Superficial X-ray Therapy Research Articles

Measurements regarding a combined therapy concept for ophthalmic tumors consisting of brachytherapy and x-rays

Objective. We present a novel concept to treat ophthalmic tumors which combines brachytherapy and low-energy x-ray therapy. Brachytherapy with 106Ru applicators is inadequate for intraocular tumors with a height of 7 mm or more. This results from a steep dose gradient, and it is unfeasible to deliver the required dose at the tumor apex without exceeding the maximum tolerable sclera dose of usually 1000 Gy to 1500 Gy. Other modalities, such as irradiation with charged particles, may be individually contraindicated. A dose boost at the apex provided by a superficial x-ray therapy unit, performed simultaneously with the brachytherapy, results in a more homogeneous dose profile than brachytherapy alone. This avoids damage to organs at risk. The applicator may also serve as a beam stop for x-rays passing through the target volume, which reduces healthy tissue dosage. This study aims to investigate the suitability of the applicator to serve as a beam stop for the x-rays. Approach. A phantom with three detector types comprising a soft x-ray ionization chamber, radiochromic films, and a self-made scintillation detector was constructed to perform dosimetry. Measurements were performed using a conventional x-ray unit for superficial therapy to investigate the uncertainties of the phantom and the ability of the applicator to absorb x-rays. The manufacturer provided a dummy plaque to obtain x-ray dose profiles without noise from 106Ru decays. Results. The phantom is generally feasible to obtain dose profiles with three different detector types. The interaction of x-rays with the silver of the applicator leads to an increased dose rate in front of the applicator. The dose rate of the x-rays is reduced by up to 90% behind a 106Ru applicator. Therefore, a 106Ru applicator can be used as a beam stop in combined x-ray and brachytherapy treatment.

Use of a PLA sleeve to remove electron enhancement in superficial X-ray therapy.

A newly installed superficial X-ray unit was found to produce enhanced electron dose at the skin surface. The ACPSEM kilovoltage dosimetry recommendations suggest using nail varnish within the treatment cones as a method to reduce this dose. In this study, a 3D PLA sleeve was produced and used as an alternative to the nail varnish for energies between 55 and 100kV. Further, plastic wrap was also investigated as an alternative method to reduce dose. It was found that a 1mm printed sleeve, inserted into the treatment cone sufficiently reduced the enhanced dose as measured with a thin-window Exradin chamber to within 3.3% of the dose measured with a Farmer-type ionisation chamber. The use of plastic wrap also reduced the enhanced dose, but impracticalities in its use make it non-viable for routine clinical use.

The efficacy and safety of topical Tretinoin combined with superficial X-ray therapy (SXRT) in treating periungual warts.

There are multiple treatment modalities for periungual warts (PWs), although most are destructive and painful, limiting their application. Radiotherapy is a non-invasive method suitable for treating PW patients with contraindications to invasive procedures. To investigate the efficacy and safety of topical Tretinoin combined with Superficial X-ray therapy (SXRT) in treating PWs. This study included patients with 65 PWs who underwent treatment and a 3-month follow-up. Twenty four PWs were subjected to SXRT alone (group A). The remaining 41 PWs were subjected to SXRT combined with the application of the Tretinoin cream from the first day (group B). The overall clinical response rate, recurrence rates, cosmetic outcomes, and adverse events were observed during the follow-up period. The complete clearance rate (75% vs. 92.7% in groups A and B, respectively) and healing times (19.9 vs. 16.0 days in groups A and B, respectively) between the two groups were significantly different (p< 0.046 and 0.04), indicating the combination treatment is more effective. Notably, there was no damaging or permanent deformation on the nail, and the other adverse effects were mild and bearable. Topical Tretinoin combined with SXRT therapy is an effective strategy for treating PWs, with minor side effects. It is painless and with excellent cosmetic outcomes.

ПАЦИЕНТОРИЕНТИРОВАННЫЙ АЛГОРИТМ РАБОТЫ РЕНТГЕНОТЕРАПЕВТИЧЕСКОГО КАБИНЕТА ОНКОЛОГИЧЕСКОГО ДИСПАНСЕРА

Results: IIntroduction: Superficial X-ray therapy is a common treatment of non-melanoma skin cancer with a high incidence worldwide. Interrupting the course of radiation therapy can negatively affect patient survival and treatment results. Low treatment adherence may be associated with a lack of a patient-centered approach and ineffective communications. The original study shows that patients undergoing X-ray therapy for cancer may have different needs. Based on the study results an algorithm for a patient-oriented approach has been developed for the X-ray cabinets.&#x0D; Purpose: To develop a patient-oriented algorithm of the X-ray therapy room to address the issues of increasing patient satisfaction and forming their adherence to treatment. The objectives of the study included studying and detailing the needs of the patients who passed the X-ray therapy and to develop the patient-oriented algorithm for the X-ray therapy room.&#x0D; Material and methods: The study of the patient's values was carried out from 2019 to 2020 by interviewing using open-ended questions to find out the deep motives and beliefs of patients. The study was based on Milton Rokich’s (2005) model of value orientations, which was adapted to the objectives of the study.&#x0D; Results: The study included 116 patients undergoing treatment with the X-ray therapy at the City Clinical Oncology Dispensary. As a result of the study, the following patient needs were identified: clinical outcome of the procedure 111 (96 %), safety of treatment and adverse reactions 106 (91 %), cosmetic outcome 53 (46 %), convenience of the treatment schedule 42 (36 %), painlessness of the procedure 39 (34 %), the ability to lead a normal lifestyle 27 (23 %), comfortable conditions for the procedure 16 (14 %), financial costs associated with treatment 10 (9 %), preservation of organ function 4 (3 %). On the basis of the data obtained, a patient-oriented algorithm for the X-ray therapy was developed, including a communication plan with the patient. The study results clearly demonstrate that even with the same disease and condition, patients may have different priorities hat need to be considered to improve patient experience and adherence to treatment.&#x0D; Conclusion: Radiation treatment decision-making based on the patients values is important for the development of the patient-centered management in oncology since this directly affects patients’ adherence to treatment. Exploring the values and needs of patients is an opportunity to influence and improve the metrics of the patient experience. Due to the mass incidence of non-melanoma skin cancer, the introduction of patient-centered approaches is an important part of patient satisfaction and increase of patients adherence to the treatment.

PO-1496 Superficial X-Ray Therapy in Keloids after surgery: our experience

PO-1496 Superficial X-Ray Therapy in Keloids after surgery: our experience

Superficial X-ray therapy beam measurements using a liquid-filled chamber array

Superficial treatment from units such as the Gulmay D3300 investigated in this study are usually measured using a single ionization chamber at the central axis. Dose falls off from the central axis towards the periphery of the field. This falloff is asymmetrical in the anode-cathode axis due to the heel effect. Current clinical practice is to prescribe dose to the central axis, which neglects the varying dose across the treatment field. Therefore, it is important to formulate a methodology to quantify this. This study investigates the viability of the PTW LA-48 Linear Chamber Array with 100 and 140 kVp beam energies with seven applicators by comparing measurements with GAFChromic EBT-3 Film measurements which is validated for use at those beam energies in previous studies. The PTW LA-48 Array has 47 isooctane-filled chambers in series allowing investigation of off-axis dose. Measurements were taken under 5 mm of liquid water using a PTW MP3 Water Tank. Film measurements were taken under 5 mm of solid water and analysed using FilmQA Pro. Both data sets were made relative to the measured central axis dose and compared. The average percentage difference between measurements for each applicator ranged between −2 ± 2% and 1.5 ± 0.5% for 100 kVp and −2 ± 1% to 2 ± 3% for 140 kVp, where the uncertainty is the standard error. These results show that the PTW LA-48 measurements were comparable to the EBT-3 Film measurements and highlight the potential for liquid-filled chamber arrays to be utilised to investigate off-axis dose for superficial X-ray therapy units.

Superficial X-ray therapy beam measurements using a liquid-filled chamber array

Superficial X-ray therapy beam measurements using a liquid-filled chamber array

Лучевая нагрузка на медицинский персонал, сопровождающий пациента при близкофокусной рентгенотерапии детей

Purpose: Assessment the radiation situation in the treatment room of superficial x-ray therapy during the irradiation process in order to inform about radiation exposure of medical personnel or a relatives. &#x0D; Material and methods: In the course of the study, a procedure of superficial radiotherapy was simulated using a tissue equivalent phantom with sizes 250×250×150 mm. The radiation control protocol of measurements on the Roentgen TA-02 apparatus was compiled on the basis of SanPiN 2.6.1.1192-03. With the help of a clinical dosimeter DKS-AT1123, the ambient dose-rate of short-term x-rays was measured. In accordance with the requirements for conducting radiation monitoring, measurements were taken directly near the apparatus in areas 60×60 cm at points located at heights corresponding to the head level (160 ± 20 cm), chest level (120 ± 20 cm), gonad level (80 ± 20 cm) and the level of the legs (30 ± 20 cm). On the basis of the obtained data, the value of the effective dose-rate of x-ray radiation for the whole human body was calculated for each area. Taking into account the characteristics of the irradiation regime used in the clinic, the total effective dose received by the medical personnel accompanying the patient for the entire course of radiotherapy was calculated.&#x0D; Results: A drawn up diagram is illustrating the radiation situation in the treatment room of superficial radiotherapy. Based on the results of calculations, it can be concluded that the radiation exposure on the accompanying person during superficial x-ray therapy of children’s hemangiomas does not exceed the maximum permissible dose specified in paragraph 5.4.4 of SanPiN 2.6.1.2523-09.&#x0D; Conclusion: In exceptional cases, a parent or medical personnel may be in the treatment room to support the patient.

Head and Neck Non-Melanoma Skin Cancer Treated By Superficial X-Ray Therapy: An Analysis of 1021 Cases

IntroductionTo report a single-institutional experience with the use of Superficial X-Ray Therapy (SXRT) for head and neck non-melanoma skin cancer (N-MSC) and to compare outcomes by prescribed fractionation schedules.Materials and MethodsThe medical records of 597 patients with 1021 lesions (720 BCC, 242 SCC, 59 SCC in situ) treated with kilovoltage radiation from 1979–2013 were retrospectively reviewed. The majority of patients were treated according to 1 of 3 institutional protocols based on the discretion of the radiation oncologist: 1) 22 x 2.5 Gy; 2) 20 x 2.5 Gy; 3) 30 x 2.0 Gy. "T" stage at first presentation was as follows: Tis (59); T1 (765); T2 (175); T3 (6), T4 (9); Tx, (7). All patients were clinical N0 and M0 at presentation. Chi-square test was used to evaluate any potential association between variables. The Kaplan-Meier method was used to analyze survival with the Log Rank test used for comparison. A Cox Regression analysis was performed for multivariate analysis.ResultsThe median follow up was 44 months. No significant difference was observed among the 3 prescribed fractionation schemes (p = 0.78) in terms of RTOG toxicity. There were no failures among SCC in situ, 37 local failures (23 BCC, 14 SCC), 5 regional failures (all SCC) and 2 distant failures (both SCC). For BCC, the 5-year LC was 96% and the 10-year LC was 94%. For SCC the corresponding rates of local control were 92% and 87%, respectively (p = 0.03). The use of >2.0 Gy daily was significantly associated with improved LC on multivariate analysis (HR: 0.17; CI 95%: 0.05–0.59).ConclusionSXRT for N-MSC of the head and neck is well tolerated, achieves excellent local control, and should continue to be recommended in the management of this disease. Fractionation schedules using >2.0 Gy daily appear to be associated with improved LC.

Superficial X-ray Therapy for Non-Melanoma Skin Cancer of the Head and Neck: Comparative Analysis of H-Zone Versus Non-H-Zone Lesions

Superficial X-ray Therapy for Non-Melanoma Skin Cancer of the Head and Neck: Comparative Analysis of H-Zone Versus Non-H-Zone Lesions

Superficial X-Ray in the Treatment of Basal and Squamous Cell Carcinomas

Despite a number of benefits, including in recurrence rates, cost, cosmetic outcome, and patient comfort, the use of superficial x-ray therapy (SXRT)

Evaluating the Effects of Field Size on Beam Homogeneity Coefficient in the Superficial Radiotherapy Machine Using Empirical Method and Simulation

Introduction Superficial X-ray therapy is one of the most important treatment methods in radiotherapy especially in the treatment of superficial skin lesions (Up to 300 kVp). Quality of the X-ray beam that can be expressed by Half-Value Layer (HVL), are important indices for this type of treatment effective energy of photon and Homogeneity Coefficient (HC). Materials and Methods The HC of the superficial X-ray machine at 180 kVp was determined by an experimental method and also by simulation (EGSnrc code) and the results were compared. The exposure after the first (0.5 mmCu) and second (1 mmCu) attenuation layers were measured by Farmer dosimeter for three different field sizes. The HC was derived from these experimental data and was compared with corresponding results acquired by EGSnrc code package. The BEAMnrc code was used to transport photons and electrons at exit level of the applicator, DOSXYZnrc code for calculation of absorbed dose in the phantom, and BEAMDP for drawing the output spectra. Results Results showed that the mean percentage difference of errors obtained by experimental data and simulation method is 3.3% and the average energy of output spectra in 180 kVp after passing through filters and attenuation layers increases to 15.3% to 25.4%. Conclusion The maximum percentage difference of errors for the applied methods is higher than analogous devolves elsewhere reports which could be due to setup parameters such as SSD and field size. However, the present method has the advantage of ease of setup and matching with clinical conditions.

Superficial x-ray in the treatment of basal and squamous cell carcinomas: A viable option in select patients

Effective nonsurgical modalities are limited in the treatment of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). We sought to evaluate the efficacy and viability of superficial x-ray therapy in the treatment of BCC and SCC in an outpatient setting. A retrospective analysis was performed on 1715 histologically confirmed primary cutaneous BCC and SCC treated with superficial x-ray therapy at Dermatology Associates of Tallahassee in Florida between 2000 and 2010. Of the 1715 tumors reviewed during this period, 712 were histologically proven BCC (631 nodular and 81 superficial), 994 were SCC (861 SCC in situ and 133 invasive SCC), and 9 displayed distinct features of both BCC and SCC in the same biopsy specimen. Kaplan-Meier estimates (with 95% confidence intervals) of cumulative recurrence rates of all tumors at 2 and 5 years were 1.9% (1%-2.7%) and 5.0% (3.2%-6.7%), respectively; of BCC at 2 and 5 years were 2% (0.8%-3.3%) and 4.2% (1.9%-6.4%), respectively; and of all SCC at 2 and 5 years were 1.8% (0.8%-2.8%) and 5.8% (2.9%-8.7%), respectively. Tumors on male patients and those with a diameter greater than 2 cm were associated with a statistically significant increase in recurrence likelihood. This study represents only patients treated in 1 dermatology office in North Florida and may not be representative of the general patient population. Superficial x-ray therapy remains a viable nonsurgical option for the treatment of primary BCC and SCC in patients where surgical intervention is declined, unadvisable, or potentially associated with significant cosmetic or functional limitations.

Sci-Sat AM: Brachy - 07: Plastic scintillation detector validation for kV dosimetry.

To characterize the plastic scintillation detectors (PSDs) response in the diagnostic energy range. A fast and adaptable method for real-time dosimetry in superficial x-ray therapy and interventional radiology is proposed. A PSD (1 mm diameter and 10 mm long) is coupled to a 5 m long optical fiber. Scintillation photons are guided to a polychromatic photodiode which provides an electrical current proportional to the input light signal. If the incident energy spectrum is known, the dose measured in the PSD's polystyrene sensitive volume can be converted to score dose in any other media such as air, water or soft tissues using the large cavity theory (LCT). A software simulating x-ray tube spectra and filtration has been benchmarked and is used for analysis. The method is confirmed by Monte Carlo simulations. PSDs cannot be assumed energy independent with low-energy photons as a factor 2 has been observed in the energy response between 80 kVp and 150 kVp. When the dose is converted to the desired medium, the PSD's energy dependence is compensated and a 2.1% standard deviation was observed upon the studied energy ranges, which is inside the measurement and calculation uncertainties. Percent depth dose (PDD) measurements are in good agreement with Monte Carlo simulations and results can be improved if the proposed method is applied to compensate beam hardening. PSDs present great potential for real-time dose measurements with radiologic photon energy.

MO-F-213AB-06: Experimental Evaluation of Radiation Dose Effect by High Atomic Number Materials for Superficial Radiation Therapy.

High atomic number (Z) materials have been considered as a method for enhancing radiation dose in tumors. The dose enhancement due to interactions of kilovoltage x-rays with high-Z materials (i.e., gold or iodine) has been well demonstrated through computational works. This study is to experimentally quantify the effect using gold nanoparticles (AuNPs) and iodine solutions, respectively. Iodine and AuNPs (AuroVist, Nanoprobes, Yaphank NY) are uniformly distributed in each cylinder phantom (1.6 cm diameter and 2.0 cm depth) separately. Concentrations of Iodine and AuNPs were varied from 40 to 225 mg/ml and 16.0 mg/ml to 42.7 mg/ml, respectively. The Iodine solutions were irradiated with 75 to 150 kVp x-rays from a superficial x-ray therapy machine at doses of 250 to 400 cGy. The AuNPs solutions in the cylinder were irradiated with 40 to 150 kVp x-rays. The phantom was placed at the center of the cone to ensure a uniform radiation field. Radiation doses were measured using GafChromic EBT2 films (International Specialty Products, Wayne NJ). Dose enhancement factors (DEF), i.e., the ratio of dose to high-Z material versus dose to water, were calculated and plotted as functions of concentration and kVp. Experimental DEFs varied between 1.01 and 1.38. The DEFs increased with increasing concentration and varied with changing kVp. The maximum DEF measured for Iodine solution was 1.38 at 225 mg/ml and 150 kVp. The maximum DEF measured for AuNPs was 1.22 at 42.7 mg/ml and 40 kVp. The target volume covered by dose enhancement is larger with relatively lower concentrations. The magnitude of dose enhancement due to AuNPs and Iodine presence has a dependency with the concentration and kVp. In clinical applications, the concentration of the high-Z material and kVp should also be selected to suit the depth and volume of the target tumor.

The role of shielding in superficial X-ray therapy

Superficial X-ray therapy is applicable in the kilovoltage range for the treatment of the cancer. Pb shielding is used to protect radiation-sensitive organs since the doses are high, however the question about shielding efficiency is still open. The role of shielding was investigated in this work based on the results of dose measurements performed using a set of pencil dosemeters and thermoluminescent dosimetries. According to the measured angular dose distributions on the phantom surface during X-ray irradiation, the area near the applicator exposed to the waste irradiation was evaluated and Pb shielding of a corresponding size was chosen. It has been shown that the dose in the area of interest decreases non-linearly, however high shielding efficiency (~90 %) remains almost stable in the whole area. No significant contribution of secondary scattered photons from Pb has been observed. The role of Pb shielding in superficial X-ray therapy is discussed on the basis of the obtained results.

Minimal stage IA mycosis fungoides. Results of radiotherapy in 15 patients

Background: Mycosis fungoides (MF) minimal disease stage IA, characterized by one or few close lesions (up to four), has been considered a distinct entity with a favourable prognosis, where local treatment such as radiotherapy could afford long-lasting remissions. Objective: To review our experience in radiologic treatment of this subset of the disease and compare our results with those reported in the literature. Methods: Fifteen patients presenting with MF minimal disease were treated with localized superficial X-ray therapy, with a total median dose of 22 Gy. Results: At 1 month from the end of radiotherapy, complete remission was observed in 95.45% of irradiation fields and partial remission in 4.54%. The 5-year local progression-free rate was 93.75%, while the overall relapse-free rate at 5 and 10 years was 51%. Conclusions: After an excellent response to radiotherapy, MF minimal disease may experience local or distant failures, even after years. The identification of an optimal dose of radiation and the collection of more cases would be useful in giving new guidelines in the treatment of this subset of the disease.

Dose reduction from loss of backscatter in superficial x-ray radiation therapy with the Pantak SXT 150 unit

Loss of backscatter has been measured for a Pantak Therapax SXT 150 superficial x-ray therapy unit. Ionisation chamber measurements at the surface were performed in solid water with and without underlying lead to confirm the applicability of previous published measurements. Measurements of loss of backscatter with and without lead allowed the effect of underlying lead to be separated from the effect of loss of backscatter. It was found that the difference between the effect of lead and that of air on surface dose is minimal for solid water phantom thickness exceeding 3 cm. Differences up to 3% in dose reduction at the surface were found between this work and previous published results with different x-ray units.

Use of injection five fluorouracil (FFU) with or without injection trimacinolone in the management of hypertrophic scars and keloids

Sir, Keloids are a common dermatological problem faced by Dermatologists and existing modalities of treatment are unsatisfactory. Though, different modalities have been tried, recurrences are common. We hereby report the efficacy of 5 fluorouracil (FFU) in treating keloids. Thirty cases were selected for the study. Local anaesthesia was administered only for keloids >3 cm length. Field block anaesthesia was achieved by infiltrating injection bupivacaine 0.25% around the lesion. Injection FFU 50 mg/ml was infiltrated along the length of the keloid with a leur-lock syringe and 25G × 1½ needle. In cases of inflammed or hard keloids, injection triamcinolone 40 mg/ml was added to injection FFU in the ratio 1:1. Maximum dose of FFU used at a time was 1.5 ml. Patient was sent home after the injection, with instruction to apply sodium fusidate or mupirocin ointment for 5 days. Non-steroidal anti-inflammatory drugs (NSAIDs) were advised for pain. Patients were assessed after 4 weeks and, the treatment was repeated if necessary. Out of the 30 patients, six were lost to follow up. Sixteen patients showed complete flattening of keloids after an average of four injections. All these patients were advised to use Silicon-gel dressing for 3 months. Out of these 16 patients, 12 patients showed no recurrence at the end of 1 year. Commonest side effect observed with FFU injection was temporary blackish discoloration in four cases. Infection was seen in one patient who received concomitant triamcenolone. Post-steroid hypopigmentation was seen in two cases. Keloid is an overgrowth of dense fibrous tissue that extends beyond the borders of the original wound, whereas hypertrophic scar remains confined to the borders of the original wound. Abnormal wound healing results in disruption of the cascade of events in collagen synthesis, which leads to formation of hypertrophic scar or keloid.[1] Exact aetiology of keloid is still not fully understood, but genetic predisposition is seen in cases of keloid, along with predisposition for anatomical sites like chest, shoulders, jaw line, upper back, gluteal region, ears, etc. Increased skin stretching at the above-mentioned anatomical sites and wound infection may be the factors contributing to the formation of keloids. Usually treatment for keloids is sought for pain, pruritus, discomfort, cosmetic disfigurement and restriction of movements. Available treatment modalities include: intralesional steroid injections, cryotherapy with or without steroid injections, intralesional cryotherapy, excision followed by silicon-gel dressings, pulsed dye laser (585 nm), superficial X-ray therapy, etc. All these therapies have shown temporary regression in the size of keloids, but recurrence is known with all the modalities.[2] Five fluorouracil has been shown to inhibit fibroblasts in tissue culture and is believed to reduce post-op scarring. Corticosteroids suppress inflammation and cause vasoconstriction. Their antimitotic effect results in inhibition of fibroblasts and keratinocytes. In our study, complete flattening of keloid was seen in 75% cases with no recurrence. These preliminary results are encouraging, but further studies are needed to confirm these early findings.

A prospective clinical review of "multi model" approach for treating ear keloids

This is a prospective clinical study of 46 ear keloids in 31 patients (with a mean follow-up of 18 months) treated from January 2006 to December 2006 at The Queen Elizabeth Public Hospital, Barbados, West Indies by a single surgeon. The mean age is 21.9 years (range 3-66 years). Seven out of 46 lesions were recurrent lesions following previous surgery. All the lesions were excised surgically (extralesional). Ten out of 31 patients were given postoperative, Intralesional Triamcinolone starting from the 1st post operative visit on three visits at monthly intervals. Fourteen patients were given postoperative superficial X-ray therapy of 12 Gy in three equal fractions on three consecutive days starting from the 3rd postoperative day. Seven recurrent keloids of this study were given a combination of both superficial X-ray therapy and intralesional triamcinolone. All patients were followed at monthly intervals for three visits from the time of surgery and every three months until the end of the 1st year and then every six months thereafter. Five of 46 postoperative surgical wounds showed evidence of recurrence during the 1st year but could be suppressed with Intralesional triamcinolone. This study confirms that surgical excision of keloids supplemented with radiotherapy and/Intralesional triamcinolone is a reliable method with few complications. In addition, the study concludes that the key in preventing recurrence is regular clinical follow-up to encounter early recurring lesion (clinical evidence of raised scars or palpable nodules if deep seated) which is 100% susceptible to Intralesional triamcinolone for 2-3 times at monthly intervals.