Health and Medical Physics Commons^™

Hyalinization-Based Pathologic Response And Immune Infiltration Following Neoadjuvant Radiotherapy With Or Without Immune-Checkpoint Blockade In Localized Undifferentiated Pleomorphic Sarcoma, R S Traweek, M Zoghbi, R Lazcano, B M Cope, A J Bishop, A Farooqi, D Mitra, A K Yoder, B A Guadagnolo, D R Ingram, K Wani, D Shamsutdinova, A J Lazar, W-L Wang, C P Scally, E Z Keung, K E Torres, K K Hunt, R Ratan, J A Livingston, M S Nakazawa, D M Araujo, S Patel, V Ravi, A P Conley, M A Zarzour, N Somaiah, C L Roland, E F Nassif Haddad

Faculty, Staff and Student Publications

BACKGROUND: Standard-of-care treatment of localized undifferentiated pleomorphic sarcoma (UPS) involves preoperative radiotherapy (RT) and surgery. Combination of RT with immune-checkpoint blockade (ICB) represents a promising new strategy.

METHODS: Our primary objective was to assess survival outcomes and pathologically documented response in patients receiving RT with or without ICB or chemotherapy.

RESULTS: In a retrospective cohort of 68 patients with primary or locally recurrent UPS who received neoadjuvant RT with or without ICB, the ICB group had greater tumor hyalinization than the non-ICB group (89% compared with 30%, P = 0.018). In the non-ICB group, 19/37 patients (51%) achieved hyalinization-based pathologic …

T2-Weighted Imaging Of Rectal Cancer Using A 3d Fast Spin Echo Sequence With And Without Deep Learning Reconstruction: A Reader Study, Dan Nguyen, Sarah Palmquist, Ken-Pin Hwang, Jingfei Ma, Usama Salem, Jia Sun, Xinzeng Wang, Jong Bum Son, Randy Ernst, Peng Wei, Harmeet Kaur, Nir Stanietzky

Faculty, Staff and Student Publications

Purpose: To compare image quality and clinical utility of a T2-weighted (T2W) 3-dimensional (3D) fast spin echo (FSE) sequence using deep learning reconstruction (DLR) versus conventional reconstruction for rectal magnetic resonance imaging (MRI).

Methods: The study included 50 patients with rectal cancer who underwent rectal MRI consecutively between July 7, 2020 and January 20, 2021 using a T2W 3D FSE sequence with DLR and conventional reconstruction. Three radiologists reviewed the two sets of images, scoring overall SNR, motion artifacts, and overall image quality on a 3-point scale and indicating clinical preference for DLR or conventional reconstruction based on those three …

American Association Of Physicists In Medicine (Aapm) Chapter Climate Check: Mixed Methods Analysis Of Survey Responses, Ashley J Cetnar, Ghada Aldosary, Meghan C Koo, Holly Lincoln, Angélica Pérez-Andújar, Surendra Prajapati, Samantha J Simiele, Kristi R G Hendrickson

Faculty, Staff and Student Publications

Introduction: The American Association of Physicists in Medicine (AAPM) recently shared results and recommendations from its first Equity, Diversity, and Inclusion (EDI) Climate Survey, which was designed to assess the climate at the workplace, the AAPM organization, and the AAPM regional chapter level. This work further explores the status of EDI at the regional chapter level.

Methods: AAPM's EDI Survey was distributed to 5500 members and had a response rate of 25%. In the survey, three open-ended comment boxes were provided for feedback, including one for regional AAPM members. Sixty-four percent of respondents indicated they were part of a regional …

Quantitative Evaluation Of 90y-Pet/Ct And 90y-Spect/Ct-Based Dosimetry Following Yttrium-90 Radioembolization, Srinivas Cheenu Kappadath, Eric Courtney Henry, Benjamin P Lopez, Armeen Mahvash

Faculty, Staff and Student Publications

Background: Following yttrium-90 radioembolization (90Y-RE), 90Y-PET/CT and 90Y-SPECT/CT imaging provide the means to calculate the voxelized absorbed dose distribution. Given the widespread use of the two imaging modalities and lack of well-established standardized dosimetry protocols for 90Y-RE, there is a clinical need to systematically investigate and evaluate differences in the performance of voxel-based dosimetry between 90Y-PET/CT and 90Y-SPECT/CT.

Purpose: To quantitatively analyze and compare 90Y-PET/CT and 90Y-SPECT/CT-based dosimetry following 90Y-RE.

Methods: 90Y-PET/CT and 90Y-SPECT/CT imaging was acquired for 35 patients following 90Y-RE with TheraSphere for the treatment of unresectable hepatocellular carcinoma. Dosimetry was performed using the local deposition method with …

Automatic End-To-End Vmat Treatment Planning For Rectal Cancers, Kai Huang, Christine Chung, Ethan B Ludmir, Lifei Zhang, Constance A Owens, Jean Gumma-De La Vega, Jack Duryea, Yao Zhao, Xinru Chen, David Fuentes, Carlos E Cardenas, Tina Marie Briere, Sam Beddar, Laurence E Court, Prajnan Das

Faculty, Staff and Student Publications

BACKGROUND: The treatment planning process from segmentation to producing a deliverable plan is time-consuming and labor-intensive. Existing solutions automate the segmentation and planning processes individually. The feasibility of combining auto-segmentation and auto-planning for volumetric modulated arc therapy (VMAT) for rectal cancers in an end-to-end process is not clear.

PURPOSE: To create and clinically evaluate a complete end-to-end process for auto-segmentation and auto-planning of VMAT for rectal cancer requiring only the gross tumor volume contour and a CT scan as inputs.

METHODS: Patient scans and data were retrospectively selected from our institutional records for patients treated for malignant neoplasm of the …

Mpla Case: How Do You Lead As A Lead Physicist?, Patricia Sansourekidou, Leonard Kim, Lee Xu, Mary Gronberg, Cassandra Stambaugh, Dongxu Wang

Faculty, Staff and Student Publications

This work of fiction is part of a case study series developed by the Medical Physics Leadership Academy (MPLA). It is intended to facilitate the discussion of the managerial and leadership challenges faced by a clinical medical physicist. In this case, a physicist David used to work in a clinic where he thrived and felt like a leader, despite not having the title. After a job change, he is now officially the "Lead Physicist" at a hospital newly affiliated with a large academic healthcare system. He believes he will be equally successful. Yet he struggles to bring about changes and …

Mpla Case: I Didn't Realize Those Were The Expectations!, Samantha J Simiele, Serdar Charyyev, Liyong Lin, Leonard Kim, Dongxu Wang, Mary P Gronberg

Faculty, Staff and Student Publications

This work of fiction is part of a case study series developed by the Medical Physics Leadership Academy (MPLA). It is intended to facilitate the discussion of how students and advisors can better communicate expectations and navigate difficult conversations. In this case, a fourth-year Ph.D. student Emma learns that her advisor Dr. So is leaving the institution and has not arranged to bring any students with him. As Emma and Dr. So meet to discuss Emma's next steps, the conversation reveals misunderstandings and miscommunications of expectations, including a specific publication requirement for graduation from Dr. So. Having just learned of …

Parametric Delineation Uncertainties Contouring (Pduc) Modeling On Ct Scans Of Prostate Cancer Patients, Vi Ly, Lizhong Liu, Carlos Cardenas, Sean Maroongroge, Brian De, Daniel El Basha, Laurence Court, Xi Luo

Faculty, Staff and Student Publications

PURPOSE: Variability in contouring contributes to large variations in radiation therapy planning and treatment outcomes. The development and testing of tools to automatically detect contouring errors require a source of contours that includes well-understood and realistic errors. The purpose of this work was to develop a simulation algorithm that intentionally injects errors of varying magnitudes into clinically accepted contours and produces realistic contours with different levels of variability.

METHODS: We used a dataset of CT scans from 14 prostate cancer patients with clinician-drawn contours of the regions of interest (ROI) of the prostate, bladder, and rectum. Using our newly developed …

Aapm Btsc Report 377: Physicist Brachytherapy Training In 2021-A Survey Of Therapeutic Medical Physics Residency Program Directors, Manik Aima, Samantha J Simiele, Susan L Richardson, Christopher S Melhus

Faculty, Staff and Student Publications

BACKGROUND: Brachytherapy (BT) was the first radiotherapeutic technique used to treat human disease and remains an essential modality in radiation oncology. A decline in the utilization of BT as a treatment modality has been observed and reported, which may impact training opportunities for medical physics residents. A survey of therapeutic medical physics residency program directors was performed as part of an assessment of the current state of BT training during residency.

METHODS: In March 2021, a survey consisting of 23 questions was designed by a working unit of the Brachytherapy Subcommittee of the American Association of Physicists in Medicine (AAPM) …