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Background: Ocular melanoma is a rare kind of eye malignancy that threatens the patient's eyesight. Radiotherapy and surgical removal are the most commonly used therapeutic modalities, and nanomedicine has lately entered this field. Brachytherapy using Ruthenium-106 ( 106 Ru) ophthalmic plaques has been used for decades to treat ocular melanoma, with the applicator placed on the patient's eyes until the prescribed dose reaches the tumor apex., Purpose: To investigate the efficiency of hydrogen nanobubbles (H 2 -NBs) employment during intraocular melanoma brachytherapy using a 106 Ru electron emitter plaque., Methods: The Monte Carlo (MC) simulation and experimental investigation using a 3D-designed phantom and thermoluminescence dosimetry (TLD) were employed. Various concentrations of H 2 -NBs with a diameter of 100 nm were simulated inside tumor tissue. The results were presented as deposited energy and dose enhancement factor (DEF). An equivalent Resin phantom of the human eyeball was made using AutoCAD and 3D-Printer technologies. The glass-bead TLDs dosimeter were employed and placed inside the phantom., Results: Using a 1% concentration of H 2 -NBs, a DEF of 93% and 98% were achieved at the tumor apex of 10 mm from the experimental setup and MC simulation, respectively. For simulated concentrations of 0.1%, 0.3%, 0.5%, 1%, and 4% H 2 -NBs, a maximum dose enhancement of 154%, 174%, 188%, 200%, and 300% were achieved, respectively, and a dose reduction was seen at about 3 mm from the plaque surface., Conclusion: H 2 -NBs can be used as an absorbed dose enhancer in 106 Ru eye brachytherapy because of their unique physical characteristics. Reducing plaque implantation time on the patient's eye, reducing sclera absorbed dose, and decreasing the risk of patients' healthy organs irradiation are reported as some of the potential benefits of using H2-NBs., (© 2023 American Association of Physicists in Medicine.)

The aim of this publication is the assessment of the existing guidelines for non-melanoma skin cancer (NMSC) superficial brachytherapy (BT) and make a critical review based on the existing literature about the maximum dose prescription depth, bolus thickness and maximum skin surface dose (D max ) of the published clinical practice. A systematic review of NMSC superficial BT published articles was carried out by the GEC-ESTRO Head & Neck and Skin (HNS) Working Group (WG). 10 members and 2 external reviewers compared the published clinical procedures with the recommendations in the current guidelines and examined the grade of evidence. Our review verified that there is a large variation among centres with regards to clinical practice in superficial BT and identified studies where published parameters such as maximum dose prescription depth, bolus thickness and D max exceed the constraints recommended in the guidelines, while showing excellent results in terms of local control, toxicity and cosmesis. This review confirmed that current recommendations on skin superficial BT do not include published experience on tumours treated with superficial BT that require dose prescription depth beyond the recommended 5 mm under the skin surface and that the existing literature does not provide sufficient evidence to relate dosimetry of superficial BT to patient reported outcome measures. The GEC-ESTRO HNS WG considers acceptable to prescribe superficial BT dose at a depth above 5 mm beyond the skin surface, and modify the bolus thickness to optimize the treatment plan and adjust the acceptable maximum dose on the skin surface, all pending clinical situation., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Purpose: This study aimed to evaluate the feasibility of defining an in vivo dosimetry (IVD) protocol as a patient-specific quality assurance (PSQA) using the bead thermoluminescent dosimeters (TLDs) for point and 3D IVD during brachytherapy (BT) of gynecological (GYN) cancer using 60 Co high-dose-rate (HDR) source., Methods: The 3D in vivo absorbed dose verification within the rectum and bladder as organs-at-risk was performed by bead TLDs for 30 GYN cancer patients. For rectal wall dosimetry, 80 TLDs were placed in axial arrangements around a rectal tube covered with a layer of gel. Ten beads were placed inside the Foley catheter to get the bladder-absorbed dose. Beads TLDs were localized and defined as control points in the treatment planning system (TPS) using CT images of the patients. Patients were planned and treated using the routine BT protocol. The experimentally obtained absorbed dose map of the rectal wall and the point dose of the bladder were compared to the TPSs predicted absorbed dose at these control points., Results: Relative difference between TPS and TLDs results were -8.3% ± 19.5% and -7.2% ± 14.6% (1SD) for rectum- and bladder-absorbed dose, respectively. Gamma analysis was used to compare the calculated with the measured absorbed dose maps. Mean gamma passing rates of 84.1%, 90.8%, and 92.5% using the criteria of 3%/2 mm, 3%/3 mm, and 4%/2 mm were obtained, respectively. Eventually, a "considering level" of at least 85% as pass rate with 4%/2-mm criteria was recommended., Conclusions: A 3D IVD protocol employing bead TLDs was presented to measure absorbed doses delivered to the rectum and bladder during GYN HDR-BT as a reliable PSQA method. 3D rectal absorbed dose measurements were performed. Differences between experimentally measured and planned absorbed dose maps were presented in the form of a gamma index, which may be used as a warning for corrective action., (© 2022 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, LLC on behalf of The American Association of Physicists in Medicine.)

Purpose: This retrospective study aims to evaluate the efficacy and safety of salvage HDR brachytherapy in second local recurrences of prostate cancer after applying radical prostatectomy (RP) and post-operative external beam radiotherapy (EBRT)., Materials and Methodology: Fifteen patients with locally recurrent prostate cancer after RP and EBRT were salvaged with HDR brachytherapy. Patients had no nodal or distant metastasis evidence on imaging findings, including whole body bone scan, CT scan, and MRI or PSMA PET scan. HDR brachytherapy was applied with 36 Gy in four fractions, in two implantations with 1 week apart. We followed the patients for a control visit every 3 months for 2 years, and every 6 months thereafter., Results: Fifteen patients with the mean age of 64 years (ranged 51-79) underwent salvage HDR brachytherapy. The mean baseline level of PSA was calculated 2.26 ng/ml (ranged from 0.21 to 9, SD = 2.33), which has been significantly decreased in all patients. Hence, two of our patients experienced a biochemical failure during the follow-up period. Our results showed that 86.6% (n = 13) of patients had never experienced a significant increment in PSA level after a median follow-up of 48 months (ranging from 12 to 132 months). Besides, salvage HDR brachytherapy did not induce any significant side effects such as acute or late rectal complications, despite causing urinary complication., Conclusions: HDR brachytherapy could be considered as a treatment in well-selected patients with the second recurrence in their prostatic bed after the former EBRT allowing for dose escalating to the second nodular recurrence., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Purpose: This study investigated the correlation between the prescription dose and dose to the Manchester and International Commission on Radiation Units and Measurements-report 38 (ICRU-38) lymphatic trapezoid points during high-dose-rate (HDR) brachytherapy of locally advanced cervical cancer with (Cobalt-60) 60Co ., Methods and Materials: A retrospective study was designed for; patients with locally advanced cervical cancer, treated by external beam radiotherapy and concurrent weekly Cisplatin-based chemotherapy, had no extended parametrial invasion and was treated by tandem-ovoid set, from 2017 to 2020. Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO) based target's volume, ICRU-89 revised version of Manchester points A and B, and ICRU-38 lymph node surrogate points were determined, and their dose was recorded. Paired sample t-test, linear regression analysis, and Pearson correlation analyses were done considering a statistical significance level of 0.05 and using IBM SPSS statistics (Version 23, IBM Crop.)., Results: Seventy-four brachytherapy cases were included. A positive and strong correlation was observed between D 90 of clinical target volume (CTV HR ) and points A and B dose for CTV HR 〈 15 cc and 〉 35 cc. Strong and significant (p < 0.05) correlations were achieved between pelvic wall points dose and D 90 and D 100 of the obturator and between D 50 and hot points of internal iliac lymph nodes. A strong correlation was obtained between D 50 and D 90 of external iliac lymph nodes and their ICRU points., Conclusions: Strong correlations were obtained between dose to the pelvic lymphatic chains and their historical ICRU-38 surrogate points during HDR brachytherapy of locally advanced cervical cancer patients with 60Co tandem-ovoid applicator sets. The correlation strength between point A and prescription dose highly depends on the CTV HR volume., (Copyright © 2021 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.)

Purpose: Iridium-192 brachytherapy dose enhancement by gold nanoparticles was investigated in five different tumor tissues to observe the tissue-related differences as an effective environmental factor in the applications of nanoparticles as radio-enhancer agents., Methods and Materials: The brachytherapy high-dose-rate source of BEBIG Ir-192, a tumor volume with five different tissues including water, Plexiglas, soft tissue, adipose, and bone with and without a uniform distribution of gold nanoparticles were mimicked by MCNPX Monte Carlo simulation code using lattice feature. Dose enhancement factors in the tumor volume were measured separately regarding the types of tissue, and a previous study using GEometry ANd Tracking 4 simulation was used for result validation., Results: The results demonstrated that various types of tissue, as the host of gold nanoparticles, lead to different dose enhancement level, so that the bone and adipose have the lowest and the highest amount of dose enhancement factor with values 20.8% and 39.75%, respectively. The maximum difference of 4.8% was achieved from data benchmarking., Conclusions: The results of this study indicate that the MCNPX code can be used as a valid tool for dose measurement in the presence of nanoparticles. Moreover, tissue types of tumor as an environmental feature, alongside with the nanoparticle's size and concentration as well as the conditions of radiotherapy, should be considered in the dose calculation., (Copyright © 2020 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.)

Purpose: This study evaluates the outcomes of ruthenium-106 (Ru-106) plaque brachytherapy for vasoproliferative tumors (VPTs) of the ocular fundus in a single referral ocular oncology center., Methods: The clinical charts of all patients diagnosed with VPT who underwent plaque radiotherapy from 2002 to 2017 were reviewed. Clinical features, types of treatment, outcomes and complications were evaluated., Results: Of 46 patients with VPT diagnosis in our ocular oncology clinic, 25 (54.34%) cases were treated with Ru-106 plaque brachytherapy. Eleven patients (44%) were male, and the mean age at the time of diagnosis was 40.92 ± 13.11 years. The mean follow-up time was 47.56 ± 36.87 months. Inferotemporal quadrant was the most common site of the tumor (64.00%). The mean delivered apex and scleral dose was 101.56 ± 6.51 and 412.26 ± 113.66 Gray (Gy), respectively. Initial tumor length, width and thickness were 10.26 ± 3.42, 8.05 ± 2.83 and 4.27 ± 1.10 mm, respectively. The mean tumor thickness decreased to 2.60 ± 0.63 mm, postoperatively. Complete resolution of subretinal fluid around the tumor was achieved in 81.80% of cases. Visual acuity was more than 20/400 in 64% of patients before treatment and 60% of patients at last follow-up., Conclusion: Our study showed that Ru-106 plaque radiotherapy is an effective and safe method of treatment in VPTs.

Purpose: To examine the efficacy and safety of Ruthenium-106 plaque radiotherapy in the treatment of circumscribed choroidal hemangioma., Methods: Twenty-one eyes of 21 patients diagnosed with symptomatic circumscribed choroidal hemangioma who underwent Ruthenium-106 plaque radiotherapy were included in the study. Clinical response, ancillary tests finding improvement, and major side effects were evaluated., Results: From the initial to the 1-year follow-up visits, vision improved in 12 eyes (57%), was stable in 7 eyes (33%), and became worse in 2 eyes (10%). Based on fluorescein angiography and optical coherence tomography, subretinal fluid and cystoid macular edema resolved in all patients. Changes in logarithm of minimum angle of resolution visual acuity (P = 0.038); tumor thickness (P = 0.0001) and largest diameter (P = 0.007) on ultrasonography; and subfoveal thickness on optical coherence tomography (P < 0.0001), were statistically significant between the initial and the 1-year follow-up visits. Side effects as observed during the follow-up period included: radiation-related retinopathy in 5 (24%) eyes, radiation-related papillopathy in 1 eye (5%), and subretinal fibrosis in 2 eyes (10%). Subretinal fibrosis was the only permanent radiation-related side effect., Conclusion: Ruthenium-106 plaque radiotherapy is an effective and safe method of treatment for symptomatic circumscribed choroidal hemangiomas. The incidence of permanent visual loss is low with prompt treatment of complications.

Purpose: To demonstrate the utility of "3D Slicer" for easy treatment verification by comparing dose-volume histograms (DVHs) calculated on pretreatment and posttreatment images., Methods and Materials: Thirty cervical cancer patients were CT scanned twice: first for treatment planning and a second time after the dose delivery. The initial plan was manually duplicated on the posttreatment image set in Flexiplan treatment planning system, and DVH parameters were calculated. Pretreatment and posttreatment images, organ structures, and plan data were exported from the treatment planning system to 3D Slicer to validate DVH parameter calculation with 3D Slicer. The gamma analysis was used to compare Flexiplan and 3D Slicer DVHs. Posttreatment images were rigidly fused on the initial CT to automatically transfer the data of the pretreatment plan onto the posttreatment images. DVH parameters were calculated in 3D Slicer for both image sets, and their relative variations were compared., Results: In calculating DVH parameter variations, no significant differences were observed between Flexiplan and 3D Slicer. Where the registration accuracy was better than 0.03, they returned similar results for D2 cm(3) of bladder, rectum, and sigmoid. Mean and standard deviation of DVH parameters were calculated on pretreatment and posttreatment images for several organs; both the manually duplicated plan and the automatically registered plan in SlicerRT returned comparable relative variations of these parameters. For 88% of the organs, more than 95% of the DVH dose bins passed the gamma analysis., Conclusions: We tested an automated DVH assessment method with an imaging freeware, 3D Slicer, for use in image-guided adaptive brachytherapy. SlicerRT is a viable verification tool to report and detect DVH variations between different contoured images series., (Copyright © 2016 American Brachytherapy Society. All rights reserved.)

The purpose of this study was to investigate the concurrent effects of tandem length and bladder volume on dose to pelvic organs at risk (OARs) in HDR intracavitary brachytherapy treatment of cervical cancer. Twenty patients with locally advanced cervical cancer were selected for brachytherapy using Rotterdam applicators. The patients were CT scanned twice with empty and full bladder. Two treatment plans were prepared on each of the image sets. Patients were categorized into two groups; those treated with a tandem length of 4 cm or smaller (T ≤ 4 cm) and those with tandem length larger than 4 cm (T > 4 cm). Only one tandem tip angle of 30° was studied. Dose-volume histograms (DVHs) of OARs were calculated and compared. Bladder dose was significantly affected by both bladder volume and tandem physical length for T ≤ 4 cm. This was reflected on the values obtained for D2cm³, D1cm³, and D0.1cm³ for both empty and full bladder cases. When T > 4 cm, no correlation could be established between variations in bladder dose and blad-der volume. Rectum dose was generally lower when the bladder was empty and T > 4 cm. Dose to sigmoid was increased when T > 4 cm; this increase was larger when the bladder was full. Our results suggest that, for tandems longer than 4 cm, keeping the bladder empty may reduce the dose to rectum and sigmoid. This is contrary to cases where a shorter than 4 cm tandem is used in which a full bladder (about 50-120 cm³) tends to result in a lower dose to rectum and sigmoid. Attention should be given to doses to sigmoid with long tandem lengths, as a larger tandem generally results in a larger dose to sigmoid.

Purpose: To evaluate the anatomical outcomes of corneal patch grafts in patients with progressive scleral necrosis secondary to plaque radiotherapy used for uveal malignant melanoma management., Methods: In this case series, 4 patients with progressive scleral necrosis after Ru-106 plaque radiotherapy underwent corneal patch grafts with the anterior corneal button from Descemet stripping automated endothelial keratoplasty donor tissue to strengthen the sclera and to improve appearance of the eye., Results: Ciliary body involvement was evident in all cases. All 4 patients had received radiation doses of 400 Gy or more to the tumor base. The mean time interval between plaque radiotherapy and scleral necrosis was 24.5 ± 7.5 months (range, 18-34 months). Successful results were achieved in all patients with tectonic graft. No patients experienced graft thinning, rejection, infection, or tumor recurrence in a mean follow-up of 28.5 ± 7.9 months (range, 20-39 months)., Conclusions: Corneal patch graft by anterior corneal button from Descemet stripping automated endothelial keratoplasty donor tissue results in successful restoration of globe integrity and satisfactory cosmetic appearance in patients with scleral necrosis secondary to plaque radiotherapy.

Purpose: This study was performed to evaluate the role of in vivo dosimetry with semiconductor detectors in gynaecological medium dose rate brachytherapy, and to compare the actual doses delivered to organs at risk (as measured using in vivo dosimetry) with those calculated during treatment planning., Materials and Methods: Doses to the rectum and bladder were measured in a group of patients with cervical carcinoma using semiconductor detectors and compared to the doses calculated using a treatment planning system. 36 applications of brachytherapy at dose rates of 1.8-2.3 Gy/h were performed in the patients., Results: The mean differences between the measured and calculated doses were 3 % for the rectum and 11 % for the bladder., Conclusions: The main reason for the differences between the measured and calculated doses was patient movement. To reduce the risk of large errors in the dose delivered, in vivo dosimetry should be performed in addition to treatment planning system computations.

The aim of this study was to assess the actual dose delivered to the rectum and compare it with the treatment planning system (TPS) reports. In this study, the dose delivered to the rectum was measured by semiconductor diode detectors (PTW, Germany). The factors that influence diode response were investigated as well. Calibration factors of diodes were measured weekly to investigate the effect of time interval on the accuracy of calibration. Then 40 applications of patients with cervix carcinoma were evaluated. Rectum dose was measured by means of rectal dosemeter and compared with the TPS-calculated dose. In this research, the differences between the measured and the calculated dose were investigated. The mean difference between the TPS-calculated dose and the measured dose was 6.5% (range: -22 to +39) for rectum. The TPS-calculated maximum dose was typically higher than the measured maximum dose. The study showed that the main reason for the difference was due to the movements of the patient and applicator shift in the elapsed time between the imaging and treatment stage. It is recommended that in vivo dosimetry should be performed in addition to treatment planning computation. In vivo dosimetry is a reliable solution to compare the planned and actual dose delivered to organs at risk.

Aims: This study investigates to what extent the dose received by lungs from a commercially available treatment planning system, Ir-192 high-dose-rate (HDR), in breast brachytherapy, is accurate, with the emphasis on tissue heterogeneities, and taking into account the presence of ribs, in dose delivery to the lung., Materials and Methods: A computed tomography (CT) scan of a breast was acquired and transferred to the 3-D treatment planning system and was also used to construct a patient-equivalent phantom. An implant involving 13 plastic catheters and 383 programmed source dwell positions were simulated, using the Monte Carlo N-Particle eXtended (MCNPX) code. The Monte Carlo calculations were compared with the corresponding commercial treatment planning system (TPS) in the form of percentage isodose and cumulative dose-volume histogram (DVH) in the breast, lungs, and ribs., Results: The comparison of the Monte Carlo results and the TPS calculations showed that a percentage of isodose greater than 75% in the breast, which was located rather close to the implant or away from the breast curvature surface and lung boundary, were in good agreement. TPS calculations overestimated the dose to the lung for lower isodose contours that were lying near the breast surface and the boundary of breast and lung and were relatively away from the implant., Conclusions: Taking into account the ribs and entering the actual data for breasts, ribs, and lungs, revealed an average overestimation of the dose by a factor of 8% in the lung for TPS calculations. Therefore, the accuracy of the TPS results may be limited to regions near the implants where the treatment is planned, and is a more conservative approach for regions at boundaries with curvatures or tissues with a different material than that in the breast.

High dose rate (HDR) brachytherapy is one of the accepted treatment modalities in gastro-intestinal tract and bladder carcinomas. Considering the shortcoming of contact brachytherapy routinely used in gastrointestinal tract in treatment of big tumors or invasive method of bladder treatment, an intraluminal applicator with the capability of insertion into the tumor depth seems to be useful. This study presents some dosimetric evaluations to introduce this applicator to the clinical use. The radiation attenuation characteristics of the applicator were evaluated by means of two dosimetric methods including well-type chamber and radiochromic film. The proposed 110 cm long applicator has a flexible structure made of stainless steel for easy passage through lumens and a needle tip to drill into big tumors. The 2mm diameter of the applicator is thick enough for source transition, while easy passage through any narrow lumen such as endoscope or cystoscope working channel is ensured. Well-chamber results showed an acceptably low attenuation of this steel springy applicator. Performing absolute dosimetry resulted in a correlation coefficient of R = 0.9916 (p-value ≈ 10-7) between standard interstitial applicator and the one proposed in this article. This study not only introduces a novel applicator with acceptable attenuation but also proves the response independency of the GAFCHROMIC EBT films to energy. By applying the dose response of the applicator in the treatment planning software, it can be used as a new intraluminal / interstitial applicator.

Dose escalation to target volume during High Dose Rate brachytherapy was effectively employed to treat locally advanced cervical cancer patients who experienced prolongation of Overall Treatment Time (OTT) due to the COVID-19 pandemic. It was tried to achieve acceptable oncological outcomes while respecting the dose constraints of Organs at Risk (OARs). Key Clinical Message: It was a severe challenge to obey the optimum treatment schedule of LACC cases during the coronavirus crisis. Increased risk of recurrence and mortality due to increased overall treatment time in cervical cancer patients proposes prioritizing. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Purpose: This study was designed to assess the dose accumulation (DA) of bladder and rectum between brachytherapy fractions using hybrid-based deformable image registration (DIR) and compare it with the simple summation (SS) approach of GEC-ESTRO in cervical cancer patients. Material and methods: Patients (n = 137) with cervical cancer treated with 3D conformal radiotherapy and three fractions of high-dose-rate brachytherapy were selected. CT images were acquired to delineate organs at risk and targets according to GEC-ESTRO recommendations. In order to determine the DA for the bladder and rectum, hybrid- based DIR was done for three different fractions of brachytherapy and the results were compared with the standard GEC-ESTRO method. Also, we performed a phantom study to calculate the uncertainty of the hybrid-based DIR algorithm for contour matching and dose mapping. Results: The mean ± standard deviation (SD) of the Dice similarity coefficient (DICE), Jaccard, Hausdorff distance (HD) and mean distance to agreement (MDA) in the DIR process were 0.94 ±0.02, 0.89 ±0.03, 8.44 ±3.56 and 0.72 ±0.22 for bladder and 0.89 ±0.05, 0.80 ±0.07, 15.46 ±10.14 and 1.19 ±0.59 for rectum, respectively. The median (Q1, Q3; maximum) GyEQD2 differences of total D2cc between DIR-based and SS methods for the bladder and rectum were reduced by -1.53 (-0.86, -2.98; -9.17) and -1.38 (-0.80, -2.14; -7.11), respectively. The mean ± SD of DICE, Jaccard, HD, and MDA for contour matching were 0.98 ±0.008, 0.97 ±0.01, 2.00 ±0.70 and 0.20 ±0.04, respectively for large deformation. Maximum uncertainty of dose mapping was about 3.58%. Conclusions: The hybrid-based DIR algorithm demonstrated low registration uncertainty for both contour matching and dose mapping. The DA difference between DIR-based and SS approaches was statistically significant for both bladder and rectum and hybrid-based DIR showed potential to assess DA between brachytherapy fractions. [ABSTRACT FROM AUTHOR]

Purpose: Skin cancers are the most common human malignancy with increasing incidence. Currently, surgery is standard of care treatment for non-melanoma skin cancers. However, brachytherapy is a growing modality in the management of skin cancers. Therefore, we aimed to assess the outcome of patients with non-melanoma skin cancers treated by high-dose-rate (HDR) brachytherapy with surface mold technique. Material and methods: In this prospective study, we recruited patients with basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) of the skin who were candidates for definitive or adjuvant brachytherapy during 2013-2014. Alginate was used for making the individualized surface molds for each patient. Patients were treated with afterloading radionuclide HDR brachytherapy machine, with a total dose of 30-52 Gy in 10-13 fractions. Participants were followed for 2 years for radiation toxicity, cosmetic results, and local failures. Results: A total of 60 patients (66.7% male; median age, 71 years) were included, of which 42 (70.0%) underwent definitive radiotherapy. Seventy-five percent of lesions were BCC. The mean total dose was 39.6 ± 5.4 Gy. Of patients in definitive group, 40/42 (95.2%) experienced complete clinical response after 3 months. The recurrence rate was 2/18 (11.11%) and 1/42 (2.38%) in adjuvant and definitive groups, respectively. The percentage of grade 3-4 acute (3-month post-treatment) and late toxicities (2 years post-treatment) was 6.7% and 0%, respectively. The cosmetic results were good/excellent in 96.2% of patients after 2 years of follow-up. Conclusions: With appropriate patient selection and choosing as lowest dose per fraction as possible, HDR brachytherapy with customized surface molds yields good oncological and cosmetic results for the treatment of localized skin BCC and SCC. [ABSTRACT FROM AUTHOR]

Purpose: Brachytherapy is a cost-effective method for the management of oral cavity cancers in low to middle income countries. We aimed to evaluate the clinical outcomes of high-dose-rate interstitial brachytherapy (HDR-IBT) in patients with oral cavity cancer. Material and methods: From 2009 to 2013, 78 patients (49 combined external beam radiotherapy [EBRT] plus IBT and 29 IBT monotherapy) with oral cavity cancers had been treated in our center. Slightly more than half the patients were male, and the median age was 54 years. The treatment was planned based on the Paris system. The main outcomes were disease-free and overall survival. Results: The median follow-up duration was 36.5 months (range, 1.17-54.23). The actuarial four-year overall and disease-free survival rates were 83% and 65%, respectively. The local and locoregional control was achieved among 89.74% and 87.17% of patients, respectively. None of the factors including tumor size, node status, gender, and radiation modality (IBT alone vs. IBT + EBRT) had a significant statistical correlation to the local control rate. All the patients tolerated the planned treatment in the IBT alone group. Late complications included a case of trismus and three cases of catheter insertion site fibrosis. Conclusions: HDR-IBT as a monotherapy or in combination with EBRT is an appropriate option for the management of oral cavity squamous cell carcinomas, and supports the improvement in treatment outcomes and toxicity profiles in adjuvant settings. [ABSTRACT FROM AUTHOR]

Purpose: To analyze the optimum organ filling point for organs at risk (OARs) dose in cervical cancer high-doserate (HDR) brachytherapy. Material and methods: In a retrospective study, 32 locally advanced cervical cancer patients (97 insertions) who were treated with 3D conformal external beam radiation therapy (EBRT) and concurrent chemotherapy during 2010- 2013 were included. Rotterdam HDR tandem-ovoid applicators were used and computed tomography (CT) scanning was performed after each insertion. The OARs delineation and GEC-ESTRO-based clinical target volumes (CTVs) contouring was followed by 3D forward planning. Then, dose volume histogram (DVH) parameters of organs were recorded and patients were classified based on their OARs volumes, as well as their inserted tandem length. Results: The absorbed dose to point A ranged between 6.5-7.5 Gy. D0.1cm3 and D2cm3 of the bladder significantly increased with the bladder volume enlargement (p value < 0.05). By increasing the bladder volume up to about 140 cm3, the rectum dose was also increased. For the cases with bladder volumes higher than 140 cm3, the rectum dose decreased. For bladder volumes lower than 75 cm3, the sigmoid dose decreased; however, for bladder volumes higher than 75 cm3, the sigmoid dose increased. The D2cm3 of the bladder and rectum were higher for longer tandems than for shorter ones, respectively. The divergence of the obtained results for different tandem lengths became wider by the extension of the bladder volume. The rectum and sigmoid volume had a direct impact on increasing their D0.1cm3 and D2cm3, as well as decreasing their D10, D30, and D50. Conclusions: There is a relationship between the volumes of OARs and their received doses. Selecting a bladder with a volume of about 70 cm3 or less proved to be better with regards to the dose to the bladder, rectum, and sigmoid. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the outcomes of ruthenium-106 (106Ru) brachytherapy in terms of radiation parameters in patients with thick uveal melanomas. Material and methods: Medical records of 51 patients with thick (thickness ≥ 7 mm and < 11 mm) uveal melanoma treated with 106Ru brachytherapy during a ten-year period were reviewed. Radiation parameters, tumor regression, best corrected visual acuity (BCVA), and treatment-related complications were assessed. Results: Fifty one eyes of 51 consecutive patients including 25 men and 26 women with a mean age of 50.5 ± 15.2 years were enrolled. Patients were followed for 36.1 ± 26.5 months (mean ± SD). Mean radiation dose to tumor apex and to sclera were 71 (± 19.2) Gy and 1269 (± 168.2) Gy. Radiation dose rates to tumor apex and to sclera were 0.37 (±0.14) Gy/h and 6.44 (± 1.50) Gy/h. Globe preservation was achieved in 82.4%. Preoperative mean tumor thickness of 8.1 (± 0.9) mm decreased to 4.5 (± 1.6) mm, 3.4 (± 1.4) mm, and 3.0 (± 1.46) mm at 12, 24, and 48 months after brachytherapy (p = 0.03). Four eyes that did not show regression after 6 months of brachytherapy were enucleated. Secondary enucleation was performed in 5 eyes because of tumor recurrence or neovascular glaucoma. Tumor recurrence was evident in 6 (11.8%) patients. Mean Log MAR (magnification requirement) visual acuity declined from 0.75 (± 0.63) to 0.94 (± 0.5) (p = 0.04). Best corrected visual acuity of 20/200 or worse was recorded in 37% of the patients at the time of diagnosis and 61.7% of the patients at last exam (p = 0.04). Non-proliferative and proliferative radiation-induced retinopathy was observed in 20 and 7 eyes. Conclusions: Thick uveal melanomas are amenable to 106Ru brachytherapy with less than recommended apex radiation dose and dose rates. [ABSTRACT FROM AUTHOR]

Summary: Aim: Dependence of diode dosimeters on variation of temperature, distance, dose rate and incident beam angle for MDR/LDR intracavitary brachytherapy was investigated. Materials/Methods: Flexible probes from PTW/Germany were irradiated using Cs-137 sources. The rectum probe (type 9112) had five semiconductors and the bladder probe had one. Firstly, detectors'' dependence on temperature was studied. The probes were immersed into a water tank and the temperature was slowly increased. To investigate the angular dependence of the diodes, the sources were placed at 5cm distance from diodes at four different angles. Probes were placed at 3cm distance from the centre of the source arrays and the responses for three different dose rates were evaluated. To assess the dependency of responses on distance, probes were placed at three different distances with constant dose rate. Results: A slight linear increase of the diode signal with temperature was found. The diodes exhibited a variation in sensitivity with dose rate less than 0.15% and with distance less than 0.04% per mm. A linear decrease of the diode responses was also observed with increase of the radiation beam angle. Conclusions: The current study showed that there is no significant variation in the response of diodes with temperature, dose rate and distance for MDR brachytherapy. However, the increase of radiation beam angle led to a significant decrease of diode response. In conclusion, the observed temperature, dose rate and distance effects are negligible but the diode correction factor as a function of the incidence beam angle must be applied to these diodes. [Copyright &y& Elsevier]

Ruthenium-106 (106Ru) plaques are specific applicators dedicated for intraocular brachytherapy. Small tumor volume and presence of vital organs in its close vicinity as well as appearance of very high dose gradient regions around the employed plaques cause unique challenges in plaque-based brachytherapy. Therefore, access to 3D dose distribution for each brachytherapy plaque is quite helpful to decide about tumor volume coverage and overexposure of surrounding sensitive organs. Current study aims to measure the 3D dose distribution for two commercially available 106Ru plaques using film dosimetry. COB (a notched-shape plaque) and CGD (a fully circular plaque) 106Ru plaques were used and dose distributions in different planes were measured by simultaneously employing a 3D printed eyeball phantom and Gafchromic EBT3 films. Finally, 3D dose distributions were acquired by interpolating the measured 2D dose data at different planes. The results showed that employing the COB plaque tilts the isodose curves toward the non-notched edge of the plaque, while no isodose tilting was observed for CGD plaque. The obtained 3D dose distributions were different for studied plaques. Non-uniform 3D dose distributions were found for both plaques which can be attributed to the plaque design and reference point position on plaque central axis. Finally, it can be concluded that the obtained 3D dose distributions can specify the optimal tumor shape which can be adequately covered by brachytherapy plaque with minimizing the dose non-uniformity and hot point formation inside the treated volume. Obtained 3D dose distribution for each plaque can be employed for patient treatment planning. • Film dosimetry of two commercially available 106Ru intraocular brachytherapy plaques. • COB (notched shape) and CGD (fully circular shape) plaques were considered. • 3D dose distribution data was measured for each plaque inside an eyeball phantom. • Non-uniform dose distribution were observed for both plaques understudy. • Followed approach can be used for plaque-based brachytherapy quality assurance. [ABSTRACT FROM AUTHOR]