Anti-biofilm mechanisms of action of essential oils by targeting genes involved in quorum sensing, motility, adhesion, and virulence: A review.

Biofilms are a critical factor for food safety, causing important economic losses. Among the novel strategies for controlling biofilms, essential oils (EOs) can represent an environmentally friendly approach, able to act both on early and mature stages of biofilm formation. This review reports the anti-biofilm mechanisms of action of EOs against five pathogenic bacterial species known for their biofilm-forming ability. These mechanisms include disturbing the expression of genes related to quorum sensing (QS), motility, adhesion, and virulence. Biofilms and QS are interconnected processes, and EOs interfere with the communication system (e.g. regulating the expression of agrBDCA, luxR, luxS, and pqsA genes), thus influencing biofilm formation. In addition, QS is an important mechanism that regulates gene expression related to bacterial survival, virulence, and pathogenicity. Similarly, EOs also influence the expression of many virulence genes. Moreover, EOs exert their effects modulating the genes associated with bacterial adhesion and motility, for example those involved in curli (csg), fimbriae (fim, lpf), and flagella (fla, fli, flh, and mot) production, as well as the ica genes responsible for synthetizing polysaccharide intercellular adhesin. This review provides a comprehensive framework on the topic for a better understanding of EOs biofilm mechanisms of action.

Laser-induced 2D/0D graphene-nanoceria freestanding paper-based films for on-site hydrogen peroxide monitoring in no-touch disinfection treatments.

A one-shot CO2 laser-based strategy to generate conductive reduced graphene oxide (rGO) decorated with nanoceria (nCe) is proposed. The 2D/0D rGO-nCe films, integrated as catalytic sensing layers in paper-based sensors, were employed for on-site monitoring of indoor fogging treatments against Listeria monocytogenes (Lm), a ubiquitous pathogenic bacterium. The rGO-nCe laser-assisted synthesis was optimized to preserve the rGO film morphological and electron-transfer features and simultaneously integrate catalytic nCe. The films were characterized by microscopical (SEM), spectroscopical (EDX, Raman, and FTIR), and electrochemical techniques. The most performing film was integrated into a nitrocellulose substrate, and the complete sensor was assembled via a combination of xurography and stencil printing. The rGO-nCe sensor's catalytic activity was proved toward the detection of H2O2, obtaining sensitive determination (LOD = 0.3 µM) and an extended linear range (0.5-1500 µM). Eventually, the rGO-nCe sensor was challenged for the real-time continuous monitoring of hydrogen peroxide aerosol during no-touch fogging treatment conducted following the EU's recommendation for biocidal product use. Treatment effectiveness was proved toward three Lm strains characterized by different origins, i.e., type strain ATCC 7644, clinical strain 338, and food strain 641/6II. The sensor allows for discrimination and quantification treatments at different environmental biocidal amounts and fogging times, and correlates with the microbiological inhibition, promoting the proposed sensor as a useful tool to modulate and monitor no-touch treatments.

Antilisterial Effectiveness of Origanum vulgare var. hirtum and Coridothymus capitatus Essential Oils and Hydrolates Alone and in Combination.

The antimicrobial activity of Origanum vulgare var. hirtum (O) and Coridothymus capitatus (C) essential oils (EOs) and hydrolates (HYs) of the same botanical species was evaluated on sixteen L. monocytogenes strains from food and clinical origins. The antimicrobial activity was assessed by Minimum Inhibitory Concentration (MIC) determination, viable cell enumeration over time up to 60 min, and evaluation of the cellular damage through Confocal Laser Scanning Microscope (CLSM) analysis. EOs exhibited antimicrobial activity with MIC values ranging from 0.3125 to 10 µL/mL. In contrast, HYs demonstrated antimicrobial effectiveness at higher concentrations (125-500 µL/mL). The effect of HYs was rapid after the contact with the cells, and the cell count reduction over 60 min of HY treatment was about 1.2-1.7 Log CFU/mL. L. monocytogenes cells were stressed by HY treatment, and red cell aggregates were revealed through CLSM observation. Moreover, the combinations of EOs and HYs had an additive antilisterial effect in most cases and allowed the concentration of use to be reduced, while maintaining or improving the antimicrobial effectiveness. The combined use of EOs and HYs can offer novel opportunities for applications, thereby enhancing the antimicrobial effectiveness and diminishing the concentration of use. This provides the added benefit of reducing toxicity and mitigating any undesirable sensory effects.

Detection and Control of Foodborne Pathogens.

The globalization of food trade and the emergence of disease outbreaks involving several foodborne pathogens and foods has focused the attention of both the research community and consumers on food safety [...].

Effectiveness of essential oils against dual-species biofilm of Listeria monocytogenes and Pseudomonas fluorescens in a Ricotta-based model system.

Biofilms represent an evolutionary form of life, which translates from life in free-living cells to a community lifestyle. In natural habitats, biofilms are a multispecies complex, where synergies or antagonisms can be established. For example, Listeria monocytogenes and Pseudomonas fluorescens are associated with a dual-species biofilm that is widespread in dairy plants. In food plants, multiple strategies are devised to control biofilms, including natural compounds such as essential oils (EOs). In this respect, this study evaluated the effectiveness of Thymbra capitata (L.) Cav. (TEO) and Cinnamomum zeylanicum (CEO) against a dual-species biofilm of L. monocytogenes and P. fluorescens, mimicking dairy process conditions. Based on Minimum Inhibitory Concentrations results, the EOs concentration (10 µL/mL) was chosen for the antibiofilm assay at 12°C on polystyrene (PS), and stainless-steel surfaces for 168 h, using a Ricotta-based model system as culture medium. Biofilm biomass was assessed by crystal violet staining, and the planktonic and sessile cells were quantified in terms of Log CFU/cm2. Results showed that CEO displayed the greatest antibiofilm activity, reducing significantly (P<0.05) P. fluorescens and L. monocytogenes sessile cells of about 2.5 and 2.8 Log CFU/cm2 after 72 h, respectively. However, L. monocytogenes gained the protection of P. fluorescens, evading CEO treatment and showing a minimal sessile cell reduction of 0.7 Log CFU/cm2 after 72 h. Considering the outcome of this study, CEO might have promising perspectives for applications in dairy facilities.

Chemical Characterization and Antimicrobial Properties of the Hydroalcoholic Solution of Echinacea purpurea (L.) Moench. and Propolis from Northern Italy.

In this study, for the first time, the chemical composition of Echinacea purpurea (L.) Moench. and propolis (EAP) hydroalcoholic solution from the Trentino Alto Adige region of northern Italy was investigated by using SPME-GC-MS to describe the volatile content and GC-MS after silylation to detect the non-volatile compounds in the extractable organic matter. The antimicrobial activity of EAP hydroalcoholic solution was evaluated by Minimum Inhibitory Concentration (MIC) determination on 13 type strains, food and clinical isolates. Time Kill Kinetics (TKK) assays and the determination on swimming and swarming motility for 48 h gave more details on the mode of action of EAP solution. The results highlighted the presence of some terpenes and a large number of compounds belonging to different chemical classes. Among these, sugars and organic acids excelled. The EAP hydroalcoholic solution exhibited a strong antimicrobial activity in terms of MIC, with a clear decrease in the cellular load after 48 h. However, the bacterial motility may not be affected by the EAP treatment, displaying a dynamic swarming and swimming motility capacity over time. Given the complexity of chemical profile and the strong antimicrobial effectiveness, the EAP hydroalcoholic solution can be considered a source of bioactive molecules, deserving further investigation for the versatility of application.

Unraveling the Antimicrobial Effectiveness of Coridothymus capitatus Hydrolate against Listeria monocytogenes in Environmental Conditions Encountered in Foods: An In Vitro Study.

The increased resistance of bacteria to antimicrobials, as well as the growing interest in innovative and sustainable alternatives to traditional food additives, are driving research towards the use of natural food preservatives. Among these, hydrolates (HYs) have gained attention as "mild" alternatives to conventional antimicrobial compounds. In this study, the response of L. monocytogenes ATCC 7644 exposed to increasing concentrations of Coridothymus capitatus HY (CHY) for 1 h at 37 °C was evaluated by means of Phenotype Microarray, modelling the kinetic data obtained by inoculating control and treated cells into GEN III microplates, after CHY removal. The results revealed differences concerning the growth dynamics in environmental conditions commonly encountered in food processing environments (different carbon sources, pH 6.0, pH 5.0, 1-8% NaCl). More specifically, for treated cells, the lag phase was extended, the growth rate was slowed down and, in most cases, the maximum concentration was diminished, suggesting the persistence of stress even after CHY removal. Confocal Laser Scanner Microscopy evidenced a diffuse aggregation and suffering of the treated cells, as a response to the stress encountered. In conclusion, the treatment with HY caused a stressing effect that persisted after its removal. The results suggest the potential of CHY application to control L. monocytogenes in food environments.

Advances in understanding the enzymatic potential and production of ochratoxin A of filamentous fungi isolated from cocoa fermented beans.

In this work, we determined the degree of filamentous fungi contamination in cocoa fermented seeds and the fungal potential to produce enzymes that could contribute to the cocoa quality. Internal transcribed spacer amplicon sequencing (ITS) showed 11 different species with Byssochlamys spectabilis, Aspergillus niger, Aspergillus flavus, Aspergillus carbonarius, Circinella muscae and Penicillium citrinum as the most abundant species. Our results evidenced intra and inter-species differences in the enzymes production. Cellulases, ß-glucosidase, ornithine decarboxylase and phenylalanine decarboxylase were the most diffused enzymes expressed in the 53 strains here studied. Moreover, A. niger (6/12), A. carbonarius (2/3), and P. citrinum (3/3) showed high pectinolytic activity. Remarkable was the amino decarboxylase activity of P. citrinum, and A. flavus strains. For the first time we reported the presence of B. spectabilis in cocoa fermented beans, which could play an important role in the biogenic amines formation. In addition, we explored the capability of the Aspergillus section Nigri strains, to produce ochratoxin A (OTA) in a cacao model system (CPMS) and in malt extract medium (MEL). We observed that CPMS, but not MEL, stimulated the OTA production in 6 out 15 strains of Aspergillus section Nigri, reaching values ranging between 1.70 and 4995 µg OTA kg-1 dry mycelium.

Effectiveness and mechanisms of essential oils for biofilm control on food-contact surfaces: An updated review.

Microbial biofilms represent a constant source of contamination in the food industry, being also a real threat for human health. In fact, most of biofilm-producing bacteria are becoming resistant to sanitizers, thus arousing the interest in natural alternatives to prevent biofilm formation on foods and food-contact surfaces. In particular, studies on biofilm control by essential oils (EOs) application are increasing, being EOs characterized by unique mixtures of compounds able to impair the mechanisms of biofilm development. This review reports the anti-biofilm properties of EOs in bacterial biofilm control (inhibition, removal and prevention of biofilm dispersion) on food-contact surfaces. The relationship between EOs effect and composition, concentration, involved bacteria, and surfaces is discussed, and the possible sites of action are also elucidated. The findings prove the high biofilm controlling capability of EOs through the regulation of genes and proteins implicated in motility, Quorum Sensing and exopolysaccharides (EPS) matrix. Moreover, incorporation in nanosized delivery systems, formulation of blends and combination of EOs with other strategies can increase their anti-biofilm activity. This review provides an overview of the current knowledge of the EOs effectiveness in controlling bacterial biofilm on food-contact surfaces, providing valuable information for improving EOs use as sanitizers in food industries.

Topical natural-origin polynucleotides in radiation-induced skin and mucosal toxicity.

Seventy to 90 percent of patients who have received radiation treatment struggle with radiation skin and mucosal toxicity. The inflicted damage to progenitor cells and local microcirculation makes it more likely that wounds, infections, and fibrosis may occur; lesions of variable severity often co-exist. Acute erythema, hyperpigmentation, and mild desquamation usually wane in weeks and require only minor treatment. Conversely, the management of persistent radiation dermatitis and telangiectasia remains unsatisfactory; chronic lesions may progress to tissue atrophy and disfiguring fibrosis.

Effectiveness of selected essential oils and one hydrolate to prevent and remove Listeria monocytogenes biofilms on polystyrene and stainless steel food-contact surfaces.

AIMS: This study aimed to evaluate the effectiveness of selected essential oils (EOs) and hydrolates (Hs) against Listeria monocytogenes biofilms on polystyrene (PS) and stainless steel (SS) surfaces. METHODS AND RESULTS: Among others, Origanum hirtum EO, Corydothymus capitatus EO and Citrus aurantium H were selected to treat L. monocytogenes biofilms during and after biofilm formation. Sub-minimum inhibitory concentrations (MICs) of C. capitatus EO (0.31 µl/ml) showed the highest inhibiting effect against biofilm formation on PS, while on SS no significant differences between the EOs were observed (43.7%-88.7% inhibition). Overall, the tested biosanitizers showed limited activity as biofilm removal agents. Although generally less effective, C. aurantium H exhibited good biofilm inhibition performance at 62.5 µl/ml, particularly on PS. Confocal laser scanning microscopy proved that sub-MICs of the biosanitizers drastically changed L. monocytogenes biofilm architecture, with bacterial cells elongation in the presence of C. capitatus EO. CONCLUSIONS: Our findings suggest that the tested EOs and H are able to control Listeria biofilms, particularly preventing biofilm formation on both materials. Considering its mild aroma and hydrophilicity, the H exhibited promising perspectives of application. SIGNIFICANCE AND IMPACT OF STUDY: This study raises the possibility of applying EOs and Hs to control biofilms on different surfaces in the food industry.

Effect of the Distillation Time on the Chemical Composition, Antioxidant Potential and Antimicrobial Activity of Essential Oils from Different Cannabis sativa L. Cultivars.

Within the unavoidable variability of various origins in the characteristics of essential oils, the aim of this study was to evaluate the effect of the distillation time on the chemical composition and biological activity of Cannabis sativa essential oils (EOs). The dry inflorescences came from Carmagnola, Kompolti, Futura 75, Gran Sasso Kush and Carmagnola Lemon varieties from Abruzzo region (Central Italy), the last two being new cultivar here described for the first time. EOs were collected at 2 h and 4 h of distillation; GC/MS technique was applied to characterize their volatile fraction. The EOs were evaluated for total polyphenol content (TPC), antioxidant capacity (AOC) and antimicrobial activity against food-borne pathogens and spoilage bacteria. The time of distillation particularly influenced EOs chemical composition, extracting more or less terpenic components, but generally enriching with minor sesquiterpenes and cannabidiol. A logical response in ratio of time was observed for antioxidant potential, being the essential oils at 4 h of distillation more active than those distilled for 2 h, and particularly Futura 75. Conversely, except for Futura 75, the effect of time on the antimicrobial activity was variable and requires further investigations; nevertheless, the inhibitory activity of all EOs against Pseudomonas fluorescens P34 was an interesting result.

Genetic relationships and biofilm formation of Listeria monocytogenes isolated from the smoked salmon industry.

Among pathogens, L. monocytogenes has the capability to persist on Food Processing Environment (FPE), first of all posing safety issues, then economic impact on productivity. The aim of this work was to determine the influence of biofilm forming-ability and molecular features on the persistence of 19 Listeria monocytogenes isolates obtained from FPE, raw and processed products of a cold-smoked salmon processing plant. To verify the phenotypic and genomic correlations among the isolates, different analyses were employed: serotyping, Clonal Complex (CC), core genome Multi-Locus Sequence Typing (cgMLST) and Single Nucleotide Polymorphisms (SNPs) clustering, and evaluation of the presence of virulence- and persistence-associated genes. From our results, the biofilm formation was significantly higher (*P < 0.05) at 37 °C, compared to 30 and 12 °C, suggesting a temperature-dependent behaviour. Moreover, the biofilm-forming ability showed a strain-specific trend, not correlated with CC or with strains persistence. Instead, the presence of internalin (inL), Stress Survival Islet (SSI) and resistance to erythromycin (ermC) genes was correlated with the ability to produce biofilms. Our data demonstrate that the genetic profile influences the adhesion capacity and persistence of L. monocytogenes in food processing plants and could be the result of environmental adaptation in response to the external selective pressure.

Colombian Essential Oil of Ruta graveolens against Nosocomial Antifungal Resistant Candida Strains.

Drug resistance in antifungal therapy, a problem unknown until a few years ago, is increasingly assuming importance especially in immunosuppressed patients and patients receiving chemotherapy and radiotherapy. In the past years, the use of essential oils as an approach to improve the effectiveness of antifungal agents and to reduce antifungal resistance levels has been proposed. Our research aimed to evaluate the antifungal activity of Colombian rue, Ruta graveolens, essential oil (REO) against clinical strains of Candida albicans, Candida parapsilopsis, Candida glabrata, and Candida tropicalis. Data obtained showed that C. tropicalis and C. albicans were the most sensitive strains showing minimum inhibitory concentrations (MIC) of 4.1 and 8.2 µg/mL of REO. Time-kill kinetics assay demonstrated that REO showed a fungicidal effect against C. tropicalis and a fungistatic effect against C. albicans. In addition, an amount of 40% of the biofilm formed by C. albicans was eradicated using 8.2 µg/mL of REO after 1 h of exposure. The synergistic effect of REO together with some antifungal compounds was also investigated. Fractional inhibitory concentration index (FICI) showed synergic effects of REO combined with amphotericin B. REO Lead a disruption in the cellular membrane integrity, consequently resulting in increased intracellular leakage of the macromolecules, thus confirming that the plasma membrane is a target of the mode of action of REO against C. albicans and C. tropicalis.

Interactions between L. monocytogenes and P. fluorescens in Dual-Species Biofilms under Simulated Dairy Processing Conditions.

In dairy processing environments, many bacterial species adhere and form biofilms on surfaces and equipment, leading to foodborne illness and food spoilage. Among them, Listeria monocytogenes and Pseudomonas spp. could be present in mixed-species biofilms. This study aimed to evaluate the interactions between L. monocytogenes and P. fluorescens in biofilms simulating dairy processing conditions, as well as the capability of P. fluorescens in co-culture to produce the blue pigment in a Ricotta-based model system. The biofilm-forming capability of single- and mixed-cultures was evaluated on polystyrene (PS) and stainless steel (SS) surfaces at 12 °C for 168 h. The biofilm biomass was measured, the planktonic and sessile cells and the carbohydrates in biofilms were quantified. The biofilms were also observed through Confocal Laser Scanning Microscopy analysis. Results showed that only P. fluorescens was able to form biofilms on PS. Moreover, in dual-species biofilms at the end of the incubation time (168 h at 12 °C), a lower biomass compared to P. fluorescens mono-species was observed on PS. On SS, the biofilm cell population of L. monocytogenes was higher in the dual-species than in mono-species, particularly after 48 h. Carbohydrates quantity in the dual-species system was higher than in mono-species and was revealed also at 168 h. The production of blue pigment by P. fluorescens was revealed both in single- and co-culture after 72 h of incubation (12 °C). This work highlights the interactions between the two species, under the experimental conditions studied in the present research, which can influence biofilm formation (biomass and sessile cells) but not the capability of P. fluorescens to produce blue pigment.

Overcoming Multidrug Resistance in Salmonella spp. Isolates Obtained From the Swine Food Chain by Using Essential Oils: An in vitro Study.

Antimicrobial resistance (AMR) is a global concern, and new approaches are needed to circumvent animal and food-borne resistant pathogens. Among the new strategies, the combination of antibiotics with natural compounds such as essential oils (EOs) could be an alternative to challenge bacterial resistance. The present study evaluates the phenotypic and genotypic antibiotic resistance of 36 Salmonella enterica (16 S. Typhimurium, 3 monophasic variant S. Typhimurium, 8 S. Enteritidis, 6 S. Rissen, 1 S. Typhi, and 2 S. Derby) strains, isolated from the swine production chain. The isolates displayed phenotypic resistance to gentamicin, amikacin, tobramycin, and tetracycline, while the resistance genes most commonly detected were parC, catA, nfsB, nfsA, blaTEM, tetA, and tetB. Then 31/36 Salmonella isolates were chosen to evaluate resistance to tetracycline and Thymus vulgaris, Eugenia caryophyllata, and Corydothymus capitatus EOs by determining minimum inhibitory concentrations (MICs). Finally, the synergistic effect between tetracycline and each EOs was evaluated by the checkerboard method, calculating the fractional inhibitory concentration (FIC) index. Among the EOs, C. capitatus displayed the best bioactivity in terms of MICs, with the lowest values (0.31 and 0.625 µl/ml). On the contrary, the strains showed the ability to grow in the presence of the maximum concentration of tetracycline employed (256 µg/ml). While not displaying a real synergism according to the FIC index, the combination of tetracycline compounds and the three EOs resulted in a significant reduction in the MIC values to tetracycline (4 µg/ml), suggesting a restoration of the susceptibility to the antibiotic in Salmonella spp.

Casing Contribution to Proteolytic Changes and Biogenic Amines Content in the Production of an Artisanal Naturally Fermented Dry Sausage.

The effect of two kinds of casings on the production and characteristics of a dry fermented sausage was investigated. In detail, an Italian product, naturally fermented at low temperatures and normally wrapped in beef casing instead of the most diffused hog one, was selected. Two different productions (one traditionally in beef casing (MCB) and another in hog casing (MCH)) were investigated over time to determine the differences particularly regarding proteolytic changes during fermentation and ripening. First of all, the product in hog casing required a longer ripening time, up to 120 days, instead of 45-50 days, because of the lower drying rate, while the microbial dynamics were not significantly modified. Conversely, the proteolysis showed a different evolution, being more pronounced, together with the biogenic amines content up to 341 mg/Kg instead of 265 mg/Kg for the traditional products. The latter products were instead characterized by higher quantities of total free amino acids, 3-methyl butanoic acid, 3-Methyl-1-butanal, and 2-Methylpropanal, enriching the final taste and aroma. The traditional product MCB also showed lower hardness and chewiness than MCH. The results highlight how the choice of casing has a relevant impact on the development of the final characteristics of fermented sausages.

Randomized controlled trial of a water-soluble nail lacquer based on hydroxypropyl-chitosan (HPCH), in the management of nail psoriasis.

BACKGROUND: Nail psoriasis occurs in up to 50% of patients affected by psoriasis, with a significant impact on quality of life that leads to a real clinical need for new therapeutic options. AIM: To confirm whether the strengthening and hardening properties of the hydroxypropyl-chitosan (HPCH) nail lacquer could improve the structure of the nail plates on psoriatic nails. MATERIALS AND METHODS: A randomized, double-blind, placebo controlled, parallel-group trial was carried out to evaluate the efficacy and tolerability of a hydrosoluble nail lacquer containing HPCH, Equisetum arvense, and methylsulfonylmethane on nail psoriasis. The test product or a placebo was applied once daily for 24 weeks to all fingernails. Efficacy assessments were performed on the target fingernail by means of the modified Nail Psoriasis Severity Index score. A cut-off score of 4 was considered to define the clinical cure rate (ie, Cure ≤4, Failure >4). RESULTS: After 24 weeks, the clinical cure rate showed the statistically significant superiority of the HPCH nail lacquer compared to placebo in both the intention-to-treat (Fisher's exact test, P=0.0445) and the per protocol population (Fisher's exact test, P=0.0437). This superiority was already present after 16 weeks of treatment. Moreover, the analysis of the modified Nail Psoriasis Severity Index-50 showed a statistically significant clinical improvement after 12 weeks of treatment in comparison to the results obtained after 8 weeks (Fisher's exact test, P<0.05). CONCLUSION: The trial showed that HPCH nail lacquer could be a new, valid, effective, and safe option for decreasing the signs of nail dystrophy in psoriatic patients.

Predictive factors for oropharyngeal mycosis during radiochemotherapy for head and neck carcinoma and consequences on treatment duration. Results of mycosis in radiotherapy (MIR): a prospective longitudinal study.

BACKGROUND AND PURPOSE: Oropharyngeal mycosis (OPM) is a complication of radiotherapy (RT) treatments for head and neck (H&N) cancer, worsening mucositis and dysphagia, causing treatment interruptions and increasing overall treatment time. Prophylaxis with antifungals is expensive. Better patient selection through the analysis of prognostic factors should improve treatment efficacy and reduce costs. MATERIALS AND METHODS: A multicentre, prospective, controlled longitudinal study, with ethics committee approval, examined H&N cancer patients who were candidates for curative treatments with radio-chemotherapy. Patients were divided in groups according to OPM appearance: before the starting of RT (cases), during RT (new cases) and never (no cases). RESULTS: Of 410 evaluable patients, 20 were existing cases, 201 new cases and 189 did not report OPM. In our study OPM appears in 42.4% of people >70years and in 58.2% of younger individuals (p=0.0042), and in 68.6% of women versus 50.8% of men (p=0.0069). Mucositis and dysphagia were higher and salivation reduced among people with OPM (p<0.0000). Patients with OPM had longer hospitalization (p=0.0002) and longer (>12days) treatment interruptions (p=0.0288). CONCLUSIONS: Patients with OPM had higher toxicity and a greater number of long treatment interruptions. Analyses of prognostic factors can help clinicians understand OPM distribution and select patients with the highest probability of OPM for antifungal prophylaxis.

Weekly concomitant boost in adjuvant radiotherapy for patients with early breast cancer: preliminary results on feasibility.

AIMS AND BACKGROUND: Recent advances in the management of patients with breast cancer are focused toward the reduction of overall treatment time of radiotherapy by delivering a dose biologically equivalent to a standard schedule. The aim of the present study was to evaluate the feasibility and preliminary toxicity of a moderately hypofractionated whole breast irradiation schedule with the addition of a concomitant boost delivered to the tumor bed once-a-week in patients with early breast cancer submitted to conservative surgery. MATERIALS: We selected patients with pT1c and pT2 N0/N+ M0 carcinoma of the breast with negative surgical margins. The basic course consisted of 4600 cGy prescribed to the ICRU 50 reference point dose and delivered in 20 fractions, 4 times a week for 5 weeks. Once a week, immediately after whole breast irradiation, a concomitant photon boost of 120 cGy was delivered to the lumpectomy area. Overall, according to the linear-quadratic model, the schedule provides a biologically equivalent dose of 87 Gy for breast tumor (assuming alpha/beta = 4 Gy), of 66 Gy for acute responding normal tissues (assuming alpha/beta = 10 Gy), and 99 Gy for late responding normal tissues (assuming alpha/beta = 3 Gy). Biologically, the schedule compares favorably with the 6-week conventional regimen consisting of 50 Gy, 2 Gy/fraction, followed by a 10 Gy boost (BED(tumor), 90 Gy; BED(acute effects), 72 Gy, and BED(late effects), 100 Gy). RESULTS: From November 2004 to April 2007, we tested this radiotherapy schedule in 176 patients. All enrolled patients had achieved a minimum follow-up of 6 months and were considered in detail for the evaluation of feasibility. Three clinical examinations were performed by a group of independent physicians at treatment end, after 1 month and after 6 months. According to the RTOG/EORTC Toxicity Criteria, of the 176 assessable patients at the end of radiotherapy, 58% showed grade 0-1 skin toxicity, 30% grade 2 and 12% grade 3. At one month of follow-up, grade 0 toxicity was observed in 47% of cases, grade 1 in 46% and grade 2 in 7%. At 6 months, late (skin and subcutaneous tissue) toxicity was assessed with the following scores: grade 0 in 68%, grade 1 in 26% and grade 2 in 6% of the patients. At 6 months, cosmesis was excellent, good and fair in 71%, 24% and 5% of patients, respectively. CONCLUSIONS: The explored adjuvant schedule planned to intensify the radiotherapy course for patients with early breast cancer by adding a weekly concomitant boost appears to be feasible and provides low local toxicity and excellent to good short-term cosmetic results.