Highly conformal CT based surface mould brachytherapy for non-melanoma skin cancers of earlobe and nose
نویسندگان
چکیده
PURPOSE Brachytherapy (BT), due to rapid dose fall off and minor set-up errors, should be superior to external beam radiotherapy (EBRT) for treatment of lesions in difficult locations like nose and earlobe. Evidences in this field are scarce. We describe computed tomography (CT) based surface mould BT for non-melanoma skin cancers (NMSC), and compare its conformity, dose coverage, and tissue sparing ability to EBRT. MATERIAL AND METHODS We describe procedure of preparation of surface mould applicator and dosimetry parameters of BT plans, which were implemented in 10 individuals with NMSC of nose and earlobe. We evaluated dose coverage by minimal dose to 90% of planning target volume (PTV) (D90), volumes of PTV receiving 90-150% of prescribed dose (PD) (VPTV90-150), conformal index for 90 and 100% of PD (COIN90, COIN100), dose homogeneity index (DHI), dose nonuniformity ratio (DNR), exposure of organs. Prospectively, we created CT-based photons and electrons plans. We compared conformity (COIN90, COIN100), dose coverage of PTV (D90, VPTV90, VPTV100), volumes of body receiving 10-90% of PD (V10-V90) of EBRT and BT plans. RESULTS We obtained mean BT-DHI = 0.76, BT-DNR = 0.23, EBRT-DHI = 1.26. We observed no significant differences in VPTV90 and D90 between BT and EBRT. Mean BT-VPTV100 (89.4%) was higher than EBRT-VPTV100 (71.2%). Both COIN90 (BT-COIN90 = 0.46 vs. EBRT-COIN90 = 0.21) and COIN100 (BT-COIN100 = 0.52 vs. EBRT-COIN100 = 0.26) were superior for BT plans. We observed more exposure of normal tissues for small doses in BT plans (V10, V20), for high doses in EBRT plans (V70, V90). CONCLUSIONS Computed tmography-based surface mould brachytherapy for superficial lesions on irregular surfaces is a highly conformal method with good homogeneity. Brachytherapy is superior to EBRT in those locations in terms of conformity and normal tissue sparing ability in high doses.
منابع مشابه
Verification of delivered dose to the Lips carcinoma tumors with HDR brachytherapy sources: 192Ir and 60CO in an exclusive plexiglass Phantom.
Introduction: Brachytherapy, especially using manually after loaded Iridium-192 and Cobalt-60, can be applied as a sole treatment, as a treatment complementary to surgery, and as a local boost in combination with EBRT. The use of HDR brachytherapy catheters incorporated in removable dental molds allows repeated, highly reproducible, fractionated outpatient brachytherapy of supe...
متن کاملIncidence of non-melanoma skin cancers in Isfahan
Background and aim: Non-melanoma skin cancers (NMSC) are one of the most prevalent malignancies of the human. Although the morality rate is not high for these cancers, they may cause high morbility for the patients. In addition to the skin type, factors such as sun exposure, head and neck radiotherapy, inappropriate use of sunscreen and cultural changes may increase the incidence of these...
متن کاملIndividualized 3D scanning and printing for non-melanoma skin cancer brachytherapy: a financial study for its integration into clinical workflow
PURPOSE Skin cancer is the most common tumor in the population. There are different therapeutic modalities. Brachytherapy is one of the techniques used, in which it is necessary to build customized moulds for some patients. Currently, these moulds are made by hand using rudimentary techniques. We present a new procedure based on 3D printing and the analysis of the clinical workflow. MATERIAL ...
متن کاملThe initial experience of electronic brachytherapy for the treatment of non-melanoma skin cancer
BACKGROUND Millions of people are diagnosed with non-melanoma skin cancers (NMSC) worldwide each year. While surgical approaches are the standard treatment, some patients are appropriate candidates for radiation therapy for NMSC. High dose rate (HDR) brachytherapy using surface applicators has shown efficacy in the treatment of NMSC and shortens the radiation treatment schedule by using a conde...
متن کاملAre there Relationships between the VDR-FokI Polymorphism and Vitamin D and the Insulin Resistance in Non-melanoma Skin Cancer (NMSC) Patients? A Protocol for Case-control Studies
Background and Objectives: Evidence indicate relationships between the sunlight exposure, vitamin D status and non-melanoma skin cancer (NMSC) risk. Vitamin D receptor (VDR) polymorphisms have been linked to metabolic changes in insulin resistance and various cancers. The purpose of this study is to investigate relationships between the sunlight exposure and the NMSC risk. Furthermore, relation...
متن کامل