Accurate target definition is critical for the appropriate application of radiation therapy. In 2008, the Radiation Therapy Oncology Group (RTOG) published an international collaborative atlas to ...define the clinical target volume (CTV) for intensity modulated pelvic radiation therapy in the postoperative treatment of endometrial and cervical cancer. The current project is an updated consensus of CTV definitions, with removal of all references to bony landmarks and inclusion of the para-aortic and inferior obturator nodal regions.
An international consensus guideline working group discussed modifications of the current atlas and areas of controversy. A document was prepared to assist in contouring definitions. A sample case abdominopelvic computed tomographic image was made available, on which experts contoured targets. Targets were analyzed for consistency of delineation using an expectation-maximization algorithm for simultaneous truth and performance level estimation with kappa statistics as a measure of agreement between observers.
Sixteen participants provided 13 sets of contours. Participants were asked to provide separate contours of the following areas: vaginal cuff, obturator, internal iliac, external iliac, presacral, common iliac, and para-aortic regions. There was substantial agreement for the common iliac region (sensitivity 0.71, specificity 0.981, kappa 0.64), moderate agreement in the external iliac, para-aortic, internal iliac and vaginal cuff regions (sensitivity 0.66, 0.74, 0.62, 0.59; specificity 0.989, 0.966, 0.986, 0.976; kappa 0.60, 0.58, 0.52, 0.47, respectively), and fair agreement in the presacral and obturator regions (sensitivity 0.55, 0.35; specificity 0.986, 0.988; kappa 0.36, 0.21, respectively). A 95% agreement contour was smoothed and a final contour atlas was produced according to consensus.
Agreement among the participants was most consistent in the common iliac region and least in the presacral and obturator nodal regions. The consensus volumes formed the basis of the updated NRG/RTOG Oncology postoperative atlas. Continued patterns of recurrence research are encouraged to refine these volumes.
Purpose: Currently, calculations of proton range in proton therapy patients are based on a conversion of CT Hounsfield units of patient tissues into proton relative stopping power. Uncertainties in ...this conversion necessitate larger proximal and distal planned target volume margins. Proton CT can potentially reduce these uncertainties by directly measuring proton stopping power. We aim to demonstrate proton CT imaging with complex porcine samples, to analyze in detail three‐dimensional regions of interest, and to compare proton stopping powers directly measured by proton CT to those determined from x‐ray CT scans.
Methods: We have used a prototype proton imaging system with single proton tracking to acquire proton radiography and proton CT images of a sample of porcine pectoral girdle and ribs, and a pig's head. We also acquired close in time x‐ray CT scans of the same samples and compared proton stopping power measurements from the two modalities. In the case of the pig's head, we obtained x‐ray CT scans from two different scanners and compared results from high‐dose and low‐dose settings.
Results: Comparing our reconstructed proton CT images with images derived from x‐ray CT scans, we find agreement within 1% to 2% for soft tissues and discrepancies of up to 6% for compact bone. We also observed large discrepancies, up to 40%, for cavitated regions with mixed content of air, soft tissue, and bone, such as sinus cavities or tympanic bullae.
Conclusions: Our images and findings from a clinically realistic proton CT scanner demonstrate the potential for proton CT to be used for low‐dose treatment planning with reduced margins.
The purpose of this study was to characterize the impact of household income disparities in the survival of patients with non-small cell lung cancer (NSCLC) presenting with brain metastasis on a ...population-based level.
This is a population-based cohort study using the Surveillance, Epidemiology, and End Results (SEER) database from 2010–2016 including 15,808 NSCLC patients presenting with brain metastasis.
This study comprises 15,808 adult patients with NSCLC presenting with brain metastases having an age range 64 ± 10 years with 51% male, 76% white, 52% married, 61% insured, and with 85% of lung adenocarcinoma histopathology. The 1-, 2- and 5-year survival rates for living in the lower household income quartile were 21%, 10%, and 3%, respectively, for the second quartile 24%, 10%, and 3%; for the third quartile 28%, 14%, and 4%; and for the top quartile 31%, 17%, and 4%, respectively. Multivariate Cox proportional hazard analysis showed that living in a higher quartile household income county is associated with increased survival (P < 0.0001), hazard ratio 0.87, 95% confidence interval (0.82–0.92).
This population-based study suggests that living in higher median household income counties is associated with increased survival time and reduced risk of mortality for patients with NSCLC who have brain metastases present at diagnosis, independent of other factors. These findings underscore the importance of ensuring adequate and easy access to care for all patients, irrespective of their economic background.
We report that a localized intracellular and extracellular Ca2+ mobilization occurs at the site of microscopic epithelial damage in vivo and is required to mediate tissue repair. Intravital ...confocal/two-photon microscopy continuously imaged the surgically exposed stomach mucosa of anesthetized mice while photodamage of gastric epithelial surface cells created a microscopic lesion that healed within 15 min. Transgenic mice with an intracellular Ca2+-sensitive protein (yellow cameleon 3.0) report that intracellular Ca2+ selectively increases in restituting gastric epithelial cells adjacent to the damaged cells. Pretreatment with U-73122, indomethacin, 2-aminoethoxydiphenylborane, or verapamil inhibits repair of the damage and also inhibits the intracellular Ca2+ increase. Confocal imaging of Fura-Red dye in luminal superfusate shows a localized extracellular Ca2+ increase at the gastric surface adjacent to the damage that temporally follows intracellular Ca2+ mobilization. Indomethacin and verapamil also inhibit the luminal Ca2+ increase. Intracellular Ca2+ chelation (1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid/acetoxymethyl ester, BAPTA/AM) fully inhibits intracellular and luminal Ca2+ increases, whereas luminal calcium chelation (N-(2-hydroxyetheyl)-ethylendiamin-N,N,N′-triacetic acid trisodium, HEDTA) blocks the increase of luminal Ca2+ and unevenly inhibits late-phase intracellular Ca2+ mobilization. Both modes of Ca2+ chelation slow gastric repair. In plasma membrane Ca-ATPase 1+/− mice, but not plasma membrane Ca-ATPase 4−/− mice, there is slowed epithelial repair and a diminished gastric surface Ca2+ increase. We conclude that endogenous Ca2+, mobilized by signaling pathways and transmembrane Ca2+ transport, causes increased Ca2+ levels at the epithelial damage site that are essential to gastric epithelial cell restitution in vivo.
Background: Calcium promotes gastric wound repair, but the in vivo mechanisms are unknown.
Results: Signaling pathways sequentially mobilize intracellular and extracellular calcium as a requirement to repair gastric lesions. PMCA1 mediates extracellular calcium increases.
Conclusion: Endogenous calcium is an essential second and third messenger driving gastric repair.
Significance: Signaling and ion flux pathways are newly identified targets for enhancing gastric repair.
Purpose: Currently, calculations of proton range in proton therapy patients are based on a conversion of CT Hounsfield Units of patient tissues into proton relative stopping power. Uncertainties in ...this conversion necessitate larger proximal and distal planned target volume margins. Proton CT can potentially reduce these uncertainties by directly measuring proton stopping power. We aim to demonstrate proton CT imaging with complex porcine samples, to analyze in detail three-dimensional regions of interest, and to compare proton stopping powers directly measured by proton CT to those determined from x-ray CT scans. Methods: We have used a prototype proton imaging system with single proton tracking to acquire proton radiography and proton CT images of a sample of porcine pectoral girdle and ribs, and a pig's head. We also acquired close in time x-ray CT scans of the same samples, and compared proton stopping power measurements from the two modalities. In the case of the pig's head, we obtained x-ray CT scans from two different scanners, and compared results from high-dose and low-dose settings. Results: Comparing our reconstructed proton CT images with images derived from x-ray CT scans, we find agreement within 1% to 2% for soft tissues, and discrepancies of up to 6% for compact bone. We also observed large discrepancies, up to 40%, for cavitated regions with mixed content of air, soft tissue, and bone, such as sinus cavities or tympanic bullae. Conclusions: Our images and findings from a clinically realistic proton CT scanner demonstrate the potential for proton CT to be used for low-dose treatment planning with reduced margins.
Women remain underrepresented at all levels within the field of radiation oncology. We sought to study current female residents' experiences and concerns to inform interventions to promote gender ...equity. Furthermore, we evaluated interest in a professional society specifically for women radiation oncologists.
An anonymous 76-item survey was designed and distributed to current women residents in radiation oncology in 2017-2018. Analyses describe personal, program, and family characteristics and experiences before and after joining the field.
Of 170 female residents surveyed, 125 responded (74% response rate). Over one-quarter were in programs with ≤2 female residents (29%) and ≤2 female attendings (29%). One-third (34%) reported having children. Over half (51%) reported that lack of mentorship affected career ambitions. Over half (52%) agreed that gender-specific bias existed in their programs, and over a quarter (27%) reported they had experienced unwanted sexual comments, attention, or advances by a superior or colleague. Only 5% reported no symptoms of burnout. Almost all (95%) agreed that radiation oncology is perceived as family friendly; however, only 52% agreed that it actually is. An overwhelming majority (90%) expressed interest in joining a professional group for women in radiation oncology.
In the first study to our knowledge to focus specifically on the experiences of women residents in radiation oncology, a number of areas for potential improvement were highlighted, including isolation and underrepresentation, mentorship needs, bias and harassment, and gender-based obstacles such as need for support during pregnancy and motherhood. These findings support the organization of groups such as the Society for Women in Radiation Oncology, which seeks to target these needs to promote gender equity.
Background
Intraprostatic local radiorecurrence (LRR) after definitive radiation is being increasingly identified due to the implementation of molecular positron emission tomography (PET)/computed ...tomography (CT) imaging for the evaluation of biochemical recurrence. Salvage high‐dose rate (HDR) brachytherapy offers a promising local therapy option, with encouraging toxicity and efficacy based on early series. Furthermore, the incorporation of advanced imaging allows for focal HDR to further reduce toxicity to maximise the therapeutic ratio. The objectives of the ‘focal salvage HDR brachytherapy for locally recurrent prostate cancer in patients treated with prior radiotherapy’ (F‐SHARP) trial are to determine the acute and late toxicity and efficacy outcomes of focal salvage HDR brachytherapy for LRR prostate cancer.
Study Design
The F‐SHARP is a multi‐institutional two‐stage Phase I/II clinical trial of salvage focal HDR brachytherapy for LRR prostate cancer enrolling patients at three centres.
Endpoints
The primary endpoint is the acute radiation‐related Grade ≥3 Common Terminology Criteria for Adverse Events (CTCAE, version 4.03) genitourinary (GU) and gastrointestinal (GI) toxicity rate, defined as within 3 months of brachytherapy. Secondary endpoints include acute and late CTCAE toxicity, biochemical failure, patterns of clinical progression, disease‐specific and overall survival, and health‐related quality of life, as measured by the International Prostate Symptom Score and 26‐item Expanded Prostate Cancer Index Composite instruments.
Patients and Methods
Key eligibility criteria include: biopsy confirmed LRR prostate adenocarcinoma after prior definitive radiation therapy using any radiotherapeutic modality, no evidence of regional or distant metastasis, and cT1–3a Nx or N0 prostate cancer at initial treatment. All patients will have multiparametric magnetic resonance imaging and molecular PET/CT imaging if possible. In Stage 1, seven patients will be accrued. If there are two or more GI or GU Grade ≥3 toxicities, the study will be stopped. Otherwise, 17 additional patients will be accrued (total of 24 patients). For Stage 2, the cohort will expand to 62 subjects to study the efficacy outcomes, long‐term toxicity profile, quality of life, and compare single‐ vs multi‐fraction HDR. Transcriptomic analysis of recurrence biopsies will be performed to identify potential prognostic and predictive biomarkers.
Our purpose was to evaluate the effect of the current structure and schedule of the American Board of Radiology (ABR) radiation oncology initial certification (RO-IC) examinations, with a primary ...focus on implications for family planning and early professional barriers among female radiation oncologists.
A survey was conducted of crowdsourced ABR candidates and diplomates for radiation oncology between June and July of 2020. The primary study cohort was early career female radiation oncologists of the 2016 through 2021 graduating classes.
The survey response rate of early career female radiation oncologists was 37% (126 of an estimated 337). Among this cohort, 58% (73 of 126) reported they delayed or are currently delaying/timing pregnancy or adoption to accommodate the annual schedule of the 4 qualifying and certifying examinations required to achieve board certification in radiation oncology. One in every 3 respondents who had attempted to become pregnant reported experiencing infertility (25 of 79, 32%). Women who reported intentionally delaying pregnancy to accommodate the ABR RO-IC examination schedule were significantly more likely to experience infertility (46% vs 18%, P = .008). Seven women (6%) reported at least a 1-year delay in sitting for a RO-IC examination due to an unavoidable scheduling conflict related to childbirth and/or the peripartum period. A majority reported that full board certification had a significant effect on achieving academic promotion or professional partnership (52%), annual compensation (54%), and nonclinical professional commitments (58%) - these rates mirror those of surveyed early career male counterparts (n = 101).
The current structure and scheduling of the ABR RO-IC examinations imposes noteworthy hurdles for many female radiation oncologists when entering the workforce. The recent transition to virtual examination platforms creates an important opportunity to increase flexibility in the structure and scheduling of the board examination process to improve equitable board certification practices.
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