Computational Model Based on Optical Coherence Tomography (OCT) Skin Scanning to Identify and Quantify Acute Radiation Dermatitis (ARD): A Prospective Diagnostic Study

BACKGROUND

Acute radiation dermatitis (ARD) is the most widely reported radiotherapy-induced adverse event. Currently, there is no objective or reliable method to measure ARD.

OBJECTIVE

Our main objective was to identify and quantify the effects of radiotherapy with a computational model using optical coherence tomography (OCT) skin scanning. Secondary objectives included determining the ARD impact of different radiotherapeutic schemes and adjuvant topical therapies.

METHODS

We conducted a prospective, single-center case series study in a tertiary referral center of patients with breast cancer who were eligible for whole breast radiotherapy (WBRT).

RESULTS

A total of 39 women were included and distributed according to the radiotherapeutic schemes (15, 20, and 25 fractions). A computational model was designed to quantitatively analyze OCT findings. After radiotherapy, OCT scanning was more sensitive revealing vascularization changes in 84.6% of the patients (vs 69.2% of the patients with ARD by clinical examination). OCT quantified an increased vascularization at the end of WBRT (P<.05) and a decrease after 3 months (P=.032). Erythematous skin changes by OCT were more pronounced in the 25-fraction regime.

CONCLUSION

An OCT computational model allowed for the identification and quantification of vascularization changes on irradiated skin, even in the absence of clinical ARD. This may allow the design of standardized protocols for ARD beyond the skin color of the patients involved.

A novel approach to predict acute radiation dermatitis in patients with head and neck cancer using a model based on Bayesian probability

PURPOSE

In this study, we aimed to establish a method for predicting the probability of each acute radiation dermatitis (ARD) grade during the head and neck Volumetric Modulated Arc Therapy (VMAT) radiotherapy planning phase based on Bayesian probability.

METHODS

The skin dose volume >50 Gy (V50), calculated using the treatment planning system, was used as a factor related to skin toxicity. The empirical distribution of each ARD grade relative to V50 was obtained from the ARD grades of 119 patients (55, 50, and 14 patients with G1, G2, and G3, respectively) determined by head and neck cancer specialists. Using Bayes' theorem, the Bayesian probabilities of G1, G2, and G3 for each value of V50 were calculated with an empirical distribution. Conversely, V50 was obtained based on the Bayesian probabilities of G1, G2, and G3.

RESULTS

The empirical distribution for each graded patient group demonstrated a normal distribution. The method predicted ARD grades with 92.4 % accuracy and provided a V50 value for each grade. For example, using the graph, we could predict that V50 should be ≤24.5 cm3 to achieve G1 with 70 % probability.

CONCLUSIONS

The Bayesian probability-based ARD prediction method could predict the ARD grade at the treatment planning stage using limited patient diagnostic data that demonstrated a normal distribution. If the probability of an ARD grade is high, skin care can be initiated in advance. Furthermore, the V50 value during treatment planning can provide radiation oncologists with data for strategies to reduce ARD.

A novel, multi-active emollient for the prevention of acute radiation dermatitis in breast cancer patients: a randomized clinical trial

PURPOSE

To investigate the efficacy of a novel, multi-active emollient in preventing and managing acute radiation dermatitis (ARD) in breast cancer patients undergoing moderate hypofractionated (HF) radiotherapy (RT) compared to standard of care.

METHODSA

A monocentric, open-label, randomized clinical trial (RCT) with breast cancer patients receiving moderate HF (dose: 40.05-55.86 Gy, fractions: 15-21) was conducted between January 2022 and May 2023. The experimental group received the novel emollient, while the control group received the standard skin care. Patients applied the skin care products twice daily during the complete RT course. The primary outcome was the severity of ARD at the final RT session measured by the modified Radiation Therapy Oncology Group (RTOG) criteria. Secondary outcomes included patient symptoms, quality of life (QoL), and treatment satisfaction.

RESULTS

A total of 100 patients with 50 patients per group were enrolled. In the control group, 50% of the patients developed RTOG grade 1 ARD and 48% grade 2 or higher, while in the experimental group, the severity of ARD was significantly lower with 82% grade 1 and 16% grade 2 ARD (P = .013, χ2-test). The frequency and severity of xerosis were significantly lower in the experimental compared to the control group (Ps ≤ .036, Mann Whiney U test). The impact of ARD on the QoL was low, and treatment satisfaction was high in both groups, with no significant difference.

CONCLUSION

This RCT shows that the novel, multi-active emollient significantly reduced the ARD RTOG grade. Research in a more diverse patient population is warranted.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04929808 (11/06/2021).

Barrier films for the prevention of acute radiation dermatitis in breast cancer: A systematic review and meta-analysis of randomised controlled trials

PURPOSE

Radiation dermatitis (RD) is the most common side effect of adjuvant whole-breast or chest wall irradiation, majorly impacting quality of life in numerous patients. The use of barrier films (polyurethane dressings such as Hydrofilm® and Mepitel® film remaining on the skin for the duration of the radiation treatment) has been investigated as a prophylactic measure in several prospective trials. Here, we critically appraise the available evidence behind preventive barrier film application in the context of breast cancer treatment.

METHODS

International literature was reviewed and high-quality randomised controlled trials (RCTs) were included in this meta-analysis.

RESULTS

The results of 5 RCTs (663 patients; >90% Caucasian) were analysed. Overall, barrier films lead to improved clinician- and patient-reported outcomes: fewer grade ≥2 RD (11% vs. 42%; OR = 0.16; p < 0.001) and moist desquamation (2% vs. 16%; OR = 0.12; p = 0.006), as well as less patient-reported pain (standardised mean difference [SMD] -0.51; p < 0.001), itching (SMD -0.52; p = 0.001), burning (SMD -0.41; p = 0.011), and limitations in daily activities (SMD -0.20; p = 0.007). Furthermore, barrier films have a high acceptance rate among patients, as well as a favourable cost-benefit ratio. Possible side effects due to its application are mild and mostly self-limiting. Overall, there was a lack of information on the radiation treatment techniques used.

CONCLUSION

The evidence presented in this meta-analysis suggests that barrier films are an excellent tool in the prevention of RD among Caucasian patients receiving whole-breast or chest wall irradiation. Its use should therefore be considered routinely in these patients.

Shedding light on the management of acute radiation dermatitis: insight from the MASCC Oncodermatology study group

This paper highlights a collection of eleven recently published manuscripts on the prevention and management of acute radiation dermatitis. These meta-analyses provide additional evidence for the updated clinical practice guidelines by the Multinational Association of Supportive Care in Cancer (MASCC) Oncodermatology study group for prevention and management of acute radiation dermatitis. The collection of papers elucidate the currently available evidence on acute radiation dermatitis, highlighting consolidated knowledge, effective treatments, and proposed areas for future clinical trials. Overall, a total of 51 randomized controlled trials were retrieved and included for quantitative analysis of an initial systematic review of literature from 1946 to January 2023. Discussion of the clinical impact of various therapeutic interventions include: antiperspirant and deodorant use, barrier films and dressings, natural and miscellaneous agents, photobiomodulation therapy, topical corticosteroids, topical non-steroidal agents, skin hygiene and washing, as well as StrataXRT and Mepitel film in breast cancer patients. The comprehensive nature of the meta-analyses and their related findings may help reduce the discrepancies in in treatment of acute radiation dermatitis and facilitate consistency of therapeutic interventions employed in clinical practice worldwide.

Mepitel Film for the prevention of acute radiation dermatitis in head and neck cancer: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

This systematic review and meta-analysis evaluates the efficacy of Mepitel Film in preventing acute radiation dermatitis (RD) in patients with head and neck cancer (HNC) across randomized controlled trials (RCTs).

METHODS

Embase, MEDLINE, and Cochrane Central Register of Controlled Trials were searched on 5 March 2023 to identify relevant RCTs. RD assessment tools and outcomes were compared across studies. Pooled effect sizes and 95% confidence intervals (CI) were estimated based on random-effects analysis using RevMan 5.4.

RESULTS

Three RCTs conducted between 2018 and 2020 were included. Mepitel Film decreased RD severity when compared to Sorbolene or Biafine but not when compared to mometasone. A per-protocol analysis of two of the trials revealed that, overall, Mepitel Film significantly reduced the incidence of grade 2-3 RD (odds ratio (OR), 0.24; 95% CI, 0.09-0.65; p = 0.005) and moist desquamation (OR, 0.21; 95% CI, 0.10-0.46; p < 0.0001) and decreased average patient, researcher, and combined components of the Radiation-Induced Skin Reaction Assessment Scale (the standardized mean difference (SMD) for patient ratings, - 2.56; 95% CI, - 3.15 to - 1.96, p < 0.00001; SMD for researcher ratings, - 3.47; 95% CI, - 6.63 to - 0.31, p = 0.03; SMD for combined scores, - 3.68; 95% CI, - 6.43 to - 0.92, p = 0.009). Noted issues with Mepitel Film included itchiness and poor adherence.

CONCLUSION

While there were discrepancies across studies, Mepitel Film demonstrated a decrease in the incidence of grade 2-3 RD and moist desquamation. These findings emphasize the need for further examining Mepitel Film's efficacy across diverse patient groups and the importance of standardizing RD severity assessment methodologies and control arms.

StrataXRT for the prevention of acute radiation dermatitis in breast cancer: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

To evaluate the overall efficacy of StrataXRT, a topical gel dressing, in preventing acute radiation dermatitis (RD) in breast cancer patients undergoing radiotherapy (RT).

METHODS

A systematic search was conducted on April 25, 2023 in Ovid MEDLINE, Embase, and Cochrane Central Register of Controlled Trials. Randomized controlled trials (RCTs) assessing the effectiveness of StrataXRT in preventing acute RD in breast cancer patients undergoing adjuvant RT to the breast or chest wall with or without regional nodes were included. Pooled incidence odds ratio (OR) and 95% confidence interval (CI) were calculated using a random-effects model, with analysis and forest plots generated in RevMan v5.4.

RESULTS

The analysis included three RCTs with a total of 189 patients assessed using per-protocol analysis. Two RCTs compared StrataXRT to standard of care, while the third compared it with Mepitel film and was reported separately. In the former RCTs, the odds ratio (OR) for developing acute grade 3 RD favored StrataXRT at 0.05 (95% CI, 0.01-0.22; P < 0.0001). The OR for developing acute grades 2-3 RD was 0.32 (95% CI, 0.03-3.18; P = 0.33). The RCT comparing StrataXRT with Mepitel film showed insignificant ORs for grade 3 and grades 2-3 RD. One RCT reported significantly lower erythema index (P = 0.008) and melanin index (P = 0.015) in StrataXRT patients. The use of StrataXRT did not raise additional safety concerns.

CONCLUSION

StrataXRT may help prevent severe acute RD in breast cancer RT patients. Further high quality, large-scale studies are needed to confirm these findings.

Photobiomodulation therapy for the prevention of acute radiation dermatitis: a systematic review and meta-analysis

PURPOSE

Approximately 95% of patients undergoing radiotherapy (RT) experience radiation dermatitis (RD). Evidence has suggested that photobiomodulation therapy (PBMT) can stimulate skin renewal and minimize RD. The aim of the present paper was to investigate the efficacy of PBMT in RD prevention through a comprehensive literature review.

METHODS

A literature search of Ovid MEDLINE, Embase, and Cochrane databases was conducted from 1980 to March 2021 to identify RCT on the use of PBMT for RD prevention. Forest plots were developed using RevMan software to quantitatively compare data between studies.

RESULTS

Five papers were identified: four in breast and one in head and neck cancer patients. Patients receiving PBMT experienced less severe RD than the control groups after 40 Gray (Gy) of RT (grade 3 toxicity: Odds Ratio (OR): 0.57, 95% CI 0.14-2.22, p = 0.42) and at the end of RT (grade 0 + 1 vs. 2 + 3 toxicity: OR: 0.28, 95% CI 0.15-0.53, p < 0.0001). RT interruptions due to RD severity were more frequent in the control group (OR: 0.81, 95% CI 0.10-6.58, p = 0.85).

CONCLUSION

Preventive PBMT may be protective against the development of severe grades of RD and reduce the frequency of RT interruptions. Larger sample sizes and other cancer sites at-risk of RD should be evaluated in future studies to confirm the true efficacy of PBMT, also in preventing the onset of RD and to finalize a standardized protocol to optimize the technique. At present, starting PBMT when RT starts is recommendable, as well as performing 2 to 3 laser sessions weekly.

Barrier Films and Dressings for the Prevention of Acute Radiation Dermatitis: A Systematic Review and Meta-Analysis

PURPOSE

This systematic review and meta-analysis aimed to evaluate the efficacy of barrier films and dressings in preventing acute radiation dermatitis (RD).

METHODS

OVID Medline, Embase, and Cochrane databases were searched from 1946 to September 2020 to identify randomized controlled trials on the use of barrier films or dressings to prevent RD. For comparable outcomes between studies, pooled effect sizes and 95% confidence intervals (CI) were calculated using the random effects analysis in RevMan 5.4.

RESULTS

Fourteen and 11 studies were included in the qualitative and quantitative analyses, respectively. Five types of barrier films used for RD were identified: Hydrofilm, StrataXRT®, Mepitel® Film, 3 M™ Cavilon™ No-Sting Barrier Film, and silver leaf nylon dressing. Hydrofilm and Mepitel Film significantly reduced the development of RD grade ≥ 2 in breast and head and neck cancer patients (RR 0.32, 95%CI 0.19, 0.56, p < 0.0001; RR 0.21, 95%CI 0.05, 0.89, p = 0.03, resp.). Moreover, Hydrofilm had a beneficial effect on patient-reported outcomes (PROs) (SMD -0.75, 95%CI -1.2, -0.29, p = 0.001). The meta-analyses on the other barrier films did not show any significant effect.

CONCLUSION

This review and meta-analysis demonstrated that Hydrofilm and Mepitel Film could effectively reduce RD severity and improve PROs. The evidence is generally weak for all the studies on barrier films and dressings due to a limited study number, high risk of bias, small sample sizes, and minimal comparable outcome measures. It's potential has been proven, but future research in this field is recommended to confirm the efficacy of these products and assess real-world feasibility.

Natural and miscellaneous agents for the prevention of acute radiation dermatitis: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to evaluate the available literature describing the efficacy of natural and miscellaneous agents in preventing acute radiation dermatitis (RD) in cancer patients.

METHODS

OVID MedLine, Embase, and Cochrane literature databases were searched from 1946 to January 2023 for randomized controlled trials studying the use of natural and miscellaneous agents to prevent RD. RevMan 5.4 was used for the meta-analysis to calculate the pooled effect sizes and 95% confidence intervals (CI) using the random effects analysis.

RESULTS

For the systematic review and meta-analysis, 19 and 16 studies were included, respectively. Of the five studied natural products (aloe vera, oral enzymes, olive oil, calendula, and curcumin), only oral enzymes and olive oil significantly reduced the incidence of Radiation Therapy Oncology Group grade 2⁺ (RR: 0.42, 95%CI 0.30-0.58, p < 0.00001, RR: 0.66, 95% CI 0.51-0.85, p = 0.001, resp.). The oral enzymes also reduced the grade 3⁺ RD incidence (RR: 0.18, 95%CI 0.06-0.55, p = 0.003). The other agents demonstrated no significant effect.

CONCLUSION

This review and meta-analysis on natural and miscellaneous agents in preventing RD in cancer patients demonstrated that oral enzymes and olive oil prevented RD severity. However, evidence supporting natural agents to prevent RD is inconsistent, mainly because of low studies numbers, low-quality study designs, and small sample sizes. Therefore, concrete conclusions cannot be made. Research on (new) natural or miscellaneous agents should focus on a randomized controlled double-blinded study design with a large patient population, a higher consistency in research methods, and clinician- and patient-reported outcomes.

The effectiveness of moisturizer on acute radiation-induced dermatitis in breast cancer patients: a systematic review and meta-analysis

PURPOSE

We conducted a systematic review and meta-analysis to investigate the effectiveness of moisturizers on acute radiation dermatitis (ARD) in breast cancer patients receiving radiotherapy (RT).

METHODS

PubMed, the Cochrane Library, CINAHL, and Ichushi-Web were searched for randomized controlled trials (RCTs) from April 2015 to March 2020. Assessments included type of intervention, cohort, outcomes, and quality of evidence. To evaluate the effect of moisturizer on ARD, we restricted analyses to studies comparing with standard skin care or no treatment. Outcomes were ARD severity and skin-related QOL (quality of life). Eligible studies were identified, and risk ratios and mean differences were extracted to compare outcome data.

RESULTS

We screened 210 RCTs along with 14 studies included in a previous iteration of this analysis (2016), supplemented by a hand search (n = 9). Finally, we included 6 RCTs that investigated the effectiveness of standard type moisturizers in breast cancer patients receiving RT. Evidence (weak certainty) suggests that moisturizer use might reduce ≥ grade 3 ARD. QOL assessed by Skindex-16 improved with moisturizer use. Pain and pruritus measured by the visual analog scale (VAS) resulted in a smaller and nonsignificant difference in favor of moisturizer use. However, the certainty of the evidence was very weak in QOL.

CONCLUSIONS

The proactive use of moisturizer may play a role in reducing ARD and improving skin-related QOL, although the certainty of the evidence was weak to very weak. Future high-quality RCTs should be initiated to strengthen these results.

Analysis of risk factors related to acute radiation dermatitis in breast cancer patients during radiotherapy

Aims

To investigate the incidence and influencing factors of acute radiation dermatitis (ARD) induced by radiotherapy in postoperative patients with breast cancer.

Methods and Materials

A retrospective analysis was conducted on 598 patients with breast cancer who received postoperative radiotherapy from November 18, 2014 to September 14, 2019. The radiotherapy technology included two-dimensional radiotherapy, three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, and tomotherapy. The occurrence of ARD in patients was then followed up and recorded. The independent risk factors for radiation-induced dermatitis were analyzed by using an orderly logistic regression model.

Results

Of the 598 patients, 431 had mild skin reactions, including pigmentation and dry desquamation (grade 1), 151 developed wet desquamation and tender erythema (grade 2), and 16 had severe skin reactions, including flaky wet scaling and erosion (grade 3). There were no grade 4 skin reactions. The severity of ARD was independent of the following factors: Age, diabetes, allergy, quadrant, pathological type, the clinical stage, the tumor stage, triple-negative breast cancer, ki-67 expression, adjuvant chemotherapy, endocrine therapy, targeted therapy, radiotherapy area, and boost irradiation. However, it was found to be dependent on the body mass index, surgery type, radiotherapy technique, node stage, and the prophylactic use of topical agents.

Conclusions

ARD in response to postoperative radiotherapy in patients with breast cancer is common and mild. Clinicians and patients need to cultivate awareness of the potential risk factors involved and then intervene to alleviate skin reactions and improve the quality of life.

A monocentric, open-label randomized standard-of-care controlled study of XONRID®, a medical device for the prevention and treatment of radiation-induced dermatitis in breast and head and neck cancer patients

Background

This study was an open-label, 2-arms, monocentric, randomized clinical trial comparing Xonrid®, a topical medical device, versus standard of care (SOC) in preventing and treating acute radiation dermatitis (ARD) in Head and Neck Cancer (HNC) and Breast Cancer (BC) patients undergoing radiotherapy (RT).

Methods

Eligible HNC and BC patients were randomized 1:1 to receive Xonrid® + SOC or SOC during RT. Patients were instructed to apply Xonrid® on the irradiated area three times daily, starting on the first day of RT and until 2 weeks after RT completion or until the development of grade ≥ 3 skin toxicity. The primary endpoint was to evaluate the proportion of patients who developed an ARD grade < 2 at the 5th week in both groups. Secondary endpoints were median time to grade 2 (G2) skin toxicity onset; changes in skin erythema and pigmentation and trans-epidermal water loss (TEWL); patient-reported skin symptoms. All patients were evaluated at baseline, weekly during RT and 2 weeks after treatment completion. The evaluation included: clinical toxicity assessment; reflectance spectrometry (RS) and TEWL examination; measurement of patients’ quality of life (QoL) through Skindex-16 questionnaire.

Results

Eighty patients (40 for each cancer site) were enrolled between June 2017 and July 2018. Groups were well balanced for population characteristics. All BC patients underwent 3-Dimensional Conformal RT (3D-CRT) whereas HNC patients underwent Volumetric-Modulated Arc Therapy (VMAT). At week 5 the proportion of BC patients who did not exhibit G2 ARD was higher in Xonrid® + SOC group (p = 0.091). In the same group the onset time of G2 ARD was significantly longer than in SOC-alone group (p < 0.0491). For HNC groups there was a similar trend, but it did not reach statistical significance. For both cancer sites, patients’ QoL, measured by the Skindex-16 score, was always lower in the Xonrid® + SOC group.

Conclusion

Despite the failure to achieve the primary endpoint, this study suggests that Xonrid® may represent a valid medical device in the prevention and treatment of ARD at least in BC patients, delaying time to develop skin toxicity and reducing the proportion of patients who experienced G2 ARD during RT treatment and 2 weeks later.

Trial registration

The study was approved by the Ethical Committee of Fondazione IRCCS Istituto Nazionale dei Tumori di Milano (INT 52/14 - NCT02261181). Registered on ClinicalTrial.gov on 21st August 2017.

Nigella sativa L. for prevention of acute radiation dermatitis in breast cancer: A randomized, double-blind, placebo-controlled, clinical trial

OBJECTIVE

The present study aimed to evaluate the effectiveness of Nigella sativa L. (N. sativa) extract on preventing the incidence of acute radiation dermatitis (ARD) in breast cancer patients.

METHODS

Sixty-two breast cancer patients undergoing radiotherapy (RT) were randomly assigned to receiveN. sativa 5% gel or placebo. Patients were instructed to apply the medications twice daily during RT period. The severity of ARD, the incidence of moist desquamation, worst experienced pain, and skin-related quality of life (SRQOL) scores were assessed weekly during RT.

RESULTS

Patients who were treated with the N. sativa gel developed ARD significantly less frequently compared to those who used the placebo (p < 0.05 for all weeks except week 2, p = 0.36). The incidence time of grade 2 and 3 of Radiation Therapy Oncology Group and the European Organization for Research and Treatment of Cancer (RTOG/EORTC) toxicity was prolonged significantly with N. sativa gel as compared to placebo (35 vs. 29 days, p = 0.00 and 42 vs. 40 days, p = 0.01, respectively). Furthermore, the occurrence of moist desquamation was delayed in the N. sativa gel group compared with the placebo group (37 vs. 33 days, p = 0.01). The mean score of the worst pain that patients experienced in the placebo group was significantly higher than that of the N. sativa gel group at week 3 (2.5 ± 0.5 vs. 1.2 ± 0.3, p < 0.05). Nonetheless, the application of N. sativa gel had no significant effect on the SRQOL of patients at any week.

CONCLUSION

N. sativa extract significantly decreases the severity of ARD and delays the onset of moist desquamation in breast cancer patients.

Prospective study of postoperative whole breast radiotherapy for Japanese large-breasted women: a clinical and dosimetric comparisons between supine and prone positions and a dose measurement using a breast phantom

BACKGROUND

This prospective study aimed to compare dose volume histograms (DVH) of the breasts and organs at risk (OARs) of whole breast radiotherapy in the supine and prone positions, and frequency and severity of acute and late toxicities were analyzed.

METHODS

Early-stage breast cancer patients with large breasts (Japanese bra size C or larger, or the widest measurements of the bust ≥ 95 cm) undergoing partial mastectomy participated in this study. CT-based treatment plans were made in each position, and various dosimetric parameters for the breast and OARs were calculated to compare the supine and prone radiotherapy plans. The actual treatment was delivered in the position regarded as better.

RESULTS

From 2009 to 2010, 22 patients were prospectively accrued. Median follow-up period was 58 months. The homogeneity index and lung doses were significantly lower in the prone position (P = 0.008, P < 0.0001 and P < 0.0001, respectively). Cardiac dose showed no significant differences between two positions. By comparing two plans, the prone position was chosen in 77 % of the patients. In the prone position, ≥ grade 2 acute dermatitis were seen in 47 % of patients treated, whereas 20 % of the patients treated in the supine position had grade 2 and no cases of grade 3, although without a statistical significance of the rates of ≥ grade 2 acute dermatitis between the two positions (P = 0.28). The actual dose measurement using a breast phantom revealed significantly higher surface dose of the breast treated in the prone position than that in the supine position.

CONCLUSIONS

Breast irradiation in the prone position improves PTV homogeneity and lowers doses to the OARs in the Japanese large-breast patients. However meticulous positioning of the breast in the prone board avoiding the bolus effect is necessary to prevent acute dermatitis.