effects of HFD and LDR (10 × 0.01Gy, or 20 × 0.01Gy) on vascular lesions. Doppler ultrasound imaging, H&E staining, oil red O staining, western blotting, and immunohistochemistry (IHC) were used to assess the pro-atherosclerotic effects. LC-MS was used to detect the non-targeted lipidomic.

RESULTS

Long-term exposure of low-dose radiation at an accumulated dose of 0.2Gy significantly increased the occurrence of vascular stiffness and the aortic lesion in ApoE-/- mice. The synergistic effect of HFD and LDR was observed in the development of atherosclerosis, which might be linked to both the dysbiosis of lipid metabolism and the stimulation of the inflammatory signaling system. Moreover, LDR but not HFD can activate the cGAS-STING signaling through increasing the yield of cytosolic mitochondrial DNAs as well as the expression of cGAS protein. The activation of cGAS-STING signal triggers the release of IFN-α/-β, which functions as an inflammatory amplifier in the formation of atherosclerotic plaque.

CONCLUSION

The current study offers fresh insights into the risks and mechanism that underlie the development of atherosclerosis by LDR, and there is a combination effect of LDR and HFD with the involvement of cGAS-STING signal pathway.

Radiation-Induced Endothelial Ferroptosis Accelerates Atherosclerosis via the DDHD2-Mediated Nrf2/GPX4 Pathway

This study sought to explore potential roles of endothelial ferroptosis in radiation-associated atherosclerosis (RAA) and molecular mechanisms behind this phenomenon. Here, an in vivo RAA mouse model was used and treated with ferroptosis inhibitors. We found that the RAA group had a higher plaque burden and a reduction in endothelial cells with increased lipid peroxidation compared to the control group, while ameliorated by liproxstatin-1. In vitro experiments further confirmed that radiation induced the occurrence of ferroptosis in human artery endothelial cells (HAECs). Then, proteomics analysis of HAECs identified domain-containing protein 2 (DDHD2) as a co-differentially expressed protein, which was enriched in the lipid metabolism pathway. In addition, the level of lipid peroxidation was elevated in DDHD2-knockdown HAECs. Mechanistically, a significant decrease in the protein and mRNA expression of glutathione peroxidase 4 (GPX4) was observed in HAECs following DDHD2 knockdown. Co-immunoprecipitation assays indicated a potential interaction between DDHD2 and nuclear factor erythroid 2-related factor 2 (Nrf2). The downregulation of Nrf2 protein was also detected in DDHD2-knockdown HAECs. In conclusion, our findings suggest that radiation-induced endothelial ferroptosis accelerates atherosclerosis, and DDHD2 is a potential regulatory protein in radiation-induced endothelial ferroptosis through the Nrf2/GPX4 pathway.

Expected role of photodynamic therapy to relieve skin damage in nuclear or radiological emergency: Review

Nuclear and radiological accidents can occur due to poor management, in transportation, radiation therapy and nuclear wards in hospitals, leading to extreme radiation exposure and serious consequences for human health. Additionally, in many of previous radiological accidents, skin damage was observed in patients and survivors due to the high radiation exposure. However, as part of a medical countermeasures in a nuclear/radiological emergency, it is critical to plan for the treatment of radiation-induced skin damage. Hence, the new, non-invasive technology of photodynamic therapy (PDT) is projected to be more effectively used for treating skin damage caused by high-dose radiation. PDT plays an important role in treating, repairing skin damage and promoting wound healing as evidenced by research. This review, highlighted and recommended potential impacts of PDT to repair and decrease radiation-induced skin tissue damage. Moreover, we have suggested some photosensitizer (PS) agent as radio-mitigator drugs to decrease radiobiological effects.

The Contemporary Role of Salvage Radical Prostatectomy in the Management of Recurrent Prostate Cancer: An Up-to-Date Review

Prostate cancer is the second most common cancer among men, with many treatment modalities available for patients, such as radical prostatectomy, external beam radiotherapy, brachytherapy, high-intensity focused ultrasound, cryotherapy, electroporation and other whole-gland or focal ablative novel techniques. Unfortunately, up to 60% of men with prostate cancer experience recurrence at 5 to 10 years. Salvage radical prostatectomy can be offered as an option in the setting of recurrence after a primary non-surgical treatment. However, the complexity of salvage radical prostatectomy is considered to be greater than that of primary surgery, making it the least popular treatment of choice. With the wide use of robotic platforms in urologic oncologic surgery, salvage radical prostatectomy has attracted attention again because, compared to past data, modern series involving salvage Robot-Assisted Radical Prostatectomy have shown promising results. In this narrative literature review, we comprehensively examined data on salvage radical prostatectomy. We investigated the correlation between the different types of primary prostate cancer therapy and the following salvage radical prostatectomy. Furthermore, we explored the concept of a robotic approach and its beneficial effect in salvage surgery. Lastly, we emphasized several promising avenues for future research in this field.

Comparing the lifespan of virgin artificial urinary sphincters in radiated patients: transcorporal vs. standard placement

PURPOSE

To compare the lifespan of first transcorporal cuff (TC) placement of an artificial urinary sphincter (AUS) versus standard placement (SP) in patients with prior radiotherapy (RT) for prostate cancer (PCa).

METHODS

We reviewed first (virgin) AUS placements from two high-volume care centers between 1/2011 and 1/2021, including PCa patients with RT history. AUS lifespan was assessed via the hazard ratio of device explantation and/or revision within a ten-year timeframe for the TC vs. SP approaches. Chi-square, Fisher's exact, and t-tests compared clinicodemographic variables. Kaplan-Meier curve compared TC and SP lifespan.

RESULTS

85/314 men with AUS met inclusion criteria, with 38.8% (33/85) in the TC group and 61.2% (52/85) in the SP group. Median ages were 69.8 (IQR = 65.2-73.6) and 67.1 (61.6-72.9), respectively, p = 0.17. Over a median follow up of 51.9 (15.8-86.1) and 80.4 (28.1-128.3) months for the TC and SP, overall, 12 (36.4%) TC devices were removed (four [12.1%] due to mechanical failures; eight [24.2%] erosions, and two [6.1%] infections) vs. 29 (55.8%) in the SP group (14 [26.9%] mechanical failures; 11 [21.1%] erosions, and five [9.6%] infections). No statistically significant differences were observed between the two approaches, with HR = 0.717, 95% CI 0.37-1.44, p = 0.35. The calculated device survival probabilities for the TC vs. SP at one, five, and 10 years were 78.8% vs. 76.9%, 69.3% vs. 58.7%, and 62.1% vs. 46.7%, respectively.

CONCLUSIONS

TC cuff insertion for the first AUS implantation in pre-radiated patients showed to be comparable to SP when it comes to device survival, with comparable complication rates. Current guidance for approach selection is primarily based on patient selection and surgeon preference.

Sinonasal Malignancy Following Cranial Irradiation: A Scoping Review and Case Report of Sinonasal Teratocarcinosarcoma

Background  Radiation therapy is a mainstay of treatment for brain tumors, but delayed complications include secondary malignancy which may occur months to years after treatment completion. Methods  We reviewed the medical records of a 41-year-old female treated with 60 Gy of radiation for a recurrent astrocytoma, who 6 years later developed a locally advanced sinonasal teratocarcinosarcoma. We searched MEDLINE, Embase, and Web of Science to conduct a scoping review of biopsy-proven sinonasal malignancy in patients who previously received cranial irradiation for a brain tumor. Results  To our knowledge, this is the first report of a patient to present with a sinonasal teratocarcinosarcoma after receiving irradiation for a brain tumor. Our scoping review of 1,907 studies produced 14 similar cases of secondary sinonasal malignancy. Median age of primary cancer diagnosis was 39.5 years old (standard deviation [SD]: 21.9), and median radiation dose was 54 Gy (SD: 20.3). Median latency time between the primary cancer and secondary sinonasal cancer was 9.5 years (SD: 5.8). Olfactory neuroblastoma was the most common sinonasal cancer ( n  = 4). Fifty percent of patients died from their sinonasal cancer within 1.5 years. Conclusion  Patients who receive radiation exposure to the sinonasal region for treatment of a primary brain tumor, including low doses or scatter radiation, may be at risk of a secondary sinonasal malignancy later in life. Physicians who monitor at-risk patients must be vigilant of symptoms which may suggest sinonasal malignancy, and surveillance should include radiographic review with careful monitoring for a secondary malignancy throughout the entire irradiated field.

Hemoglobin Concentration as an Indicator of Skin Radiation Damage During Radiation Therapy Treatments

PURPOSE

Acute radiation dermatitis (ARD) is the most common side effect reported by patients undergoing radiation therapy (RT). Currently, the assessment of the severity of the reaction is based on the visual assessment of the skin, which is a subjective method, depending on many factors. The main aim of this study was to investigate the usefulness of hyperspectral imaging (HSI) in the assessment of ARD and find physiological factors that could be correlated with ARD.

METHODS AND MATERIALS

In this clinical pilot trial, weekly acquisitions of hyperspectral camera images of irradiated skin were performed for 5 weeks of RT and at the posttreatment follow-up visit which took place 30 to 40 days after the last fraction of RT. At the same time, the severity of radiodermatitis was assessed based on the criteria of the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE). The content and concentration of chromophores in irradiated skin were quantitatively determined using a hyperspectral camera.

RESULTS

The use of HSI supported by image analysis and processing methods allowed for the determination of the content and distribution of hemoglobin and melanin in the irradiated skin. It was found that the hemoglobin concentration is correlated with the subjective assessment made according to the CTCAE protocol.

CONCLUSIONS

HSI is a sensitive and specific method of analyzing the concentration of chromophores in the skin, including hemoglobin. A clear correlation was found between hemoglobin concentration and CTCAE v.5 scale because of which HSI can be considered as an objective method of skin assessment during RT.

Does Prior Breast Irradiation Increase Complications of Subsequent Reduction Surgery in Breast Cancer Patients? A systematic Review and Meta-Analysis

BACKGROUND

Reduction mammoplasty and mastopexy are potentially complicated by prior breast irradiation as part of breast conserving therapy. Associated tissue changes with therapeutic irradiation have led to surgeons deciding the risks may outweigh potential benefit for those patients. A systematic review of the existing literature was performed to explore surgical outcomes of patients undergoing delayed bilateral reduction mammoplasty or mastopexy following unilateral breast irradiation as part of breast conserving therapy.

METHODS

Medline, PubMed and EMBASE were searched from 1990 to 2023 according to PRISMA guidelines. Studies were combined by the generic inverse variance method on the natural logarithms of rate ratios (RR) using a random effect model in Review manager 5.4.1.

RESULTS

Fifteen studies reported outcomes in 188 patients who underwent breast reduction (BR) following unilateral breast conserving surgery and radiotherapy. The median age at BR was 51.5 years (range 39-60), and median time since radiotherapy was 48 months (range 11.7-86). We compared outcomes for irradiated breast (IB) versus non-irradiated breast (NIB). Pooled results showed higher rate of major complications in the IB (RR 2.52, 95%CI 0.96-6.63, p=0.06), but not statistically significant. However, rate of minor complications was significantly higher in the IB (RR 3.97 95%CI 1.86-8.50, p<0.0004). Incidence of fat necrosis as a discrete complication was 2× higher in IB (RR 2.14 95%CI 0.85-5.35, p-value 0.10) compared to the NIB, but not significant.

CONCLUSION

We found breast reduction to be safe with acceptable risk of major complications. However, the overall complication rate remains higher in IB compared to NIB.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of contents or the online Instructions to Authors www.springer.com/00266 .

FLASH radiotherapy: A new milestone in the field of cancer radiotherapy

Radiotherapy plays a pivotal role in the control and eradication of tumors, but it can also induce radiation injury to surrounding normal tissues while targeting tumor cells. In recent years, FLASH-Radiotherapy (FLASH-RT) has emerged as a cutting-edge research focus in the field of radiation therapy. By delivering high radiation doses to the treatment target in an ultra-short time, FLASH-RT produces the FLASH effect, which reduces the toxicity to normal tissues while achieving comparable tumor control efficacy to conventional radiotherapy. This review provides a brief overview of the development history of FLASH-RT and its impact on tumor control. Additionally, it focuses on introducing the protective effects and molecular mechanisms of this technology on various normal tissues, as well as exploring its synergistic effects when combined with other tumor therapies. Importantly, this review discusses the challenges faced in translating FLASH-RT into clinical practice and outlines its promising future applications.

The clinical manifestations and molecular pathogenesis of radiation fibrosis

Advances in radiation techniques have enabled the precise delivery of higher doses of radiotherapy to tumours, while sparing surrounding healthy tissues. Consequently, the incidence of radiation toxicities has declined, and will likely continue to improve as radiotherapy further evolves. Nonetheless, ionizing radiation elicits tissue-specific toxicities that gradually develop into radiation-induced fibrosis, a common long-term side-effect of radiotherapy. Radiation fibrosis is characterized by an aberrant wound repair process, which promotes the deposition of extensive scar tissue, clinically manifesting as a loss of elasticity, tissue thickening, and organ-specific functional consequences. In addition to improving the existing technologies and guidelines directing the administration of radiotherapy, understanding the pathogenesis underlying radiation fibrosis is essential for the success of cancer treatments. This review integrates the principles for radiotherapy dosimetry to minimize off-target effects, the tissue-specific clinical manifestations, the key cellular and molecular drivers of radiation fibrosis, and emerging therapeutic opportunities for both prevention and treatment.

Prediction of auditory brain stem responses damage in patients with head-and-neck cancers receiving radiotherapy using the functional assays of normal tissue complication probability models

AIM

The purpose of this study was to set four NTCP models on clinical data and develop a model that calculates the possibility of hearing damage due to irradiation of healthy and at-risk brainstem tissue.

MATERIALS AND METHODS

ABR tests were performed on 50 head-and-neck cancer patients three years after radiotherapy for evaluation of lesions in a part of the auditory nerve or the auditory pathway in the brainstem.

RESULTS

It indicated a significant difference in the latency of the waves assessed by the ABR test between the two groups. The paired sample t-test indicated the latency time of waves I, III, V, I-III, and I-V (P < 0.001) in the right ear, and in the left ear latency time of waves III, V, I-III, I-V, and III-V (P < 0.001) were significantly higher in the case group's ear than those in the control group. The confidence interval of the fitted parameters was 95% for NTCP models. ABR test's binary outcome with differential dose-volume histograms (dDVHs) was calculated and imported as input to the NTCP modeling. The values of the parameters n = 2.3-2.9 and the value s = 1 were obtained, which indicated that the brainstem organ is seriality.

CONCLUSION

The best model ranked for the prediction of brainstem hearing damage was the logit model, which had the lowest Akaike value. The nervousness of the auditory organ of the brainstem (VIII nerve) can be declared as one of the reasons for being independent of the received dose.

Molecular Changes in Breast Cancer Induced by Radiation Therapy

PURPOSE

Breast cancer treatments are based on prognostic clinicopathologic features that form the basis for therapeutic guidelines. Although the utilization of these guidelines has decreased breast cancer-associated mortality rates over the past three decades, they are not adequate for individualized therapy. Radiation therapy (RT) is the backbone of breast cancer treatment. Although a highly successful therapeutic modality clinically, from a biological perspective, preclinical studies have shown RT to have the potential to alter tumor cell phenotype, immunogenicity, and the surrounding microenvironment, potentially changing the behavior of cancer cells and resulting in a significant variation in RT response. This review presents the recent advances in revealing the complex molecular changes induced by RT in the treatment of breast cancer and highlights the complexities of translating this information into clinically relevant tools for improved prognostic insights and the revelation of novel approaches for optimizing RT.

METHODS AND MATERIALS

Current literature was reviewed with a focus on recent advances made in the elucidation of tumor-associated radiation-induced molecular changes across molecular, genetic, and proteomic bases. This review was structured with the aim of providing an up-to-date overview over the very broad and complex subject matter of radiation-induced molecular changes and radioresistance, familiarizing the reader with the broader issue at hand.

RESULTS

The subject of radiation-induced molecular changes in breast cancer has been broached from various physiological focal points including that of the immune system, immunogenicity and the abscopal effect, tumor hypoxia, breast cancer classification and subtyping, molecular heterogeneity, and molecular plasticity. It is becoming increasingly apparent that breast cancer clinical subtyping alone does not adequately account for variation in RT response or radioresistance. Multiple components of the tumor microenvironment and immune system, delivered RT dose and fractionation schedules, radiation-induced bystander effects, and intrinsic tumor physiology and heterogeneity all contribute to the resultant RT outcome.

CONCLUSIONS

Despite recent advances and improvements in anticancer therapies, tumor resistance remains a significant challenge. As new analytical techniques and technologies continue to provide crucial insight into the complex molecular mechanisms of breast cancer and its treatment responses, it is becoming more evident that personalized anticancer treatment regimens may be vital in overcoming radioresistance.

Pelvic Floor Therapy and Initial Interventions for Pelvic Floor Dysfunction in Gynecologic Malignancies

PURPOSE OF REVIEW

This review provides evidence-based updates for the first-line management approaches for pelvic floor disorders in patients with gynecologic malignancies, as well as important provider considerations when referring for pelvic floor physical therapy.

RECENT FINDINGS

Currently, there is strong evidence to recommend pelvic floor muscle training as initial treatment for urinary incontinence and for pelvic organ prolapse; some evidence to recommend a more targeted pelvic floor muscle training program for fecal incontinence; and mostly expertise-based evidence to recommend vaginal gels or estrogen to aid with dyspareunia causing sexual dysfunction. More research is greatly needed to understand the role of overactive pelvic floor muscles in survivors with chronic pelvic pain and the treatment of post-radiation pelvic complications such as vaginal stenosis and cystitis. While pelvic floor disorders are common concerns in gynecologic cancer survivors, there are evidence-based initial noninvasive treatment approaches that can provide relief for many individuals.

Senescent fibroblast facilitates re-epithelization and collagen deposition in radiation-induced skin injury through IL-33-mediated macrophage polarization

BACKGROUND

The need for radiotherapy among the elderly rises with increasing life expectancy and a corresponding increase of elderly cancer patients. Radiation-induced skin injury is one of the most frequent adverse effects in radiotherapy patients, severely limiting their life quality. Re-epithelialization and collagen deposition have essential roles in the recovery of skin injuries induced by high doses of ionizing radiation. At the same time, radiation-induced senescent cells accumulate in irradiated tissues. However, the effects and mechanisms of senescent cells on re-epithelialization and collagen deposition in radiation-induced skin injury have not been fully elucidated.

RESULTS

Here, we identified a role for a population of senescent cells expressing p16 in promoting re-epithelialization and collagen deposition in radiation-induced skin injury. Targeted ablation of p16+ senescent cells or treatment with Senolytics resulted in the disruption of collagen structure and the retardation of epidermal coverage. By analyzing a publicly available single-cell sequencing dataset, we identified fibroblasts as a major contributor to the promotion of re-epithelialization and collagen deposition in senescent cells. Notably, our analysis of publicly available transcriptome sequencing data highlighted IL-33 as a key senescence-associated secretory phenotype produced by senescent fibroblasts. Neutralizing IL-33 significantly impedes the healing process. Finally, we found that the effect of IL-33 was partly due to the modulation of macrophage polarization.

CONCLUSIONS

In conclusion, our data suggested that senescent fibroblasts accumulated in radiation-induced skin injury sites participated in wound healing mainly by secreting IL-33. This secretion regulated the local immune microenvironment and macrophage polarization, thus emphasizing the importance of precise regulation of senescent cells in a phased manner.

Utilizing a Second Flap to Address the Effect of Postradiotherapy Soft Tissue Fibrosis in Head and Neck Malignancy

Background  Late effects of adjuvant radiation therapy (RT) on soft tissues can lead to hair loss, pigmentary changes, loss of tissue volume, and fibrosis, which appear months to years after the treatment. These changes are often progressive and are because of tissue hypoxia due to radiation-induced capillary endothelial damage. Tissue hypoxia may be compounded by subclinical infection following minor trauma, exposed hardware, or associated osteoradionecrosis. The combined effect of these factors causes significant deformities in soft tissue, affecting both function and appearance. Such changes are also seen in primarily transferred flaps, which have been radiated, resulting in severe, progressive soft tissue fibrosis, compromising function and aesthetics. In selected cases, a second flap may be needed to restore function and volume. Methods  Data of patients who underwent secondary soft tissue transfers for postradiotherapy-related soft tissue changes were collected from the hospital electronic medical records, from January 2019 to 2023. Details regarding the primary surgery, dose, duration of adjuvant RT, time interval between adjuvant RT and secondary soft tissue transfer, indications, and the choice of the second flap were analyzed. Results  Twenty-one patients had undergone secondary soft tissue transfer for extensive soft tissue fibrosis. In addition, associated compounding features like exposed implant and volume loss were observed. Two patients with osteoradionecrosis also had associated extensive soft tissue fibrosis necessitating replacement. Out of these 21 patients, 13 had undergone free tissue transfers, while 7 locoregional tissue transfers. Conclusion  Late sequelae of adjuvant RT changes usually present from 6 months onwards. The radiated hypoxic tissue, due to capillary damage, leads to a chronic progressive fibrotic stage, causing loss of soft tissue volume and fibrosis. Replacing this tissue with a vascularized flap helps to restore volume and correct these secondary changes, improving overall quality of life.

Radiation-targeted immunotherapy: A new perspective in cancer radiotherapy

In contemporary oncology, radiation therapy and immunotherapy stand as critical treatments, each with distinct mechanisms and outcomes. Radiation therapy, a key player in cancer management, targets cancer cells by damaging their DNA with ionizing radiation. Its effectiveness is heightened when used alongside other treatments like surgery and chemotherapy. Employing varied radiation types like X-rays, gamma rays, and proton beams, this approach aims to minimize damage to healthy tissue. However, it is not without risks, including potential damage to surrounding normal cells and side effects ranging from skin inflammation to serious long-term complications. Conversely, immunotherapy marks a revolutionary step in cancer treatment, leveraging the body's immune system to target and destroy cancer cells. It manipulates the immune system's specificity and memory, offering a versatile approach either alone or in combination with other treatments. Immunotherapy is known for its targeted action, long-lasting responses, and fewer side effects compared to traditional therapies. The interaction between radiation therapy and immunotherapy is intricate, with potential for both synergistic and antagonistic effects. Their combined use can be more effective than either treatment alone, but careful consideration of timing and sequence is essential. This review explores the impact of various radiation therapy regimens on immunotherapy, focusing on changes in the immune microenvironment, immune protein expression, and epigenetic factors, emphasizing the need for personalized treatment strategies and ongoing research to enhance the efficacy of these combined therapies in cancer care.

Association between ICW/TBW ratio and cancer prognosis: Subanalysis of a population-based retrospective multicenter study

BACKGROUND & AIMS

Disease burden is known to alter cellular integrity and water balance. Therefore, the intracellular water/total body water (ICW/TBW) ratio is used as an adjunctive indicator to predict disease severity and prognosis. The ICW/TBW ratio of patients with cancer, who typically present with low muscle mass, poor nutritional status, and high inflammatory response, reportedly differs from that of the healthy population. Herein, we aimed to evaluate the effect of the ICW/TBW ratio on the prognosis of different subgroups of patients with cancer.

METHODS

This multicenter cohort study included 2787 patients with malignancies between June 2014 and December 2018. The association between covariates and overall survival (OS) was assessed using restricted cubic spline models. The multivariate Cox regression model included variables demonstrating a statistical significance in the univariate Cox regression analysis (P < 0.05) without multicollinearity. The generated nomogram used the C-index and calibration curves to validate the predictive accuracy of the scoring system.

RESULTS

The optimal cut-off value for the ICW/TBW ratio was 0.61. The ICW/TBW ratio was an independent prognostic factor (hazard ratio [HR]: 0.621; 95 % confidence interval [CI]: 0.537-0.719, P < 0.001). Moreover, the ICW/TBW ratio had a greater impact on the prognosis of patients receiving chemoradiotherapy than on those receiving chemotherapy alone (chemoradiotherapy: HR = 0.495, P = 0.005 vs. chemotherapy: HR = 0.646, P < 0.001). Multivariate Cox regression analysis showed that sex, age, tumor stage, body mass index, neutrophil-to-lymphocyte ratio (NLR), and ICW/TBW ratio were associated with OS. Subsequently, a nomogram was developed incorporating these variables and yielded a C-index of 0.743.

CONCLUSIONS

The ICW/TBW ratio was associated with muscle mass, nutritional status, and inflammation. A low ICW/TBW ratio is an independent risk factor for poor prognosis in patients with cancer, especially when they are female, have advanced cancer stage, have sarcopenia, and are receiving radiotherapy.

The Impact of Nanomedicine on Soft Tissue Sarcoma Treated by Radiotherapy and/or Hyperthermia: A Review

This article presents a comprehensive review of nanoparticle-assisted treatment approaches for soft tissue sarcoma (STS). STS, a heterogeneous group of mesenchymal-origin tumors with aggressive behavior and low overall survival rates, necessitates the exploration of innovative therapeutic interventions. In contrast to conventional treatments like surgery, radiotherapy (RT), hyperthermia (HT), and chemotherapy, nanomedicine offers promising advancements in STS management. This review focuses on recent research in nanoparticle applications, including their role in enhancing RT and HT efficacy through improved drug delivery systems, novel radiosensitizers, and imaging agents. Reviewing the current state of nanoparticle-assisted therapies, this paper sheds light on their potential to revolutionize soft tissue sarcoma treatment and improve patient therapy outcomes.

Repurposing of FDA approved kinase inhibitor bosutinib for mitigation of radiation induced damage via inhibition of JNK pathway

Radiotherapy is a common modality for cancer treatment. However, it is often associated with normal tissue toxicity in 20-80% of the patients. Radioprotectors can improve the outcome of radiotherapy by selectively protecting normal cells against radiation toxicity. In the present study, compound libraries containing 54 kinase inhibitors and 80 FDA-approved drugs were screened for radioprotection of lymphocytes using high throughput cell analysis. A second-generation FDA-approved kinase inhibitor, bosutinib, was identified as a potential radioprotector for normal cells. The radioprotective efficacy of bosutinib was evinced from a reduction in radiation induced DNA damage, caspase-3 activation, DNA fragmentation and apoptosis. Oral administration of bosutinib protected mice against whole body irradiation (WBI) induced morbidity and mortality. Bosutinib also reduced radiation induced bone-marrow aplasia and hematopoietic damage in mice exposed to 4 Gy and 6 Gy dose of WBI. Mechanistic studies revealed that the radioprotective action of bosutinib involved interaction with cellular thiols and modulation of JNK pathway. The addition of glutathione and N-acetyl cysteine significantly reduced the radioprotective efficacy of bosutinib. Moreover, bosutinib did not protect cancer cells against radiation induced toxicity. On the contrary, bosutinib per se exhibited anticancer activity against human cancer cell lines. The results highlight possible use of bosutinib as a repurposable radioprotective agent for mitigation of radiation toxicity in cancer patients undergoing radiotherapy.

The role of platelet rich plasma enriched fat graft for correction of deformities after conservative breast surgery

BACKGROUND

Fat transfer has been widely used after breast conservative surgery (BCS) where it aims to recover shapes as a simple, inexpensive, biocompatible method but the technique is not without complications. Platelet Rich Plasma (PRP) is a promising approach to enhance fat graft survival and subsequently improve the outcome. The aim of this study was to evaluate the effect of enriching fat graft with PRP for delayed correction of deformities after conservative surgery for breast cancer regarding esthetic outcome and incidence of complications.

METHODS

The current study included 50 female patients who were scheduled for delayed lipofilling for correction of deformities after conservative surgery for breast cancer. The studied patients were randomly allocated into 2 groups: Group I (G I) included 25 patients scheduled for PRP enriched lipoinjection and Group II (G II) included 25 patients scheduled for lipoinjection without PRP as a control group.

RESULTS

Number of sessions of lipoinjection was significantly less in G I in comparison to G II (P = 0.024). During the 2nd session; the amounts of fat injected and harvested were significantly less in G I in comparison to G II (P = 0.049 and 0.001 respectively). Recipient site complications were significantly more evident in G II in comparison to G I (P = 0.01). Surgeon and patient satisfactions were significantly more evident in GI in comparison to G II (P = 0.005 and 0.029 respectively).

CONCLUSION

The addition of PRP to fat grafts is a simple, cost-effective and safe method to improve esthetic outcome and decrease complications.

Mapping the impact of malnutrition as defined by the Global Leadership Initiative on Malnutrition and nutrition impact symptoms on the possibility of returning to work after treatment for head and neck cancer

PURPOSE

This study aimed to investigate whether malnutrition or nutrition impact symptoms (NIS) affect the possibility of returning to work after treatment for head and neck cancer.

METHODS

Patients of working age with head and neck cancer were followed up from treatment initiation to 3 months (n = 238), 1 year (n = 182), and 2 years (n = 130) after treatment completion. The observed decrease in the number of patients over time was due to retirement, lack of follow-up, or death. Returning to work was dichotomised as yes or no. Malnutrition was diagnosed 7 weeks after treatment initiation using the Global Leadership Initiative on Malnutrition (GLIM) criteria. This time-point corresponds to the end of chemoradiotherapy or radiotherapy (with or without prior surgery), except for patients who underwent exclusive surgery. NIS were scored on a Likert scale (1-5) at each follow-up using the Head and Neck Patient Symptom Checklist© (HNSC©). Nonparametric tests were used to analyse the ability of patients with/without malnutrition and high/low NIS scores to return to work.

RESULTS

At 3 months, 1 year, and 2 years after treatment completion, 135/238 (56.7%), 49/182 (26.9%), and 23/130 (17.7%) patients had not returned to work. Patients with malnutrition at 7 weeks after treatment initiation were more likely to not return to work at 3 months than those without malnutrition, 70.5% compared to 47.1% (p < 0.001). At all three follow-up time-points, patients reporting high scores for a number of NIS had more often not returned to work, with this pattern being most distinct at 2 years.

CONCLUSION

Malnutrition according to the GLIM criteria at 7 weeks after treatment initiation and NIS assessed by the HNSC© at subsequent follow-ups were predictors of the return-to-work process after treatment for up to 2 years.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT03343236 (date of registration 17/11/2017).

Proposal of a diagnostic algorithm for radiation-induced dropped head syndrome in long-term childhood cancer survivors based on a prospective study in a specialized clinical setting and a review of the literature

PURPOSE

To prospectively assess the incidence of Dropped Head Syndrome (DHS) in childhood cancer survivors (CCS) and to develop and evaluate a diagnostic algorithm for DHS.

METHODS

A systematic literature search for DHS in combination with neck radiotherapy (RT) exposure was performed. Analyses and a combination of the most common examination methods were integrated into a diagnostic algorithm. Almost all CCSs visiting the local late effects clinic between May 2020 and April 2022 were included in the study. CCS exposed to neck RT with doses ≥ 19 Gy received standardized clinical and neurological assessment and, in case of abnormal results, an MRI scan to confirm muscle atrophy.

RESULTS

Two hundred and five CCS were included of whom 41 received RT to the neck with ≥ 19 Gy. In the entire cohort and in the subgroup receiving RT, 2.4% and 12% of CCS were affected by DHS, respectively. Results of clinical and neurological assessment correlated well with MRI results. Neck circumference and neck/thigh ratio were lower after neck RT. Over 50% of CCS experienced neck disability and pain.

CONCLUSIONS

A relevant proportion of CCS exposed to neck RT is affected by DHS. High concordance of MRI results with the neurological examination supports the clinical value of the diagnostic algorithm. Measurement of neck circumference might be an easy tool for assessment of neck muscle atrophy in survivors at risk.

IMPLICATIONS FOR CANCER SURVIVORS

Integration of a diagnostic algorithm for DHS in standard long-term follow-up care facilitates diagnosis as well as initiation of early treatment and obviates the need for invasive examinations.

Evolution of non-perfused volume after transurethral ultrasound ablation of prostate: A retrospective 12-month analysis

Background

A detailed understanding of the non-perfused volume (NPV) evolution after prostate ablation therapy is lacking. The impact of different diseased prostate tissues on NPV evolution post-ablation is unknown.

Purpose

To characterize the NPV evolution for three treatment groups undergoing heat-based prostate ablation therapy, including benign prostatic hyperplasia (BPH), primary prostate cancer (PCa), and radiorecurrent PCa.

Materials and methods

Study design and data analysis were performed retrospectively. All patients received MRI-guided transurethral ultrasound ablation (TULSA). 21 BPH, 28 radiorecurrent PCa and 40 primary PCa patients were included. Using the T1-weighted contrast-enhanced MR image, the NPV was manually contoured by an experienced radiologist. All patients received an MRI immediately following the ablation. Follow-up included MRI at 3- and 12 months for BPH and radiorecurrent PCa patients and at 6- and 12 months for primary PCa patients.

Results

A significant difference between BPH and radiorecurrent PCa patients was observed at three months (p < 0.0001, Wilcoxon rank sum test), with the median NPV decreasing by 77 % for BPH patients but increasing by 4 % for radiorecurrent PCa patients. At six months, the median NPV decreased by 97 % for primary PCa. Across all groups, although 40 % of patients had residual NPV at 12 months, it tended to be < 1 mL.

Conclusion

The resolution of necrotic tissue after ablation was markedly slower for irradiated than treatment-naïve prostate tissue. These results may account for the increased toxicity observed after radiorecurrent salvage therapy. By 12 months, most necrotic prostate tissue had disappeared in every treatment group.

Risk factors for malnutrition in patients with nasopharyngeal carcinoma

BACKGROUND

Malnutrition is a common complication in patients with nasopharyngeal carcinoma (NPC). However, there are few studies on risk factors for malnutrition in NPC patients. Our aims were to identify the risk factors for malnutrition in NPC patients.

METHODS

NPC patients were recruited in this cross-sectional study, and they were divided into well-nourished and malnourished groups according to the Global Leadership Initiative on Malnutrition (GLIM). Potential risk factors were initially screened using univariate analysis (p < 0.1), and the selected ones were analyzed by logistic regression analysis (p < 0.05) to identify the risk factors for malnutrition in NPC patients.

RESULTS

In total, 305 NPC patients meeting eligibility criteria were enrolled. Multivariate logistic regression analysis revealed that low body mass index (BMI) (OR = 0.596, 95% CI 0.520-0.683, p < 0.001), the high total radiation dose received (OR = 1.046, 95% CI 1.023-1.069, p < 0.001), appetite loss (OR = 2.839, 95% CI 1.269-6.353, p = 0.011), and low PA (OR = 0.993, 95% CI 0.988-0.998, p = 0.008) were risk factors for malnutrition in NPC patients.

CONCLUSIONS

The low BMI, the high total radiation dose received, appetite loss, and low prealbumin were risk factors for malnutrition in NPC patients.

Biomedical advances and future prospects of high-precision three-dimensional radiotherapy and four-dimensional radiotherapy

Biomedical advances of external-beam radiotherapy (EBRT) with improvements in physical accuracy are reviewed. High-precision (±1 mm) three-dimensional radiotherapy (3DRT) can utilize respective therapeutic open doors in the tumor control probability curve and in the normal tissue complication probability curve instead of the one single therapeutic window in two-dimensional EBRT. High-precision 3DRT achieved higher tumor control and probable survival rates for patients with small peripheral lung and liver cancers. Four-dimensional radiotherapy (4DRT), which can reduce uncertainties in 3DRT due to organ motion by real-time (every 0.1-1 s) tumor-tracking and immediate (0.1-1 s) irradiation, have achieved reduced adverse effects for prostate and pancreatic tumors near the digestive tract and with similar or better tumor control. Particle beam therapy improved tumor control and probable survival for patients with large liver tumors. The clinical outcomes of locally advanced or multiple tumors located near serial-type organs can theoretically be improved further by integrating the 4DRT concept with particle beams.

Cytokine Levels in Saliva Are Associated with Salivary Gland Fibrosis and Hyposalivation in Mice after Fractionated Radiotherapy of the Head and Neck

Cytokines are mediators of inflammation that could lead to fibrosis. The aim was to monitor cytokine levels in saliva and serum after locally fractionated radiotherapy of the head and neck in mice and investigate associations with salivary gland fibrosis and hyposalivation. C57BL/6 mice were randomized to sham or X-ray irradiation of 66 Gy in 10 fractions over 5 days. Blood and saliva were collected on days -7, 5, 35, 80, and 105 following cytokine analysis. The harvested submandibular salivary gland was assessed for the presence of fibrosis. Decision tree regression analysis was used to investigate whether cytokine levels could predict late endpoints in terms of hyposalivation or fibrosis. Significant formation of fibrosis in gland tissue and reduced saliva production was found after irradiation. The pro-inflammatory cytokines IL-1α, TNF, TIMP1, G-CSF, KC, and MIP-1α showed increased levels in saliva in irradiated mice and a strong correlation with late endpoints. The decision tree analysis largely separated controls from irradiated animals, with IL-1α being the strongest predictor. Pro-inflammatory cytokines in saliva, but not in serum, were associated with late endpoints. This indicates that cytokine expression in saliva is a good biomarker for local salivary gland damage with IL-1α as the strongest single predictor.

Preoperative and postoperative blood testosterone levels in patients with acromegaly: a prospective study

Purpose

To investigate the prevalence of low blood testosterone level (LTL) and its determinant factors among active male acromegaly patients, as well as the effect of surgery on LTL in male acromegaly patients.

Methods

A retrospective, single-center study focused on 252 male acromegaly patients aged 18 years-60 years diagnosed in the Peking Union Medical College Hospital from January 2015 to December 2018 was carried out. The measurements of preoperative and postoperative testosterone levels, serum growth hormone (GH), insulin-like growth factor 1 (IGF-1), and other clinical data were analyzed.

Results

Forty per cent of subjects included were diagnosed with LTL pre surgery. Patients were divided into normal testosterone level (NTL) and LTL groups based on their testosterone level. There were significant differences (p < 0.01) between groups in the presence of macroadenomas, invasion of the cavernous sinus, compression of the optic chiasm, and serum GH and prolactin levels pre surgery. Invasion of the cavernous sinus [odds ratio (OR) = 4.299; p = 0.000] and serum prolactin level (OR = 1.023, p = 0.001) were independent predictors of LTLs in male patients before surgical intervention. A total of 67.9% of LTL patients recovered during the follow-up, with a new-onset rate of 3.4%. Body mass index, invasion of the cavernous sinus, GH, IGF-1, and prolactin levels, the presence of a prolactin-secreting tumor, and recovery from acromegaly were significantly different (p < 0.05) in the NTL group and in the LTL group during the follow-up. The presence of a prolactin-secreting tumor (OR = 0.224; p = 0.001) and recovery from acromegaly (OR = 0.168; p = 0.006) were independent predictors of LTLs in male acromegaly patients during the follow-up.

Conclusion

The invasiveness of tumor and levels of blood prolactin are independent factors for LTLs before surgery, whereas GH and IGF-1 levels are not. Most male patients can recover from LTL after tumor restriction surgery: those who recover from acromegaly have a better chance of recovering from LTL.

Free-flap volume correlates with body mass index in patients with tongue squamous cell carcinoma

Objectives

This study aimed to investigate the relationship between postoperative reconstructed tongue flap volume (RTFV) and body mass index (BMI) and identify factors affecting the flap volume in patients with tongue squamous cell carcinoma.

Methods

Thirty-two patients were evaluated for RTFV from computed tomography images and BMI. The first and second evaluations were done at 6 months and 1.5 years after surgery respectively. RTFV rate changes and BMI differences from the first and second evaluations were calculated. The correlation between RTFV rate change and BMI difference was assessed using Spearman's rank correlation coefficient. Multiple regression analysis evaluated the relationship between the flap volume rate change and age, sex, flap type, and BMI difference to identify influencing factors.

Results

The flap volume rate change and BMI difference correlated significantly (r = .594, p < .05). BMI difference and flap type were independent factors that affected reconstructed flap volume rate change in multiple regression analysis (p < .05).

Conclusion

The flap volume of patients with tongue squamous cell carcinoma correlates with the BMI change in the chronic phase. Patients after tongue reconstruction need to be well nourished to maintain BMI and thus postoperative tongue volume to maintain the quality of life.

Level of Evidence

Level 3.

Radiomic Assessment of Radiation-Induced Alterations of Skeletal Muscle Composition in Head and Neck Squamous Cell Carcinoma within the Currently Clinically Defined Optimal Time Window for Salvage Surgery-A Pilot Study

Patients with locally advanced head and neck squamous cell carcinoma (HNSCC) frequently require primary radiochemotherapy (RCT). Despite intensity modulation, the desired radiation-induced effects observed in HNSCC may also be observed as side effects in healthy tissue, e.g., the sternocleidomastoid muscle (SCM). These side effects (e.g., tissue fibrosis) depend on the interval between the completion of RCT and restaging CT. For salvage surgery, the optimal time window for surgery is currently clinically postulated at between 6 and 12 weeks after completion of RCT. Thus, no extensive tissue fibrosis is to be expected. This interval is based on clinical studies exploring surgical complications. Studies directly exploring radiation-induced changes of the SCM in HNSCC patients are sparse. The present study quantified tissue alterations in the SCM and paravertebral musculature (PVM) after RCT, applying radiomics to determine the optimal time window for salvage surgery. Three radiomic key parameters, (1) volume, (2) mean positivity of pixels (MPP), and (3) uniformity, were extracted with mint LesionTM in the staging CTs and restaging CTs of 98 HNSCC patients. Of these, 25 were female, the mean age was 62 (±9.6) years, and 80.9% were UICC Stage IV. The mean restaging interval was 55 (±28; range 29-229) days. Only the mean volume significantly decreased after RCT, from 9.0 to 8.4 and 96.5 to 91.9 mL for the SCM and PVM, respectively (both p = 0.007, both Cohen's d = 0.28). In addition, the mean body mass index (BMI) decreased from 23.9 (±4.2) to 21.0 (±3.6) kg/m² (p < 0.001; Cohen's d = 0.9). The mean BMI decreased significantly and was correlated with the volume decrease for the SCM (r = 0.27; p = 0.007) and PVM (r = 0.41; p < 0.001). If t-test p-values were adjusted for the BMI decrease, no significant change in volumes for the SCM and PVM was observed (both p > 0.05). The present data support the clinically postulated optimal interval for salvage surgery of 6 to 12 weeks.

Hyperbaric oxygen therapy for late radiation tissue injury

BACKGROUND

This is the third update of the original Cochrane Review published in July 2005 and updated previously in 2012 and 2016. Cancer is a significant global health issue. Radiotherapy is a treatment modality for many malignancies, and about 50% of people having radiotherapy will be long-term survivors. Some will experience late radiation tissue injury (LRTI), developing months or years following radiotherapy. Hyperbaric oxygen therapy (HBOT) has been suggested as a treatment for LRTI based on the ability to improve the blood supply to these tissues. It is postulated that HBOT may result in both healing of tissues and the prevention of complications following surgery and radiotherapy.

OBJECTIVES

To evaluate the benefits and harms of hyperbaric oxygen therapy (HBOT) for treating or preventing late radiation tissue injury (LRTI) compared to regimens that excluded HBOT.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 24 January 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing the effect of HBOT versus no HBOT on LRTI prevention or healing.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. survival from time of randomisation to death from any cause; 2. complete or substantial resolution of clinical problem; 3. site-specific outcomes; and 4.

ADVERSE EVENTS

Our secondary outcomes were 5. resolution of pain; 6. improvement in quality of life, function, or both; and 7. site-specific outcomes. We used GRADE to assess certainty of evidence.

MAIN RESULTS

Eighteen studies contributed to this review (1071 participants) with publications ranging from 1985 to 2022. We added four new studies to this updated review and evidence for the treatment of radiation proctitis, radiation cystitis, and the prevention and treatment of osteoradionecrosis (ORN). HBOT may not prevent death at one year (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.47 to 1.83; I2 = 0%; 3 RCTs, 166 participants; low-certainty evidence). There is some evidence that HBOT may result in complete resolution or provide significant improvement of LRTI (RR 1.39, 95% CI 1.02 to 1.89; I2 = 64%; 5 RCTs, 468 participants; low-certainty evidence) and HBOT may result in a large reduction in wound dehiscence following head and neck soft tissue surgery (RR 0.24, 95% CI 0.06 to 0.94; I2 = 70%; 2 RCTs, 264 participants; low-certainty evidence). In addition, pain scores in ORN improve slightly after HBOT at 12 months (mean difference (MD) -10.72, 95% CI -18.97 to -2.47; I2 = 40%; 2 RCTs, 157 participants; moderate-certainty evidence). Regarding adverse events, HBOT results in a higher risk of a reduction in visual acuity (RR 4.03, 95% CI 1.65 to 9.84; 5 RCTs, 438 participants; high-certainty evidence). There was a risk of ear barotrauma in people receiving HBOT when no sham pressurisation was used for the control group (RR 9.08, 95% CI 2.21 to 37.26; I2 = 0%; 4 RCTs, 357 participants; high-certainty evidence), but no such increase when a sham pressurisation was employed (RR 1.07, 95% CI 0.52 to 2.21; I2 = 74%; 2 RCTs, 158 participants; high-certainty evidence).

AUTHORS' CONCLUSIONS

These small studies suggest that for people with LRTI affecting tissues of the head, neck, bladder and rectum, HBOT may be associated with improved outcomes (low- to moderate-certainty evidence). HBOT may also result in a reduced risk of wound dehiscence and a modest reduction in pain following head and neck irradiation. However, HBOT is unlikely to influence the risk of death in the short term. HBOT also carries a risk of adverse events, including an increased risk of a reduction in visual acuity (usually temporary) and of ear barotrauma on compression. Hence, the application of HBOT to selected participants may be justified. The small number of studies and participants, and the methodological and reporting inadequacies of some of the primary studies included in this review demand a cautious interpretation. More information is required on the subset of disease severity and tissue type affected that is most likely to benefit from this therapy, the time for which we can expect any benefits to persist and the most appropriate oxygen dose. Further research is required to establish the optimum participant selection and timing of any therapy. An economic evaluation should also be undertaken.

Normal tissue complication probability of acute eyelids erythema following radiotherapy of head and neck cancers and skull-base tumors

PURPOSE

Radiation therapy is broadly used as one of the main treatment methods for patients with head and neck cancers and skull base tumors. However, it can lead to normal tissue complications. Therefore, this study aimed to model normal tissue complication probability (NTCP) of eyelid skin erythema after radiation therapy.

METHODS

The dataset of 45 patients with head and neck and skull base tumors was prospectively collected from their dose-volume histograms (DVHs). Grade 1 + eyelid skin erythema based on the Common Terminology Criteria for Adverse Events (CTCAE 4.0) was evaluated as the endpoint after a three-month follow-up. The Lyman-Kutcher-Burman (LKB) radiobiological model was developed based on generalized equivalent uniform dose (gEUD). Model parameters were calculated by maximum likelihood estimation. Model performance was evaluated by ROC-AUC, Brier score and Hosmer-Lemeshow test.

RESULTS

After three months of follow-up, 13.33% of patients experienced eyelids skin erythema grade 1 or more. The parameters of the LKB model were: TD50 = 30 Gy, m = 0.14, and n = 0.10. The model showed good predictive performance with ROC-AUC = 0.80 (CI:0.66-0.94) and a Brier score of 0.20.

CONCLUSIONS

In this study, NTCP of eyelid skin erythema was modeled based on the LKB radiobiological model with good predictive performance.

Effect of Lactobacillus delbrueckii subsp. lactis on vaginal radiotherapy for gynecological cancer

The aim of this study was to evaluate the effect of Lactobacillus delbrueckii subsp. lactis (L.del) on vaginal microbiota (VM) dysbiosis and vaginal radiation injury in gynecologic cancer patients. The inhibitory effects of L.del on cervical cancer cells were also studied in vitro. Gynecologic cancer patients receiving radiotherapy were randomized into control and L.del intervention groups. The control group received radiotherapy, while the intervention group received radiotherapy and L.del intervention (1 capsule/day placed into the deep vagina from the first day of radiotherapy until the end of treatment). Vaginal swab samples were collected on the first day pre-treatment and the last day post-treatment. DNA from 54 patients was extracted and assessed by the 16S rRNA sequencing method. Radiotherapy resulted in vaginal microbiome dysbiosis characterized by increased phylogenetic diversity and increased abundance of Brevundimonas, Streptococcus and Prevotella, but a decreased abundance of Lactobacillus. Level 2 vaginal radiation injury was positively associated with the abundance of Brevundimonas and gram-negative non-fermenting bacteria. Administration of L.del attenuated the reduction of Lactobacillus while also inhibiting the abundance of Streptococcus and Prevotella, thereby ameliorating radiotherapy-related vaginal microbiota dysbiosis. CLD inhibited the in vitro proliferation of SiHa cells by altering the expression of BCL2, HPV16-E6, HPV16-E7, IL6, MAP7, BAX, Caspase-3, Caspase-9 and LTF. In conclusion, L. del application can alleviate radiation-induced vaginal dysbiosis and restore Lactobacillus dominance of the vaginal microbiome. Moreover, CLD was found to inhibit cell growth and promote the apoptosis of SiHa cells in vitro. The registration number for this clinical trial is ChiCTR1900021784.

Cold atmospheric plasma alleviates radiation-induced skin injury by suppressing inflammation and promoting repair

Currently, there is no effective treatment for chronic skin radiation injury, which burdens patients significantly. Previous studies have shown that cold atmospheric plasma has an apparent therapeutic effect on acute and chronic skin injuries in clinical. However, whether CAP is effective for radiation-induced skin injury has not been reported. We created 35Gy X-ray radiation exposure within 3 * 3 cm² region of the left leg of rats and applied CAP to the wound bed. Wound healing, cell proliferation and apoptosis were examined in vivo or vitro. CAP alleviated radiation-induced skin injury by enhancing proliferation and migration and cellular antioxidant stress and promoting DNA damage repair through regulated nuclear translocation of NRF2. In addition, CAP inhibited the proinflammatory factors' expression of IL-1β, TNF-α and temporarily increased the pro repair factor's expression of IL-6 in irradiated tissues. At the same time, CAP also changed the polarity of macrophages to a repair-promoting phenotype. Our finding suggested that CAP ameliorated radiation-induced skin injury by activating NRF2 and ameliorating the inflammatory response. Our work provided a preliminary theoretical foundation for the clinical administration of CAP in high-dose irradiated skin injury.

Further Characterization of Multi-Organ DEARE and Protection by 16,16 Dimethyl Prostaglandin E2 in a Mouse Model of the Hematopoietic Acute Radiation Syndrome

Survivors of acute radiation exposure suffer from the delayed effects of acute radiation exposure (DEARE), a chronic condition affecting multiple organs, including lung, kidney, heart, gastrointestinal tract, eyes, and brain, and often causing cancer. While effective medical countermeasures (MCM) for the hematopoietic-acute radiation syndrome (H-ARS) have been identified and approved by the FDA, development of MCM for DEARE has not yet been successful. We previously documented residual bone marrow damage (RBMD) and progressive renal and cardiovascular DEARE in murine survivors of H-ARS, and significant survival efficacy of 16,16-dimethyl prostaglandin E2 (dmPGE2) given as a radioprotectant or radiomitigator for H-ARS. We now describe additional DEARE (physiological and neural function, progressive fur graying, ocular inflammation, and malignancy) developing after sub-threshold doses in our H-ARS model, and detailed analysis of the effects of dmPGE2 administered before (PGE-pre) or after (PGE-post) lethal total-body irradiation (TBI) on these DEARE. Administration of PGE-pre normalized the twofold reduction of white blood cells (WBC) and lymphocytes seen in vehicle-treated survivors (Veh), and increased the number of bone marrow (BM) cells, splenocytes, thymocytes, and phenotypically defined hematopoietic progenitor cells (HPC) and hematopoietic stem cells (HSC) to levels equivalent to those in non-irradiated age-matched controls. PGE-pre significantly protected HPC colony formation ex vivo by >twofold, long term-HSC in vivo engraftment potential up to ninefold, and significantly blunted TBI-induced myeloid skewing. Secondary transplantation documented continued production of LT-HSC with normal lineage differentiation. PGE-pre reduced development of DEARE cardiovascular pathologies and renal damage; prevented coronary artery rarefication, blunted progressive loss of coronary artery endothelia, reduced inflammation and coronary early senescence, and blunted radiation-induced increase in blood urea nitrogen (BUN). Ocular monocytes were significantly lower in PGE-pre mice, as was TBI-induced fur graying. Increased body weight and decreased frailty in male mice, and reduced incidence of thymic lymphoma were documented in PGE-pre mice. In assays measuring behavioral and cognitive functions, PGE-pre reduced anxiety in females, significantly blunted shock flinch response, and increased exploratory behavior in males. No effect of TBI was observed on memory in any group. PGE-post, despite significantly increasing 30-day survival in H-ARS and WBC and hematopoietic recovery, was not effective in reducing TBI-induced RBMD or any other DEARE. In summary, dmPGE2 administered as an H-ARS MCM before lethal TBI significantly increased 30-day survival and ameliorated RBMD and multi-organ and cognitive/behavioral DEARE to at least 12 months after TBI, whereas given after TBI, dmPGE2 enhances survival from H-ARS but has little impact on RBMD or other DEARE.

Noninvasive Monitoring of Radiation-Induced Salivary Gland Vascular Injury

Xerostomia is a common side effect of radiation therapy (RT) in patients with head and neck cancer. However, limited information is available on the temporal dynamics of parenchymal and vascular changes in salivary glands following RT. To address this gap in knowledge, we conducted experimental studies in mice employing ultrasound (US) with coregistered photoacoustic imaging (PAI) to noninvasively assess the early and late changes in salivary gland size, structure, vascularity, and oxygenation dynamics following RT. Multiparametric US-PAI of salivary glands was performed in immune-deficient and immune-competent mice before and after RT along with correlative sialometry and ex vivo histologic-immunohistochemical validation. US revealed reduction in gland volume and an early increase in vascular resistance postradiation. This was accompanied by a reduction in glandular oxygen consumption on PAI. Imaging data correlated strongly with salivary secretion and histologic evidence of acinar damage. The magnitude and kinetics of radiation response were impacted by host immune status, with immunodeficient mice showing early and more pronounced vascular injury and DNA damage response compared to immunocompetent animals. Our findings demonstrate the ability of noninvasive US-PAI to monitor dynamic changes in salivary gland hemodynamics following radiation and highlight the impact of the host immune status on salivary gland radiation injury.

Secondary Reconstruction of Head and Neck Cancer Defects-Principles in its Practice

Objective

Secondary reconstruction is requested by patients who have completed their head and neck cancer treatment. The reason for the request for reconstruction may be to improve the functional deficits, achieve aesthetic refinements or most commonly both. The article looks at various issues related to reconstruction in the secondary setting and suggesting the ways to approaching patients requesting secondary reconstruction.

Discussion

While considering secondary reconstruction, various factors need to be considered. These include issues related to the disease, the treatment received as well as the patient's comorbid conditions. Aggressive disease and multiple recurrences should deter from undertaking complex reconstructions. Lack of tissue pliability resulting in a woody neck due to radiation makes dissection difficult and wound healing poor. The reconstructive requirements include release of contractures inside the mouth, reconstruction of the missing jaws, replacement of the missing volume of the tongue and correction of the incompetent angle of mouth. Goals of reconstruction should be prioritized by the surgical team. Free soft tissue or bone containing flaps would be provided ideal tissue to meet the reconstructive requirements in secondary reconstruction. However, several impediments could exist for their safe use. Release of contractures and provision of adequate soft tissue should be given priority and must be addressed before bony reconstruction is contemplated.

Conclusion

Bony reconstruction of both mandible and maxilla is possible, with the former being more difficult to deliver good results due to the associated soft tissue fibrosis. Virtual surgical planning with the aid of Stereo lithographic models and planning software will improve the quality of bony reconstruction. Detailed counseling sessions involving patient and the family are essential before embarking on secondary reconstruction as the patient expectations and the surgical outcome may not be easy to match. However excellent improvement in function and appearance will be possible in many patients with appropriate reconstructive procedure.

Therapeutic effect of turmeric on radiodermatitis: A systematic review

Radiodermatitis (RD) occurs in 95% of cancer patients undergoing radiation therapy. At present, there is no effective treatment for the management of this complication of radiotherapy. Turmeric (Curcuma longa) is a polyphenolic and biologically active natural compound with various pharmacological functions. The aim of this systematic review was to determine the efficacy of curcumin supplementation for reducing RD severity. This review complied with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A comprehensive literature search was conducted in Cochrane library, PubMed, Scopus, Web of Science, and MEDLINE databases. A total of seven studies comprising 473 cases and 552 controls were included in this review. Four studies demonstrated that curcumin supplementation had a beneficial effect on RD intensity. These data provide evidence for the potential clinical use of curcumin in supportive cancer care. Further large prospective and well-designed trials are warranted to exactly determine the "real effective extract, supplemental form and dose of curcumin" for RD prevention and treatment of patients receiving radiotherapy.

Radiation-induced pulmonary fibrosis: roles of therapy-induced senescence and microRNAs

PURPOSE

Progressive, irreversible radiation-induced pulmonary fibrosis (RIPF) is a clinically significant intermediate- to a late-occurring side effect of radiotherapy. Known mechanisms of RIPF include oxidative stress-induced activation of TGF-β with activation of SMAD signaling, TNF-α elaboration, and activation of the Angiotensin Converting Enzyme (ACE) mediated production of angiotensin II with resulting activation of profibrotic cytokine signaling and vasoconstriction. The pioneering work of John Moulder, to whom this paper is dedicated, and several of his colleagues demonstrated that inhibiting the conversion of ACE with drugs such as Captopril, Enalapril, and Losartan can ameliorate radiation fibrosis in various tissues. While this work led several groups to probe mechanism-based pharmacological mitigation of RIPF, in this article, we explore and discuss the roles of microRNAs (miRNA) and therapy-induced senescence (TIS) in the pathogenesis of and potential biomarkers for RIPF.

CONCLUSION

Our analysis of the published literature in the last decade on RIPF, miRNA, and TIS identifies TIS as a mechanism in the onset and progression of RIPF, which is regulated through several miRNAs. This work may lead to the discovery and development of the next generation of miRNA therapeutics and/or the repurposing of approved pharmaceutical agents and the development of early biomarker panels to predict RIPF.

Factors that affect quality of life for older people with head and neck cancer: A systematic review

PURPOSE

Quality of life is a critical aspect in the management of older head and neck cancer patients. It needs to be considered alongside survival benefit, treatment burden, and longer-term outcomes. The purpose was to undertake a systematic review of empirical peer-reviewed studies with a primary focus on factors impacting quality of life for older head and neck cancer patients.

METHODS

A systematic review, searching 5 electronic databases (PsychoINFO, MEDLINE, CINHAL, Embase, and Scopus) using PRISMA methodology was conducted. Data was appraised using the Newcastle-Ottawa scale and a narrative synthesis performed.

RESULTS

Only 10 papers fulfilled the inclusion criteria. Two main themes emerged: 1) Impact of head and neck cancer on quality of life domains and 2) quality of life in treatment decision-making.

CONCLUSIONS

In an era of progressive personalised care, there is an evident need for more qualitative and quantitative studies focusing on quality of life for older head and neck cancer patients. However, older head and neck cancer patients experience notable differences, especially with poorer physical functioning and greater eating and drinking challenges. Quality of life impacts older patients decision-making, treatment planning and intensifies post-treatment support.

Technical note: Noninvasive monitoring of normal tissue radiation damage using spectral quantitative ultrasound spectroscopy

BACKGROUND

While radiation therapy (RT) is a critical component of breast cancer therapy and is known to decrease overall local recurrence rates, recent studies have shown that normal tissue radiation damage may increase recurrence risk. Fibrosis is a well-known consequence of RT, but the specific sequence of molecular and mechanical changes induced by RT remains poorly understood.

PURPOSE

To improve cancer therapy outcomes, there is a need to understand the role of the irradiated tissue microenvironment in tumor recurrence. This study seeks to evaluate the use of spectral quantitative ultrasound (spectral QUS) for real time determination of the normal tissue characteristic radiation response and to correlate these results to molecular features in irradiated tissues.

METHODS

Murine mammary fat pads (MFPs) were irradiated to 20 Gy, and spectral QUS was used to analyze tissue physical properties pre-irradiation as well as at 1, 5, and 10 days post-irradiation. Tissues were processed for scanning electron microscopy imaging as well as histological and immunohistochemical staining to evaluate morphology and structure.

RESULTS

Tissue morphological and structural changes were observed non-invasively following radiation using mid-band fit (MBF), spectral slope (SS), and spectral intercept (SI) measurements obtained from spectral QUS. Statistically significant shifts in MBF and SI indicate structural tissue changes in real time, which matched histological observations. Radiation damage was indicated by increased adipose tissue density and extracellular matrix (ECM) deposition.

CONCLUSIONS

Our findings demonstrate the potential of using spectral QUS to noninvasively evaluate normal tissue changes resulting from radiation damage. This supports further pre-clinical studies to determine how the tissue microenvironment and physical properties change in response to therapy, which may be important for improving treatment strategies.

Risk factors for primary site necrosis after definitive concurrent chemoradiotherapy in head and neck cancer

OBJECTIVE

To identify risk factors of primary site necrosis (PSN) after definitive concurrent chemoradiation therapy (CCRT) in patients with nonoral cavity head and neck cancer (HNC).

METHODS

We retrospectively reviewed the records of 256 patients treated with CCRT for HNC during 2010-2018. Patient-related (age, sex, history of smoking, hypertension, diabetes mellitus, serum hemoglobin and albumin), tumor-related (tumor site, American Joint Committee on Cancer stage), and treatment-related (induction chemotherapy, maximum point dose and mean dose of planning target volume [PTV] of primary site, absolute volumes of the PTV receiving >50-75 Gy [V₅₀-V₇₅]) variables were analyzed. Critical dosimetric parameters of PSN were identified using receiver operating characteristic (ROC) curve analysis. Univariate and multivariate Cox regression analyses were used to select the significant variables for PSN development.

RESULTS

After median follow-up of 44 months (range, 5-127), 7 patients (2.7%) developed PSN with a median time to event of 10 months (range, 3-12). V₇₀ ⩾79.8 mL was the most critical dosimetric parameter for PSN (area under the ROC curve 0.873, sensitivity 0.857, specificity 0.747). In univariate analyses, pretreatment serum hemoglobin <11.0 g/dL and V₇₀ ⩾79.8 mL were significantly associated with higher risk of PSN occurrence. V₇₀ ⩾79.8 mL (hazard ratio 5.960, 95% confidence interval 1.289-27.548; p = 0.022) remained significant predictors of PSN in multivariate analyses.

CONCLUSIONS

V₇₀ ⩾79.8 mL is significantly related to the risk of developing PSN. These findings offer valuable clues for clinicians to minimize PSN incidence in HNC treated with curative CCRT.

A novel long noncoding RNA SP100-AS1 induces radioresistance of colorectal cancer via sponging miR-622 and stabilizing ATG3

Although radiotherapy is an essential modality in the treatment of colorectal cancer (CRC), the incidence of radioresistance remains high clinically. Long noncoding RNAs (lncRNAs) reportedly play critical roles in CRC radioresistance by regulating genes or proteins at the transcriptional or post-translational levels. This study aimed to identify novel lncRNAs involved in radioresistance. We found that SP100-AS1 (lncRNA targeting antisense sequence of SP100 gene) was upregulated in radioresistant CRC patient tissues using RNA-seq analysis. Importantly, knockdown of SP100-AS1 significantly reduced radioresistance, cell proliferation, and tumor formation in vitro and in vivo. Mechanistically, mass spectrometry and bioinformatics analyses were used to identify the interacting proteins and microRNAs of SP100-AS1, respectively. Moreover, SP100-AS1 was found to interact with and stabilize ATG3 protein through the ubiquitination-dependent proteasome pathway. In addition, it could serve as a sponge for miR-622, which targeted ATG3 mRNA and affected autophagic activity. Thus, lncRNA SP100-AS1 could act as a radioresistance factor in CRC patients via RNA sponging and protein stabilizing mechanisms. In conclusion, the present study indicates that SP100-AS1/miR-622/ATG3 axis contributes to radioresistance and autophagic activity in CRC patients, suggesting it has huge prospects as a therapeutic target for improving CRC response to radiation therapy.

Capsular inflammation after immediate breast reconstruction - Gene expression patterns and inflammatory cell infiltration in irradiated and non-irradiated breasts

BACKGROUND

Capsular contracture following post-mastectomy radiotherapy (PMRT) is commonly seen in patients undergoing implant-based immediate breast reconstruction (IBR). Further understanding of the underlying biology is needed for the development of preventive or therapeutic strategies. Therefore, we conducted a comparative study of gene expression patterns in capsular tissue from breast cancer patients who had received versus those who had not received PMRT after implant-based IBR.

METHODS

Biopsies from irradiated and healthy non-irradiated capsular tissue were harvested during implant exchange following IBR. Biopsies from irradiated (n = 13) and non-irradiated (n = 12) capsules were compared using Affymetrix microarrays to identify the most differentially regulated genes. Further analysis using immunohistochemistry was performed in a subset of materials to compare the presence of T cells, B cells, and macrophages.

RESULTS

Enrichment testing using Gene Ontology (GO) analysis revealed that the 227 most differentially expressed genes were mainly involved in an inflammatory response. Twenty-one GO biological processes were identified [p < 0.05, false discovery rate (FDR) < 5%], several with B-cell-associated inflammation. Cell-type Identification by Estimating Relative Subsets of RNA Transcripts (CIBERSORT) analysis identified macrophages as the most common inflammatory cell type in both groups, further supported by immunostaining of CD68. Radiation remarkably increased B-cell infiltration in the capsular region of biopsies, as quantified by immunostaining of CD20 (p = 0.016).

CONCLUSIONS

Transcript analysis and immunohistochemistry revealed inflammatory responses in capsular biopsies regardless of radiotherapy. However, the radiation response specifically involved B-cell-associated inflammatory responses.

Responses of hematopoietic cells after ionizing-irradiation in anemic adult medaka (Oryzias latipes)

PURPOSE

Hematopoietic tissues of vertebrates are highly radiation sensitive and the effects of ionizing radiation on the hematopoiesis have been studied in mammals and teleosts for decades. In this study, radiation responses in the kidney, the main hematopoietic organ in teleosts, were investigated in Japanese medaka (Oryzias latipes), which has been a model animal and a large body of knowledge has been accumulated in radiation biology.

METHODS

Kidney, the main hematopoietic tissue of adult medaka fish, was locally irradiated using proton and carbon ion beams irradiation system of Takasaki Ion Accelerator for Advanced Radiation Application (TIARA), QST, and the effects on peripheral blood cells and histology of the kidney were investigated.

RESULTS

When only kidneys were locally irradiated with proton or carbon ion beam (15 Gy), the hematopoietic cells in the irradiated kidney and cell density in the peripheral blood decreased 7 days after the irradiation in the same manner as after the whole-body irradiation with γ-rays (15 Gy). These results demonstrate that direct irradiation of the hematopoietic cells in the kidney induced cell death and/or cell cycle arrest and stopped the supply of erythroid cells. Then, the cell density in the peripheral blood recovered to the control level within 4 days and 7 days after the γ-ray and proton beam irradiation (15 Gy), respectively, while the cell density in the peripheral blood did not recover after the carbon ion beam irradiation (15 Gy). The hematopoietic cells in the irradiated kidneys temporarily decreased and recovered to the control level within 21 days after the γ-ray or proton beam irradiation (15 Gy), while it did not recover after the carbon ion beam irradiation (15 Gy). In contrast, the recovery of the cell density in the peripheral blood delayed when anemic medaka were irradiated 1 day after the administration of phenylhydrazine. With and without γ-ray irradiation, a large number of hematopoietic cells was still proliferating in the kidney 7 days after the anemia induction.

CONCLUSIONS

The results obtained strongly suggest that the hematopoietic stem cells in medaka kidney prioritize to proliferate and increase peripheral blood cells to eliminate anemia, even when they are damaged by high-dose irradiation.

The Impact of Postmastectomy Radiation Therapy on the Outcomes of Prepectoral Implant-Based Breast Reconstruction: A Systematic Review and Meta-Analysis

BACKGROUND

Breast reconstruction is the mainstay treatment choice for patients subjected to a mastectomy. Prepectoral implant-based breast reconstruction (IBBR) is deemed to be a promising alternative to subpectoral reconstruction. Postmastectomy radiation therapy (PMRT) is necessary for locoregional recurrence control and to improve the disease-free survival rate in locally advanced breast cancer. This systematic review and meta-analysis study was designed to reveal the surgical, aesthetic, and oncological outcomes of prepectoral IBBR after PMRT.

METHODS

An extensive literature search was performed from inception to March 28, 2022. All clinical studies that included patients who were subjected to prepectoral IBBR and PMRT were included. Studies that included patients who received radiation therapy before prepectoral IBBR were excluded.

RESULTS

This systematic review included six articles encompassing 1234 reconstructed breasts. Of them, 391 breasts were subjected to PMRT, while 843 breasts were not subjected. Irradiated breasts were more susceptible to develop wound infection (RR 2.49; 95% 1.43, 4.35; P = 0.001) and capsular contracture (RR 5.17; 95% 1.93, 13.80; P = 0.001) than the non-irradiated breasts. Furthermore, irradiated breasts were more vulnerable to losing implants (RR 2.89; 95% 1.30, 6.39; P = 0.009) than the non-irradiated breast. There was no significant difference between both groups regarding the risk of implant extrusion (RR 1.88; 95% 0.20, 17.63; P = 0.58).

CONCLUSIONS

Patients with prepectorally IBBR and PMRT were more vulnerable to developing poor outcomes. This included a higher risk of breast-related and implant-related adverse events.

LEVEL OF EVIDENCE III

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