Long term outcomes of gastric mucosa-associated lymphoid tissue lymphoma treated with radiotherapy: A multi-center retrospective cohort study.

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is a rare disease. Radiotherapy remains an important definitive modality. We assessed the long term outcomes of patients with early stage gastric MALT marginal zone lymphoma (MZL) treated with definitive radiotherapy at three institutions in New South Wales, Australia. A retrospective, multi-center study of patients with gastric MALT MZ lymphoma treated with radiotherapy between 1st of March 1999 and 31st of May 2020 was conducted. Eligible patients were: age ≥18 years, treated with curative-intent radiotherapy, pathological diagnosis of MALT MZ lymphoma. There were 33 eligible patients. Complete response (CR) was reported in 30/31 (96.7%) of endoscopically assessed cases. During median follow up of 66.2 months (IQR 22-119 months), estimated 5 and 10 years local relapse free survival were 92.6% (95% CI: 83-100) and 92.6% (95% CI: 83-100); distant relapse free survival 95.8% (95% CI 88.2-100) and 64.7% (95% CI 43.4-96.4); freedom from treatment failure 92.6% (95% CI; 83.1-100) and 62.5% (95% CI; 41.7-93.7), respectively. There were six documented recurrences; one local, four distant, and both in one patient; two cases were high grade recurrences. 5 and 10 years OS were 92.4% and 73.5% respectively. There were no grade 3-5 late toxicities or treatment related deaths. Patients with gastric MALT MZL treated with definitive radiotherapy have excellent outcomes. In long term follow up a significant proportion developed distant low grade disease. Extended follow up should be considered in these patients. Treatment is well tolerated with minimal toxicity. Radiotherapy remains an important modality in the treatment of gastric MALT MZ lymphoma.

Communication and collaboration skills training in radiation oncology: A quantitative validation survey.

INTRODUCTION: Communication and collaboration are integral in radiation oncology practice. A recently published qualitative study identified several deficiencies in skills development for Australian/New Zealand trainees. We aim to validate these findings to guide curriculum development. METHODS: A quantitative survey was developed through an iterative process, using themes identified in the previous qualitative investigation. This survey was distributed to radiation oncologists and trainees across Australia and New Zealand via email. Data collection and management utilised the REDCap system. Question types varied to maximise richness of data, including ranking, likert-scales and free-text questions. Results are primarily reported descriptively. RESULTS: Totally 35 participants submitted completed survey responses with broad representation across geography, gender and clinician seniority. To learn communication, participants reported strong preferences towards informal observation (60% agreement) and self-reflection (49% agreement), and against online learning (77% disagreement) methodologies. Nearly 35% acknowledge poor communication at least weekly, with time pressure being a major barrier (63% agreement). Clinical uncertainty and existing patient/family assumptions (both 74% agreement) contribute to difficulties in breaking bad news, with online learning being the only negatively perceived training modality (23% agreement). No participants reported any formal training/mentoring in multi-disciplinary team (MDT) engagement. Conflict was commonly witnessed/experienced (97%) and 26% of participants avoid MDTs due to difficulties experienced. CONCLUSIONS: This study validates the themes previously identified. We identified a strong preference for informal learning methodologies and against online modules, discordant to published literature. Effective collaboration within MDTs is identified as a particular area of need. We recommend future curriculum modification considers these results to maximise efficacy.

SABR for Early Non-Small Cell Lung Cancer: Changes in Pulmonary Function, Dyspnea, and Quality of Life.

PURPOSE: The aim of this study was to report pulmonary function tests (PFTs) and clinician-reported and patient-reported quality-of-life (QoL) outcomes on a cohort of patients with non-small cell lung cancer (NSCLC) treated with SABR. METHODS AND MATERIALS: A total of 119 patients with NSCLC were treated with SABR in the prospective cohort SSBROC study of patients with T1-T2N0M0 NSCLC. PFTs and QoL measures were obtained at baseline pretreatment and at 6-month intervals. Here we report on the 6- to 18-month time points. Analysis of covariance (ANCOVA) methods adjusting for baseline analyzed potential predictors on outcomes of PFTs and patient-reported dyspnea at 18 months. RESULTS: The only statistically significant decline in PFTs was seen in forced expiratory volume in 1 second (FEV1) at 18 months post-SABR, with a decline of -0.11 L (P = .0087; 95% CI, -0.18 to -0.02). Of potential predictors of decline, only a 1-unit increase in smoking pack-years resulted in a -0.12 change in diffusing capacity for carbon monoxide (P = .026; 95% CI, -0.02 to -0.23) and a 0.003 decrease in FEV1 (P = .026; 95% CI, -0.006 to -0.0004). For patient-reported outcomes, statistically significant worsening in both the European Organisation for Research and Treatment of Cancer Quality of Life Core Questionnaire (QLQ-C30 Version 3) and the lung module (QLQ-LC13) dyspnea scores occurred at the 18-month time point, but not earlier. No potential predictors of worsening dyspnea were statistically significant. There was no statistically significant decline in clinician-reported outcomes or global QoL scores. CONCLUSIONS: We found a statistically significant decline in FEV1 at 18 months posttreatment. Smoking pack-years was a predictor for decline in diffusing capacity for carbon monoxide and FEV1 at 18 months. Worsening of patient-reported dyspnea scores was observed, consistent with the expected progression of lung comorbid disease.

Extreme hypofractionation in radiation therapy for patients with early breast cancer: what is the optimal technique?

Many radiation techniques have been employed in the trend of moving towards more hypofractionated regimens in the treatment of early breast cancer. This editorial articulates the advantages of using multi-catheter interstitial brachytherapy when delivering extreme hypofractionation for partial breast radiation.

Communication and collaboration skills training in Radiation Oncology in Australia and New Zealand: A qualitative study.

PURPOSE: Effective communication and collaboration with patients, carers and between healthcare professionals improves patient management. This study aimed to explore essential communication and collaboration skills training (CCST) for a radiation oncologist (RO) to inform competencies, learning outcomes and enhance curriculum training methods. MATERIALS AND METHODS: Eight focus group discussions with 10 fellows and 14 trainees of the Faculty of Radiation Oncology, Royal Australian and New Zealand College of Radiologists (FRO RANZCR) were conducted face to face between October 2018 and March 2019. Participants included doctors from culturally and linguistically diverse backgrounds, working in public and private, metropolitan, and rural sectors. Data were recorded, transcribed verbatim, managed in Excel, and coded using a qualitative content analysis framework. The study was approved by South Eastern Sydney Local Health District HREC (18/186). Participants provided informed written consent. RESULTS: After achieving thematic saturation, four predominant themes emerged. These were as follows: (1) Enablers and barriers to effective communication and collaboration; (2) written communication; (3) communicating bad news; and (4) multidisciplinary team meeting collaboration. Managing uncertainty and workplace culture emerged as interconnected sub-themes. CONCLUSIONS: There is a current lack of CCST in radiation oncology in Australia and New Zealand. The most common theme that emerged to improve CCST focused on increasing the exposure to a variety of communication and collaboration clinical scenarios, which are observed and upon which immediate structured feedback is given. Consultants and trainees offered tangible suggestions on how to improve the curriculum. These findings underscore the importance of using a combination of structured teaching methods and work-based assessments. CCST templates are recommended.

Comparison of TG43 and Hounsfield Unit-based TG186 brachytherapy dose metrics in Oncentra Brachy for 100 patients receiving interstitial partial breast irradiation.

PURPOSE: The aim of the study was to conduct a retrospective analysis of 100 patients who received interstitial accelerated partial breast irradiation at a single institution, comparing the standard American Association of Physicists in Medicine Task Group (TG) 43 dose calculation algorithm to the model-based dose calculation algorithms (MBDCAs) available in the Oncentra Brachy treatment planning system. METHODS AND MATERIALS: Dose-volume histogram parameters were compared between the different dose calculation algorithms for the planning target volume and organs at risk. and a statistical analysis was performed. The resulting changes in isodose distribution were assessed, with the worst-case data presented. RESULTS: The TG43 algorithm calculated higher doses to all structures compared with the MBDCAs. The largest discrepancy was observed for the skin, with maximum doses on average 2.0% lower with the MBDCA. The newly released Hounsfield Unit-based algorithm further decreased the skin dose compared with TG43 by <0.5%. CONCLUSIONS: This study demonstrates that the differences between TG43 and MBDCA as implemented in Oncentra Brachy for accelerated partial breast irradiation are clinically insignificant in the treatment area and nearby organs at risk. Justification for investing in MBDCAs for this treatment site is limited when considering the additional calculation time, introduced uncertainties, and cost.

Ultrasonic Transducer From Piezoelectric Polymer Multilayer Through Electrophoretic Deposition for Photoacoustic Imaging.

Emerging ultrasound imaging modality based on optical-generated acoustic waves, such as photoacoustic (PA) imaging, has enabled novel functional imaging on biological samples. The performance of the ultrasonic transducer plays a critical role in producing higher quality PA images. However, the high electrical impedance of the small piezoelectric elements in the transducer array causes an electrical mismatch with external circuitry and results in degraded sensitivity. One effective method for reducing the electrical impedance is to implement a piezoelectric multilayer configuration instead of the conventional single layer for the transducer. In this work, we introduced an ultrasonic transducer comprising a piezoelectric polymer multilayer structure produced by an innovative multicycle powder-based electrophoretic deposition, using a suspension of polymer nanoparticles. The multicycle electrophoretic deposition overcomes the redissolution issue in solution-based methods. The ultrasonic transducer comprising the piezoelectric polymer multilayer exhibits significantly enhanced receiving sensitivity as compared to the ultrasonic transducer using a single layer. Ultrasonic transducer with multielement array configuration is obtained using the piezoelectric polymer multilayer, and PA imaging with improved resolution is demonstrated. Theoretical analysis shows that the enhanced transducer performance is mainly attributed to the improved electrical impedance match between the piezoelectric polymer element in the transducer and external receiving circuit.

Concave Array Ultrasonic Transducer From Multilayer Piezoelectric Ceramic for Photoacoustic Imaging.

Implementation of piezoelectric multilayer ceramic (MLC) is an effective way to reduce impedance and improve the performance of linear-array transducer for ultrasonic system applications. However, the ultrasonic image derived from a planar linear-array transducer generally suffers from degradation of lateral resolution and contrast. In this article, we designed and fabricated a focused 5-MHz 128-element linear-array ultrasonic transducer with concave structure using five-layered 0.1Pb (Ni1/3Nb2/3)O3 -0.35Pb(Zn1/3Nb2/3)O3 -0.15Pb(Mg1/3Nb2/3)O3-0.1PbZrO3-0.3PbTiO3 (PNN-PZN-PMN-PZ-PT) piezo- electric ceramic. The transducer showed a bandwidth of 63% at -6 dB and the lateral resolution up to 0.33 mm. An improved transmission signal of 90% higher than a commercial single-layer ceramic transducer was also achieved. We further demonstrated high-resolution photoacoustic imaging with the obtained concave linear-array transducer.

Graphene field-effect transistors with ferroelectric gating.

Recent experiments on ferroelectric gating have introduced a novel functionality, i.e., nonvolatility, in graphene field-effect transistors. A comprehensive understanding in the nonlinear, hysteretic ferroelectric gating and an effective way to control it are still absent. In this Letter, we quantitatively characterize the hysteretic ferroelectric gating using the reference of an independent background doping (n(BG)) provided by normal dielectric gating. More importantly, we prove that n(BG) can be used to control the ferroelectric gating by unidirectionally shifting the hysteretic ferroelectric doping in graphene. Utilizing this electrostatic effect, we demonstrate symmetrical bit writing in graphene-ferroelectric field-effect transistors with resistance change over 500% and reproducible no-volatile switching over 105 cycles.

A Clinician's Guide to Cancer-Derived Exosomes: Immune Interactions and Therapeutic Implications.

Understanding of the role of immunity in the regulation of cancer growth continues to rapidly increase. This is fuelled by the impressive results yielded in recent years by immune checkpoint inhibitors, which block regulatory pathways to increase immune-mediated cancer destruction. Exosomes are cell-secreted membranous nanoscale vesicles that play important roles in regulating physiological and pathophysiological processes. Cancer-derived exosomes (CDEXs) and their biologically-active cargos have been proven to have varied effects in malignant progression, including the promotion of angiogenesis, metastasis, and favorable microenvironment modification. More recently, there is an increasing appreciation of their role in immune evasion. In addition to CDEXs, there are immune-derived exosomes that facilitate communication between immune cells in the non-malignant setting. Investigation of cancer-mediated mechanisms behind interruption or modification of these normal exosomal pathways may provide further understanding of how malignant immune evasion is accomplished. Accumulating evidence indicates that immune-active CDEXs also have the potential to impact clinical oncological management. Whilst immune checkpoint inhibitors have well-established pharmacologically-targeted pathways involving the immune system, other widely used treatments such as radiation and cytotoxic chemotherapies do not. Thus, investigating exosomes in immunotherapy is important for the development of next-generation combination therapies. In this article, we review the ways in which CDEXs impact individual immune cell types and how this contributes to the development of immune evasion. We discuss the relevance of lymphocytes and myeloid-lineage cells in the control of malignancy. In addition, we highlight the ways that CDEXs and their immune effects can impact current cancer therapies and the resulting clinical implications.

Collaborative implementation of stereotactic ablative body radiotherapy: A model for the safe implementation of complex radiotherapy techniques in Australia.

INTRODUCTION: Stereotactic ablative radiotherapy (SABR) for lung cancer is a modality of treatment that has improved outcomes for lung cancer patients. However, radiotherapy for lung cancer is underutilized and fewer than half of elderly patients with non-small cell lung cancer (NSCLC) receive active treatment. The purpose of this study is to report on a collaboration in implementing an NSCLC SABR (stereotactic ablative body radiation) program safely, efficiently, and uniformly across several centers, including regional sites. The first aim of this paper is to detail the collaboration and implementation that started in 2013 and is ongoing. The second aim of this paper is to document early toxicities and quality of life outcomes. METHOD: A tripartite approach was used to develop the protocol and networks required for the implementation of SABR across multiple sites in NSW. Departments starting the programmes were supported and physics credentialing with central site submission was required before commencing the treatment. Additional ongoing support was available via an email discussion group involving all members of the collaboration. RESULTS: Between July 22, 2013 and February 22, 2016, 41 patients were enrolled with 34 patients in active follow up. The toxicity profile so far is similar to those of published studies with no appreciable effect on quality of life outcomes. CONCLUSION: The collaboration formed an effective framework in facilitating the implementation of SABR across several sites in NSW and could be used as a model for the safe and uniform implementation of new technologies in Australia.

Current indications for post-mastectomy radiation.

It has been long established that post-mastectomy radiotherapy reduces the risk of locoregional failure. A survival advantage, however, has only recently been demonstrated. We here provide a review of the literature as regards to the current indications for post-mastectomy radiotherapy.

Proposal for a gold standard for cosmetic evaluation after breast conserving therapy: Results from the St George and Wollongong Breast Boost trial.

INTRODUCTION: Breast cosmesis is an important endpoint of breast conserving therapy (BCT), but a gold standard method of its evaluation is not yet established. The St. George and Wollongong Randomised Breast Boost trial used five different methods of cosmetic assessment, including both subjective and objective, to comprehensively evaluate the cosmetic outcome of the trial patients. This current study analyses the level of concordance between these methods in an attempt to determine a possible standard in the evaluation of breast cosmesis. METHODS: Patients attending follow-up clinic reviews at 5 years post breast radiotherapy were evaluated. Patients completed a cosmesis and functional assessment questionnaire, assessing clinicians completed an EORTC (European Organization for Research and Treatment of Cancer) cosmetic rating questionnaire and photographs were obtained. The photographs were later assessed by a panel of five experts, as well as analysed using the objective pBRA (relative Breast Retraction Assessment) and the BCCT.core (Breast Cancer Conservative Treatment.cosmetic results) computer software. Scores were dichotomised to excellent/good and fair/poor. Pairwise comparisons between all methods, except pBRA, were carried out using overall agreement calculations and kappa scores. pBRA scores were compared on a continuous scale with each of the other dichotomised scores obtained by the other four methods. RESULTS: Of 513 St George patients alive at 5 years, 385 (75%) attended St George for follow-up and consented to photography. Results showed that assessment by physicians in clinic and patient self-assessment were more favourable regarding overall cosmetic outcome than evaluation of photographs by the panel or the BCCT.core software. Excellent/good scores by clinician-live and patient self-assessments were 93% and 94% respectively (agreement 89%), as compared to 75% and 74% only by BCCT.core and panel assessments respectively (agreement 83%, kappa 0.57). For the pBRA measurements, there was a statistically significant difference (P <0.001) between scores for excellent/good versus fair/poor cosmesis by all four methods. The range of median pBRA measurements for fair/poor scores was 13.4-14.8 and for excellent/good scores was 8.0-9.4. CONCLUSION: Incorporating both BCCT.core assessment and patient self-assessment could potentially provide the basis of a gold standard method of breast cosmetic evaluation. BCCT.core represents an easy, time efficient, reproducible, cost effective and reliable method, however, it lacks the functional and psychosocial elements of cosmesis that only patient self-reported outcomes can provide.

Hemiablative Focal Low Dose Rate Brachytherapy: A Phase II Trial Protocol.

BACKGROUND: The objective of focal brachytherapy (BT) is to provide effective prostate cancer control for low-risk disease but with reduced genitourinary, gastrointestinal and sexual side effects in a cost-effective way. OBJECTIVE: The aim of this study is to describe a phase II study examining technical and dosimetric feasibility and toxicity, quality of life changes, and local control with post-treatment biopsy outcomes in men with early stage low volume prostate cancer treated with focal iodine-125 seed BT. METHODS: The study design is a prospective, multicenter trial with a planned sample size of 20 patients including men with a minimum age of 60 years, a life expectancy estimated to be greater than 10 years, with low or low-tier intermediate risk prostate cancer, unilateral disease on the biopsy, and a Gleason score of ≤3+4 and <25% cores involved. The investigations specific for the study are multi-parametric magnetic resonance imaging (Mp-MRI) baseline, at 20 and 36 months to rule out high grade disease and a transperineal mapping biopsy (baseline and at 36 months) for more accurate patient selection. The hemigland region will receive 144 Gy. Standard normal tissue constraints will be considered as for a whole gland (WG) implant. Dosimetric parameters will be evaluated at day 30 after the implant. Toxicity and quality of life will be evaluated with international validated questionnaires focusing on urinary, rectal, sexual domain, and general health-related quality of life. The patients will complete this assessment at baseline and then approximately every 6 months after the implant up to 10 years. RESULTS: To date, one patient is involved in the trial. He underwent the pre-implant investigations which found bilateral disease. Therefore, a standard seed implant was performed. If the results from this trial provide evidence that the treatment is safe, feasible, and improves toxicity, funding will be sought to conduct a large, multicenter, randomized controlled trial (RCT). CONCLUSIONS: This protocol is designed to show feasibility in delivering hemigland focal therapy with seed BT. It may answer crucial questions and obtain data which will enable downstream decisions on focal low dose rate (LDR) prostate BT. CLINICALTRIAL: Clinicaltrial.gov NCT02643511; https://www.clinicaltrials.gov/ct2/show/NCT02643511 (Archived by Webcite at http://www.webcitation.org/6ghLCzIhY).

The risk of second malignancies after 125I prostate brachytherapy as monotherapy in a single Australian institution.

PURPOSE: To report the incidence of second primary cancer (SPC) after 125I brachytherapy (BT) for early prostate cancer in an Australian institution. METHODS AND MATERIALS: All the patients in our cohort had a cystoscopy before the implant. Data were prospectively collected on all subsequent SPC diagnoses. Standardized incidence ratios (SIRs) were calculated to compare data with the Australian population. Kaplan-Meier analysis was used to determine the actuarial second malignancy and pelvic malignancy rates and the death from SPC and from any cause. RESULTS: A total of 889 patients were followed up for a median of 4.16 (0-13) years with 370 (42%) patients having ≥5 years of followup. Sixty patients subsequently developed an SPC of which 11 were pelvic malignancies. The 5- and 10-year cumulative incidences were 1.3% (95% confidence interval [CI]: 0.6-3) and 3.3% (95% CI: 1-7) for any pelvic malignancy and 1% (95% CI: 0.4-2) and 2.6% (1-6) for bladder cancer, respectively. The SIR was significantly higher than expected for all bladder cancers at 2.9 (95% CI: 1-6) and close to significance (SIR, 3.0; 95% CI: 0.97-7) for bladder cancers within the first 5 years of followup in the subgroup analysis. On multivariate analysis, older age was associated with increased SPC risk and older age and positive smoking status were associated with increased overall mortality, mortality due to SPC, and mortality from second malignancy (p < 0.05). CONCLUSIONS: There may be a small increased risk of bladder SPC after prostate BT. A tendency toward a higher risk of bladder SPC after BT was found within the first 5 years of followup probably reflecting screening bias.

Iodine-125 thin seeds decrease prostate swelling during transperineal interstitial permanent prostate brachytherapy.

INTRODUCTION: Prostate swelling following seed implantation is a well-recognised phenomenon. The purpose of this intervention was to assess whether using thinner seeds reduces post-implant swelling with permanent prostate brachytherapy. METHODS: Eighteen consecutive patients eligible for prostate seed brachytherapy underwent seed implantation using iodine-125 (I-125) thin seeds. Operative time, dosimetry, prostate swelling and toxicity were assessed and compared with standard I-125 stranded seed controls, sourced from the department's brachytherapy database. RESULTS: A learning curve was noted with the thin seeds in terms of greater bending and deviation of needles from their intended path. This translated into significantly longer total operative time (88 vs 103 minutes; P = 0.009, 95% confidence interval (CI) 4.1-24.3) and time per needle insertion (2.6 vs 3.7 minutes; P < 0.001, 95% CI 0.5-1.3) for the thin seeds. Day 30 prostate volumes were significantly smaller in the thin seed group compared with standard seeds (40.9 cc vs 46.8 cc; P = 0.001, 95% CI 1.5-5.6). The ratio of preoperative transrectal ultrasound to day 30 post-implant CT volume was also smaller in the thin seed group (1.2 ± 0.1 for standard seeds vs 1.1 ± 0.1 for thin seeds). Post-implant dosimetric parameters were comparable for both groups. No significant differences were seen in acute urinary morbidity or quality of life between the two groups. CONCLUSIONS: I-125 thin seeds are associated with an initial learning curve, with longer operative time, even for experienced brachytherapists. The significant reduction in day 30 prostate volumes with the thin seeds has useful implications in terms of optimising dose coverage to the prostate in the early period post-implantation, as well as improving the accuracy of post-implant dosimetric assessments.

Prospective study of exercise intervention in prostate cancer patients on androgen deprivation therapy.

INTRODUCTION: Androgen deprivation therapy (ADT) is an important component of modern prostate cancer treatment. Survival benefits from neo-adjuvant and adjuvant hormones may take years to manifest, and balancing this with potential morbidity of therapy can be challenging. This study aimed to assess whether education and short-term combined aerobic and resistance exercises could help to ameliorate the adverse side effects of ADT. METHODS: Eight hundred fifty-nine patients with relapsed or metastatic prostate cancer on leuprorelin acetate were allocated to three interventional streams based on patient preference and medical fitness: supervised group (Face-to-Face) exercise sessions, home-based (At Home) exercise or a support programme for those incapable of exercising (Support). Patients enrolled onto Face to Face underwent measurement of body composition and cardiorespiratory fitness variables at baseline and programme completion. Patients in the exercise streams were surveyed to determine the programme's impact on physical fitness and well-being. RESULTS: Statistically significant improvements (p < 0.001) were seen in all measured cardiorespiratory fitness and strength variables. Programme attrition rates were low (75/859; 8.7%), the primary reason for withdrawal being discontinuation of hormones (70%). Programme satisfaction was high, with 98% of surveyed patients reporting a positive impact on fitness and 97% planning to continue exercising after programme completion. At 6 months, improved physical and emotional well-being was reported by 93 and 79% of patients, respectively. CONCLUSIONS: A short-term structured exercise intervention results in high compliance and significant improvements in muscle strength and cardiorespiratory fitness in prostate cancer patients on ADT.

Breast irradiation causes pallor in the nipple-areolar complex in women with Celtic skin type (result from the St. George and Wollongong randomised breast boost trial).

INTRODUCTION: The nipple-areolar complex (NAC) has special histological properties with higher melanocyte concentration than breast skin. To date, there are no data describing the late effects on the NAC following breast-conserving therapy (BCT). This study evaluated colour changes in the NAC in patients treated with breast-conserving surgery and adjuvant radiotherapy after 5 years. METHODS: Digital photographs obtained at 5 years following breast irradiation from the St. George and Wollongong (SGW) trial (NCT00138814) were evaluated by five experts using an iPad® (Apple Inc., Cupertino, CA, USA) application specifically created for this study. The SGW trial randomised 688 patients with Tis-2, N0-1, M0 carcinoma to the control arm of 50 Gy in 25 fractions and boost arm of 45 Gy in 25 fractions and 16 Gy in 8 fractions electron boost. RESULTS: A total of 141/372 (38%) patients had altered NAC (86% lighter, 10% darker). Patients with Celtic skin type had increased likelihood of having an altered NAC (odds ratio (OR), 1.75 (CI 1.1-2.7, P = 0.011)). On subgroup analysis, those with Celtic skin type receiving biologically equivalent dose (BED) Gy3 ≥ 80 Gy had OR of 3.03 (95% CI 1.2-7.5, P = 0.016) for having altered colour. There was a dose response with more profound changes seen in the NAC compared with irradiated breast skin if BED Gy3 ≥ 80 Gy with OR of 2.42 (95% CI 1.1-5.6, P = 0.036). CONCLUSION: In this Caucasian BCT population, over 30% of patients developed lighter NAC and more commonly in women with Celtic skin type. The degree of this effect increased with higher radiation dose.

First report of transperineal polyethylene glycol hydrogel spacer use to curtail rectal radiation dose after permanent iodine-125 prostate brachytherapy.

PURPOSE: To demonstrate the feasibility of transperineal polyethylene glycol (PEG) hydrogel insertion into anterior perirectal fat for reducing rectal radiation dose in patients with suboptimal rectal dosimetry after permanent iodine-125 prostate brachytherapy. METHODS AND MATERIALS: Five patients with suboptimal rectal dosimetry after iodine-125 seed brachytherapy implant underwent a single transperineal injection of PEG hydrogel into the anterior perirectal fat under general anesthetic using transrectal ultrasound guidance. Prostate-rectum separation and rectal radiation dose before and after PEG hydrogel spacer insertion were measured. Toxicity because of spacer insertion was assessed at Days 0-1 and 4-6 weeks using National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. RESULTS: All patients experienced a clinically significant reduction in the volume of rectum receiving greater than or equal to the prescription dose (RV100) on the postspacer postimplant dosimetry, compared with the prespacer postimplant dosimetry. Mean prostate-rectum separation that was achieved with the insertion of the spacer was 15.1 mm (±3.4). The mean difference in separation from before to after spacer insertion was 12.5 mm (±4.5). This was associated with a reduction in mean RV100 from 3.04 (±1.2) to 0.06 (±0.1) cc. Toxicities were limited to Grade 1 (National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0) perineal pain and rectal discomfort (3/5 patients). There were no Grade 2 or greater toxicities reported after insertion of the spacer. CONCLUSIONS: PEG hydrogel is safe and effective at reducing rectal radiation dose in select patients with suboptimal rectal dosimetry after prostate seed brachytherapy.

Piezoelectric polymer multilayer on flexible substrate for energy harvesting.

A piezoelectric polymer multilayer structure formed on a flexible substrate is investigated for mechanical energy harvesting under bending mode. Analytical and numerical models are developed to clarify the effect of material parameters critical to the energy harvesting performance of the bending multilayer structure. It is shown that the maximum power is proportional to the square of the piezoelectric stress coefficient and the inverse of dielectric permittivity of the piezoelectric polymer. It is further found that a piezoelectric multilayer with thinner electrodes can generate more electric energy in bending mode. The effect of improved impedance matching in the multilayer polymer on energy output is remarkable. Comparisons between piezoelectric ceramic multilayers and polymer multilayers on flexible substrate are discussed. The fabrication of a P(VDF-TrFE) multilayer structure with a thin Al electrode layer is experimentally demonstrated by a scalable dip-coating process on a flexible aluminum substrate. The results indicate that it is feasible to produce a piezoelectric polymer multilayer structure on flexible substrate for harvesting mechanical energy applicable for many low-power electronics.