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5 result(s) for "valencia applicator"
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Non-melanoma skin cancer treated with HDR Valencia applicator: clinical outcomes
Radiotherapy (RT) has played a significant role in treating non melanoma skin cancer (NMSC). High-dose-rate brachytherapy (HDR-BT) approaches have a paramount relevance due to their adaptability, patient protection, and variable dose fractionation schedules. Several innovative applicators have been introduced to the brachytherapy community. The Valencia applicator is a new superficial device that improves the dose distribution compared with the Leipzig applicator. The purpose of this work is to assess the tumor control, cosmesis, and toxicity in patients with NMSC treated with the Valencia applicator and a new regimen of hypofractionation. From January 2008 to March 2010, 32 patients with 45 NMSC lesions were treated with the Valencia applicator in the Hospital La Fe. The gross tumor volume was visually assessed, but the tumor depth was evaluated using ultrasound imaging. All lesions for the selected cases were limited to 4 mm depth. The prescription dose was 42 Gy in 6 or 7 fractions (biologically effective dose [BED] ≈ 70 Gy), delivered twice a week. Ninety-eight percent of the lesions were locally controlled at 47 months from treatment. Ninety-three percent of patients were out at least 36 months from treatment. The treatment was well tolerated in all cases. The highest skin toxicity was grade 1 RTOG/EORTC, having resolved with topical treatment at 4 weeks in all but one case which required 2 months. There were no grade 2 or higher late adverse events. In patients with superficial basal cell carcinoma lesions less than 25 mm in maximum diameter, HDRBT treatment with the Valencia applicator using a hypofractionated regimen provides excellent results, for both cosmetic and local control at a minimum of 3 years follow-up. Moreover, the shorter hypofractionated regimen facilitates compliance, which is very relevant for the elderly patients in our series. Valencia applicators offer a simple, safe, quick, and attractive nonsurgical treatment option.
Two different sizes of Valencia applicators in non-melanoma skin cancer treatment with iridium-192 high-dose-rate brachytherapy
The aim of this retrospective study was to analyze tumor control, toxicity, and aesthetic outcome of patients affected by non-melanoma skin cancer (NMSC) and treated with iridium-192 ( Ir) high-dose-rate (HDR) brachytherapy (BT) using Valencia applicators at the Division of Radiotherapy, University of Pisa. From June 2015 to December 2020, 95 NMSC patients, including 61.5% basal cell carcinoma and 38.5% squamous cell carcinoma patients, with median age of 83 years (range, 32-96 years) were treated. In total, 182 lesions with a diameter ≤ 25 mm (median, 12 mm) and a depth ≤ 4 mm, located in scalp (19.2%), face (20.9%), chest (8.8%), nose (16.5%), ear (15.4%), and extremities (19.2%) were analyzed. All lesions were treated with Ir-based HDR afterloader using Valencia applicators. 105 lesions (57.7%) were treated with applicator of 20 mm and 77 lesions (42.3%) with applicator of 30 mm in diameter, depending on the size of lesions. Prescribed dose was 40 Gy in 8 fractions (5 Gy/fraction) delivered 2-3 times a week. Biological effective dose (BED) was ≈ 60 Gy. The median follow-up was 14 months (range, 3-59 months). The 2-year local control rate was 96%. According to common terminology criteria for adverse events (CTCAE v. 5.0), G1-G2 acute toxicities included dermatitis (22.0%) and pain (8.2%). The most common G1 late toxicities were hypopigmentation (27.5%) and fibrosis (8.2%), and G2 late toxicity included ulceration (0.5%). No G3 or higher acute or late toxicities were reported. Excellent cosmetic results were observed in 77.5% of the lesions, with one only (0.5%) reported as a poor cosmetic result (ulceration refractory to therapy). HDR-BT using Valencia applicators is a safe, effective, and well-tolerated treatment modality for NMSC, and can be considered a good alternative for treatment, especially in elderly patients who are often unfit for surgery.
High-dose-rate brachytherapy in the treatment of skin Kaposi sarcoma
The aim of the study is to review our experience in treatment of Kaposi sarcoma (KS) lesions with high-dose-rate (HDR) brachytherapy. We present five new KS lesions (three patients) that were treated in our hospital from May 2016 to February 2017 with HDR brachytherapy using Valencia applicators. The treatment was delivered in 5 Gy fractions over five sessions, on alternate days. Total dose of 25 Gy (EQD 31.25 Gy) was delivered. All patients were male, Caucasian, without a history of HIV, organ transplantation, or current immunosuppressive therapy. The median age was 76 years. All lesions (100%) were located in lower limbs (60% in the ankle, 20% in the leg, and 20% in the foot), and their development was progressive. No lesion was greater than 2 cm (range, 0.5-1.5 cm). With a median follow-up of 15 months, all patients had a complete response to the treatment, with no evidence of local recurrence or tumor progression. Most of the patients (80%) had no acute toxicity; only one patient developed erythema grade 2. HDR brachytherapy could be a good option of treatment for these types of lesions, especially in elderly patients, or when cosmetic results are not good after surgery. Brachytherapy with the Valencia applicator, using hypofractionated regimen provides excellent results in terms of cosmetic and local control, and furthermore, facilitates treatment compliance, which is very relevant in elderly patients. HDR brachytherapy offers a simple, safe, quick, and attractive non-surgical treatment option.
Commissioning and quality assurance procedures for the HDR Valencia skin applicators
The Valencia applicators (Nucletron, an Elekta company, Elekta AB, Stockholm, Sweden) are cup-shaped tungsten applicators with a flattening filter used to collimate the radiation produced by a high-dose-rate (HDR) Ir source, and provide a homogeneous absorbed dose at a given depth. This beam quality provides a good option for the treatment of skin lesions at shallow depth (3-4 mm). The user must perform commissioning and periodic testing of these applicators to guarantee the proper and safe delivery of the intended absorbed dose, as recommended in the standards in radiation oncology. In this study, based on AAPM and GEC-ESTRO guidelines for brachytherapy units and our experience, a set of tests for the commissioning and periodic testing of the Valencia applicators is proposed. These include general considerations, verification of the manufacturer documentation and physical integrity, evaluation of the source-to-indexer distance and reproducibility, setting the library plan in the treatment planning system, evaluation of flatness and symmetry, absolute output and percentage depth dose verification, independent calculation of the treatment time, and visual inspection of the applicator before each treatment. For each test, the proposed methodology, equipment, frequency, expected results, and tolerance levels (when applicable) are provided.
The use of Valencia applicators at extended source surface distances for irregular surface contours
The use of Valencia applicators across irregular surface contours results in significant dose heterogeneities at the prescription depth. Investigations were carried out using extended source surface distances (standoff) to reduce these dose heterogeneities. Relative output factors were measured with a Roos chamber and Gafchromic EBT3 film was used to measure profiles and percentage depth doses at numerous standoff distances. The use of 20 mm standoff was found to reduce the relative difference in delivered dose across a 4 mm change in surface contour by 10.6 % for the H2 applicator and 10.0 % for the H3 applicator. The radiation became more penetrating with standoff and the field size larger, as expected. The results show that standoff can be used with the Valencia applicator to reduce dose heterogeneities across changes in surface contour.