Consequential late effects in normal tissues

Stereotactic Body Radiotherapy as a Curative Treatment for De Novo Mucosal Carcinoma of the Head and Neck: A Feasible Alternative Option for Fragile Patients with Small Lesion: A Systematic Review

Stereotactic body radiotherapy (SBRT) is characterized by a high dose per fraction, well-defined small targets, superior dose conformity, and a steep off-target dose gradient. A literature search was conducted to examine the experience with SBRT as a curative treatment for newly diagnosed mucosal carcinoma of the head and neck (MCHN). Four retrospective case series and one prospective phase I clinical trial published between 2012 and 2020 described 124 patients. SBRT was mainly performed in older patients with different tumor sites. The median size of the planning target volumes ranged from 5.3 to 41 cm3. Different approaches were used to create margins. In two studies, limited elective nodal irradiation was performed. The equivalent doses used were 60-83.33 Gy delivered in five fractions. Considerable heterogeneity was observed in the radiation dose specification. The incidence of grade ≥3 late toxicity was 0-8.3%, with local and regional control ranging from 73% to 100%. Improved or stable quality of life after SBRT was reported in two studies. Curative-intent SBRT for de novo MCHN appears to be an effective and relatively safe treatment for small tumor targets, preferably without concomitant elective tissue irradiation. Standardization of SBRT practice and well-designed prospective clinical trials are needed to better define the role of SBRT in this setting.

Salvage radiofrequency ablation followed by external beam radiotherapy for inoperable recurrent differentiated thyroid cancer

PURPOSE

The treatment of recurrent thyroid cancer with critical organ invasion is challenging. The combination of radiofrequency ablation (RFA) and external beam radiation therapy (EBRT) has been proposed as an effective option. This study evaluates outcomes for inoperable residual/recurrent differentiated thyroid cancer (rDTC) patients treated with RFA followed by EBRT.

MATERIALS AND METHODS

Patients with rDTC treated with RFA followed by EBRT were retrospectively studied. RFA was performed using a free-hand, 'moving-shot' technique under US or CT guidance. For lesions invading critical structures intolerant to 'en bloc' high-temperature RFA, limited-field EBRT using 6- or 10-MV photons was used for adjuvant treatment at a dose of 66 Gy in 33 daily fractions. Toxicities and outcomes were reviewed.

RESULTS

Between April 2020 and January 2022, 11 patients with 14 rDTC lesions underwent RFA followed by EBRT. Five patients had metastatic lesions at rDTC diagnosis. With a median follow-up period of 33.7 months, all patients maintained locoregional control, while achieving a 2-year survival rate of 90.9%. This combined treatment achieved a volume reduction ratio of 92.1% ± 5.1%. The mean nadir thyroglobulin level in patients without initial distant metastases after treatment was 1.40 ± 0.81 ng/ml. Regarding treatment-related complications, one patient (9%) experienced temporary hoarseness after RFA, grade 2 radiation dermatitis occurred in 3 patients (27.2%), and grade 2 dysphagia was noted in 4 patients (36.4%). No grade 3 or greater toxicities occurred.

CONCLUSIONS

Salvage RFA followed by EBRT is feasible, effective and safe for patients with rDTC.

KDM3B Single-Nucleotide Polymorphisms Impact Radiation Therapy Toxicity Through Circular RNA-Mediated KDM3B Expression and Inflammatory Responses

PURPOSE

Genome-wide association studies have identified single-nucleotide polymorphisms (SNPs) associated with radiation therapy (RT) toxicities in patients with prostate cancer. SNP rs17599026 in intron 21 of KDM3B is significantly associated with the development of late urinary toxicity, specifically in the increase in urinary frequency 2 years after RT compared with pretreatment conditions. The present study aimed to provide mechanistic insights for this association.

METHODS AND MATERIALS

Using human tissues and cell lines, we examined the protein expression of KDM3B and molecular mechanisms underlying the SNP modulation by variants of KDM3B SNP alleles. In animals with normal and heterozygous expressions of Kdm3b, we examined the relationship between Kdm3b expression and radiation toxicity.

RESULTS

KDM3B rs17599026 lies in a motif important for circular RNA expression that is responsible for sponging miRNAs to regulate KDM3B expression. Using a murine model with heterozygous deletion of the Kdm3b gene, we found that lower Kdm3b expression is associated with altered pattern of urination after bladder irradiation, which is related to differential degrees of tissue inflammation as measured by analyses of gene expression, lymphocyte infiltration, and noninvasive ultrasound imaging.

CONCLUSIONS

KDM3B SNPs can impact its expression through regulating noncoding RNA expression. Differential KDM3B expression underlies radiation toxicity through tissue inflammation at the molecular and physiological level. Our study outcome offers a foundation for mechanism-based mitigation for radiation toxicity for prostate cancer survivors.

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.

Health-related quality of life (HRQoL) after different axillary treatments in women with breast cancer: a 1-year longitudinal cohort study

PURPOSE

As life expectancy continues to rise, post-treatment health-related quality of life (HRQoL) of breast cancer patients becomes increasingly important. This study examined the one-year longitudinal relation between axillary treatments and physical, psychosocial, and sexual wellbeing and arm symptoms.

METHODS

Women diagnosed with breast cancer who received different axillary treatments being axilla preserving surgery (APS) with or without axillary radiotherapy or full axillary lymph node dissection (ALND) with or without axillary radiotherapy were included. HRQoL was assessed at baseline, 6- and 12-months postoperatively using the BREAST-Q and the European Organization for Research and Treatment of Cancer QoL Questionnaire Breast Cancer Module (EORTC QLQ-BR23). Mixed regression models were constructed to assess the impact of axillary treatment on HRQoL. HRQoL at baseline was compared to HRQoL at 6- and at 12-months postoperatively.

RESULTS

In total, 552 patients were included in the mixed regressions models. Except for ALND with axillary radiotherapy, no significant differences in physical and psychosocial wellbeing were found. Physical wellbeing decreased significantly between baseline and 6- and 12-months postoperatively (p < 0.001, p = 0.035) and psychosocial wellbeing decreased significantly between baseline and 12 months postoperatively (p = 0.028) for ALND with axillary radiotherapy compared to APS alone. Arm symptoms increased significantly between baseline and 6 months and between baseline and 12 months postoperatively for APS with radiotherapy (12.71, 13.73) and for ALND with radiotherapy (13.93, 16.14), with the lowest increase in arm symptoms for ALND without radiotherapy (6.85, 7.66), compared to APS alone (p < 0.05).

CONCLUSION

Physical and psychosocial wellbeing decreased significantly for ALND with radiotherapy compared to APS alone. Shared decision making and expectation management pre-treatment could be strengthened by discussing arm symptoms per axillary treatment with the patient.

Stereotactic reirradiation in the treatment of head and neck cancers: A retrospective study on the long-term experience of the Oscar Lambret Center

BACKGROUND AND PURPOSE

Stereotactic radiotherapy potentially treats unresectable recurrences of previously irradiated head and neck (H&N) cancer. This study aimed to assess its efficacy and safety and evaluate prognostic factors.

MATERIALS AND METHODS

We conducted a large retrospective series that included 110 patients who had undergone 36-Gy, six-fraction stereotactic reirradiation (CyberKnife®) for recurrent/secondary H&N cancer between 2007 and 2020 at the Oscar Lambret Center. Patient characteristics and toxicities were assessed. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method.

RESULTS

Median follow-up time was 106.3 months. The 2-year OS rate was 43.8 % (95 % confidence interval, 95 % CI, 34.3-52.9) and the median survival was 20.8 months (95 % CI, 16.5-26.3). The cumulative 2-year local-recurrence, regional-recurrence, and distant-metastasis rates were 52.2 % (95 % CI, 42.4-61.1 %), 12.8 % (95 % CI, 7.4-19.8 %), and 11 % (95 % CI, 6.0-17.6 %), respectively. 73 patients received concomitant cetuximab, and it was not significantly beneficial (HR = 1.34; 95 % CI, 0.80-2.26; p = 0.26). The cumulative incidences of grade ≥ 2 late toxicity was 42 % (CI95%: 33-51) at 24 months. Two grade 4 bleedings and no treatment-related deaths were reported.

CONCLUSION

In a large retrospective series of SBRT reirradiation for recurrent or second primary H&N cancers, we observed a median OS of 20.8 months, with a cumulative incidence of grade ≥ 2 late toxicity of 42 % at 24 months. Such a treatment is feasible. However, local recurrence rates remain non-negligible, warranting further research. Radiosensitizer use is currently under study. Therefore, establishing a balance between therapeutic modifications and toxicity is essential.

Toxicity, normal tissue and dose-volume planning parameters for radiotherapy in soft tissue sarcoma of the extremities: A systematic review of the literature

BACKGROUND

Patients with soft tissue sarcoma of the extremities (STSE) are left with high incidence of toxicities after Radiotherapy (RT). Understanding the normal tissue dose relationship with the development of long-term toxicities may enable better RT planning in order to reduce treatment toxicities for STSE. This systematic review of the literature aims at reporting the incidence of acute and late toxicities and identifying RT delineation guidance the normal tissues structures and dose-volume parameters for STSE.

METHODS

A literature search of PUBMED-MEDLINE for studies that reported data on RT toxicity outcomes, delineation guidelines and dose-volume parameters for STSE from 2000 to 2022. Data has been tabulated and reported.

RESULTS

Thirty of 586 papers were selected after exclusion criteria. External beam RT prescriptions ranged from 30 to 72 Gy. The majority of studies reported the use of Intensity Modulated RT (IMRT) (27%). Neo-adjuvant RT was used in 40%. The highest long-term toxicities were subcutaneous and lymphoedema, reported when delivering 3DCRT. IMRT had a lower incidence of toxicities. Normal tissue outlining such as weight-bearing bones, skin and subcutaneous tissue, corridor and neurovascular bundle was recommended in 6 studies. Nine studies recommended the use of dose-volume constraints, but only one recommended evidence-based dose-volume constraints.

CONCLUSION

Although the literature is replete with toxicity reports, there is a lack of evidence-based guidance on normal tissue and dose-volume parameters and strategies to reduce the normal tissues irradiation when optimising RT plans for STSE are poor compared to other tumour sites.

Reactive Oxygen Species Produced by 5-Aminolevulinic Acid Photodynamic Therapy in the Treatment of Cancer

Cancer is the leading cause of death worldwide and several anticancer therapies take advantage of the ability of reactive oxygen species to kill cancer cells. Added to this is the ancient hypothesis that light alone can be used to kill cancer cells. 5-aminolevulinic acid-photodynamic therapy (5-ALA-PDT) is a therapeutic option for a variety of cutaneous and internal malignancies. PDT uses a photosensitizer that, activated by light in the presence of molecule oxygen, forms ROS, which are responsible for the apoptotic activity of the malignant tissues. 5-ALA is usually used as an endogenous pro-photosensitizer because it is converted to Protoporphyrin IX (PpIX), which enters into the process of heme synthesis and contextually becomes a photosensitizer, radiating a red fluorescent light. In cancer cells, the lack of the ferrochelatase enzyme leads to an accumulation of PpIX and consequently to an increased production of ROS. PDT has the benefit of being administered before or after chemotherapy, radiation, or surgery, without impairing the efficacy of these treatment techniques. Furthermore, sensitivity to PDT is unaffected by the negative effects of chemotherapy or radiation. This review focuses on the studies done so far on 5-ALA-PDT and its efficacy in the treatment of various cancer pathologies.

The Association between Acute and Late Genitourinary and Gastrointestinal Toxicities: An Analysis of the PACE B Study

Several studies have demonstrated the association between acute and late radiotherapy toxicity in prostate cancer using older radiotherapy techniques. However, whether this association is present with newer techniques such as stereotactic body radiotherapy (SBRT), remains unclear. We use univariable and multivariable logistic regression to analyse the association between grade 2 or worse acute gastrointestinal (GI) and genitourinary (GU) toxicities with equivalent late toxicities in patients treated with SBRT and conventional or moderately fractionated radiotherapy (CRT) within the PACE-B study. 842 patients were included in this analysis. Common Terminology Criteria for Adverse Events (CTCAE) was the primary clinician reported outcome measure used in this analysis. In univariable analysis, experiencing a grade 2+ acute GU toxicity was significantly associated with developing a grade 2+ late GU toxicity after SBRT (OR 4.63, 95% CI (2.96-7.25), p < 0.0001) and CRT (OR 2.83, 95% CI (1.69-4.71), p < 0.0001). This association remained significant in multivariable analysis. In univariable analysis, experiencing a grade 2+ acute GI toxicity was also associated with developing a grade 2+ late GI toxicity after SBRT (OR 3.67, 95% CI (1.91-7.03), p < 0.0001) and CRT (OR 4.4, 95% CI (2.04-9.47), p < 0.0001). This association also remained significant in multivariable analysis. Grade 2+ baseline GU symptoms were also associated with grade 2+ late urinary toxicity in both univariable and multivariable analysis. Overall, acute toxicity is an important predictor variable for late GU/GI toxicity after localised prostate radiotherapy using SBRT and CRT. Future work should test whether optimising symptoms pre-treatment and early intervention in those with significant acute toxicities could mitigate the development late of toxicity.

Post radiation mucosal ulcer risk after a hypofractionated stereotactic boost and conventional fractionated radiotherapy for oropharyngeal carcinoma

BACKGROUND/PURPOSE

Post radiation mucosal ulcers (PRMU) after treatment for oropharyngeal squamous cell carcinoma (OPSCC) can have a huge negative impact on patients' quality of life, but little is known concerning risk factors and the impact of fraction size. Therefore, the goal of this study was to determine the pattern of PRMU development and to identify risk factors after a hypofractionated stereotactic body radiotherapy boost (SBRT) compared to conventionally fractionated radiotherapy for OPSCC.

MATERIAL AND METHODS

We performed a retrospective cohort study (N = 332) of OPSCC patients with ≥ 1-year disease-free survival, treated with 46 Gy Intensity Modulated Radiotherapy (IMRT) (2 Gy fractions) followed by either an SBRT boost of 16.5 Gy (5.5 Gy fractions) (N = 180), or 24 Gy IMRT (2 Gy fractions) (N = 152). PRMU (grade ≥ 2) was scored when observed > three months after the last radiotherapy (RT) fraction (CTCAE v5.0). Potential risk factors were analyzed with Cox regression models using death as competing risk. Dose at the PRMU site was calculated by projecting delineated PRMU on the planning CT.

RESULTS

All cases of PRMU (N = 64) occurred within 24 months; all were grade 2. The cumulative incidence at 2 years in the SBRT boost group was 26% (N = 46) vs. 12% (N = 18) for conventional fractionation (p = 0.003). Most PRMU developed within nine months (N = 48). PRMU occurring > nine months (N = 16) were mainly observed in the SBRT boost group (N = 15). Sex (p = 0.048), acute tube feeding (p = < 0.001), tumor subsite tonsil (p = 0.001), and N stage (p = 0.017) were associated with PRMU risk at multivariable regression in the hypofractionated SBRT boost group. All 25 delineated PRMU were located within the high dose regions.

CONCLUSION

The risk of PRMU should be included in the cost benefit analysis when considering future research using a hypofractionated SBRT boost for OPSCC patients.

Clinical Radiobiology for Radiation Oncology

This chapter is focused on radiobiological aspects at the molecular, cellular, and tissue level which are relevant for the clinical use of ionizing radiation (IR) in cancer therapy. For radiation oncology, it is critical to find a balance, i.e., the therapeutic window, between the probability of tumor control and the probability of side effects caused by radiation injury to the healthy tissues and organs. An overview is given about modern precision radiotherapy (RT) techniques, which allow optimal sparing of healthy tissues. Biological factors determining the width of the therapeutic window are explained. The role of the six typical radiobiological phenomena determining the response of both malignant and normal tissues in the clinic, the 6R’s, which are Reoxygenation, Redistribution, Repopulation, Repair, Radiosensitivity, and Reactivation of the immune system, is discussed. Information is provided on tumor characteristics, for example, tumor type, growth kinetics, hypoxia, aberrant molecular signaling pathways, cancer stem cells and their impact on the response to RT. The role of the tumor microenvironment and microbiota is described and the effects of radiation on the immune system including the abscopal effect phenomenon are outlined. A summary is given on tumor diagnosis, response prediction via biomarkers, genetics, and radiomics, and ways to selectively enhance the RT response in tumors. Furthermore, we describe acute and late normal tissue reactions following exposure to radiation: cellular aspects, tissue kinetics, latency periods, permanent or transient injury, and histopathology. Details are also given on the differential effect on tumor and late responding healthy tissues following fractionated and low dose rate irradiation as well as the effect of whole-body exposure.

Concordance between General Practitioners and Radiation Oncologists for Cancer Follow-Up Care

(1) Background: Patients treated with radiotherapy require follow-up care to detect and treat acute and late side effects, and to monitor for recurrence. The increasing demand for follow-up care poses a challenge for specialists and general practitioners. There is a perception that general practitioners do not have the specialised knowledge of treatment side effects and how to manage these. Knowing the concordance between general practitioner and oncologist clinical assessments can improve confidence in healthcare professionals. This study aimed to measure the level of agreement between general practitioners and radiation oncologists using a standardised clinical assessment; (2) Methods: a cross-sectional clinical practice study; sample aim of 20 breast, prostate or colorectal patients, three years post-radiotherapy treatment; their general practitioner and radiation oncologist; (3) Results: There was acceptable percent agreement (>75%) and a moderate to almost perfect agreement (Fleiss kappa) for all variables between the 15 general practitioner-radiation oncologist dyads; (4) Conclusions: The general practitioner and radiation oncologist concordance of a clinical follow-up assessment for radiation oncology patients is an important finding. These results can reassure both general practitioners and oncologists that general practitioners can provide cancer follow-up care. However, further studies are warranted to confirm the findings and improve reassurance for health professionals.

Deferoxamine to Minimize Fibrosis During Radiation Therapy

Significance: By 2030, there will be >4 million radiation-treated cancer survivors living in the United States. Irradiation triggers inflammation, fibroblast activation, and extracellular matrix deposition in addition to reactive oxygen species generation, leading to a chronic inflammatory response. Radiation-induced fibrosis (RIF) is a progressive pathology resulting in skin pigmentation, reduced elasticity, ulceration and dermal thickening, cosmetic deformity, pain, and the need for reconstructive surgery. Recent Advances: Deferoxamine (DFO) is a U.S. Food and Drug Administration (FDA)-approved iron chelator for blood dyscrasia management, which has been found to be proangiogenic, to decrease free radical formation, and reduce cell death. DFO has shown great promise in the treatment and prophylaxis of RIF in preclinical studies. Critical Issues: Systemic DFO has a short half-life and is cumbersome to deliver to patients intravenously. Transdermal DFO delivery is complicated by its high atomic mass and hydrophilicity, preventing stratum corneum penetration. A transdermal drug delivery system was developed to address these challenges, in addition to a strategy for topical administration. Future Directions: DFO has great potential to translate from bench to bedside. An important step in translation of DFO for RIF prophylaxis is to ensure that DFO treatment does not affect the efficacy of radiation therapy. Furthermore, after an initial plethora of studies reporting DFO treatment by intravenous and subcutaneous routes, a significant advantage of recent studies is the success of transdermal and topical delivery. Given the strong foundation of basic scientific research supporting the use of DFO treatment on RIF, clinicians will be closely following the results of the ongoing human studies.

Photobiomodulation therapy in management of cancer therapy-induced side effects: WALT position paper 2022

Disclaimer

This article is based on recommendations from the 12th WALT Congress, Nice, October 3-6, 2018, and a follow-up review of the existing data and the clinical observations of an international multidisciplinary panel of clinicians and researchers with expertise in the area of supportive care in cancer and/or PBM clinical application and dosimetry. This article is informational in nature. As with all clinical materials, this paper should be used with a clear understanding that continued research and practice could result in new insights and recommendations. The review reflects the collective opinion and, as such, does not necessarily represent the opinion of any individual author. In no event shall the authors be liable for any decision made or action taken in reliance on the proposed protocols.

Objective

This position paper reviews the potential prophylactic and therapeutic effects of photobiomodulation (PBM) on side effects of cancer therapy, including chemotherapy (CT), radiation therapy (RT), and hematopoietic stem cell transplantation (HSCT).

Background

There is a considerable body of evidence supporting the efficacy of PBM for preventing oral mucositis (OM) in patients undergoing RT for head and neck cancer (HNC), CT, or HSCT. This could enhance patients’ quality of life, adherence to the prescribed cancer therapy, and treatment outcomes while reducing the cost of cancer care.

Methods

A literature review on PBM effectiveness and dosimetry considerations for managing certain complications of cancer therapy were conducted. A systematic review was conducted when numerous randomized controlled trials were available. Results were presented and discussed at an international consensus meeting at the World Association of photobiomoduLation Therapy (WALT) meeting in 2018 that included world expert oncologists, radiation oncologists, oral oncologists, and oral medicine professionals, physicists, engineers, and oncology researchers. The potential mechanism of action of PBM and evidence of PBM efficacy through reported outcomes for individual indications were assessed.

Results

There is a large body of evidence demonstrating the efficacy of PBM for preventing OM in certain cancer patient populations, as recently outlined by the Multinational Association for Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO). Building on these, the WALT group outlines evidence and prescribed PBM treatment parameters for prophylactic and therapeutic use in supportive care for radiodermatitis, dysphagia, xerostomia, dysgeusia, trismus, mucosal and bone necrosis, lymphedema, hand-foot syndrome, alopecia, oral and dermatologic chronic graft-versus-host disease, voice/speech alterations, peripheral neuropathy, and late fibrosis amongst cancer survivors.

Conclusions

There is robust evidence for using PBM to prevent and treat a broad range of complications in cancer care. Specific clinical practice guidelines or evidence-based expert consensus recommendations are provided. These recommendations are aimed at improving the clinical utilization of PBM therapy in supportive cancer care and promoting research in this field. It is anticipated these guidelines will be revised periodically.

Acute toxicity in patients treated with concurrent chemoradiotherapy with proton versus intensity-modulated radiation therapy for nonmetastatic head and neck cancers

BACKGROUND

We evaluated if proton therapy is associated with decreased acute toxicities compared to intensity-modulated radiation therapy (IMRT) in patients receiving concurrent chemoradiotherapy for head and neck cancers.

METHODS

We analyzed 580 patients with nonmetastatic head and neck cancers. Primary endpoint was any 90-day grade ≥3 toxicity, prospectively collected and graded per CTCAEv4. Modified Poisson regression models were used.

RESULTS

Ninety-five patients received proton and 485 IMRT. The proton group had more HPV-positive tumors (65.6 vs. 58.0%, p = 0.049), postoperative treatment (76.8 vs. 62.1%, p = 0.008), unilateral neck treatment (18.9 vs. 6.6%, p < 0.001) and significantly lower doses to organs-at-risk compared to IMRT group. Adjusted for patient and treatment characteristics, the proton group had decreased grade 2 dysgeusia (RR0.67, 95%CI 0.53-0.84, p = 0.004) and a trend toward lower grade ≥3 toxicities (RR0.60, 95%CI 0.41-0.88, p = 0.06).

CONCLUSIONS

Proton therapy was associated with significantly reduced grade 2 dysgeusia and nonstatistically significant decrease in acute grade ≥3 toxicities compared to IMRT.

Response Evaluation Following Radiation Therapy With 18F-FDG PET/CT: Common Variants of Radiation-Induced Changes and Potential Pitfalls

Radiation therapy (RT) is one of the cornerstones in cancer treatment and approximately half of all patients will receive some form of RT during the course of their cancer management. Response evaluation after RT and follow-up imaging with ¹⁸F-Fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) can be complicated by RT-induced acute, chronic or consequential effects. There is a general consensus that ¹⁸F-FDG PET/CT for response evaluation should be delayed for 12 weeks after completing RT to minimize the risk of false-positive findings. Radiation-induced late side effects in normal tissue can take years to develop and eventually cause symptoms that on imaging can potentially mimic recurrent disease. Imaging findings in radiation induced injuries depend on the normal tissue included in the irradiated volume and the radiation therapy regime including the total dose delivered, dose per fraction and treatment schedule. The intent for radiation therapy should be taken in consideration when evaluating the response on imaging, that is palliative vs curative or neoadjuvant vs adjuvant RT. Imaging findings can further be distorted by altered anatomy and sequelae following surgery within the radiation field. An awareness of common PET/CT-induced changes/injuries is essential when interpreting ¹⁸F-FDG PET/CT as well as obtaining a complete medical history, as patients are occasionally scanned for an unrelated cause to previously RT treated malignancy. In addition, secondary malignancies due to carcinogenic effects of radiation exposure in long-term cancer survivors should not be overlooked. ¹⁸F-FDG PET/CT can be very useful in response evaluation and follow-up in patients treated with RT, however, variants and pitfalls are common and it is important to remember that radiation-induced injury is often a diagnosis of exclusion.

Protective effects of Brownea grandiceps (Jacq.) against ϒ-radiation-induced enteritis in rats in relation to its secondary metabolome fingerprint

Radiation enteritis is the most common complication of radiotherapy in patients with pelvic malignancies. Thus, the radioprotective activity of the total hydro-alcoholic extract (BGE) and the ethyl acetate soluble fraction (EAF) of Brownea grandiceps leaves was evaluated against ϒ-radiation-induced enteritis in rats. (BGE) and (EAF) were characterized using HPLC-PDA-ESI-MS/MS analysis. The total phenolic and flavonoid contents were also quantified. In vivo administration of (BGE) (400 mg/kg) and (EAF) (200 & 400 mg/kg) prevented intestinal injury and maintained the mucosal integrity of irradiated rats through increasing villi length and promoting crypt regeneration. Also, (EAF) showed more potent antioxidant activity than (BGE) through reduction of MDA level and enhancement of GSH content and catalase enzyme activity. (BGE) and (EAF) down-regulated intestinal NF-κB expression leading to diminished expression of downstream inflammatory cytokine TNF-α. Moreover, (EAF) markedly reduced the expression of profibrotic marker TGF-β1. Seventy-nine compounds were tentatively identified, including flavonoids, proanthocyanidins, polar lipids and phenolic acids. (EAF) showed significantly higher total phenolic and flavonoid contents, as compared to (BGE). Results revealed remarkable radioprotective activity of (BGE) and (EAF), with significantly higher activity for (EAF). The chemical constituents of (BGE) and (EAF) strongly supported their radioprotective activity. To the best of our knowledge, the present study describes for the first time the radioprotective activity of B. grandiceps leaves in relation to its secondary metabolome fingerprint; emphasizing the great promise of B. grandiceps leaves, especially (EAF), to be used as natural radio-protective agent.

Assessment of cough in head and neck cancer patients at risk for dysphagia-An overview

BACKGROUND

This literature review explores the terminology, the neurophysiology, and the assessment of cough in general, in the framework of dysphagia and regarding head and neck cancer patients at risk for dysphagia. In the dysphagic population, cough is currently assessed perceptually during a clinical swallowing evaluation or aerodynamically.

RECENT FINDINGS

Recent findings have shown intra and inter-rater disagreements regarding perceptual scoring of cough. Also, aerodynamic measurements are impractical in a routine bedside assessment. Coughing, however, is considered to be a clinically relevant sign of aspiration and dysphagia in head and cancer patients treated with concurrent chemoradiotherapy.

CONCLUSION

This article surveys the literature regarding the established cough assessment and stresses the need to implement innovative methods for assessing cough in head and neck cancer patients treated with concurrent chemoradiotherapy at risk for dysphagia.

Response of Canine Soft Tissue Sarcoma to Stereotactic Body Radiotherapy

Canine soft tissue sarcoma (STS) has served as a preclinical model for radiation, hyperthermia, experimental therapeutics, and tumor microenvironmental research for decades. Stereotactic body radiotherapy (SBRT) demonstrates promising results for the control of various tumors in human and veterinary medicine; however, there is limited clinical data for the management of STS with SBRT. In this retrospective study, we aimed to define overall efficacy and toxicity of SBRT for the treatment of macroscopic canine STS to establish this preclinical model for comparative oncology research. Fifty-two canine patients met inclusion criteria. Total radiation dose prescribed ranged from 20-50 Gy delivered in 1-5 fractions. Median progression-free survival time (PFST) was 173 days and overall survival time (OST) 228 days. Best overall response was evaluable in 46 patients, with 30.4% responding to treatment (complete response n = 3; partial response n = 11). For responders, OST significantly increased to 475 days vs. 201 days (P = 0.009). Prognostic factors identified by multivariable Cox regressions included size of tumor and metastasis at presentation. Dogs were 3× more likely to progress (P = 0.009) or 3.5× more likely to experience death (P = 0.003) at all times of follow up if they presented with metastatic disease. Similarly, every 100-cc increase in tumor volume resulted in a 5% increase in the risk of progression (P = 0.002) and death (P = 0.001) at all times of follow up. Overall, 30.8% of patients developed acute toxicities, 7.7% grade 3; 28.8% of patients developed late toxicities, 11.5% grade 3. Increased dose administered to the skin significantly affected toxicity development. SBRT serves as a viable treatment option to provide local tumor control for canine macroscopic STS, particularly those with early-stage disease and smaller tumors. The results of this study will help to define patient inclusion criteria and to set dose limits for preclinical canine STS trials involving SBRT.

Modern radiation techniques in early stage breast cancer for the breast radiologist

Partial breast irradiation (PBI) and ultra-hypofractionated whole breast irradiation (uWBI) are contemporary alternatives to conventional and standard hypofractionated whole breast irradiation (WBI), which shorten treatment from 3 to 6 weeks to 1-2 weeks for select patients. PBI and accelerated PBI (APBI) can be delivered with external beam radiation (3D conformal radiation therapy (3D-CRT) or intensity modulated radiation therapy (IMRT)), intraoperative radiation (IORT), or brachytherapy. These new radiation techniques offer the advantage of convenience and lower cost, which ultimately improves access to care. Globally, the COVID 19 pandemic has accelerated APBI/PBI and ultra-hypofractionated regimens into routine practice for carefully selected patients. Recent long-term data from randomized controlled trials (RCTs) have demonstrated these techniques are safe and effective in suitable patients demonstrating equivalent or improved local recurrence, acute/late toxicity, and cosmesis. PBI and APBI should be limited to low risk unifocal invasive ductal carcinoma and ductal carcinoma in situ with tumor size < 2 cm, clear margins (≥2 mm), ER+, and negative nodes. Based on the results from UK Fast-Forward and UK FAST ultra-hypofractionated breast radiation can be safely employed for early stage node negative patients, but is not yet considered an international standard of care. In this review, authors will appraise recent data for these shorter course radiation treatment regimens, as well as, considerations for breast radiologists including surveillance imaging and radiographic findings.

Randomised clinical trial of a gastrointestinal care bundle to reduce symptoms in patients with pelvic cancer undergoing chemoradiotherapy

OBJECTIVE

Pelvic radiotherapy is used to treat 17 000 people in the UK each year. Eight in 10 develop difficult bowel problems during pelvic treatment, especially diarrhoea, urgency and incontinence. Some cannot complete treatment, reducing the chance of cancer cure. Undertaking gastroenterologist-led investigation and management during pelvic radiotherapy has never been evaluated. In this study, we aimed to assess whether patients could successfully receive a novel gastrointestinal (GI) care bundle during chemoradiotherapy (feasibility aim) and would experience reduced symptom severity (clinical impact aim).

DESIGN

This randomised controlled trial recruited patients with cervical and bladder cancers undergoing radical chemoradiotherapy. Participants were randomised to intervention or control groups. Questionnaire and anthropometric data were collected. All intervention group patients received individualised dietary counselling weekly throughout treatment, and if bowel symptoms developed they were offered rapid-access investigation and treatment for any identified pathology: lactose intolerance, bacterial overgrowth or bile acid malabsorption.

RESULTS

Feasibility: 50 participants were recruited, 24 were randomised to the intervention group and 26 to the control group. All completed 20 fractions of external beam pelvic radiotherapy. It was possible to perform 57/72 (79%) of proposed intervention tests with no disruption of oncological management.

CLINICAL IMPACT

All participants developed GI symptoms during radiotherapy. The median symptom score for each group increased from baseline at 6 weeks. This was from 0.156 (0.000-0.333) to 0.600 (0.250-1.286) in the control group, and from 0.00 (0.000-0.300) to 0.402 (0.000-0.667) in the intervention group.

CONCLUSION

It was feasible to recruit to and deliver a randomised controlled trial of interventions in patients undergoing pelvic chemoradiotherapy. Lower median bowel scores were reported in the intervention group at 6 weeks, with fewer patients experiencing symptoms overall.

TRIAL REGISTRATION NUMBER

ISRCTN783488.

Clinical features and dosimetric evaluation of carbon ion radiation-induced osteoradionecrosis of mandible in head and neck tumors

BACKGROUND AND PURPOSE

Osteoradionecrosis (ORN) affects the patient's quality of life by making eating and maintaining oral hygiene painful. This study aimed to analyze carbon ion radiotherapy (C-ion RT)-induced ORN of the mandible.

MATERIALS AND METHODS

A retrospective study of 199 patients with head and neck tumors treated with C-ion RT was performed from 2010 to 2019. Only 11 patients with tumors located in the oropharynx and floor of the mouth were analyzed. C-ion RT consisted of 57.6 Gy or 64.0 Gy (relative biological effectiveness) in 16 fractions. The mandible was analyzed for magnetic resonance imaging (MRI) changes and bone exposure. The relationship between the radiation dose and ORN of the mandible was analyzed.

RESULTS

Five patients (45.5%) had ORN of the mandible. The median follow-up time was 68 months. The median onset times based on MRI changes and bone exposure were 9 and 15 months, respectively. Doses of 30 Gy (relative biological effectiveness) to the mandible and teeth showed the most significant effect, causing ORN at 29.5 ± 6.7 cc and 3.9 ± 1.8 cc, respectively, with cut-off values at 16.5 cc (p = 0.002) and 1.8 cc (p = 0.0059), respectively.

CONCLUSION

This is the first study reporting the incidence, onset time, and risk-predictive dosimetry parameters of C-ion RT-induced ORN of the mandible. Our study will be useful for establishing clinical strategies for C-ion RT to the head and neck near the mandible.

Development of a Management Algorithm for Acute and Chronic Radiation Urethritis and Cystitis

OBJECTIVE

The purpose of this review was to summarize the current literature on the assessment and treatment of radiation urethritis and cystitis (RUC) for the development of an evidenced-based management algorithm.

MATERIAL AND METHODS

The PubMed/MEDLINE database was searched by a multidisciplinary group of experts in January 2021.

RESULTS

In total, 48 publications were identified. Three different types of RUC can be observed in clinical practice: inflammation-predominant, bleeding-predominant, and the combination of inflammation- and bleeding-RUC. There is no consensus on the optimal treatment of RUC. Inflammation-predominant RUC should be treated symptomatically based on the existence of bothersome storage or voiding lower urinary tract symptom as well as on pain. When bleeding-predominant RUC has occurred, hydration and hyperbaric oxygen therapy (HOT) should be used first and, if HOT is not available, oral drugs instead (sodium pentosane polysulfate, aminocaproic acid, immunokine WF 10, conjugated estrogene, or pentoxifylline + vitamin E). If local bleeding persists, focal therapy of bleeding vessels with a laser or electrocoagulation is indicated. In case of generalized bleeding, intravesical installation should be initiated (formalin, aluminium salts, and hyaluronic acid/chondroitin). Vessel embolization is a less invasive treatment with potentially less complications and good clinical outcomes. Open- or robot-assisted surgery is indicated in patients with permanent, life-threatening bleeding, or fistulae.

CONCLUSIONS

Treatment of RUC, if not self-limiting, should be done according to the type of RUC and in a stepwise approach. Conservative/medical treatment (oral and topic agents) should primarily be used before invasive (transurethral) treatments.

Volumetric Modulated Arc Therapy Improves Outcomes in Definitive Radiochemotherapy for Anal Cancer Whilst Reducing Acute Toxicities and Increasing Treatment Compliance

Simple Summary

Intensity-modulated radiotherapy (IMRT) is the standard of care in definitive chemoradiotherapy (CRT) for anal cancer. Only a limited number of studies have analyzed the clinical results with VMAT (volumetric modulated arc therapy, the advanced form of IMRT). We conducted a retrospective study on patients treated at our institution. We compared the outcomes of VMAT-treated and 3DCRT (3D conformal radiotherapy)-treated patients. VMAT reduced acute toxicities (i.e., primarily dermatitis and enteritis) to a great extent. Additionally, VMAT relevantly improved treatment compliance (i.e., less CRT interruptions/delays, shorter overall treatment time, and higher absolute 5-fluorouracil dose applied). Finally, we found improved cancer-specific survival and distant control in VMAT-treated patients. The present study underlines the great progress that has been achieved with IMRT/VMAT in the CRT of anal cancer. Our study is the first to demonstrate an improvement in treatment compliance and outcomes with VMAT. Future studies could address whether VMAT is advantageous when compared to conventional IMRT.

Abstract

Background: Intensity-modulated radiotherapy (IMRT) is the standard of care in chemoradiotherapy (CRT) for anal cancer. Until now, only a limited number of studies have analyzed the results with VMAT (volumetric modulated arc therapy). We conducted a retrospective study on patients treated at our institution. Patients and Methods: We included patients who received curative CRT for anal cancer. We compared VMAT-treated and 3DCRT (3D conformal radiotherapy)-treated patients. We analyzed toxicities (acute: CTCAE criteria; late: LENT/SOMA criteria), treatment compliance, overall survival, cancer-specific survival (CSS), distant control (DC), and locoregional control. Results: A total of 149 patients (3DCRT: n = 87, VMAT: n = 62) were included. The median follow-up was longer in 3DCRT-treated patients (3DCRT: 61.3 months; VMAT: 39.1 months; p < 0.05). VMAT-treated patients had more G3 tumors (3DCRT: 12/87 (13.8%); VMAT: 18/62 (29.0%), p < 0.001). VMAT reduced acute toxicities ≥grade 3 (3DCRT: n = 48/87 (55.2%); VMAT: n = 11/62 (17.7%), p < 0.001). VMAT improved treatment compliance (less interruptions/delays) (3DCRT: 37/87, 42.5%; VMAT: 4/62, 6.5%; p < 0.001), provided a shorter median overall treatment time (3DCRT: 41 days; VMAT: 38 days; p = 0.02), and gave a higher median absolute 5-fluorouracil dose (3DCRT: 13,700 mg; VMAT: 14,400 mg; p = 0.001). Finally, we found improved CSS (p = 0.02; 3DCRT: 81.9% at 3 years; VMAT: 94.1% at 3 years) and DC (p = 0.01; 3DCRT: 89.4% at 3 years; VMAT: 100.0% at 3 years) with VMAT. Summary: Our study is the first to demonstrate improved treatment compliance and outcomes with VMAT for anal cancer. Previous studies have indicated that organs at risk sparing might be more improved with the use of VMAT vs. with conventional IMRT. Future studies should address whether these advantages lead to a further reduction in CRT-associated morbidity.

Radiomic and radiogenomic modeling for radiotherapy: strategies, pitfalls, and challenges

The power of predictive modeling for radiotherapy outcomes has historically been limited by an inability to adequately capture patient-specific variabilities; however, next-generation platforms together with imaging technologies and powerful bioinformatic tools have facilitated strategies and provided optimism. Integrating clinical, biological, imaging, and treatment-specific data for more accurate prediction of tumor control probabilities or risk of radiation-induced side effects are high-dimensional problems whose solutions could have widespread benefits to a diverse patient population-we discuss technical approaches toward this objective. Increasing interest in the above is specifically reflected by the emergence of two nascent fields, which are distinct but complementary: radiogenomics, which broadly seeks to integrate biological risk factors together with treatment and diagnostic information to generate individualized patient risk profiles, and radiomics, which further leverages large-scale imaging correlates and extracted features for the same purpose. We review classical analytical and data-driven approaches for outcomes prediction that serve as antecedents to both radiomic and radiogenomic strategies. Discussion then focuses on uses of conventional and deep machine learning in radiomics. We further consider promising strategies for the harmonization of high-dimensional, heterogeneous multiomics datasets (panomics) and techniques for nonparametric validation of best-fit models. Strategies to overcome common pitfalls that are unique to data-intensive radiomics are also discussed.

Early morbidity and dose-volume effects in definitive radiochemotherapy for locally advanced cervical cancer: a prospective cohort study covering modern treatment techniques

PURPOSE

Predicting morbidity for patients with locally advanced cervix cancer after external beam radiotherapy (EBRT) based on dose-volume parameters remains an unresolved issue in definitive radiochemotherapy. The aim of this prospective study was to correlate patient characteristics and dose-volume parameters to various early morbidity endpoints for different EBRT techniques, including volumetric modulated arc therapy (VMAT) and adaptive radiotherapy (ART).

METHODS AND MATERIALS

The study population consisted of 48 patients diagnosed with locally advanced cervix cancer, treated with definitive radiochemotherapy including image-guided adaptive brachytherapy (IGABT). Multiple questionnaires (CTCAE 4.03, QLQ-C30 and EORTC QLQ-CX24) were assessed prospectively for patients treated with different EBRT techniques, including online adaptive VMAT. Contouring and treatment planning was based on the EMBRACE protocols. Acute toxicity, classified as general, gastrointestinal (GI) or genitourinary (GU) and their corresponding dose-volume histograms (DVHs) were first correlated by applying least absolute shrinkage and selection operator (LASSO) and subsequently evaluated by multiple logistic binomial regression.

RESULTS

The treated EBRT volumes varied for the different techniques with ~2500 cm³ for 3D conformal radiotherapy (3D-CRT), ~2000 cm³ for EMBRACE‑I VMAT, and ~1800 cm³ for EMBRACE-II VMAT and ART. In general, a worsening of symptoms during the first 5 treatment weeks and recovery afterwards was observed. Dose-volume parameters significantly correlating with stool urgency, rectal and urinary incontinence were as follows: bowel V_40Gy < 250 cm³, rectum V_40Gy < 80% and bladder V_40Gy < 80-90%.

CONCLUSION

This prospective study demonstrated the impact of EBRT treatment techniques in combination with chemotherapy on early morbidity. Dose-volume effects for dysuria, urinary incontinence, stool urgency, diarrhea, rectal bleeding, rectal incontinence and weight loss were found.

Fat Grafting in Radiation-Induced Soft-Tissue Injury: A Narrative Review of the Clinical Evidence and Implications for Future Studies

SUMMARY

Radiation-induced changes in skin and soft tissue result in significant cosmetic and functional impairment with subsequent decrease in quality of life. Fat grafting has emerged as a therapy for radiation-induced soft-tissue injury, and this narrative review aims to evaluate the current clinical evidence regarding its efficacy. A review was conducted to examine the current clinical evidence of fat grafting as a therapy for radiation-induced injury to the skin and soft tissue and to outline the clinical outcomes that can be used to more consistently quantify chronic radiation-induced injury in future clinical studies. The current clinical evidence regarding the efficacy of fat grafting to treat radiation-induced injury of the skin and soft tissue suggests that fat grafting increases skin softness and pliability, induces volume restoration, improves hair growth in areas of alopecia, reduces pain, and improves cosmetic and functional outcomes. However, literature in this field is far from robust and mired by the retrospective nature of the studies, lack of adequate controls, and inherent limitations of small case series and cohorts. A series of actions have been identified to strengthen future clinical data, including the need for physical examination using a validated scale, appropriate imaging, skin biomechanics and microcirculation testing, and histologic analysis. In conclusion, radiation-induced soft-tissue injury is a significant health burden that can lead to severe functional and aesthetic sequelae. Although still in a preliminary research phase, there is promising clinical evidence demonstrating the benefits of fat grafting to treat chronic changes after radiation therapy. Future clinical studies will require larger cohorts, adequate controls, and consistent use of objective measurements.

Effect of irradiation on the expression of E-cadherin and β-catenin in early and late radiation sequelae of the urinary bladder and its modulation by NF-κB inhibitor thalidomide

Purpose

In a previous study we have shown in a mouse model that administration of nuclear factor-kappa B (NF-κB) inhibitor thalidomide has promising therapeutic effects on early radiation cystitis (ERC) and late radiation sequelae (LRS) of the urinary bladder. The aim of this study was to evaluate in the same mice the effect of thalidomide on adherens junction (AJ) proteins in ERC and LRS.

Methods

Urothelial expressions of E‑cadherin and β‑catenin were assessed by immunohistochemistry in formalin-fixed paraffin-embedded (FFPE) bladder specimens over 360 days post single-dose irradiation on day 0. First, the effect of irradiation on AJ expression and then effects of thalidomide on irradiation-induced AJ alterations were assessed using three different treatment times.

Results

Irradiation provoked a biphasic upregulation of E‑cadherin and β‑catenin in the early phase. After a mild decrease of E‑cadherin and a pronounced decrease of β‑catenin at the end of the early phase, both increased again in the late phase. Early administration of thalidomide (day 1–15) resulted in a steeper rise in the first days, an extended and increased expression at the end of the early phase and a higher expression of β‑catenin alone at the beginning of the late phase.

Conclusion

Upregulation of AJ proteins is an attempt to compensate irradiation-induced impairment of urothelial barrier function. Early administration of thalidomide improves these compensatory mechanisms by inhibiting NF-κB signaling and its interfering effects.

Administration of TGF-ß Inhibitor Mitigates Radiation-induced Fibrosis in a Mouse Model

BACKGROUND

Radiation-induced fibrosis is a long-term adverse effect of external beam radiation therapy for cancer treatment that can cause pain, loss of function, and decreased quality of life. Transforming growth factor beta (TGF-β) is believed to be critical to the development of radiation-induced fibrosis, and TGF-β inhibition decreases the development of fibrosis. However, no treatment exists to prevent radiation-induced fibrosis. Therefore, we aimed to mitigate the development of radiation-induced fibrosis in a mouse model by inhibiting TGF-β.

QUESTION/PURPOSES

Does TGF-β inhibition decrease the development of muscle fibrosis induced by external beam radiation in a mouse model?

METHODS

Twenty-eight 12-week-old male C57BL/6 mice were assigned randomly to three groups: irradiated mice treated with TGF-βi, irradiated mice treated with placebo, and control mice that received neither irradiation nor treatment. The irradiated mice received one 50-Gy fraction of radiation to the right hindlimb before treatment initiation. Mice treated with TGF-c (n = 10) received daily intraperitoneal injections of a small-molecule inhibitor of TGF-β (1 mg/kg) in a dimethyl sulfoxide vehicle for 8 weeks (seven survived to histologic analysis). Mice treated with placebo (n = 10) received daily intraperitoneal injections of only a dimethyl sulfoxide vehicle for 8 weeks (10 survived to histologic analysis). Control mice (n = 8) received neither radiation nor TGF-β treatment. Control mice were euthanized at 3 months because they were not expected to exhibit any changes related to treatment. Mice in the two treatment groups were euthanized 9 months after radiation, and the quadriceps of each thigh was sampled. Masson's trichome stain was used to assess muscle fibrosis. Slides were viewed at 10 × magnification using bright-field microscopy, and in a blinded fashion, five representative images per mouse were used to quantify fibrosis. The mean ± SD fibrosis pixel densities in the TGF-βi and radiation-only groups were compared using Mann-Whitney U tests. The ratio of fibrosis to muscle was calculated using the mean fibrosis per slide in the TGF-βi group to standardize measurements. Alpha was set at 0.05.

RESULTS

The mean (± SD) percentage of fibrosis per slide was greater in the radiation-only group (1.2% ± 0.42%) than in the TGF-βi group (0.14% ± 0.09%) (odds ratio 0.12 [95% CI 0.07 to 0.20]; p < 0.001). Among control mice, mean fibrosis was 0.05% ± 0.02% per slide. Mice in the radiation-only group had 9.1 times the density of fibrosis as did mice in the TGF-βi group.

CONCLUSION

Our study provides preliminary evidence that the fibrosis associated with radiation therapy to a quadriceps muscle can be reduced by treatment with a TGF-β inhibitor in a mouse model.

CLINICAL RELEVANCE

If these observations are substantiated by further investigation into the role of TGF-β inhibition on the development of radiation-induced fibrosis in larger animal models and humans, our results may aid in the development of novel therapies to mitigate this complication of radiation treatment.

Prospective evaluation of probabilistic dose-escalated IMRT in prostate cancer

BACKGROUND

Cure- and toxicity rates after intensity-modulated radiotherapy (IMRT) of prostate cancer are dose-and volume dependent. We prospectively studied the potential for organ at risk (OAR) sparing and compensation of tumor movement with the coverage probability (CovP) concept.

PATIENTS AND METHODS

Twenty-eight prostate cancer patients (median age 70) with localized disease (cT1c-2c, N0, M0) and intermediate risk features (prostate-specific antigen [PSA] < 20, Gleason score ≤ 7b) were treated in a prospective study with the CovP concept. Planning-CTs were performed on three subsequent days to capture form changes and movement of prostate and OARs. The clinical target volume (CTV) prostate and the OARs (bladder and rectum) were contoured in each CT. The union of CTV1-3 was encompassed by an isotropic margin of 7 mm to define the internal target volume (ITV). Dose prescription/escalation depended on coverage of all CTVs within the ITV. IMRT was given in 39 fractions to 78 Gy using the Monte-Carlo algorithm. Short-term androgen deprivation was recommended and given in 78.6% of patients.

RESULTS

Long-term toxicity was evaluated in 26/28 patients after a median follow-up of 7.1 years. At last follow-up, late bladder toxicity (Radiation Therapy Oncology Group, RTOG) G1 was observed in 14.3% of patients and late rectal toxicities (RTOG) of G1 (7.1%) and of G2 (3.6%) were observed. No higher graded toxicity occurred. After 7.1 years, biochemical control (biochemically no evidence of disease, bNED) was 95.5%, prostate cancer-specific survival and the distant metastasis-free survival after 7.1 years were 100% each.

CONCLUSIONS

CovP-based IMRT was feasible in a clinical study. Dose escalation with the CovP concept was associated by a low rate of toxicity and a high efficacy regarding local and distant control.

Dermatologic sequelae of breast cancer: From disease, surgery, and radiation

The care of breast cancer patients is important to dermatologists. Breast cancer's initial presentation, clinical progression, and its associated treatments can result in a variety of cutaneous complications. Dermatologists may be the first to identify a breast cancer diagnosis, as a subset of patients first present with direct extension of an underlying tumor or with a cutaneous metastasis. The surgical treatment of breast cancer also begets a variety of skin sequelae, including postoperative lymphedema, soft tissue infections, seromas, pyoderma gangrenosum, and scarring disorders. Moreover, breast cancer radiation treatment commonly results in skin changes, which can range from mild and temporary dermatoses to chronic and disfiguring skin ulceration, fibrosis, and necrosis. Radiation may also precipitate secondary malignancies, such as angiosarcoma, as well as rarer dermatologic diseases, such as radiation-induced morphea, lichen planus, and postirradiation pseudosclerodermatous panniculitis. Finally, breast cancer is also associated with an array of paraneoplastic phenomena, including Sweet's syndrome and the rarer intralymphatic histiocytosis. Herein, we review the dermatological manifestations of breast cancer, including conditions associated with its presentation, progression, and treatment sequelae. Chemotherapy-induced cutaneous side effects are beyond the scope of this review. This article provides a comprehensive review for dermatologist to be able to identify, diagnose, and manage breast cancer patients from initial presentation to treatment monitoring and subsequent follow-up.

Predictive Model and Precaution for Oral Mucositis During Chemo-Radiotherapy in Nasopharyngeal Carcinoma Patients

PURPOSE

To explore risk factors for severe acute oral mucositis of nasopharyngeal carcinoma (NPC) patients receiving chemo-radiotherapy, build predictive models and determine preventive measures.

METHODS AND MATERIALS

Two hundred and seventy NPC patients receiving radical chemo-radiotherapy were included. Oral mucosa structure was contoured by oral cavity contour (OCC) and mucosa surface contour (MSC) methods. Oral mucositis during treatment was prospectively evaluated and divided into severe mucositis group (grade ≥ 3) and non-severe mucositis group (grade < 3) according to RTOG Acute Reaction Scoring System. Nineteen clinical features and nineteen dosimetric parameters were included in analysis, least absolute shrinkage and selection operator (LASSO) logistic regression model was used to construct a risk score (RS) system.

RESULTS

Two predictive models were built based on the two delineation methods. MSC based model is more simplified one, it includes body mass index (BMI) classification before radiation, retropharyngeal lymph node (RLN) area irradiation status and MSC V55%, RS = -1.480 + (0.021 × BMI classification before RT) + (0.126 × RLN irradiation) + (0.052 × MSC V55%). The cut-off of MSC based RS is -1.011, with an area under curve (AUC) of 0.737 (95%CI: 0.672-0.801), a specificity of 0.595 and a sensitivity of 0.786. OCC based model involved more variables, RS= -4.805+ (0.152 × BMI classification before RT) + (0.080 × RT Technique) + (0.097 × Concurrent Nimotuzumab) + (0.163 × RLN irradiation) + (0.028 × OCC V15%) + (0.120 × OCC V60%). The cut-off of OCC based RS is -0.950, with an AUC of 0.767 (95%CI: 0.702-0.831), a specificity of 0.602 and a sensitivity of 0.819. Analysis in testing set shown higher AUC of MSC based model than that of OCC based model (AUC: 0.782 vs 0.553). Analysis in entire set shown AUC in these two method-based models were close (AUC: 0.744 vs 0.717).

CONCLUSION

We constructed two risk score predictive models for severe oral mucositis based on clinical features and dosimetric parameters of nasopharyngeal carcinoma patients receiving chemo-radiotherapy. These models might help to discriminate high risk population in clinical practice that susceptible to severe oral mucositis and individualize treatment plan to prevent it.

Ten-Year Results of FAST: A Randomized Controlled Trial of 5-Fraction Whole-Breast Radiotherapy for Early Breast Cancer

PURPOSE

Previous studies of hypofractionated adjuvant whole-breast radiotherapy for early breast cancer established a 15- or 16-fraction (fr) regimen as standard. The FAST Trial (CRUKE/04/015) evaluated normal tissue effects (NTE) and disease outcomes after 5-fr regimens. Ten-year results are presented.

METHODS

Women ≥ 50 years of age with low-risk invasive breast carcinoma (pT1-2 pN0) were randomly assigned to 50 Gy/25 fr (5 weeks) or 30 or 28.5 Gy in 5 once-weekly fr of 6.0 or 5.7 Gy. The primary end point was change in photographic breast appearance at 2 and 5 years; secondary end points were physician assessments of NTE and local tumor control. Odds ratios (ORs) from longitudinal analyses compared regimens.

RESULTS

A total of 915 women were recruited from 18 UK centers (2004-2007). Five-year photographs were available for 615/862 (71%) eligible patients. ORs for change in photographic breast appearance were 1.64 (95% CI, 1.08 to 2.49; P = .019) for 30 Gy and 1.10 (95% CI, 0.70 to 1.71; P = .686) for 28.5 Gy versus 50 Gy. α/β estimate for photographic end point was 2.7 Gy (95% CI, 1.5 to 3.9 Gy), giving a 5-fr schedule of 28 Gy (95% CI, 26 to 30 Gy) estimated to be isoeffective with 50 Gy/25 fr. ORs for any moderate/marked physician-assessed breast NTE (shrinkage, induration, telangiectasia, edema) were 2.12 (95% CI, 1.55 to 2.89; P < .001) for 30 Gy and 1.22 (95% CI, 0.87 to 1.72; P = .248) for 28.5 Gy versus 50 Gy. With 9.9 years median follow-up, 11 ipsilateral breast cancer events (50 Gy: 3; 30 Gy: 4; 28.5 Gy: 4) and 96 deaths (50 Gy: 30; 30 Gy: 33; 28.5 Gy: 33) have occurred.

CONCLUSION

At 10 years, there was no significant difference in NTE rates after 28.5 Gy/5 fr compared with 50 Gy/25 fr, but NTE were higher after 30 Gy/5 fr. Results confirm the published 3-year findings that a once-weekly 5-fr schedule of whole-breast radiotherapy can be identified that appears to be radiobiologically comparable for NTE to a conventionally fractionated regimen.

Multi-slice spiral CT evaluation of chronic radiation colitis and rectitis

The aim of the present study was to retrospectively analyse the multi-slice spiral CT (MSCT) findings of radiation colitis and rectitis (RC&R). A total of 23 cases of RC&R detected by helical CT were included. The CT findings and clinical and endoscopy data of the patients were reviewed. The primary tumours included cancers of the cervix (n=17), rectum (n=4), ovaries (n=1) and bladder (n=1). The total dose of radiation per patient was 46-60 Gy (mean, 49.7 Gy) delivered over 5 weeks. The CT manifestations included different degrees of increased thickness of the intestinal wall (n=20, 87.0%), with a maximum thickness of 16.6 mm. On enhanced CT, the target sign was observed (n=16, 69.9%), with an obviously enhanced mucosa and/or serosa and the following changes observed: Oedema and increased density of the mesentery (n=15, 65.2%); increased density of the subcutaneous fat, and blurred and oedematous pelvic wall muscles (n=4, 17.4%), with the obturator internus and levator ani muscles being most commonly affected; narrowed intestinal lumen (n=3, 13.0%); and a small amount of ascitic fluid (n=2, 8.7%) located in the paracolic sulci and bladder or Douglas pouch. The 23 patients underwent colonoscopy and were diagnosed with RC&R. The major manifestations included telangiectasia and mucosal hyperaemia (n=21, 91.3%). MSCT of chronic RC&R (CRC&R) was associated with certain characteristic findings, which, combined with a medical history of radiotherapy and the clinical manifestations, may prove to be of value in the diagnosis of CRC&R.

Randomised clinical trial on 7-days-a-week postoperative radiotherapy vs. concurrent postoperative radio-chemotherapy in locally advanced cancer of the oral cavity/oropharynx

OBJECTIVE

To compare the efficacy and tolerance of 7-days-a-week accelerated postoperative radiotherapy (p-CAIR) vs postoperative radio-chemotherapy (p-RTCT).

METHODS

Between September 2007 and October 2013, 111 patients were enrolled and randomly assigned to receive 63 Gy in 1.8 Gy fractions 7-days-a-week (n = 57, p-CAIR) or 63 Gy in 1.8 Gy fractions 5-days-a-week with concurrent cisplatin 80-100 mg per square meter of body-surface area on days 1, 22 and 43 of the radiotherapy course (p-RTCT). It represents approximately 40% of the intended trial size, that was closed prematurely due to slowing accrual. Only high-risk patients with squamous cell cancer of the oropharynx/oral cavity, considered fit for concurrent treatment were enrolled.

RESULTS

The rate of locoregional control (LRC) did not differ significantly between treatment arms (p = 0.18, HR = 0.56), 5 year LRC tended, however, to favour p-RTCT (81%) vs p-CAIR (62%). There was no difference in overall survival between treatment arms (p = 0.90, HR = 1.03).The incidence and severity of acute mucosal reactions and late reactions did not differ significantly between treatment arms. Haematological toxicity of p-RTCT was, however, considerably increased compared to p-CAIR.

CONCLUSION

Concurrent postoperative RTCT tended to improve locoregional control rate as compared to p-CAIR. This, however, did not transferred into improved overall survival. Postoperative RTCT was associated with a substantial increase in haematological toxicity that negatively affected treatment compliance in this arm.

ADVANCES IN KNOWLEDGE

To our knowledge, this is the first trial that compares accelerated radiotherapy and radio-chemotherapy in postoperative treatment for oralcavity/oropharyngeal cancer.

Targets for protection and mitigation of radiation injury

Protection of normal tissues against toxic effects of ionizing radiation is a critical issue in clinical and environmental radiobiology. Investigations in recent decades have suggested potential targets that are involved in the protection against radiation-induced damages to normal tissues and can be proposed for mitigation of radiation injury. Emerging evidences have been shown to be in contrast to an old dogma in radiation biology; a major amount of reactive oxygen species (ROS) production and cell toxicity occur during some hours to years after exposure to ionizing radiation. This can be attributed to upregulation of inflammatory and fibrosis mediators, epigenetic changes and disruption of the normal metabolism of oxygen. In the current review, we explain the cellular and molecular changes following exposure of normal tissues to ionizing radiation. Furthermore, we review potential targets that can be proposed for protection and mitigation of radiation toxicity.

Photobiomodulation Therapy to Mitigate Radiation Fibrosis Syndrome

Objective: We evaluated the role of photobiomodulation (PBM) in radiation fibrosis syndrome (RFS). Background: Radiation therapy (RT) is an important treatment utilized in over half of newly diagnosed cancers. Despite its benefits, patients treated with RT may experience acute and chronic significant side effects depending on both treatment- and patient-related factors. RFS is an important long-term side effect of RT, which can adversely impact patient's quality of life and organ function. With improved oncologic outcomes and survival for cancer patients after radiation, there is an unmet need to address long-term side effects of RT, particularly RFS. Results: Photobiomodulation (PBM) using low energy, nonionizing light primarily in the visible (especially red) or near-infrared spectrum has been demonstrated to decrease acute side effects of radiation in rigorously conducted phase III randomized studies; however, its potential benefit in ameliorating chronic radiation side effects, particularly RFS remains to be investigated. Conclusions: This review summarizes the in vitro data, preclinical animal studies and clinical reports, which showcase the potential benefits of PBM treatments in preventing and reversing RFS.

NTCP Models for Severe Radiation Induced Dermatitis After IMRT or Proton Therapy for Thoracic Cancer Patients

Radiation therapy (RT) of thoracic cancers may cause severe radiation dermatitis (RD), which impacts on the quality of a patient's life. Aim of this study was to analyze the incidence of acute RD and develop normal tissue complication probability (NTCP) models for severe RD in thoracic cancer patients treated with Intensity-Modulated RT (IMRT) or Passive Scattering Proton Therapy (PSPT). We analyzed 166 Non-Small-Cell Lung Cancer (NSCLC) patients prospectively treated at a single institution with IMRT (103 patients) or PSPT (63 patients). All patients were treated to a prescribed dose of 60 to 74 Gy in conventional daily fractionation with concurrent chemotherapy. RD was scored according to CTCAE v3 scoring system. For each patient, the epidermis structure (skin) was automatically defined by an in house developed segmentation algorithm. The absolute dose-surface histogram (DSH) of the skin were extracted and normalized using the Body Surface Area (BSA) index as scaling factor. Patient and treatment-related characteristics were analyzed. The Lyman-Kutcher-Burman (LKB) NTCP model recast for DSH and the multivariable logistic model were adopted. Models were internally validated by Leave-One-Out method. Model performance was evaluated by the area under the receiver operator characteristic curve, and calibration plot parameters. Fifteen of 166 (9%) patients developed severe dermatitis (grade 3). RT technique did not impact RD incidence. Total gross tumor volume (GTV) size was the only non dosimetric variable significantly correlated with severe RD (p = 0.027). Multivariable logistic modeling resulted in a single variable model including S_20Gy, the relative skin surface receiving more than 20 Gy (OR = 31.4). The cut off for S_20Gy was 1.1% of the BSA. LKB model parameters were TD₅₀ = 9.5 Gy, m = 0.24, n = 0.62. Both NTCP models showed comparably high prediction and calibration performances. Despite skin toxicity has long been considered a potential limiting factor in the clinical use of PSPT, no significant differences in RD incidence was found between RT modalities. Once externally validated, the availability of NTCP models for prediction of severe RD may advance treatment planning optimization.

[From fibrogenesis towards fibrosis: Pathophysiological mechanisms and clinical presentations]

Fibrogenesis is a universal and ubiquitous process associated with tissue healing. The impairment of tissue homeostasis resulting from the deregulation of numerous cellular actors, under the effect of specific cytokine and pro-oxidative environments can lead to extensive tissue fibrosis, organ dysfunction and significant morbidity and mortality. This situation is frequent in internal medicine, since fibrosis is associated with most organ insufficiencies (i.e. cardiac, renal, or hepatic chronic failures), but also with cancer, a condition with common pathophysiological mechanisms. Finally, fibrosis is a hallmark of numerous systemic autoimmune diseases such as connective tissue disorders (in particular systemic sclerosis), vasculitides, granulomatoses, histiocytoses, and IgG4-associated disease. Although the process leading to tissue fibrosis may be in part irreversible, new pharmacological approaches or cell therapies bring hope in the field of fibrotic conditions.

Translational Aspects of Nuclear Factor-Kappa B and Its Modulation by Thalidomide on Early and Late Radiation Sequelae in Urinary Bladder Dysfunction

PURPOSE

This preclinical study aimed to investigate the role of nuclear factor (NF)-κB in early and late radiogenic sequelae of urinary bladder dysfunction in mice. Thalidomide was applied either during the early or late response phase to determine potential effects of NF-κB inhibition on functional bladder impairment.

METHODS AND MATERIALS

After pelvic irradiation on day 0, female C3H/Neu mice were observed over a period of 360 days and radiation response was evaluated for alterations in bladder functionality and NF-κB activation. Functionality was determined in graded dose experiments (14-24 Gy) and assessed by micturition frequency analysis and transurethral cystotonometry to reveal alterations in voiding and volume. The induction of the NF-κB proteins p50 and p65 was evaluated by immunohistochemistry in response to a single dose of 23 Gy (ED₉₀). Thalidomide (100 mg/kg/d) was applied intraperitoneally in 3 treatment groups: daily from day 1 to 15, daily from day 16 to 30, and in 2-day-intervals from day 150 to 180.

RESULTS

Immunohistochemical analysis showed a biphasic activation of p50 and p65 during the early radiation cystitis phase (day 1-30). After a transient decrease, p50, but not p65, was reactivated permanently leading to increased levels, which suggests an occurrence of chronic inflammation correlated with functional impairment. Both early thalidomide treatments reduced NF-κB activation and shifted the ED₅₀ value for early radiation cystitis and late radiation sequelae to higher doses.

CONCLUSIONS

These data clearly demonstrate the involvement of NF-κB signaling in the pathogenesis of radiation-induced urinary bladder dysfunction. Additionally, this study emphasizes that biological targeting of early radiogenic processes has enormous effect on chronic symptoms. The late administration of thalidomide showed no significant effect on functionality.

Immediate breast reconstruction with latissimus dorsi flap for patients with local recurrence of breast cancer

BACKGROUND

Ipsilateral breast cancer recurrence (IBTR) occurs in about 7% of patients with primary invasive breast tumor. Salvage mastectomy and breast reconstruction are often discussed and latissimus dorsi (LD) flap is frequently proposed.

METHODS

We retrospectively investigated 111 consecutive locally relapsing patients who underwent salvage mastectomy and immediate LD reconstruction. All included patients with IBTR previously underwent conserving surgery for BC, and received a postoperative irradiation. Primary endpoints were disease free survival and overall survival. Secondary endpoints were surgical complications and re-interventions.

RESULTS

Invasive ductal cancer was the most frequent histotype (60.4%) of breast cancer reappearance. rpT1, rpT2 and rpT3 were observed respectively in 50.5%, 20,7% and 3,6% of the patients. rpTis occurred in 11,7% of cases. Positive axillary nodes were observed in 9,9% of patients at reappearance. Post-operative complication other than seroma occurred in 17,1% of patients, while seroma at the donor site was observed in 61.3% of cases. At 5-year after surgery overall survival was 92% (95% CI: 85%-96%) and disease free survival was 78% (95% CI: 69%-85%).

CONCLUSIONS

Immediate latissimus dorsi flap reconstruction in selected patients with isolated breast tumor recurrence, which occurred after breast irradiation, provides an effective treatment with a satisfactory outcome.

Modelling the risk of radiation induced alopecia in brain tumor patients treated with scanned proton beams

PURPOSE

To develop normal tissue complication probability (NTCP) models for radiation-induced alopecia (RIA) in brain tumor patients treated with proton therapy (PT).

METHODS AND MATERIALS

We analyzed 116 brain tumor adult patients undergoing scanning beam PT (median dose 54 GyRBE; range 36-72) for CTCAE v.4 grade 2 (G2) acute (≤90 days), late (>90 days) and permanent (>12 months) RIA. The relative dose-surface histogram (DSH) of the scalp was extracted and used for Lyman-Kutcher-Burman (LKB) modelling. Moreover, DSH metrics (Sx: the surface receiving ≥ X Gy, D_2%: near maximum dose, D_mean: mean dose) and non-dosimetric variables were included in a multivariable logistic regression NTCP model. Model performances were evaluated by the cross-validated area under the receiver operator curve (ROC-AUC).

RESULTS

Acute, late and permanent G2-RIA was observed in 52%, 35% and 19% of the patients, respectively. The LKB models showed a weak dose-surface effect (0.09 ≤ n ≤ 0.19) with relative steepness 0.29 ≤ m ≤ 0.56, and increasing tolerance dose values when moving from acute and late (22 and 24 GyRBE) to permanent RIA (44 GyRBE). Multivariable modelling selected S_21Gy for acute and S_25Gy, for late G2-RIA as the most predictive DSH factors. Younger age was selected as risk factor for acute G2-RIA while surgery as risk factor for late G2-RIA. D_2% was the only variable selected for permanent G2-RIA. Both LKB and logistic models exhibited high predictive performances (ROC-AUCs range 0.86-0.90).

CONCLUSION

We derived NTCP models to predict G2-RIA after PT, providing a comprehensive modelling framework for acute, late and permanent occurrences that, once externally validated, could be exploited for individualized scalp sparing treatment planning strategies in brain tumor patients.

Radiation-induced intestinal damage: latest molecular and clinical developments

Aim: To systematically review the prophylactic and therapeutic interventions for reducing the incidence or severity of intestinal symptoms among cancer patients receiving radiotherapy. Materials & methods: A literature search was conducted in the PubMed database using various search terms, including 'radiation enteritis', 'radiation enteropathy', 'radiation-induced intestinal disease', 'radiation-induced intestinal damage' and 'radiation mucositis'. The search was limited to in vivo studies, clinical trials and meta-analyses published in English with no limitation on publication date. Other relevant literature was identified based on the reference lists of selected studies. Results: The pathogenesis of acute and chronic radiation-induced intestinal damage as well as the prevention and treatment approaches were reviewed. Conclusion: There is inadequate evidence to strongly support the use of a particular strategy to reduce radiation-induced intestinal damage. More high-quality randomized controlled trials are required for interventions with limited evidence suggestive of potential benefits.

Hypofractionation for clinically localized prostate cancer

BACKGROUND

Using hypofractionation (fewer, larger doses of daily radiation) to treat localized prostate cancer may improve convenience and resource use. For hypofractionation to be feasible, it must be at least as effective for cancer-related outcomes and have comparable toxicity and quality of life outcomes as conventionally fractionated radiation therapy.

OBJECTIVES

To assess the effects of hypofractionated external beam radiation therapy compared to conventionally fractionated external beam radiation therapy for men with clinically localized prostate cancer.

SEARCH METHODS

We searched CENTRAL, MEDLINE (Ovid), Embase (Ovid) and trials registries from 1946 to 15 March 2019 with reference checking, citation searching and contact with study authors. Searches were not limited by language or publication status. We reran all searches within three months (15th March 2019) prior to publication.

SELECTION CRITERIA

Randomized controlled comparisons which included men with clinically localized prostate adenocarcinoma where hypofractionated radiation therapy (external beam radiation therapy) to the prostate using hypofractionation (greater than 2 Gy per fraction) compared with conventionally fractionated radiation therapy to the prostate delivered using standard fractionation (1.8 Gy to 2 Gy per fraction).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology. Two authors independently assessed trial quality and extracted data. We used Review Manager 5 for data analysis and meta-analysis. We used the inverse variance method and random-effects model for data synthesis of time-to-event data with hazard ratios (HR) and 95% confidence intervals (CI) reported. For dichotomous data, we used the Mantel-Haenzel method and random-effects model to present risk ratios (RR) and 95% CI. We used GRADE to assess evidence quality for each outcome.

MAIN RESULTS

We included 10 studies with 8278 men in our analysis comparing hypofractionation with conventional fractionation to treat prostate cancer.Primary outcomesHypofractionation may result in little or no difference in prostate cancer-specific survival [PC-SS] (HR 1.00, 95% CI 0.72 to 1.39; studies = 8, participants = 7946; median follow-up 72 months; low-certainty evidence). For men in the intermediate-risk group undergoing conventional fractionation this corresponds to 976 per 1000 men alive after 6 years and 0 more (44 fewer to 18 more) alive per 1000 men undergoing hypofractionation.We are uncertain about the effect of hypofractionation on late radiation therapy gastrointestinal (GI) toxicity (RR 1.10, 95% CI 0.68 to 1.78; studies = 4, participants = 3843; very low-certainty evidence).Hypofractionation probably results in little or no difference to late radiation therapy genitourinary (GU) toxicity (RR 1.05, 95% CI 0.93 to 1.18; studies = 4, participants = 3843; moderate-certainty evidence). This corresponds to 262 per 1000 late GU radiation therapy toxicity events with conventional fractionation and 13 more (18 fewer to 47 more) per 1000 men when undergoing hypofractionation.Secondary outcomesHypofractionation results in little or no difference in overall survival (HR 0.94, 95% CI 0.83 to 1.07; 10 studies, 8243 participants; high-certainty evidence). For men in the intermediate-risk group undergoing conventional fractionation this corresponds to 869 per 1000 men alive after 6 years and 17 fewer (54 fewer to 17 more) participants alive per 1000 men when undergoing hypofractionation.Hypofractionation may result in little to no difference in metastasis-free survival (HR 1.07, 95% CI 0.65 to 1.76; 5 studies, 4985 participants; low-certainty evidence). This corresponds to 981 men per 1000 men metastasis-free at 6 years when undergoing conventional fractionation and 5 more (58 fewer to 19 more) metastasis-free per 1000 when undergoing hypofractionation.Hypofractionation likely results in a small, possibly unimportant reduction in biochemical recurrence-free survival based on Phoenix criteria (HR 0.88, 95% CI 0.68 to 1.13; studies = 5, participants = 2889; median follow-up 90 months to 108 months; moderate-certainty evidence). In men of the intermediate-risk group, this corresponds to 804 biochemical-recurrence free men per 1000 participants at six years with conventional fractionation and 42 fewer (134 fewer to 37 more) recurrence-free men per 1000 participants with hypofractionationHypofractionation likely results in little to no difference to acute GU radiation therapy toxicity (RR 1.03, 95% CI 0.95 to 1.11; 4 studies, 4174 participants at 12 to 18 weeks' follow-up; moderate-certainty evidence). This corresponds to 360 episodes of toxicity per 1000 participants with conventional fractionation and 11 more (18 fewer to 40 more) per 1000 when undergoing hypofractionation.

AUTHORS' CONCLUSIONS

These findings suggest that moderate hypofractionation (up to a fraction size of 3.4 Gy) results in similar oncologic outcomes in terms of disease-specific, metastasis-free and overall survival. There appears to be little to no increase in both acute and late toxicity.

Gene therapy and cell therapy for the management of radiation damages to healthy tissues: Rationale and early results

Nowadays, ionizing radiations have numerous applications, especially in medicine for diagnosis and therapy. Pharmacological radioprotection aims at increasing detoxification of free radicals. Radiomitigation aims at improving survival and proliferation of damaged cells. Both strategies are essential research area, as non-contained radiation can lead to harmful effects. Some advances allowing the comprehension of normal tissue injury mechanisms, and the discovery of related predictive biomarkers, have led to developing several highly promising radioprotector or radiomitigator drugs. Next to these drugs, a growing interest does exist for biotherapy in this field, including gene therapy and cell therapy through mesenchymal stem cells. In this review article, we provide an overview of the management of radiation damages to healthy tissues via gene or cell therapy in the context of radiotherapy. The early management aims at preventing the occurrence of these damages before exposure or just after exposure. The late management offers promises in the reversion of constituted late damages following irradiation.

Tongue surface model can predict radiation tongue mucositis due to intensity-modulated radiation therapy for head and neck cancer

Acute radiation tongue mucositis has a profound effect on talking and eating. We examined whether the dose-volume histogram obtained from the tongue surface model correlates with mucositis severity, and whether it is useful for predicting acute radiation tongue mucositis in patients with head and neck cancer treated with intensity-modulated radiation therapy. Thirty-six patients who received intensity-modulated radiation therapy for head and neck cancer were analysed for acute radiation tongue mucositis according to the Common Terminology Criteria for Adverse Events, version 4.0, as well as the Radiation Therapy Oncology Group scoring systems. The corresponding high-dose locations in anatomical sub-regions in the tongue surface model and the development of high-grade acute radiation tongue mucositis were compared. The mucositis sites coincided with the high-dose anatomical sub-regions in the tongue surface model. There was a clear dose-response relationship between the mean dose to the tongue and the acute radiation tongue mucositis Radiation Therapy Oncology Group grade. According to the dose-volume histogram, patients receiving 16.0-73.0 Gy to the tongue were susceptible to grade 2-3 toxicity. The tongue surface model can predict the site and severity of acute radiation tongue mucositis. In future, radiation treatment plans ccould be optimized using this model.

Multi-centre technical evaluation of the radiation-induced lymphocyte apoptosis assay as a predictive test for radiotherapy toxicity

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The RILA assay is the leading candidate biomarker for radiotherapy toxicity.

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We describe work to standardise its use across multiple centres.

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Patient factors including smoking and arthritis were found to affect RILA score.

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RILA predicts acute breast pain but not other acute end-points.

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This work establishes the basis for implementing the assay clinically.

Predicting which patients will develop adverse reactions to radiotherapy is important for personalised treatment. Prediction will require an algorithm or nomogram combining clinical and biological data. The radiation-induced lymphocyte apoptosis (RILA) assay is the leading candidate as a biological predictor of radiotherapy toxicity. In this study we tested the potential of the assay for standardisation and use in multiple testing laboratories.

The assay was standardised and reproducibility determined using samples from healthy volunteers assayed concurrently in three laboratories in Leicester (UK), Mannheim (Germany) and Montpellier (France). RILA assays were performed on samples taken prior to radiotherapy from 1319 cancer patients enrolled in the REQUITE project at multiple centres. The patients were being treated for breast (n = 753), prostate (n = 506) or lung (n = 60) cancer.

Inter-laboratory comparisons identified several factors affecting results: storage time, incubation periods and type of foetal calf serum. Following standardisation, there was no significant difference in results between the centres. Significant differences were seen in RILA scores between cancer types (prostate > breast > lung), by smoking status (non-smokers > smokers) and co-morbidity with rheumatoid arthritis (arthritics > non-arthritics).

An analysis of acute radiotherapy toxicity showed as expected that RILA assay does not predict most end-points, but unexpectedly did predict acute breast pain. This result may elucidate the mechanism by which the RILA assay predicts late radiotherapy toxicity.

The work shows clinical trials involving multiple laboratory measurement of the RILA assay are feasible and the need to account for tumour type and other variables when applying to predictive models.

Potential skin morbidity reduction with intensity-modulated proton therapy for breast cancer with nodal involvement

Background: Different modern radiation therapy treatment solutions for breast cancer (BC) and regional nodal irradiation (RNI) have been proposed. In this study, we evaluate the potential reduction in radiation-induced skin morbidity obtained by intensity modulated proton therapy (IMPT) compared with intensity modulated photon therapy (IMXT) for left-side BC and RNI. Material and Methods: Using CT scans from 10 left-side BC patients, treatment plans were generated using IMXT and IMPT techniques. A dose of 50 Gy (or Gy [RBE] for IMPT) was prescribed to the target volume (involved breast, the internal mammary, supraclavicular, and infraclavicular nodes). Two single filed optimization IMPT (IMPT₁ and IMPT₂) plans were calculated without and with skin optimization. For each technique, skin dose-metrics were extracted and normal tissue complication probability (NTCP) models from the literature were employed to estimate the risk of radiation-induced skin morbidity. NTCPs for relevant organs-at-risk (OARs) were also considered for reference. The non-parametric Anova (Friedman matched-pairs signed-rank test) was used for comparative analyses. Results: IMPT improved target coverage and dose homogeneity even if the skin was included into optimization strategy (HI_IMPT2 = 0.11 vs. HI_IMXT = 0.22 and CI_IMPT2 = 0.96 vs. CI_IMXT = 0.82, p < .05). A significant relative skin risk reduction (RR = NTCP_IMPT/NTCP_IMXT) was obtained with IMPT₂ including the skin in the optimization with a RR reduction ranging from 0.3 to 0.9 depending on the analyzed skin toxicity endpoint/model. Both IMPT plans attained significant OARs dose sparing compared with IMXT. As expected, the heart and lung doses were significantly reduced using IMPT. Accordingly, IMPT always provided lower NTCP values. Conclusions: IMPT guarantees optimal target coverage, OARs sparing, and simultaneously minimizes the risk of skin morbidity. The applied model-based approach supports the potential clinical relevance of IMPT for left-side BC and RNI and might be relevant for the setup of cost-effectiveness evaluation strategies based on NTCP predictions, as well as for establishing patient selection criteria.