Ankur Sharma

High-grade glioma management and response assessment—recent advances and current challenges

The management of high-grade gliomas (hggs) is complex and ever-evolving. The standard of care for the treatment of hggs consists of surgery, chemotherapy, and radiotherapy. However, treatment options are influenced by multiple factors such as patient age and performance status, extent of tumour resection, biomarker profile, and tumour histology and grade. Follow-up cranial magnetic resonance imaging (mri) to differentiate treatment response from treatment effect can be challenging and affects clinical decision-making. An assortment of advanced radiologic techniques-including perfusion imaging with dynamic susceptibility contrast mri, dynamic contrast-enhanced mri, diffusion-weighted imaging, proton spectroscopy, mri subtraction imaging, and amino acid radiotracer imaging-can now incorporate novel physiologic data, providing new methods to help characterize tumour progression, pseudoprogression, and pseudoresponse. In the present review, we provide an overview of current treatment options for hgg and summarize recent advances and challenges in imaging technology.

How, When and Where to Discuss Do Not Resuscitate: A Prospective Study to Compare the Perceptions and Preferences of Patients, Caregivers, and Health Care Providers in a Multidisciplinary Lung Cancer Clinic

Background: Do Not Resuscitate (DNR) is a significant but challenging part of end-of-life discussions when dealing with incurable lung cancer patients. We have explored the perceptions and preferences of patients, their caregivers (CGs), and health care providers (HCPs) and the current practice and opinions on DNR discussions in a multidisciplinary lung cancer clinic. Materials and Methods: This is a prospective descriptive study with a mixed quantitative and qualitative methodology to capture perceptions of the participants. To obtain a rich description of participant responses to questionnaire items, we employed a ‘think aloud’ process that prompted participants to immediately verbalize their thoughts when responding to questionnaire items. We used content analysis and constant comparison techniques to identify, code and categorize primary themes in the captured data. Results: Ten patients with advanced-stage lung cancer; nine CGs from the lung clinic and ten HCPs from the Thoracic Disease Site Group (DSG) were enrolled in the study. Most patients had only a limited understanding of DNR. Most CGs had a fair to good understanding of DNR. Most HCPs perceived their patients to have understood DNR most of the time. When patients were interviewed, a theme of “anticipated discussion” about DNR was identified. Patients and CGs expressed having faith in the system and responsible physicians as to when to discuss DNR. HCPs embraced a clinician preference-based decision-making approach to engaging in DNR discussions. They desired more resources, more knowledge, more structure and more time to discuss DNR. Most HCPs felt that it would be worth conducting a prospective clinical trial to determine the best time to discuss DNR. Conclusions: This pilot study provides a unique mixed quantitative and qualitative understanding of the perceptions of patients with lung cancer and their CGs and HCPs regarding DNR discussion. Our findings will help further the development of evidence-based guidelines and a broad prospective study that would have important implications for policies and practices around DNR discussions in order to reduce the emotional pain of dying patients, their CGs and HCPs.

Low-cost optical scanner and 3-dimensional printing technology to create lead shielding for radiation therapy of facial skin cancer: First clinical case series

Purpose Three-dimensional printing has been implemented at our institution to create customized treatment accessories, including lead shields used during radiation therapy for facial skin cancer. To effectively use 3-dimensional printing, the topography of the patient must first be acquired. We evaluated a low-cost, structured-light, 3-dimensional, optical scanner to assess the clinical viability of this technology. Methods and materials For ease of use, the scanner was mounted to a simple gantry that guided its motion and maintained an optimum distance between the scanner and the object. To characterize the spatial accuracy of the scanner, we used a geometric phantom and an anthropomorphic head phantom. The geometric phantom was machined from plastic and included hemispherical and tetrahedral protrusions that were roughly the dimensions of an average forehead and nose, respectively. Polygon meshes acquired by the optical scanner were compared with meshes generated from high-resolution computed tomography images. Most optical scans contained minor artifacts. Using an algorithm that calculated the distances between the 2 meshes, we found that most of the optical scanner measurements agreed with those from the computed tomography scanner within approximately 1 mm for the geometric phantom and approximately 2 mm for the head phantom. We used this optical scanner along with 3-dimensional printer technology to create custom lead shields for 10 patients receiving orthovoltage treatments of nonmelanoma skin cancers of the face. Patient, tumor, and treatment data were documented. Results Lead shields created using this approach were accurate, fitting the contours of each patients face. This process added to patient convenience and addressed potential claustrophobia and medical inability to lie supine. Conclusions The scanner was found to be clinically acceptable, and we suggest that the use of an optical scanner and 3-dimensional printer technology become the new standard of care to generate lead shielding for orthovoltage radiation therapy of nonmelanoma facial skin cancer.

Analysis of First Case Series in the World of Skin Cancer Patients Where Lead Shielding for Radiation Therapy of Facial Skin Cancer was Designed Utilizing Optical Scanner and 3D Printer Technology

Purpose Radiation is one of the modalities used to treat non-melanoma skin cancers. For facial lesions; ortho-voltage radiotherapy (RT) can require the creation of lead shielding to protect vulnerable organs at risk (OAR). Creating a lead shield is often difficult due to the complex contours of the face. The traditional method involves creating a plaster mould of a patients face to use as a template for creating a shield. This requires another patient visit, and for patients who are claustrophobic or medically unable to lie flat, this strategy is not ideal. We address this by utilizing optical scanner and 3D printer technology to create lead shields and report the first case series in the English literature here.

86: Using Optical Scanner and 3D Printer Technology to Create Lead Shielding for Radiotherapy of Facial Skin Cancer with Low Energy Photons: An Exciting Innovation

Treatment of non-melanoma skin cancers of the face using ortho-voltage radiotherapy may require lead shielding to protect vulnerable organs at risk (OAR). As the human face has many complex and intricate contours, creating a lead shield can be difficult. The process can include creating a plaster mould of a patients face to create the shield. It can be difficult or impossible for a patient who is claustrophobic or medically unable to lie flat to have a shield made by this technique. Other methods have their own shortcomings. We aimed to address some of these issues using an optical scanner and 3D printer technology.

74: Innovative Approach for Generating Soft Silicone Bolus using 3D Printing for Electron Treatment of Skin Cancers in Areas with Irregular Contours

S29 _________________________________________________________________________________________________________ cardiac four-dimensional CT (4D-CT) synchronized to the electrocardiogram were obtained in treatment position, using a prospective sequential acquisition method including the extreme phases of systole and diastole. On a MimVista® image registration workstation, dose distributions were transferred to the cardiac 4D-CT. The left coronary artery, left ventricle and heart were contoured on both phases of the cardiac cycle. The maximum and minimum doses to the left coronary, left ventricle and heart were compared using a bilateral paired Student T test. Results: Preliminary data from the first eight patients enrolled are presented. Median age was 60 years (56-71) and median planned dose to the left breast was 42.56 Gy (42.56-50) in 16 fractions (16-20). For the left coronary artery, mean dose, V5 and V20 in systole versus diastole were 6.1 Gy versus 7.9 Gy (p = 0.02), 37% versus 48% (p = 0.02) and 10% versus 16% (p = 0.04), respectively. For the left ventricle, mean dose, V5 and V20 in systole versus diastole were 1.3 Gy versus 1.6 Gy (p = 0.005), 6% versus 9% (p = 0.03) and 1% versus 2% (p > 0.1), respectively. For the whole heart, mean dose, V5 and V20 in systole versus diastole were 0.9 Gy versus 1.3 Gy (p = 0.005), 21 cc versus 32 cc (p = 0.07) and 4 cc versus 5 cc (p > 0.1), respectively. Conclusions: Beyond DIBH, systolic irradiation would be associated with a further reduction in V5, V20 and mean dose to the left coronary artery, as well as a reduction in V5 and mean dose to the left ventricle and heart as a whole. The potential clinical impact of this reduction as well as the feasibility of cardiac gated irradiation are to be further investigated.

218: Using 3D Printer Technology to Manufacture Anatomic Models for Patient Education: A New Frontier

PURPOSE/OBJECTIVES The use of 3D printing technology to create precise anatomical models is well documented. These models are used by surgeons to better plan upcoming operations and to save valuable operating room time. They are also used to educate other members of the health care team, such as residents, medical students and nurses. However, the use of these anatomically accurate models to educate patients in the clinical setting has been underutilized. At our centre, we are using 3D printer technology to generate accurate clinical models of mandibles. Our objective is to use these models to better educate and prepare head and neck cancer patients for upcoming surgery where manibulectomy is part of the surgical procedure. This has been used to educate 3 consecutive patients.

Sci‐Sat AM: Radiation Dosimetry and Practical Therapy Solutions ‐ 07: A mould room in a box – 3D scanning and printing technology in the radiotherapy clinic

Purpose: We describe the process by which our centre is currently implementing 3D printing and scanning technology for treatment accessory fabrication. This technology can increase efficiency and accuracy of accessory design, production and placement during daily use. Methods: A low-cost 3D printer and 3D optical scanner have been purchased and are being commissioned for clinical use. Commissioning includes assessing: the accuracy of the 3D scanner through comparison with high resolution CT images; the dosimetric characteristics of polylactic acid (PLA) for electron beams; the clinical utility of the technology, and; methods for quality assurance. Results: The agreement between meshes generated using the 3D scanner and CT data was within 2 millimeters for an anthropomorphic head phantom. In terms of electron beam attenuation, 1 centimetre of printed PLA was found equivalent to 1.17 cm of water. In proof-of-concept tests, several types of treatment accessories have been prototyped to date that will benefit from this technology. These include electron and photon bolus for areas with complex surface contours including the ear for electron treatments, the extremities for photon treatments and lead shielding for orthovoltage treatments. Imaging with CT and x-ray showed minimal defects, which will have no significant clinical impact. Geometric fidelity and fit to volunteers and patients was found to be excellent. Conclusions: 3D Printing and scanning can increase efficiency in the clinic for treatments requiring custom accessories. Customized boluses and shielding had excellent fit and reduced uncertainty in positioning.

Poster – 39: Using Optical Scanner and 3D Printer Technology to Create Lead Shielding for Radiotherapy of Facial Skin Cancer with Low Energy Photons

Purpose: Treatment of skin cancers of the face using orthovoltage radiotherapy often requires lead shielding. However, creating a lead shield can be difficult because the face has complex and intricate contours. The traditional process involved creating a plaster mould of the patients face can be difficult for patients. Our goal was to develop an improved process by using an optical scanner and 3D printer technology. Methods: The oncologist defined the treatment field by drawing on each patients skin. Three-dimensional images were acquired using a consumer-grade optical scanner. A 3D model of each patients face was processed with mesh editing software before being printed on a 3D printer. Using a hammer, a 3 mm thick layer of lead was formed to closely fit the contours of the model. A hole was then cut out to define the field. Results: The lead shields created were remarkably accurate and fit the contours of the patients. The hole defining the field exposed only a minimally sized site to be exposed to radiation, while the rest of the face was protected. It was easy to obtain perfect symmetry for the definition of parallel opposed beams. Conclusion: We are routinely using this technique to build lead shielding that wraps around the patient as an alternative to cut-outs. We also use it for treatment of the tip of the nose using a parallel opposed pair beams with a wax nose block. We found this technique allows more accurate delineation of the cut-out and a more reproducible set-up.

Perceptions and Preferences of Patients with Terminal Lung Cancer and Family Caregivers about DNR

Background: Patients with terminal lung cancer and their families are challenged and stressed with the end of life discussions. Do Not Resuscitate (DNR) orders are a critical part of such discussions. Objective: To understand the perceptions and preferences of patients with terminal lung cancer and their family caregivers around DNR discussions. . Methods: Our quantitative component consisted of a pen-and-paper questionnaire that was followed by a ‘think aloud’ process to capture perceptions of participants in response to questionnaire items. Qualitative methods included content analysis and constant comparison techniques to identify, code, and categorize primary themes arising from ‘think aloud’ responses. Results: In this pilot study, 10 patients with advanced stage lung cancer and nine family caregivers were enrolled from one tertiary cancer care centre. Three major themes and several sub-themes were identified reflecting participants’ psychosocial environment, emotional responses to DNR discussions, and suggestions to improve DNR discussions. Most of the time, both patients and caregivers perceived a supportive environment within their family unit. Some patients were uncertain about their disease extent but most had entertained thoughts about prognosis and DNR status prior to having a discussion with their physician. A range of situations stimulated the DNR discussion. Most patients were uncertain about identifying the most appropriate health care provider (HCP) for DNR discussion. While participants found DNR discussions distressing, patients maintained hope in the face of accepting a terminal diagnosis. There were mixed feelings about the reversibility of a DNR decision and concerns about the care of the patients after being stated as DNR. Participants desired their HCP to be emotionally sensitive, knowledgeable, respectful, and straightforward. Conclusions: Most participants were open about their experiences with psychosocial supports and emotional reactions and made suggestions to HCP to improve DNR discussions. Further examination in larger longitudinal studies is required to validate the observations in the current study.