Search

This visual anthropology project was informed by a series of plein-air water-color sketches of panel-block apartment buildings, painted in conversation with ethnographic research participants in Moscow in 2021. Such housing, built on an industrial scale during Nikita Khrushchev’s mass-housing campaign between 1955 and 1964, and which came to be nicknamed khrushchevkas, became ubiquitous across the Soviet Union. In 2017, in Moscow, Russia, panel-block apartments were threatened by the renovatsiya campaign, which asked residents to vote to demolish their own homes, now declared dilapidated housing. The author painted a number of these apartment buildings slated for demolition, recording details in the construction, ornamentation, and topography of each apartment block. The author also gathered testimonies of artists who live in-, and whose artistic practice revolves around such housing, asking participants to share their artistic process, memories of growing up and living in such housing, and feelings about the prospect of losing their home. While supported by the majority of the population, the renovatsiya campaign would erase local histories, revealing the state’s authoritarian attitude towards its own citizenry, but much worse, it served as premonition for Russia’s renewed aggression in Ukraine, which, less than a year later, caused a widespread political and humanitarian disaster, closing all possibility for further research.

Background: Proton minibeam radiation therapy (pMBRT) can deliver spatially fractionated dose distributions with submillimeter resolution. These dose distributions exhibit significant heterogeneity in both depth and lateral directions. Accurate characterization of pMBRT doses requires dosimetry devices with high spatial resolution and a wide dynamic range. Furthermore, the dependency of dosimetric measurements on Linear Energy Transfer (LET), as observed in conventional proton therapy, is also present in pMBRT depth dosemeasurements. Purpose: This work demonstrates the process of performing comprehensive dosimetric measurements to characterize the pMBRT collimator on a clinical single-gantry proton machine, utilizing commercially available dosimetry devices. Methods: The minibeam collimator is designed to be mounted on the clinical nozzle as a beam-modifying accessory. Three collimators, each with a slit opening of 0.4 mm, are thoroughly evaluated. The center-to-center (c-t-c) distances of the slits for these collimators are 2.8 mm, 3.2 mm, and 4.0 mm, respectively. High spatial resolution dosimetry devices are essential for PMBRT dose characterizations. To meet this requirement, two-dimensional (2D) dose measurement devices, Gafchromic films, are used to measure lateral profiles at various depths. Films are also used for depth dose profile measurements in solid water. Additionally, high-resolution point dose detectors, microDiamond, and Razor diode detectors are employed for lateral profile measurements at various depths. Percent depth dose (PDD) measurements of pMBRT in solid water, with various proton energies, collimators, and air gaps, are performed using Gafchromic films. The film's LET dependency for proton beams is corrected to ensure accurate pMBRT PDD measurements. The Monte Carlo simulation tool TOPAS is utilized to compare and validate all experimental measurements. Results: At depths where LET is not a concern, film dose measurements were consistent with microDiamond and Razor diode point measurements. The point detectors need to be orientated with the thin side aligned to the incoming beam. Comparison of the lateral dose profiles extracted from TOPAS simulations, films, microDiamond, and Razor diode detectors shows a passing rate exceeding 98% in 1D gamma analysis at 3% 0.1 mm criteria. However, when the microDiamond detector is orientated to face the pMBRT beam, its spatial resolution may not be sufficient to capture the peak and valley dose accurately. Nevertheless, an accuracy within 2% can still be achieved when comparing the average dose. The PDD measurements show that the peak valley dose ratio (PVDR) of pMBRT can be altered at different depths with different air gaps using the same collimator or different collimators of different c-t-c distances. Conclusion: Our study demonstrates that comprehensive dose measurements for pMBRT can be conducted using standard clinical dose measurement devices. These measurements are indispensable for guiding and ensuring accurate dose reporting in pre-clinical studies using the pMBRT technique. [ABSTRACT FROM AUTHOR]

Objective: To determine differences in post‐treatment QoL across treatment settings in patients receiving adjuvant radiation therapy for head and neck squamous cell carcinoma (HNSCC). Methods: This was a prospective observational cohort study of patients with HNSCC initially evaluated in a head and neck surgical oncologic and reconstructive clinic at an academic medical center (AMC). Participants were enrolled prior to treatment in a prospective registry collecting demographic, social, and clinical data. Physical and social–emotional QoL (phys‐QoL and soc‐QoL, respectively) was measured using the University of Washington‐QoL questionnaire at pre‐treatment and post‐treatment visits. Results: A cohort of 177 patients, primarily male and White with an average age of 61.2 ± 11.2 years, met inclusion criteria. Most patients presented with oral cavity tumors (n = 132, 74.6%), had non‐HPV‐mediated disease (n = 97, 61.8%), and were classified as Stage IVa (n = 72, 42.8%). After controlling for covariates, patients treated at community medical centers (CMCs) reported a 7.15‐point lower phys‐QoL compared with those treated at AMCs (95% CI: −13.96 to −0.35, p = 0.040) up to 12 months post‐treatment. Additionally, patients who were treated at CMCs had a 5.77‐point (−11.86–0.31, p = 0.063) lower soc‐QoL score compared with those treated at an AMC, which was not statistically significant. Conclusion: This study revealed that HNSCC patients treated with radiation at AMCs reported significantly greater phys‐QoL in their first‐year post‐treatment compared to those treated at CMCs, but soc‐QoL did not differ significantly. Further observational studies are needed to explore potential factors, including treatment planning and cancer resource engagement, behind disparities between AMCs and CMCs. Level of Evidence: 3 Laryngoscope, 134:3645–3655, 2024 [ABSTRACT FROM AUTHOR]

Background: Although the FLASH radiotherapy (FLASH) can improve the sparing of organs‐at‐risk (OAR) via the FLASH effect, it is generally a tradeoff between the physical dose coverage and the biological FLASH coverage, for which the concept of FLASH effective dose (FED) is needed to quantify the net improvement of FLASH, compared to the conventional radiotherapy (CONV). Purpose: This work will develop the first‐of‐its‐kind treatment planning method called simultaneous dose and dose rate optimization via dose modifying factor modeling (SDDRO‐DMF) for proton FLASH that directly optimizes FED. Methods: SDDRO‐DMF models and optimizes FED using FLASH dose modifying factor (DMF) models, which can be classified into two categories: (1) the phenomenological model of the FLASH effect, such as the FLASH effectiveness model (FEM); (2) the mechanistic model of the FLASH radiobiology, such as the radiolytic oxygen depletion (ROD) model. The general framework of SDDRO‐DMF will be developed, with specific DMF models using FEM and ROD, as a demonstration of general applicability of SDDRO‐DMF for proton FLASH via transmission beams (TB) or Bragg peaks (BP) with single‐field or multi‐field irradiation. The FLASH dose rate is modeled as pencil beam scanning dose rate. The solution algorithm for solving the inverse optimization problem of SDDRO‐DMF is based on iterative convex relaxation method. Results: SDDRO‐DMF is validated in comparison with IMPT and a state‐of‐the‐art method called SDDRO, with demonstrated efficacy and improvement for reducing the high dose and the high‐dose volume for OAR in terms of FED. For example, in a SBRT lung case of the dose‐limiting factor that the max dose of brachial plexus should be no more than 26 Gy, only SDDRO‐DMF met this max dose constraint; moreover, SDDRO‐DMF completely eliminated the high‐dose (V70%) volume to zero for CTV10mm (a high‐dose region as a 10 mm ring expansion of CTV). Conclusion: We have proposed a new proton FLASH optimization method called SDDRO‐DMF that directly optimizes FED using phenomenological or mechanistic models of DMF, and have demonstrated the efficacy of SDDO‐DMF in reducing the high‐dose volume or/and the high‐dose value for OAR, compared to IMPT and a state‐of‐the‐art method SDDRO. [ABSTRACT FROM AUTHOR]

Background: Minibeam represents a preclinical spatially fractionated radiotherapy modality with great translational potential. The advantage lies in its high therapeutic index (compared to GRID and LATTICE) and ability to treat at greater depth (compared to microbeam). Proton minibeam radiotherapy (pMBRT) is a synergy of proton and minibeam. While the single‐gantry proton facility has gained popularity due to its affordability and compact design, it often has limited beam time available for research purposes. Conversely, given the current requirement of pMBRT on specific minibeam hardware collimators, necessitates a reproducible and fast setup to minimize pMBRT treatment time and streamline the switching time between pMBRT and conventional treatment for clinically translation. Purpose: The contribution of this work is the development and characterization of the first pMBRT system tailored for single‐gantry proton facility. The system allows for efficient and reproducible plug‐and‐play setup, achievable within minutes. Methods: The single room pMBRT system is constructed based on IBA ProteusONE proton machine. The end of nozzle is attached with beam modifying accessories though an accessory drawer. A small snout is attached to the accessory drawer and used to hold apertures and range shifters. The minibeam aperture consists of two components: a fitting ring and an aperture body. Three minibeam apertures were manufactured. The first‐generation apertures underwent qualitatively analysis with film, and the second generation aperture underwent more comprehensive quantitative measurement. The reproducibility of the setup is accessed, and the film measurements are performed to characterize the pMBRT system in cross validation with Monte Carlo (MC) simulations. Results: We presented initial results of large field pMBRT aperture and the film measurements indicates the effect of source‐to‐isocenter distance = 930 cm in Y proton scanning direction. Consistent with TOPAS MC simulation, the dose uniformity of pMBRT field <2 cm is demonstrated to be better than 2%, rendering its suitability for pre‐clinical studies. Subsequently, we developed the second generation of aperture with five slits and characterized the aperture with film dosimetry studies and compared the results to the benchmark MC. Comprehensive film measurements were also performed to evaluate the effect of divergence, air gap and gantry‐angle dependency and repeatability and revealing a consistent performance within 5%. Furthermore, the 2D gamma analysis indicated a passing rate exceeding 99% using 3% dose difference and 0.2 mm distance agreement criteria. We also establish the peak valley dose ratio and the depth dose profile measurements, and the results are within 10% from MC simulation. Conclusions: We have developed the first pMBRT system tailored for a single‐gantry proton facility, which has demonstrated accuracy in benchmark with MC simulations, and allows for efficient plug‐and‐play setup, emphasizing efficiency. [ABSTRACT FROM AUTHOR]

Local control and overall survival in patients with advanced head and neck squamous cell cancer (HNSCC) remains dismal. Signaling through the Hedgehog (Hh) pathway is associated with epithelial-to-mesenchymal transition, and activation of the Hh effector transcription factor Gli1 is a poor prognostic factor in this disease setting. Here, we report that increased GLI1 expression in the leading edge of HNSCC tumors is further increased by irradiation, where it contributes to therapeutic inhibition. Hh pathway blockade with cyclopamine suppressed GLI1 activation and enhanced tumor sensitivity to radiotherapy. Furthermore, radiotherapy-induced GLI1 expression was mediated in part by the mTOR/S6K1 pathway. Stroma exposed to radiotherapy promoted rapid tumor repopulation, and this effect was suppressed by Hh inhibition. Our results demonstrate that Gli1 that is upregulated at the tumor-stroma intersection in HNSCC is elevated by radiotherapy, where it contributes to stromal-mediated resistance, and that Hh inhibitors offer a rational strategy to reverse this process to sensitize HNSCC to radiotherapy.

Objective: In patients with head and neck squamous cell carcinoma (HNSCC), initiating postoperative radiotherapy (PORT) greater than 42 days after surgery is associated with a higher risk of poor survival outcomes. Social support has been shown to modulate behaviors related to care‐seeking and treatment adherence. In this study, we sought to determine the relationship between social support metrics and PORT delays. Study Design: Prospective cohort study. Setting: Single tertiary medical center. Methods: Patients with HNSCC who underwent primary surgical excision requiring PORT were prospectively enrolled. Patient‐perceived social support metrics were assessed using the Medical Outcomes Study Social Support Survey (MOS‐SSS) at initial presurgical evaluation. Associations with PORT delays were evaluated via univariable and multivariable logistic regression analysis. Results: A total of 111 patients met the inclusion criteria for the study. An additional 28 patients were recommended to receive PORT but did not initiate treatment and were included for secondary analysis. All four subscales of the MOS‐SSS (positive social interaction, affectionate support, tangible support, and emotional/informational support) were significantly associated with PORT initiation delays on univariable analysis. On multivariable analysis, the overall MOS‐SSS score (odds ratio [OR] 2.08, 1.15‐4.35, p =.028) was significantly associated with PORT initiation delays. On secondary analysis, lower tangible support was associated with a lack of PORT initiation (OR 1.63, 1.05‐2.54, p =.028). Conclusion: Social support metrics were significantly associated with PORT delays, which may help promote tighter scheduling and closer monitoring of high‐risk patients. [ABSTRACT FROM AUTHOR]

Byline: Angelo. Bergamo, Kevin. Kauweloa, Gregory. Gan, Zheng. Shi, Janeen. Daniels, Richard. Crownover, Ganesh. Narayanasamy, Sotirios. Stathakis, Panayiotis. Mavroidis, Niko. Papanikolaou, Alonso. Gutierrez Background: The prevention of radiation-induced liver disease [...]