Radiotherapy treatment for nonmelanoma skin cancer

Enhanced Skin Penetration and Efficacy: First and Second Generation Lipoidal Nanocarriers in Skin Cancer Therapy

Skin carcinoma remains one of the most widespread forms of cancer, and its global impact continues to increase. Basal cell carcinoma, melanoma, and squamous cell carcinoma are three kinds of cutaneous carcinomas depending upon occurrence and severity. The invasive nature of skin cancer, the limited effectiveness of current therapy techniques, and constraints to efficient systems for drug delivery are difficulties linked with the treatment of skin carcinoma. In the present era, the delivery of drugs has found a new and exciting horizon in the realm of nanotechnology, which presents inventive solutions to the problems posed by traditional therapeutic procedures for skin cancer management. Lipid-based nanocarriers like solid lipid nanoparticles and nanostructured lipid carriers have attracted a substantial focus in recent years owing to their capability to improve the drug's site-specific delivery, enhancing systemic availability, and thus its effectiveness. Due to their distinct structural and functional characteristics, these nanocarriers can deliver a range of medications, such as peptides, nucleic acids, and chemotherapeutics, via different biological barriers, such as the skin. In this review, an effort was made to present the mechanism of lipid nanocarrier permeation via cancerous skin. In addition, recent research advances in lipid nanocarriers have also been discussed with the help of in vitro cell lines and preclinical studies. Being a nano size, their limitations and toxicity aspects in living systems have also been elaborated.

Unveiling the potential of photodynamic therapy with nanocarriers as a compelling therapeutic approach for skin cancer treatment: current explorations and insights

Skin carcinoma is one of the most prevalent types of carcinomas. Due to high incidence of side effects in conventional therapies (radiotherapy and chemotherapy), photodynamic therapy (PDT) has gained huge attention as an alternate treatment strategy. PDT involves the administration of photosensitizers (PS) to carcinoma cells which produce reactive oxygen species (ROS) on irradiation by specific wavelengths of light that result in cancer cells' death via apoptosis, autophagy, or necrosis. Topical delivery of PS to the skin cancer cells at the required concentration is a challenge due to the compounds' innate physicochemical characteristics. Nanocarriers have been observed to improve skin permeability and enhance the therapeutic efficiency of PDT. Polymeric nanoparticles (NPs), metallic NPs, and lipid nanocarriers have been reported to carry PS successfully with minimal side effects and high effectiveness in both melanoma and non-melanoma skin cancers. Advanced carriers such as quantum dots, microneedles, and cubosomes have also been addressed with reported studies to show their scope of use in PDT-assisted skin cancer treatment. In this review, nanocarrier-aided PDT in skin cancer therapies has been discussed with clinical trials and patents. Additionally, novel nanocarriers that are being investigated in PDT are also covered with their future prospects in skin carcinoma treatment.

miRNAs in radiotherapy resistance of cancer; a comprehensive review

While intensity-modulated radiation therapy-based comprehensive therapy increases outcomes, cancer patients still have a low five-year survival rate and a high recurrence rate. The primary factor contributing to cancer patients' poor prognoses is radiation resistance. A class of endogenous non-coding RNAs, known as microRNAs (miRNAs), controls various biological processes in eukaryotes. These miRNAs influence tumor cell growth, death, migration, invasion, and metastasis, which controls how human carcinoma develops and spreads. The correlation between the unbalanced expression of miRNAs and the prognosis and sensitivity to radiation therapy is well-established. MiRNAs have a significant impact on the regulation of DNA repair, the epithelial-to-mesenchymal transition (EMT), and stemness in the tumor radiation response. But because radio resistance is a complicated phenomena, further research is required to fully comprehend these mechanisms. Radiation response rates vary depending on the modality used, which includes the method of delivery, radiation dosage, tumor stage and grade, confounding medical co-morbidities, and intrinsic tumor microenvironment. Here, we summarize the possible mechanisms through which miRNAs contribute to human tumors' resistance to radiation.

Depth Dose Enhancement in Orthovoltage Nanoparticle-Enhanced Radiotherapy: A Monte Carlo Phantom Study

BACKGROUND

This study was to examine the depth dose enhancement in orthovoltage nanoparticle-enhanced radiotherapy for skin treatment by investigating the impact of various photon beam energies, nanoparticle materials, and nanoparticle concentrations.

METHODS

A water phantom was utilized, and different nanoparticle materials (gold, platinum, iodine, silver, iron oxide) were added to determine the depth doses through Monte Carlo simulation. The clinical 105 kVp and 220 kVp photon beams were used to compute the depth doses of the phantom at different nanoparticle concentrations (ranging from 3 mg/mL to 40 mg/mL). The dose enhancement ratio (DER), which represents the ratio of the dose with nanoparticles to the dose without nanoparticles at the same depth in the phantom, was calculated to determine the dose enhancement.

RESULTS

The study found that gold nanoparticles outperformed the other nanoparticle materials, with a maximum DER value of 3.77 at a concentration of 40 mg/mL. Iron oxide nanoparticles exhibited the lowest DER value, equal to 1, when compared to other nanoparticles. Additionally, the DER value increased with higher nanoparticle concentrations and lower photon beam energy.

CONCLUSIONS

It is concluded in this study that gold nanoparticles are the most effective in enhancing the depth dose in orthovoltage nanoparticle-enhanced skin therapy. Furthermore, the results suggest that increasing nanoparticle concentration and decreasing photon beam energy lead to increased dose enhancement.

Hypofractionated radiotherapy for invasive squamous cell carcinoma of the scalp in the elderly: Efficacy and tolerance, preliminary results

PURPOSE

Skin squamous cells carcinomas (SCC) are frequently tumor, especially in the elderly population. Surgical excision is the standard treatment. But for patients suffering large tumor or/with comorbidity, a conservative approach with irradiation can be proposed. The hypofractionated schedule is used to shorten the overall treatment time with same results and without compromising therapeutic outcomes. The aim of this study is to assess the efficacy and tolerance of hypofractionated radiotherapy for invasive SCC of the scalp in elderly.

PATIENTS AND METHODS

We included patients suffering from SCC of the scalp and treated by hypofractionated radiotherapy at the Institut de cancérologie de Lorraine or centre Émile-Durkeim d'Épinal, from January 2019 to December 2021. Characteristics of patients, size of the lesion and side effects were collected retrospectively. Tumor size at 6 months corresponded to the primary endpoint. Toxicity was collected for the secondary endpoint.

RESULTS

Twelve patients with a median age of 85 years old were included. The mean size was 4,5cm with a bone invasion in 2/3 of cases. Radiotherapy was delivered after surgical excision for half of the patient. The dose delivered was 54Gy in 18 daily fractions size. Six months after irradiation: 6/11 patients had no residual lesion, 2/11 had a partial response with a residual lesion of about 1cm. 3 patients presented local recurrence. One patient died within 6 months of radiotherapy because of another comorbidity. In total, 25% had presented a grade 3 acute radiation dermatitis, no grade 4 toxicity.

CONCLUSION

Short term of moderately hypofractionated schedule radiotherapy was a success with complete or partial response for more than 70% of the patients in squamous cell carcinomas. There is no major side effect.

On the measurement of scaling factors in the RW3 plastic phantom during high energy electron beam dosimetry

Ionometric electron dosimetry inside water-equivalent plastic phantoms demands special considerations including determination of depth scaling and fluence scaling factors (c_pl and h_pl) to shift from in-phantom measurements to those relevant to water. This study evaluates these scaling factors for RW3 slab phantom and also introduces a new coefficient, k(RW3), for direct conversion from RW3 measurements to water without involving scaling factors. The RW3 solid phantom developed by the PTW Company was used and the corresponding scaling factors including c_pl, h_pl, and k(RW3) were measured for conventional electron energies of 4, 6, 9, 12, and 16 MeV. Separate measurements were performed in water and the RW3 slab phantom using the Advanced Markus chamber. The validity of the reported scaling factors was confirmed by comparing the direct and indirect percentage depth dose (PDD) measurements in water and in the RW3 phantom. The c_pl values for the RW3 phantom were respectively equal to 0.915, 0.927, 0.934, 0.937, and 0.937 for 4, 6, 9, 12, and 16 MeV electron energies. The h_pl and k(RW3) values were dependent on the depth of investigation and electron energy. Application of the c_pl-h_pl factors and k(RW3) coefficients to measured data inside the RW3 can reliably reproduce the measured PDD curves in water. The mean difference between the PDDs measured directly and indirectly in water and in the RW3 phantom was less than 1.2% in both approaches for PDD conversion (c_pl-h_pl coupling and the use of k(RW3)). The measured scaling factors and k(RW3) coefficients are sufficiently relevant to mimic water-based dosimetry results through indirect measurements inside the RW3 slab phantom. Nevertheless, employing k(RW3) is more straightforward than the c_pl-h_pl approach because it does not involve scaling and it is also less time-consuming.

Implementation of superficial radiation therapy (SRT) using SRT-100 Vision™ for non-melanoma skin cancer in a Radiation Oncology clinic

PURPOSE

This article describes our experience in implementation of superficial radiation therapy (SRT) using SRT-100 Vision™ for non-melanoma skin cancer.

METHODS

Following the American Association of Physicists in Medicine Task Group-61 protocol, absolute output (absorbed dose to water at surface (cGy/min)) was measured for three energies (50, 70, and 100 kV) and for six applicators (1.5-5.0 cm in diameter). Percent depth dose (PDD) and profiles were also measured. Timer testing and ultrasound testing were performed. A treatment time calculation worksheet was created. Quality assurance (QA) of SRT-100 Vision was implemented. After treatment workflow for our clinic was developed, end-to-end (E2E) testing was performed using a Rando phantom. Considerations for treatment using SRT-100 Vision were made.

RESULTS

Absolute output (cGy/min) decreases as energy increases and applicator size decreases. Due to scatter from the applicator, PDD at depths ≤5 mm does not follow conventional trends but PDD at depths ≥15 mm increases with increasing applicator size. Profiles for the 5 cm applicator do not have strong dependence on depth except profiles at 5 mm for 50 kV. Timer/end errors are negligible for all three energies. Ultrasound images confirm allowed field of view and depth as well as no image artifacts and spatial integrity. Daily, monthly and annual QA of SRT-100 Vision implemented in our clinic is listed in a table format. E2E testing results (<1%) demonstrate the functionality and performance of our treatment workflow. Our considerations for SRT treatment include patient, applicator size and energy selections, patient setup, and shields.

CONCLUSIONS

This article is expected to serve as guidance for Radiation Oncology and/or Dermatology clinics aspiring to initiate an SRT program in their clinics.

Immunotherapy for the Treatment of Squamous Cell Carcinoma: Potential Benefits and Challenges

Melanoma and nonmelanoma skin cancers (NMSCs) are recognized as among the most common neoplasms, mostly in white people, with an increasing incidence rate. Among the NMSCs, squamous cell carcinoma (SCC) is the most prevalent malignancy known to affect people with a fair complexion who are exposed to extreme ultraviolet radiation (UVR), have a hereditary predisposition, or are immunosuppressed. There are several extrinsic and intrinsic determinants that contribute to the pathophysiology of the SCC. The therapeutic modalities depend on the SCC stages, from actinic keratosis to late-stage multiple metastases. Standard treatments include surgical excision, radiotherapy, and chemotherapy. As SCC represents a favorable tumor microenvironment with high tumor mutational burden, infiltration of immune cells, and expression of immune checkpoints, the SCC tumors are highly responsive to immunotherapies. Until now, there are three checkpoint inhibitors, cemiplimab, pembrolizumab, and nivolumab, that are approved for the treatment of advanced, recurrent, or metastatic SCC patients in the United States. Immunotherapy possesses significant therapeutic benefits for patients with metastatic or locally advanced tumors not eligible for surgery or radiotherapy to avoid the potential toxicity caused by the chemotherapies. Despite the high tolerability and efficiency, the existence of some challenges has been revealed such as, resistance to immunotherapy, less availability of the biomarkers, and difficulty in appropriate patient selection. This review aims to accumulate evidence regarding the genetic alterations related to SCC, the factors that contribute to the potential benefits of immunotherapy, and the challenges to follow this treatment regime.

Optical scan and 3D printing guided radiation therapy - an application and provincial experience in cutaneous nasal carcinoma

Background

Single field Orthovoltage radiation is an acceptable modality used for the treatment of nasal cutaneous cancer. However, this technique has dosimetric pitfalls and unnecessary excessive exposure of radiation to organs at risk (OAR). We present the clinical outcome of a case series of cutaneous nasal tumours using a novel technique incorporating an optical scanner and a 3-dimensional (3D) printer to deliver treatments using parallel opposed (POP) fields.

Materials and methods

The POP delivery method was validated using ion chamber and phantom measurements before implementation. A retrospective chart review of 26 patients treated with this technique between 2015 and 2019 was conducted. Patients’ demographics and treatment outcomes were gathered and tabulated. These patients first underwent an optical scan of their faces to collect topographical data. The data were then transcribed into 3D printing algorithms, and positive impressions of the faces were printed. Custom nose block bolus was made with wax encased in an acrylic shell; 4 cm thick using the printed face models. Custom lead shielding was also generated. Treatments were delivered using 250 KeV photons POP arrangement with 4 cm diameter circle applicator cone and prescribed to the midplane. Dose and fractionation were as per physician discretion.

Results

Phantom measurements at mid-plane were found to match the prescribed dose within ±0.5%. For the 26 cases in this review, the median age was 78.5 years, with 15 females and 11 males. 85% of cases had Basal cell carcinoma (BCC); 1 had squamous cell carcinoma (SCC), one had synchronous BCC + SCC, and 1 had Merkel cell carcinoma. Twenty-one cases had T1N0 disease, 4 had T2N0, and 1 had T3N0. Dose and fractionation delivered were 40Gy in 10 fractions for the majority of cases. The complete response rate at a median follow-up of 6 months was 88%; 1 patient had a refractory tumour, and one patient had a recurrence. Toxicities were minor with 81% with no reported side effects. Three patients experienced grade 3 skin toxicity.

Conclusions

Utilization of optic scanner and 3D printing technology, with the innovative approach of using POP orthovoltage beams, allows an effective and efficient way of treatment carcinomas of the nose with a high control rate and low toxicity profiles.

Radiotherapy in the Adjuvant and Advanced Setting of CSCC

Introduction

The use of radiotherapy for cutaneous squamous cell carcinoma (CSCC) has solid historical roots. It is used with patients who are not suitable for surgery, with patients with high-risk histological features in the adjuvant setting, and in palliative care.

Objectives

The aim of this article is to summarize and provide a radiation therapy overview on the indications, effectiveness, and potential adverse events of radiotherapy in the adjuvant and advanced setting of CSCC.

Methods

We performed a comprehensive literature review on PubMed, adopted as our biomedical literature database. Articles were selected based on their date of publication (in the last 30 years) and relevance.

Results

Radiotherapy (RT) can safely be used to manage non-surgical patients and high-risk patients in the advanced CSCC setting. The remarkable progress of delivery techniques has greatly improved the effectiveness and toxicity profile of RT treatments. From 2D techniques to intensity modulated radiation therapy (IMRT), and brachytherapy, all RT techniques have greatly advanced. To improve acute and chronic side effects, a deeper care has been used. As regards CSCC, several dose fractionations and schedules have been suggested, in line with the patient's age and medical conditions.

Conclusions

RT is a fundamental and constantly evolving therapeutic option in the treatment of CSCC, to minimize the risk of recurrence and metastases in the adjuvant setting and in the exclusive treatment for non-surgical patients. Patients' selection is crucial, together with and a collaborative team working approach among the specialists involved in disease management in the perspective of the best multidisciplinary assessment.

Acute and late complications and toxicities of skin brachytherapy

Skin cancer is the most prevalent malignancy, and its incidence is rising. Surgery is the primary treatment, however, morbidity of surgical resection in certain parts of the body warrant alternate treatment options such as radiation therapy. Complex topology of the skin can pose a challenge for treatment with photon and electron external beam radiotherapy techniques. Brachytherapy can be an attractive radiotherapy technique for these regions. Furthermore, brachytherapy results in lower dose to the underlying deep organs. The goal of this manuscript is to provide a brief overview of the role of brachytherapy for skin malignancies and to outline potential acute and long-term toxicities.

Impact of the Spectral Composition of Kilovoltage X-rays on High-Z Nanoparticle-Assisted Dose Enhancement

Nanoparticles (NPs) with a high atomic number (Z) are promising radiosensitizers for cancer therapy. However, the dependence of their efficacy on irradiation conditions is still unclear. In the present work, 11 different metal and metal oxide NPs (from Cu (Z_Cu = 29) to Bi₂O₃ (Z_Bi = 83)) were studied in terms of their ability to enhance the absorbed dose in combination with 237 X-ray spectra generated at a 30–300 kVp voltage using various filtration systems and anode materials. Among the studied high-Z NP materials, gold was the absolute leader by a dose enhancement factor (DEF; up to 2.51), while HfO₂ and Ta₂O₅ were the most versatile because of the largest high-DEF region in coordinates U (voltage) and E_eff (effective energy). Several impacts of the X-ray spectral composition have been noted, as follows: (1) there are radiation sources that correspond to extremely low DEFs for all of the studied NPs, (2) NPs with a lower Z in some cases can equal or overcome by the DEF value the high-Z NPs, and (3) the change in the X-ray spectrum caused by a beam passing through the matter can significantly affect the DEF. All of these findings indicate the important role of carefully planning radiation exposure in the presence of high-Z NPs.

Evaluation of bone dose arising from skin cancer brachytherapy: A comparison between 192Ir and 60Co sources through Monte Carlo simulations

PURPOSE

This study aimed to calculate and compare absorbed dose to bone following exposure to ¹⁹²Ir and ⁶⁰Co sources in high dose rate (HDR) skin brachytherapy. Moreover, effects of the bone thickness and soft tissue thickness before the bone on absorbed dose to the bone are evaluated .

MATERIALS AND METHODS

¹⁹²Ir and ⁶⁰Co sources inserted in Leipzig applicators with internal diameters of 1, 2 and 3 cm with/without their optimal flattening filters were simulated by MCNPX Monte Carlo code. Then, heterogeneous phantoms (including skin, soft tissue before and after the bone, cortical bone and bone marrow) were defined. Finally, relative depth dose values for the bone and other tissues in the heterogeneous phantoms were obtained and compared.

RESULTS

The average relative depth dose values of the skin, soft tissue before and after bone and bone marrow were almost similar for both ¹⁹²Ir and ⁶⁰Co sources, with a maximum difference less than 2%. However, a 0.1-6.8% difference was observed between average relative depth dose values of these two sources for the cortical bone. The results showed that with increasing the bone thickness and bone distance from the skin surface, the average relative depth dose values of the bone marrow and cortical bone decreased for both ¹⁹²Ir and ⁶⁰Co sources inserted in the applicators without/with their optimal flattening filters. For most of evaluated the applicators without/with their flattening filters, the average relative depth dose values of the bone marrow arisen from the ⁶⁰Co source were higher than those obtained from the ¹⁹²Ir source, while an opposite trend was observed for the cortical bone .

CONCLUSION

The obtained findings showed that the average relative depth dose values of ¹⁹²Ir and ⁶⁰Co sources at the corresponding depths of the designed heterogeneous phantoms were almost similar (expect for the cortical bone). Hence, it is concluded that ⁶⁰Co source can be used instead of ¹⁹²Ir source in HDR skin brachytherapy, particularly in developing countries.

Management of Acute Radiodermatitis in Non-Melanoma Skin Cancer Patients Using Electrospun Nanofibrous Patches Loaded with Pinus halepensis Bark Extract

Simple Summary

The most frequent adverse effect for patients receiving radiotherapy, an effective treatment for skin cancer when surgical removal of the tumor is impossible, is acute radiodermatitis, affecting patients’ physical function and often leading to therapy termination. Creams and other topical formulations used so far for the prevention of acute radiodermatitis are applied at regular intervals but do not ensure a constant and controlled transepidermal absorption. The aqueous extract of Aleppo pine bark, previously preclinically and clinically assessed in the form of gel, was herein loaded on micro/nanofibrous patches and clinically evaluated in comparison with a commercially used reference cream on non-melanoma skin carcinoma patients undergoing radiotherapy. The experimental patch significantly contributed to prophylaxis and successful management of acute radiodermatitis, safely restoring skin and its biophysical parameters to normal levels and reducing patients’ discomfort. Topical application of pine-loaded micro/nanofibrous patches holds great potential for the development of a new generation of anti-inflammatory skin care dressings against radiodermatitis.

Abstract

Acute radiodermatitis is the most common side effect in non-melanoma skin cancer patients undergoing radiotherapy. Nonetheless, despite the ongoing progress of clinical trials, no effective regimen has been found yet. In this study, a non-woven patch, comprised of electrospun polymeric micro/nanofibers loaded with an aqueous extract of Pinus halepensis bark (PHBE), was fabricated and clinically tested for its efficacy to prevent radiodermatitis. The bioactivity of the PHBE patch was evaluated in comparison with a medical cream indicated for acute radiodermatitis. Twelve volunteer patients were selected and randomly assigned to two groups, applying either the PHBE patch or the reference cream daily. Evaluation of radiation-induced skin reactions was performed during the radiotherapy period and 1 month afterwards according to the Radiation Therapy Oncology Group (RTOG) grading scale, photo-documentation, patient-reported outcomes (Visual Analog Scale, questionnaire), biophysical measurements (hydration, transepidermal water loss, erythema, melanin), and image analysis. In contrast with the reference product, the PHBE patch showed significant anti-inflammatory activity and restored most skin parameters to normal levels 1 month after completion of radiation therapy. No adverse event was reported, indicating that the application of the PHBE patch can be considered as a safe medical device for prophylactic radiodermatitis treatment.

Novel method of combined photon beam radiotherapy and brachytherapy for treatment of extensive advanced scalp squamous cell carcinoma

Radiotherapy of extensive malignant scalp lesions has always been a challenge for radiation oncologists considering the proximity of critical structures. We treated a 39-year-old patient with extensive scalp squamous cell carcinoma with application of adjuvant concurrent chemoradiation and external beam radiation therapy (EBRT), followed by high-dose-rate (HDR) surface brachytherapy boost using an exclusively designed mould, and assessed the radiation dose reaching planning target volume, brain, and optic structures. Comparison between conventional planning with sole EBRT and combined treatment planning with EBRT and brachytherapy, assured the use of the latter treatment to avoid high radiation doses from reaching critical organs at risk without compromising the required dose for planning target volume.

Design and characterization of flattening filter for high dose rate 192Ir and 60Co Leipzig applicators used in skin cancer brachytherapy: A Monte Carlo study

PURPOSE

This study aimed to design optimal flattening filters for high dose rate (HDR) ¹⁹²Ir and ⁶⁰Co Leipzig applicators which are used to treat skin cancer.

MATERIALS AND METHODS

MCNPX Monte Carlo code was used to design flattening filters for Leipzig applicators with inner diameters of 1, 2 and 3 cm. Then, their dosimetric characterizations such as dose distribution, dose profile, percentage depth dose, flatness, symmetry and homogeneity were evaluated in a 20 × 20 × 20 cm³ water phantom and compared with those without the flattening filter.

RESULTS

The flattening filter thickness varied from 0 mm (at the edge) to the maximum values of 0.30, 1.18, and 2.41 mm for the ¹⁹²Ir Leipzig applicators of H1, H2, and H3 type, respectively. This quantity has maximum values of 0.96, 6.27, and 12.31 mm for the ⁶⁰Co double wall applicators of D1, D2, and D3 type, respectively. The dose profile flatness values for the H1, H2, and H3 ¹⁹²Ir Leipzig applicators with the optimal flattening filters were 0.76, 1.26, and 1.85%, respectively. Furthermore, the dose profile flatness values for the D1, D2, and D3 ⁶⁰Co double wall applicators with the optimal flattening filters were 1.11, 2.10 and 3.12%, respectively. The dose profile symmetry values obtained from various source-applicator combinations were less than 1.02. Compared to the applicators without flattening filter, the homogeneity values for the H1, H2, and H3 ¹⁹²Ir Leipzig applicators with the optimal flattening filters were improved 1.68, 6.51, and 13.17 times, respectively, and for the D1, D2, and D3 ⁶⁰Co double wall applicators were improved 1.23, 6.21 and 9.54 times, respectively.

CONCLUSION

The findings revealed that the inhomogeneous dose distribution resulted from the Leipzig applicators without the optimal flattening filter at the treatment surface could be improved by insertion of optimal lead flattening filters between the sources and treatment surface.

An Internet of Things app for monitor unit calculation in superficial and orthovoltage skin therapy

Purpose: We developed an app for Internet of Things (IoT) device such as smartphone or tablet to calculate the monitor unit in superficial and orthovoltage skin therapy. The app can run both on the Windows and Android operation system. Methods: The IoT app was created based on the formula to calculate the monitor unit in skin therapy using kV photon beams. The calculation was based on databases of dose variables such as relative exposure factor and backscatter factor. The calculation also considered the stand-off and stand-in correction according to the inverse-square and inverse-cube law. Verification of the app was carried out by comparing the monitor unit results with those from hand calculations. Results: The frontend window of the app provided a user-friendly interface to the user for inputting prescription dose, beam and treatment setup variables. The user could save the calculation record electronically, generate a printout or send it to other radiation staff using the IoT. Verification of the app showing that deviation between the monitor units calculated by the app and by hand is insignificant. Conclusion: The verified IoT app can effectively calculate the monitor unit in superficial and orthovoltage skin therapy. The app takes advantages of all innate features of IoT such as real time communication, Internet access, data transfer and sharing.

Advanced cutaneous squamous cell carcinoma: how is it defined and what new therapeutic approaches are available?

PURPOSE OF REVIEW

Despite the overall excellent survival rates in patients with cutaneous squamous cell carcinoma (cSCC), advanced cutaneous SCCs are associated with high patient morbidity and mortality. Therefore, important unmet clinical needs persist: identifying high risk patients and choosing optimal treatment approaches.

RECENT FINDINGS

In recent years, a better understanding of the biology of cSCC and its clinical progression have led to improved staging systems and new promising treatments for advanced disease. Such treatments include PD1 inhibitors, such as cemiplimab, which was recently approved for the treatment of cutaneous SCC, and pembrolizumab whose efficacy in the treatment cSCC is still being investigated. Other treatments, such as epidermal growth factor receptor inhibitors have also been used in the treatment of cSCC with moderate success. Several clinical and histological risk factors are considered key in estimating the risk or recurrence or metastasis in cSCCs and, therefore, influence the appropriate treatment choice and patient monitoring.

SUMMARY

The present study reviews the current definition of advanced cSCC and discusses the new systemic approaches, including checkpoint inhibitors.

Effectiveness of radiotherapy for head and neck skin cancers: a single-institution study

Purpose

External beam radiotherapy (EBRT) is a useful option to treat head and neck skin cancer patients who are not indicated for surgery. In this study, we evaluated the treatment outcomes of EBRT in an Asian population.

Materials and Methods

The records from 19 head and neck skin cancer patients (10 with squamous cell carcinoma and 9 with basal cell carcinoma) who were treated with definitive or adjuvant EBRT from 2009 to 2017 were retrospectively reviewed. The radiotherapy doses administered ranged from 50 to 66 Gy (median, 55 Gy) with 2.0–2.75 Gy per daily fraction (median, 2.5 Gy). The T stage at presentation was as follows: Tis (1 patient), T1 (11 patients), T2 (6 patients), and T3 (1 patient). None had regional lymph node disease or distant metastasis at presentation. The local failure-free survival (LFFS) rates, toxicity, and cosmetic results were analyzed.

Results

The median age was 75.5 years (range, 52.6 to 92.5 years). The median follow-up duration from the completion of radiotherapy was 44.9 months (range, 5.8 to 82.6 months). One local failure occurred in a patient with a 2.1-cm posterior neck squamous cell carcinoma at 32.5 months after radiotherapy (1/19, 5.3%). The 3-year LFFS rate was 91.7%. No patients died from skin cancer during follow-up, and no grade 3 complications occurred. The cosmetic outcomes were excellent for 16 (84.2%) and good for 3 (15.8%) of the 19 patients.

Conclusion

EBRT offers good local control and cosmetic outcomes in patients with head and neck skin cancer, with no grade 3 complications.

Emerging Perspective: Role of Increased ROS and Redox Imbalance in Skin Carcinogenesis

Strategies to battle malignant tumors have always been a dynamic research endeavour. Although various vehicles (e.g., chemotherapeutic therapy, radiotherapy, surgical resection, etc.) are used for skin cancer management, they mostly remain unsatisfactory due to the complex mechanism of carcinogenesis. Increasing evidence indicates that redox imbalance and aberrant reactive oxygen species (ROS) are closely implicated in the oncogenesis of skin cancer. When ROS production goes beyond their clearance, excessive or accumulated ROS could disrupt redox balance, induce oxidative stress, and activate the altered ROS signals. These would damage cellular DNA, proteins, and lipids, further leading to gene mutation, cell hyperproliferation, and fatal lesions in cells that contribute to carcinogenesis in the skin. It has been known that ROS-mediated skin carcinogenesis involves multiple ways, including modulating related signaling pathways, changing cell metabolism, and causing the instability of the genome and epigenome. Nevertheless, the exact role of ROS in skin cancer has not been thoroughly elucidated. In spite of ROS inducing skin carcinogenesis, toxic-dose ROS could trigger cell death/apoptosis and, therefore, may be an efficient therapeutic tool to battle skin cancer. Considering the dual role of ROS in the carcinogenesis and treatment of skin cancer, it would be essential to clarify the relationship between ROS and skin cancer. Thus, in this review, we get the related data together to seek the connection between ROS and skin carcinogenesis. Besides, strategies basing on ROS to fight skin cancer are discussed.

Health-Related Quality of Life, Satisfaction with Care, and Cosmetic Results in Relation to Treatment among Patients with Keratinocyte Cancer in the Head and Neck Area: Results from the PROFILES Registry

BACKGROUND

Little is known about the impact of keratinocyte cancer (KC) and its treatment on health-related quality of life (HRQoL).

OBJECTIVES

The objectives of the present study were (1) to evaluate HRQoL among patients with KC in a population-based setting and compare this with an age- end sex-matched normative population and (2) to compare HRQoL, satisfaction with care, and cosmetic results among patients who underwent conventional excision, Mohs' micrographic surgery, or radiotherapy.

METHOD

A random sample of 347 patients diagnosed with cutaneous basal cell or squamous cell carcinoma in the head and neck area between January 1, 2010, and December 31, 2014, were selected from the Netherlands Cancer Registry (NCR) and were invited to complete a questionnaire on HRQoL, satisfaction with care, and cosmetic results. Data were collected within Patient-Reported Outcomes Following Initial Treatment and Long-term Evaluation of Survivorship (PROFILES). Outcomes were compared to an age- and sex-matched normative population.

RESULTS

Two hundred fifteen patients with KC returned a completed questionnaire (62% response). Patients with KC reported better global quality of life (79.6 vs. 73.3, p < 0.01) and less pain (p < 0.01) compared to the normative population. No statistically significant differences in HRQoL, satisfaction with care, and cosmetic results were found between patients with KC who underwent conventional excision, Mohs' micrographic surgery, or radiotherapy.

CONCLUSIONS

The impact of KC and its treatment seems relatively low and more positive than negative as patients reported better HRQoL compared to an age- and sex-matched normative population, probably due to adaptation. No statistically significant differences between treatment types were found concerning HRQoL, patient satisfaction, and cosmetic results. This information could be used by healthcare professionals involved in KC care to improve patients' knowledge about different aspects of the disease as patient's preference is an important factor for treatment choice.

Low-cost optical scanner and 3-dimensional printing technology to create lead shielding for radiation therapy of facial skin cancer: First clinical case series

Purpose

Three-dimensional printing has been implemented at our institution to create customized treatment accessories, including lead shields used during radiation therapy for facial skin cancer. To effectively use 3-dimensional printing, the topography of the patient must first be acquired. We evaluated a low-cost, structured-light, 3-dimensional, optical scanner to assess the clinical viability of this technology.

Methods and materials

For ease of use, the scanner was mounted to a simple gantry that guided its motion and maintained an optimum distance between the scanner and the object. To characterize the spatial accuracy of the scanner, we used a geometric phantom and an anthropomorphic head phantom. The geometric phantom was machined from plastic and included hemispherical and tetrahedral protrusions that were roughly the dimensions of an average forehead and nose, respectively. Polygon meshes acquired by the optical scanner were compared with meshes generated from high-resolution computed tomography images. Most optical scans contained minor artifacts. Using an algorithm that calculated the distances between the 2 meshes, we found that most of the optical scanner measurements agreed with those from the computed tomography scanner within approximately 1 mm for the geometric phantom and approximately 2 mm for the head phantom. We used this optical scanner along with 3-dimensional printer technology to create custom lead shields for 10 patients receiving orthovoltage treatments of nonmelanoma skin cancers of the face. Patient, tumor, and treatment data were documented.

Results

Lead shields created using this approach were accurate, fitting the contours of each patient's face. This process added to patient convenience and addressed potential claustrophobia and medical inability to lie supine.

Conclusions

The scanner was found to be clinically acceptable, and we suggest that the use of an optical scanner and 3-dimensional printer technology become the new standard of care to generate lead shielding for orthovoltage radiation therapy of nonmelanoma facial skin cancer.

High dose rate brachytherapy with customized applicators for malignant facial skin lesions

PURPOSE

Brachytherapy is a well-known treatment in the management of skin tumors. For facial or scalp lesions, applicators have been developed to deliver non-invasive treatment. We present cases treated with customized applicators with high dose rate system.

MATERIAL AND METHODS

Patients with poor performance status treated for malignant skin lesions of the scalp or the facial skin between 2011 and 2014 were studied. Afterloading devices were chosen between Freiburg(®) Flap, silicone-mold or wax applicators. The clinical target volume (CTV) was created by adding margins to lesions (10mm to 20mm). The dose schedules were 25Gy in five fractions for postoperative lesions, 30Gy in six fractions for exclusive treatments and a single session of 8Gy could be considered for palliative treatments.

RESULTS

In 30 months, 11 patients received a treatment for a total of 12 lesions. The median age was 80 years. The median follow-up was 17 months and the 2-year local control rate was 91%. The mean CTV surface was 41.1cm(2) with a mean thickness of 6.1mm. We conceived three wax applicators, used our silicone-mold eight times and the Freiburg(®) Flap one time. We observed only low-grade radiodermitis (grade I: 50%, grade II: 33%), and no high-grade skin toxicity.

CONCLUSION

High dose rate brachytherapy with customized applicators for facial skin and scalp lesions is efficient and safe. It is a good modality to treat complex lesions in patients unfit for invasive treatment.

Novel treatment options for nonmelanoma skin cancer: focus on electronic brachytherapy

Nonmelanoma skin cancer (NMSC) is an increasing health care issue in the United States, significantly affecting quality of life and impacting health care costs. Radiotherapy has a long history in the treatment of NMSC. Shortly after the discovery of X-rays and ²²⁶Radium, physicians cured patients with NMSC using these new treatments. Both X-ray therapy and brachytherapy have evolved over the years, ultimately delivering higher cure rates and lower toxicity. Electronic brachytherapy for NMSC is based on the technical and clinical data obtained from radionuclide skin surface brachytherapy and the small skin surface applicators developed over the past 25 years. The purpose of this review is to introduce electronic brachytherapy in the context of the history, data, and utilization of traditional radiotherapy and brachytherapy.

A pilot study of ultrasound-guided electronic brachytherapy for skin cancer

PURPOSE

Electronic brachytherapy (eBT) has gained acceptance over the past 5 years for the treatment of non-melanomatous skin cancer (NMSC). Although the prescription depth and radial margins can be chosen using clinical judgment based on visual and biopsy-derived information, we sought a more objective modality of measurement for eBT planning by using ultrasound (US) to measure superficial (< 5 mm depth) lesions.

MATERIAL AND METHODS

From December 2013 to April 2015, 19 patients with 23 pathologically proven NMSCs underwent a clinical examination and US evaluation of the lesions prior to initiating a course of eBT. Twenty lesions were basal cell carcinoma and 3 lesions were squamous cell carcinoma. The most common location was the nose (10 lesions). A 14 or 18 MHz US unit was used by an experienced radiologist to determine depth and lateral extension of lesions. The US-measured depth was then used to define prescription depth for eBT planning without an added margin. A margin of 7 mm was added radially to the US lateral extent measurements, and an appropriate cone applicator size was chosen to cover the target volume.

RESULTS

The mean depth of the lesions was 2.1 mm with a range of 1-3.4 mm, and the mean largest diameter of the lesions was 8 mm with a range of 2.6-20 mm. Dose ranged from 32-50 Gy in 8-20 fractions with a median dose of 40 Gy in 10 fractions. All patients had a complete response and no failures have occurred with a median follow-up of 12 months (range of 6-22 months). Also, no prolonged skin toxicities have occurred.

CONCLUSIONS

A routinely available radiological US unit can objectively determine depth and lateral extension of NMSC lesions for more accurate eBT treatment planning, and should be considered in future eBT treatment guidelines.

Combined Treatments with Photodynamic Therapy for Non-Melanoma Skin Cancer

Non-melanoma skin cancer (NMSC) is the most common form of cancer in the Caucasian population. Among NMSC types, basal cell carcinoma (BCC) has the highest incidence and squamous cell carcinoma (SCC) is less common although it can metastasize, accounting for the majority of NMSC-related deaths. Treatment options for NMSC include both surgical and non-surgical modalities. Even though surgical approaches are most commonly used to treat these lesions, Photodynamic Therapy (PDT) has the advantage of being a non-invasive option, and capable of field treatment, providing optimum cosmetic outcomes. Numerous clinical research studies have shown the efficacy of PDT for treating pre-malignant and malignant NMSC. However, resistant or recurrent tumors appear and sometimes become more aggressive. In this sense, the enhancement of PDT effectiveness by combining it with other therapeutic modalities has become an interesting field in NMSC research. Depending on the characteristics and the type of tumor, PDT can be applied in combination with immunomodulatory (Imiquimod) and chemotherapeutic (5-fluorouracil, methotrexate, diclofenac, or ingenol mebutate) agents, inhibitors of some molecules implicated in the carcinogenic process (COX2 or MAPK), surgical techniques, or even radiotherapy. These new strategies open the way to a wider improvement of the prevention and eradication of skin cancer.