Safety of high-dose-rate brachytherapy in patients with prostate cancer and inflammatory bowel disease: A case series.

Introduction: Inflammatory bowel disease (IBD) is a relative contraindication to external beam radiation therapy (EBRT) for prostate cancer patients due to fear of increased risk of gastrointestinal (GI) toxicity. High-dose-rate (HDR) brachytherapy, capable of minimizing radiation dose to surrounding tissues, is a feasible alternative. Given limited data, this study examined the safety profile of HDR brachytherapy in this setting. Material and methods: We conducted a retrospective review of patients with localized prostate cancer and IBD treated with HDR brachytherapy at the University of California San Francisco (UCSF), between 2010 and 2022. Eligibility criteria included biopsy-proven prostate cancer, no distant metastases, absence of prior pelvic radiotherapy, IBD diagnosis, and at least one follow-up visit post-treatment. Results: Eleven patients were included, with a median follow-up of 28.7 months. The median dose administered was 2700 cGy (range, 1500-3150 cGy) over 2 fractions (range, 1-3 fractions). Two patients also received EBRT. Rectal spacers (SpaceOAR) were applied in seven patients. All patients experienced acute genitourinary (GU) toxicity, ten of which were grade 1 and one was grade 2. Eight patients experienced late grade 1 GU toxicity, and three patients had late grade 2 GU toxicity. GI toxicities were similarly low-grade, with six grade 1 acute toxicity, no grade 2 or higher acute toxicity, six grade 1 late toxicity, and one late grade 2 GI toxicity. No grade 3 or higher acute or late GI or GU toxicities were reported. Conclusions: HDR brachytherapy appears to be a safe and tolerable treatment modality for patients with prostate cancer and IBD, with minimal acute and late GI and GU toxicity. These findings warrant multi-institutional validation due to small sample size.

Patient Education Practices and Preferences of Radiation Oncologists and Interprofessional Radiation Therapy Care Teams: A Mixed-Methods Study Exploring Strategies for Effective Patient Education Delivery.

PURPOSE: Patients' understanding of radiation therapy (RT) and data regarding optimal approaches to patient education (PE) within radiation oncology (RO) are limited. We aimed to evaluate PE practices of radiation oncologists and interprofessional RT care team members to inform recommendations for delivering inclusive and accessible PE. METHODS AND MATERIALS: An anonymous survey was administered to all Radiation Oncology Education Collaborative Study Group members (10/5/22-11/23/22). Respondent demographics, individual practices/preferences, and institutional practices were collected. Qualitative items explored strategies, challenges, and desired resources for PE. Descriptive statistics summarized survey responses. The Fisher exact test compared PE practices by respondent role and PE timing. Thematic analysis was used for qualitative responses. RESULTS: One hundred thirteen Radiation Oncology Education Collaborative Study Group members completed the survey (28.2% response rate); RO attendings comprised 68.1% of respondents. Most practiced in an academic setting (85.8%) in North America (80.5%). Institution-specific materials were the most common PE resource used by radiation oncologists (67.6%). Almost half (40.2%) reported that their PE practices differed based on clinical encounter type, with paper handouts commonly used for in-person and multimedia for telehealth visits. Only 57.7% reported access to non-English PE materials. PE practices among radiation oncologists differed according to RT clinical workflow timing (consultation versus simulation versus first RT, respectively): one-on-one teaching: 88.5% versus 49.4% versus 56.3%, P < .01, and paper handouts: 69.0% versus 28.7% versus 16.1%, P < .01. Identified challenges for PE delivery included limited time, administrative barriers to the development or implementation of new materials or practices, and a lack of customized resources for tailored PE. Effective strategies for PE included utilization of visual diagrams, multimedia, and innovative education techniques to personalize PE delivery/resources for a diverse patient population, as well as fostering interprofessional collaboration to reinforce educational content. CONCLUSIONS: Radiation oncologists and interprofessional RO team members engage in PE, with most using institution-specific materials often available only in English. PE practices differ according to clinical encounter type and RT workflow timing. Increased adoption of multimedia materials and partnerships with patients to tailor PE resources are needed to foster high-quality, patient-centered PE delivery.

Higher area deprivation index is associated with poorer local control and overall survival in non-metastatic nasopharyngeal carcinoma.

BACKGROUND: Neighborhood socioeconomic deprivation impacts outcomes in various cancers. We examined this association in nasopharyngeal carcinoma (NPC) patients using the area deprivation index (ADI). METHODS: We conducted a single-institution retrospective cohort study on NPC patients treated with definitive radiotherapy from 1980 to 2023. ADI was used as the primary exposure measure. Higher ADI indicates higher levels of socioeconomic deprivation. RESULTS: Of 561 patients, those with higher ADI (6-10 vs. 1-5) presented more commonly with AJCC stage III/IV compared to I/II (87% vs. 76%, p = 0.03). Increasing ADI decile score correlated with poorer overall survival (HR 1.14, 95% CI 1.01-1.28, p = 0.04). Local control was worse in patients from the most deprived quartile in the cohort ADI 5-10 (HR 2.11, 95% CI 1.01-4.41, p = 0.05). CONCLUSIONS: NPC patients from more disadvantaged neighborhoods undergoing radiotherapy had worse local control and survival outcomes. Interventions to address structural determinants of health and neighborhood disparities may improve these outcomes.

Safety of high-dose rate (HDR) brachytherapy for patients with prostate cancer and history of prior chemoradiation for rectal cancer: A case series.

PURPOSE: A history of prior pelvic radiation therapy (RT) for rectal cancer is a relative contraindication for definitive RT for prostate cancer. High-dose-rate (HDR) brachytherapy can significantly limit the dose to surrounding tissues compared to external beam RT. However, there is limited data surrounding its safety in patients with prior pelvic RT. METHODS AND MATERIALS: A retrospective chart review was performed at the University of California, San Francisco to identify patients diagnosed with prostate cancer with a history of pelvic RT for rectal cancer who were treated with high-dose-rate brachytherapy (HDR-BT) between 2006 and 2022. Inclusion criteria were biopsy-confirmed prostate cancer with no evidence of distant disease on clinical examination or imaging, and at least one post-treatment clinic appointment. RESULTS: Seven patients were treated with salvage HDR-BT at a median interval of 17.7 years after RT for rectal cancer. HDR-BT doses included 3600 cGy in six fractions (n = 5), 2700 cGy in 2 fractions (n=1), or 2800 cGy in four fractions (n = 1). There was no acute grade ≥2 gastrointestinal toxicity, and 1 patient developed late grade 2 rectal bleeding. Two patients developed acute grade 2 genitourinary toxicity consisting of urinary frequency and urgency, which persisted through long-term follow up. At a median follow up of 29.5 months after HDR brachytherapy, one patient developed regional and distant failure, and another had seminal vesicle recurrence. CONCLUSIONS: HDR-BT is a safe treatment for patients with prostate cancer who previously received RT for rectal cancer. Further studies are needed to better characterize the long-term toxicity of HDR-RT in this population.

Surgical Adaptation of the Situation Awareness Rating Technique (S-SART): Assessing Situational Awareness Among Medical Students.

OBJECTIVE: Situational awareness (SA) impacts team dynamics and patient care. However, few formal curricula and tools exist to teach and assess longitudinal SA in surgical environments. We sought to evaluate medical students' SA in the operating room (OR) during surgical clerkships over time. DESIGN: We prospectively administered pre- and post-rotation surveys using a surgical adaptation of the previously validated Situation Awareness Rating Technique (SART). Surgical SART (S-SART) scores were calculated as: Situational Awareness = Understanding - (Attentional Demand - Attentional Supply) + 14. Each of 10 questions was scored from 1 to 7, with a maximum possible score of 60. Two-tailed two-sample and paired t-tests were conducted to determine differences in S-SART scores. PARTICIPANTS/SETTING: Sixty-nine of 75 second- and third-year medical students rotating in Surgery and Obstetrics/Gynecology clerkships at a tertiary academic medical center from September 2018 to September 2019 completed the surveys for a response rate of 92.0%. RESULTS: The mean baseline pre-rotation baseline S-SART score was 29.5 (SD=8.3), which increased by 20.9% to 35.9 (SD=6.9) post-rotation (p<0.001). Significant predictors of higher baseline S-SART scores included age ≥25 (p=0.02), surgical career interest (p=0.01), completion of prior surgical rotations (p<0.001), confidence about pre-procedural OR steps (p<0.001), and knowledge of OR item locations (p<0.001). There were increases in each of the subdomains of Understanding-including OR familiarity (3.2 to 4.3, p<0.001), knowledge of the medical student OR role (3.5 to 5.7, p<0.001), and knowledge of others' OR roles (4.1 to 5.9, p<0.001)-along with increases in alertness within Attentional Supply (5.1 to 5.5, p=0.001). CONCLUSIONS: SA is a learnable skill with increases in S-SART scores from pre- to post-rotation, with the greatest gains in the domain of Understanding. More advanced aspects of SA such as Attentional Demand may require further surgical training or curricular innovations to address these needs.

Prognostic Understanding and Goals of Palliative Radiotherapy: A Qualitative Study.

CONTEXT: There is a paucity of data describing patients' expectations of goals of palliative radiotherapy (RT) and overall prognosis. OBJECTIVES: To explore patients' perceptions of and preferences for communication surrounding goals of palliative RT and cancer prognosis. METHODS: We conducted a qualitative study utilizing semi-structured interviews with seventeen patients with either bone or lung metastases receiving their first course of palliative RT at a comprehensive cancer center. All patient interviews were recorded, transcribed verbatim, and thematically analyzed. RESULTS: Themes of goals of palliative RT centered on either restoration, such as through improving quality of life or minimizing pain, or on a desire to combat cancer by eliminating tumor. While most patients perceived that palliative RT would palliate symptoms but not cure their cancer, some patients believed that the goal of palliative RT was to cure. Themes that emerged surrounding patients' understanding of prognosis and what lies ahead included uncertainty and apprehension about the future, a focus on additional treatment, and confronting mortality. Most patients preferred to receive information about goals of treatment and prognosis from their doctors, including radiation oncologists, rather than other members of the medical team. Patients also expressed a desire for written patient education materials on palliative RT. CONCLUSION: Unclear perceptions of goals of treatment and prognosis may motivate some patients to pursue unnecessarily aggressive cancer treatments. Patients desire prognostic information from their doctors, including radiation oncologists, who are important contributors to goals of care discussions and may improve patient understanding and well-being by using restorative rather than combat-oriented language.

Longitudinal symptoms and temporal trends in palliative care, palliative radiotherapy, and anti-cancer treatment near end of life among patients with metastatic cancer.

BACKGROUND: Early specialty palliative care (PC) integration improves oncologic outcomes. We aimed to examine longitudinal relationships between specialty PC and palliative radiotherapy (RT), temporal distribution of symptoms, and predictors of earlier specialty PC. METHODS: We retrospectively reviewed 135 patients with metastatic cancer who received palliative RT at our institution (7/2017-2/2018) and who had died by final study follow-up (6/2021). Descriptive statistics summarized frequencies of clinical visits and symptoms over relative survival time (quartiles 1-3: first 75% of life remaining from metastatic diagnosis to death versus quartile 4: last 25% of life remaining from metastatic diagnosis to death). Logistic regression analyses revealed predictors of receiving earlier (quartiles 1-3) versus later (quartile 4) specialty PC. RESULTS: There were 16.3%, 10.4%, 26.7%, and 46.7% of palliative RT consultations, compared to 4.7%, 7.6%, 14.0%, and 73.7% of specialty PC visits, that occurred in quartiles 1, 2, 3, and 4, respectively. On multivariable analysis, pain significantly predicted for receiving earlier specialty PC [odds ratios (OR) =15.34; 95% confidence interval (CI): 2.16-324.23; P=0.020], while patients with ≥2 prior chemotherapy regimens were less likely to have received earlier specialty PC (OR =0.16; 95% CI: 0.04-0.58; P=0.009). The most common reasons for first specialty PC visit were addressing pain (61.0%) and goals of care (19.5%). Overall, 73.3% (99/135) of patients were referred to hospice and 9.6% (13/135) received either palliative RT, chemotherapy, or surgery within 30 days of death. CONCLUSIONS: Nearly 47% of palliative RT visits compared with 74% of specialty PC visits occurred in the last quarter of life from metastatic diagnosis to death. Multidisciplinary efforts are needed to manage longitudinal symptoms and offer goal-concordant care.

Aligning Student-Faculty Mentorship Expectations and Needs to Promote Professional Identity Formation in Undergraduate Medical Education.

Background: During professional identity formation, medical students integrate their newly developing professional identities with their longstanding personal identities. Longitudinal mentorship has been shown to aid students in this process. Lack of clear relationship expectations among students and faculty is a barrier to effective longitudinal mentorship relationships. Methods: A cross-sectional, survey-based study collected information about experiences from both students (mentees) and faculty (mentors). Surveys focused on collecting participants' attitudes and expectations regarding ideal and actual mentorship experiences. Descriptive statistics and Fisher's exact test analyses were used to compare the responses within and between students and faculty. Results: A total of 234 faculty and 181 medical students completed the survey. There were 187 faculty respondents (79.9%) who had previously mentored students. Faculty who had versus had not previously mentored students differed significantly in their responses on the importance of mentors discussing aspects of their personal lives (71.1% vs. 54.3%, respectively, p = 0.0491), a quality valued by the majority of student respondents. As students progressed through medical school, they expressed increasing needs for personal mentorship and conversations regarding work/life integration and wellness (M1: 12.2%, M2: 18.8%, M3: 29.3%, M4: 51.7%). A minority of students (27% of M3 and 14.8% of M4 students) reported meeting faculty mentors through their clinical year experiences. Conclusions: Faculty mentoring experience may improve student-faculty value alignment, which may in turn help to address student-identified needs pertaining to personal development and professional identity formation in medical school. By contrasting student-identified mentorship expectations with those of faculty at various stages of mentorship experience, this study lays the groundwork for the formation of more effective longitudinal mentorship programs.

Development of a Novel Mentorship Platform to Foster Relational Mentoring, Empowered Vulnerability, and Professional Identity Formation in Undergraduate Medical Education.

PROBLEM: Mentorship is valuable to medical students undergoing professional identity formation. Many institutions lack infrastructure to facilitate the personalized mentoring that supports students' integration of new professional identities with their personal identities and values. APPROACH: The authors developed a novel mentorship platform called Weave via a multistep, iterative design process, incorporating in-person and survey-based student and faculty feedback. Features of Weave include clear communication of mentorship offerings and expectations, plus opportunities to engage mentors based on professional and personal (identity-based) attributes. Faculty at Harvard Medical School who created a mentor profile within the first 3 months of launch and students who visited the website within the same period were invited to complete usability surveys in February 2019; students were invited to complete impact surveys in August 2020. OUTCOMES: Fifty-two of 132 invited faculty members (39.4%) and 80 of 185 students (43.2%) completed the usability surveys. Most of these faculty (86.5%) and students (73.8%) reported navigating the website was easy/very easy; 36 faculty (69.2%) created a mentor profile within 10 minutes. Key innovations highlighted by faculty and students were the listing of personal attributes and identities of diverse faculty; centralized, increased access to faculty mentors; ease of use; and provision of clear expectations. Nearly all students who completed the impact surveys agreed that Weave allowed them to connect with a faculty mentor whom they would not have found through other sources and to learn about the dimensions of diverse faculty. NEXT STEPS: Weave is a customizable online mentorship platform that fosters empowered vulnerability and increases dialogue between medical students and faculty based on professional and personal interests and identities. Weave may be expanded to other mentoring contexts and adapted for implementation at other institutions to help cultivate an institutional culture that values mentoring and to strengthen broader diversity and inclusion efforts.

Characteristics and Predictors of Radiographic Local Failure in Patients With Spinal Metastases Treated With Palliative Conventional Radiation Therapy.

PURPOSE: Although local control is an important issue for longer-term survivors of spinal metastases treated with conventional external beam radiation therapy (EBRT), the literature on radiographic local failure (LF) in these patients is sparse. To inform clinical decision-making, we evaluated rates, consequences, and predictors of radiographic LF in patients with spinal metastases managed with palliative conventional EBRT alone. METHODS AND MATERIALS: We retrospectively reviewed 296 patients with spinal metastases who received palliative EBRT at a single institution (2006-2013). Radiographic LF was defined as radiologic progression within the treatment field, with death considered a competing risk. Kaplan-Meier, cumulative incidence, and Cox regression analyses determined overall survival estimates, LF rates, and predictors of LF, respectively. RESULTS: There were 182 patients with follow-up computed tomography or magnetic resonance imaging; median overall survival for these patients was 7.7 months. Patients received a median of 30 Gy in 10 fractions to a median of 4 vertebral bodies. Overall, 74 of 182 patients (40.7%) experienced LF. The 6-, 12-, and 18-month LF rates were 26.5%, 33.1%, and 36.5%, respectively, while corresponding rates of death were 24.3%, 38.1%, and 45.9%. Median time to LF was 3.8 months. Of those with LF, 51.4% had new compression fractures, 39.2% were admitted for pain control, and 35.1% received reirradiation; median time from radiation therapy (RT) to each of these events was 3.0, 5.7, and 9.2 months, respectively. Independent predictors of LF included single-fraction RT (8 Gy) (hazard ratio [HR], 2.592; 95% confidence interval [CI], 1.437-4.675; P = .002), lung histology (HR, 3.568; 95% CI, 1.532-8.309; P = .003), and kidney histology (HR, 4.937; 95% CI, 1.529-15.935; P = .008). CONCLUSIONS: Patients experienced a >30% rate of radiographic LF by 1 year after EBRT. Single-fraction RT and lung or kidney histology predicted LF. Given the high rates of LF for patients with favorable prognosis, assessing the risk of death versus LF is important for clinical decision-making.

Patient-Provider Communication, Decision-Making, and Psychosocial Burdens in Palliative Radiotherapy: A Qualitative Study on Patients' Perspectives.

CONTEXT: Patient-provider communication impacts how patients with cancer make decisions about treatment. OBJECTIVES: To examine patient perceptions of discussions, decision-making, and psychosocial burdens related to receiving palliative radiotherapy (RT), in order to inform best practices for communication about palliative RT. METHODS: We conducted an exploratory qualitative study using oral questionnaires and semi-structured interviews. Seventeen patients receiving their first course of palliative RT for lung or bone metastases at a comprehensive cancer center were interviewed. Patient interviews were transcribed verbatim and thematically analyzed using NVivo software. RESULTS: Themes that impacted patients' decisions to initiate RT included a desire to minimize pain, optimism about what RT could provide for the future, perception of having "no other choice," disappointment about cancer progression, and unfamiliarity with RT. Most patients preferred shared decision-making regarding RT initiation and reported patient empowerment, effective communication, and team collaboration as contributing to shared decision-making. Most patients preferred their physicians to make decisions about RT treatment intensity and described trust in their physicians, institutional reputation, and RT expertise as motivators for this preference. Patients who possessed a proactive decisional mindset about initiating RT as opposed to having "no other choice" were less likely to report experiencing psychosocial burdens. CONCLUSION: Most patients prefer shared decision-making regarding RT initiation but prefer their radiation oncologists to make decisions regarding treatment intensity. Communication that empowers patients in their desired level of engagement for RT decision-making may help patients make informed decisions, contribute toward a proactive decisional mindset, and reduce their perception of psychosocial burdens.

Patterns of Specialty Palliative Care Utilization Among Patients Receiving Palliative Radiation Therapy.

CONTEXT: Palliative radiation therapy (RT) is frequently used to ameliorate cancer-associated symptoms and improve quality of life. OBJECTIVES: To examine how palliative care (PC) as a specialty is integrated at the time of RT consultation for patients with advanced cancer. METHODS: We retrospectively reviewed 162 patients with metastatic cancer who received palliative RT at our institution (7/2017-2/2018). Fisher's exact test identified differences in incidence of receiving any specialty PC. Logistic regression analyses determined predictors of receiving PC. RESULTS: Of the 74 patients (46%) who received any specialty PC, 24 (32%) initiated PC within four weeks of RT consultation. The most common reasons for specialty PC initiation were pain (64%) and goals of care/end-of-life care management (23%). Referrals to specialty PC were made by inpatient care teams (48.6%), medical oncologists (48.6%), radiation oncologists (1.4%), and self-referring patients (1.4%). Patients with pain at RT consultation had a higher incidence of receiving specialty PC (58.7% vs. 37.4%, P = 0.0097). There was a trend toward decreased PC among patients presenting with neurological symptoms (34.8% vs. 50%, P = 0.084). On multivariable analysis, receiving specialty PC significantly differed by race (non-white vs. white, odds ratio [OR] = 6.295 [95% CI 1.951-20.313], P = 0.002), cancer type (lung vs. other histology, OR = 0.174 [95% CI 0.071-0.426], P = 0.0006), and RT consultation setting (inpatient vs. outpatient, OR = 3.453 [95% CI 1.427-8.361], P = 0.006). CONCLUSION: Fewer than half of patients receiving palliative RT utilized specialty PC. Initiatives are needed to increase PC, especially for patients with lung cancer and neurological symptoms, and to empower radiation oncologists to refer patients to specialty PC.

Development of a Classification Tree to Predict Implant-Based Reconstruction Failure with or without Postmastectomy Radiation Therapy for Breast Cancer.

PURPOSE: The aim of this study was to determine the complications, incidence, and predictors of implant-based reconstruction failure (RF) among patients treated with mastectomy for breast cancer. METHODS: We retrospectively reviewed 108 patients who underwent mastectomy, tissue expander, and implant-based breast reconstruction with or without radiation therapy (RT) at our institution (2000-2014). Descriptive statistics determined complication incidences, with major complications defined as any complications requiring surgical intervention or inpatient management. Chi square and Fisher's exact tests determined differences in RF incidences, defined as implant loss. Logistic regression analyses identified predictors of RF. RESULTS: Median follow-up was 42.5 months. Sixty patients (55.6%) experienced major complications. Overall, 27 patients (25%) experienced RF. Incidences of RF were significantly increased in patients who had any major complication (43.3% vs. 2.1%; p < 0.0001), especially infection (61.3% vs. 10.4%; p < 0.0001), delayed wound healing (83.3% vs. 21.7%; p = 0.004), and implant exposure (80.0% vs. 19.4%; p = 0.0002). Receiving RT, but not timing of RT, significantly predicted RF [odds ratio (OR) 4.00, 95% confidence interval (CI) 1.11-14.47; p = 0.03]. On multivariable analysis, infection (OR 7.69, 95% CI 2.12-27.89; p = 0.002) and delayed wound healing (OR 17.86, 95% CI 1.59-200.48; p = 0.02) independently predicted for RF. Our newly developed classification tree, which includes stepwise assessment of major infection, delayed wound healing, implant exposure, age ≥ 50 years, and total number of lymph nodes removed ≥ 10, accurately predicted 74% of RF events and 75% of non-RF events. CONCLUSIONS: Infection or delayed wound healing requiring surgical intervention or hospitalization and receipt of RT, but not radiation timing, were significant predictors of RF. Our classification tree demonstrated > 70% accuracy for stepwise prediction of RF.

Association Between Patient Education Videos and Knowledge of Radiation Treatment.

PURPOSE: Patient knowledge of radiation therapy (RT) before consult is typically limited, with many having misconceptions or fears. There exists a need to improve patient education in RT. Our purpose was to study the impact of patient education videos on patient-reported knowledge of RT, anxiety/fear, and satisfaction. METHODS AND MATERIALS: At our institution, we created 2 RT educational videos: a general RT video and a breast cancer-specific video. Patients presenting for breast RT who agreed to participate (n = 107) were randomly assigned to receive a link to the videos (video group; n = 58) or not (no-video group; n = 49) before consultation. Pre- and postconsult surveys were administered assessing patient-reported measures on a 5-point Likert-type scale. RESULTS: Patients in the video group reported significantly higher levels of confidence in their knowledge of radiation side effects, with 45.6.% at least somewhat confident versus 21.3% in the no-video group (P = .009; median on a 5-point Likert-type scale, 2 [interquartile range {IQR}, 2-3] versus 2 [IQR, 1-2], respectively [P = .012]). There was a trend toward higher knowledge of the radiation treatment process in the video group (median, 3 [IQR, 2-3] versus 2 [IQR, 2-3] for no-video group; P = .064). There were no significant differences in preconsult anxiety or fear between the groups, but of those who were assigned videos, 46.8% reported decreased anxiety afterward, and 66.0% felt more comfortable coming to a consult. While those in the no-video group hypothesized that a video would be helpful (median, 3; IQR, 3-4), those in the video group found them to be very helpful in real life (median, 4; IQR, 45; P = .0009). After the consult, all patients in both groups were satisfied. CONCLUSIONS: Patient education videos increase patient-reported knowledge of RT and are found to be very helpful.

Impact of primary tumor-specific growth rate on treatment failure for nonoropharyngeal head and neck cancers.

OBJECTIVES: To investigate the prognostic impact of primary tumor-specific growth rate (TSGR) on treatment outcomes after definitive radiation therapy (RT) for nonoropharyngeal squamous cell carcinoma (non-OPSCC). METHODS: The diagnostic tumor and nodal volumes of 39 non-OPSCC patients were contoured and compared to corresponding RT planning scan volumes to determine TSGR. Overall survival (OS), disease-free survival (DFS), and local recurrence-free survival were evaluated according to the Kaplan-Meier method; and hazard ratios (HR) were estimated using Cox regression. Based on the 75th percentile TSGR of 2.18%, we stratified patients into a high TSGR group (≥ 2.18% per day) and low TSGR group (< 2.18% per day). RESULTS: The median follow-up was 22 months (range: 1-86 months) and median time between diagnostic and simulation computed tomography scans was 22 days (range: 7-170 days). Median RT dose was 70 Gy (range: 60-79.2 Gy). Based on the 75th percentile TSGR, OS at median follow-up was 50.0% for the high TSGR group compared to 92.5% for the low TSGR group (HR [95% confidence interval (CI)] = 2.12[1.16-11.42], P = 0.018). There was a trend toward worse DFS at median follow-up for the high versus low TSGR groups, at 55.6% and 82.3%, respectively (HR [95% CI] = 2.29[0.82-6.38], P = 0.103). CONCLUSION: Our study contributes to growing literature on TSGR as a temporal biomarker in patients with non-OPSCC. Patients with high TSGR ≥2.18% per day have significantly worse OS compared to those with TSGR below this threshold. Efforts to address treatment initiation delays may benefit patients with particularly aggressive and rapidly growing tumors. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:2378-2384, 2020.