Dataset Information

Assessing the Validity of Clinician Advice That Patients Avoid Use of Topical Agents Before Daily Radiotherapy Treatments.

ABSTRACT:

Importance

Radiation dermatitis is common and often treated with topical therapy. Patients are typically advised to avoid topical agents for several hours before daily radiotherapy (RT) out of concern that topical agents might increase the radiation dose to the skin. With modern RT's improved skin-sparing properties, this recommendation may be irrelevant.

Objective

To assess whether applying either metallic or nonmetallic topical agents before radiation treatment alters the skin dose.

Design, setting, and participants

A 24-question online survey of patients and clinicians was conducted from January 15, 2015, to March 15, 2017, to determine current practices regarding topical therapy use. In preclinical studies, dosimetric effect of the topical agents was evaluated by delivering 200 monitor units and measuring the dose at the surface and at 2-cm depth in a tissue-equivalent phantom with or without 2 common topical agents: a petroleum-based ointment (Aquaphor, petrolatum 41%) and silver sulfadiazine cream, 1%. Skin doses associated with various photon and electron energies, topical agent thicknesses, and beam incidence were assessed. Whether topical agents altered the skin dose was also evaluated in 24 C57BL/6 mice by using phosphorylated histone (γ-H2AX) immunofluorescent staining and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Preclinical studies took place at the University of Pennsylvania.

Main outcomes and measures

Patient and clinician survey responses; surface radiation dose readings in tissue-equivalent phantom; and γ-H2AX and TUNEL intensity measured in mice.

Results

The 133 patients surveyed received RT for cancer and had a median (range) age of 60 (18-86) years; 117 (87.9%) were women. One hundred eight clinicians completed the survey with 105 reporting that they were involved in managing patient skin care during RT. One hundred eleven (83.4%) of the patients and 96 (91.4%) of the 105 clinicians received or gave the advice to avoid applying topical agents before RT treatments. Dosimetric measurements showed no difference in the delivered dose at either the surface or a 2-cm depth with or without a 1- to 2-mm application of either topical agent when using en face 6- or 15-megavoltage (MV) photons. The same application of topicals did not alter the surface dose as a function of beam incident angle from 15° to 60°, except for a 6% increase at 60° with the silver sulfadiazine cream. Surface dose for 6- and 15-MV beams were significantly increased with a thicker (≥3-mm) topical application. For 6 MV, the surface dose was 1.05 Gy with a thick layer of petroleum-based ointment and 1.02 Gy for silver sulfadiazine cream vs 0.88 Gy without topical agents. For 15 MV, the doses were 0.70 Gy for a thick layer of petroleum-based ointment and 0.60 Gy for silver sulfadiazine cream vs 0.52 Gy for the controls. With 6- and 9-MeV electrons, there was a 2% to 5% increase in surface dose with the use of the topical agents. There were no dose differences at 2-cm depth. Irradiated skin in mice showed no differences in γ-H2AX-positive foci or in TUNEL staining with or without topical agents of varying thickness.

Conclusions and relevance

Thin or moderately applied topical agents, even if applied just before RT, may have minimal influence on skin dose regardless of beam energy or beam incidence. The findings of this study suggest that applying very thick amounts of a topical agent before RT may increase the surface dose and should be avoided.

SUBMITTER: Baumann BC

PROVIDER: S-EPMC6440719 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:ImportanceKnowing the expected effect of treatment on an individual patient is essential for patient care.ObjectiveTo explore clinicians' conceptualizations of the chance that treatments will decrease the risk of disease outcomes.Design, setting, and participantsThis survey study of attending and resident physicians, nurse practitioners, and physician assistants was conducted in outpatient clinical settings in 8 US states from June 2018 to November 2019. The survey was an in-person, paper, 26-item survey in which clinicians were asked to estimate the probability of adverse disease outcomes and expected effects of therapies for diseases common in primary care.Main outcomes and measuresEstimated chance that treatments would benefit an individual patient.ResultsOf 723 clinicians, 585 (81%) responded, and 542 completed all the questions necessary for analysis, with a median (interquartile range [IQR]) age of 32 (29-44) years, 287 (53%) women, and 294 (54%) White participants. Clinicians consistently overestimated the chance that treatments would benefit an individual patient. The median (IQR) estimated chance that warfarin would prevent a stroke in the next year was 50% (5%-80%) compared with scientific evidence, which indicates an absolute risk reduction (ARR) of 0.2% to 1.0% based on a relative risk reduction (RRR) of 39% to 50%. The median (IQR) estimated chance that antihypertensive therapy would prevent a cardiovascular event within 5 years was 30% (10%-70%) vs evidence of an ARR of 0% to 3% based on an RRR of 0% to 28%. The median (IQR) estimated chance that bisphosphonate therapy would prevent a hip fracture in the next 5 years was 40% (10%-60%) vs evidence of ARR of 0.1% to 0.4% based on an RRR of 20% to 40%. The median (IQR) estimated chance that moderate-intensity statin therapy would prevent a cardiovascular event in the next 5 years was 20% (IQR 5%-50%) vs evidence of an ARR of 0.3% to 2% based on an RRR of 19% to 33%. Estimates of the chance that a treatment would prevent an adverse outcome exceeded estimates of the absolute chance of that outcome for 60% to 70% of clinicians. Clinicians whose overestimations were greater were more likely to report using that treatment for patients in their practice (eg, use of warfarin: correlation coefficient, 0.46; 95% CI, 0.40-0.53; P < .001).Conclusions and relevanceIn this survey study, clinicians significantly overestimated the benefits of treatment to individual patients. Clinicians with greater overestimates were more likely to report using treatments in actual patients.

Project description:Eosinophilic esophagitis (EoE) is a chronic inflammatory disorder characterized by symptoms of esophageal dysfunction and eosinophil-predominant inflammation. Left untreated, EoE progresses to fibrous remodeling and stricture formation that impairs quality of life. Therefore, EoE requires either repeated treatments or maintenance therapy. Current guidelines recommend swallowed topical corticosteroids (STCs), proton-pump inhibitors (PPIs), or dietary intervention as initial options to induce and maintain long-term disease remission. Impractical exclusive elemental diets and suboptimal allergy testing-directed food avoidance paved the way for empirical elimination diets. These are moderately effective and highly reproducible in inducing EoE remission and allow for identification of specific food triggers. Step-up strategies, including two- and four-food rather than six-food elimination diets, should be considered as initial approaches for dietary treatment in patients of all ages, as they reduce the need for endoscopic procedures, shorten diagnostic processing time, and avoid unnecessary restrictions. Formulations of STC originally designed for asthma therapy are suboptimal for EoE treatment, with new effervescent orodispersible tablets and viscose formulations designed to coat the esophageal mucosa providing increased effectiveness at reduced doses. The anti-inflammatory effects of PPI in EoE are independent from gastric acid secretion inhibition; despite evidence from observational research, PPIs are the most commonly prescribed first-line therapy for EoE due to their accessibility, low cost, and safety profile. Double doses of PPI only induce remission in half of EoE patients, irrespective of the drug used or patients' age. Inflammatory rather than stricturing EoE phenotype and treatment duration up to 12 weeks increase chances of achieving EoE remission. Most responders effectively maintain long-term remission with standard PPI doses. Finally, endoscopic dilation should be considered in patients with reduced esophageal caliber or persistent dysphagia despite histological remission. This article provides a state-of-the-art review and updated discussion of current therapies and newly developed options for EoE.