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To examine clinicodemographic determinants associated with breast cancer survivorship follow-up during COVID-19. We performed a retrospective, population-based cohort study including early stage (Stage I-II) breast cancer patients who underwent resection between 2006 and 2018 in a New York City hospital system. The primary outcome was oncologic follow-up prior to and during the COVID-19 pandemic. Secondary analyses compared differences in follow-up by COVID-19 case rates stratified by ZIP code. A total of 2942 patients with early-stage breast cancer were available for analysis. 1588 (54%) of patients had attended follow-up in the year prior to the COVID-19 period but failed to continue to follow-up during the pandemic, either in-person or via telemedicine. 1242 (42%) patients attended a follow-up appointment during the COVID-19 pandemic. Compared with patients who did not present for follow-up during COVID-19, patients who continued their oncologic follow-up during the pandemic were younger (p = 0.049) more likely to have received adjuvant radiation therapy (p = 0.025), and have lower household income (p = 0.031) on multivariate modeling. When patients who live in Bronx, New York, were stratified by ZIP code, there was a modest negative association (r = −0.56) between COVID-19 cases and proportion of patients who continued to follow-up during the COVID-19 period. We observed a dramatic disruption in routine breast cancer follow-up during the COVID-19 pandemic. Providers and health systems should emphasize reintegrating patients who missed appointments during COVID-19 back into regular surveillance programs to avoid significant morbidity and mortality from missed breast cancer recurrences. • A dramatic disruption in routine oncologic follow-up was observed during the COVID-19 period. • Over half of patients with breast cancer at our center did not attend routine oncologic follow-up during COVID-19. • Patients who were younger, had lower SES, and who received radiotherapy were more likely to follow-up during the pandemic. • A modest negative association was observed between local ZIP code COVID-19 infection rates and follow-up attendance rate. [ABSTRACT FROM AUTHOR]

Purpose To evaluate the prognostic value of prostate-specific antigen (PSA) decline during salvage radiation therapy (SRT) after prostatectomy. Methods and materials We reviewed an institutional database and identified all prostate cancer patients who were treated with SRT between the years 2003 and 2010, had at least 1 PSA measurement during their SRT course, and had no history of androgen deprivation therapy use prior to or during SRT. Disease characteristics, treatment information, and clinical outcomes data were tabulated for each patient. The PSA response during SRT was defined as a PSA decline of at least 0.2 ng/mL compared with the pretreatment PSA level. Bivariate and multivariate analyses using Cox proportional hazards modeling were performed to identify predictors of biochemical recurrence. Results Sixty-four patients met eligibility criteria for this analysis. Median PSA before SRT was 0.63 ng/mL (interquartile range: 0.42-1.00). With a median follow-up time of 70 months after SRT, 5-year actuarial rates for biochemical control and metastasis-free survival were 61% (95% confidence interval [CI], 48%-75%) and 88% (95% CI, 79%-97%), respectively. The median number of PSA measurements per patient during SRT was 3 (range, 1-5). On bivariate analysis, PSA response during SRT and positive surgical margins were significantly associated with a decreased risk of biochemical recurrence (BR), with hazard ratios of 0.160 (95% CI, 0.059-0.431, P < .001) and 0.396 (95% CI, 0.168-0.935, P = .035). On multivariate analysis, PSA response during SRT and positive surgical margin were independent, favorable predictors for BR, with hazard ratios of 0.171 (95% CI, 0.063-0.463, P < .001) and 0.411 (95% CI, 0.177-0.956, P = .039). The 5-year biochemical control rate for PSA responders was 81%, compared with 37% for nonresponders ( P < .001). Conclusions Prostate-specific antigen decline during SRT may be a valuable prognostic factor for subsequent clinical outcomes. Future studies should investigate the value of monitoring PSA during SRT and how PSA response may be used to personalize therapy. [ABSTRACT FROM AUTHOR]

The introduction of image-guided radiation therapy and intensity-modulated radiation therapy has led to unparalleled advances in achieving precise dose conformality in radiation therapy and ushered in new possibilities in organ preservation. Without the ability to meticulously delineate radiation treatment volumes, these advantages would be clinically irrelevant. Positron emission tomography (PET)/computed tomography (CT) has revolutionized the management of head and neck cancers in all areas, including diagnosis, staging, radiation treatment planning, and response evaluation. It has been shown to have a superior sensitivity for defining primary disease and both higher sensitivity and specificity for nodal disease in comparison with CT or magnetic resonance imaging during treatment planning. Thus, PET/CT frequently leads to an alteration of gross tumor volume/clinical target volume/planning target volume and often changes a patient''s tumor, nodes, metastases staging. According to our data, the addition of PET to CT alone led to a modification in treatment planning in 55% of patients studied. PET/CT also helps to standardize radiation therapy between institutions and decreases interobserver variability. PET/CT is a powerful predictor of outcome after treatment. Although technical obstacles do exist and PET/CT does have small inherent inaccuracies, these can usually be overcome with careful planning and specification of setup error/margins, thereby allowing PET/CT to remain an essential and necessary tool in our fight against head and neck cancers. [Copyright &y& Elsevier]

This issue of Seminars in Nuclear Medicine deals with a watershed event in cancer treatment—the combined use of functional and anatomical information to guide therapeutic interventions. The use of positron emission tomography/computed tomography (PET/CT) in radiation treatment planning and tumor response evaluation brings a paradigm change in the development of image-guided therapies into routine clinical practice. The implications, as seen in the following articles, are not only promising but also groundbreaking. And, as in every new scientific breakthrough, each step forward generates a myriad of additional important clinical and research questions. Functional imaging takes advantage of the subtle differences between normal and malignant tissues at the cellular level to reveal in vivo unique functional characteristics of neoplasms. The ultimate goal of the partnership between nuclear medicine physicians and radiation oncologists is to use this information with absolute clarity in target definition for radiation treatment planning and therapy, as well as response evaluation. Functional imaging can provide metabolic information and behavioral correlation along with the anatomical imaging for correlative target delineation. Additionally, as a purely diagnostic instrument, PET/CT provides a tool for oncologists to make critical decisions regarding radiation treatment planning modifications secondary to changes in tumor staging (up or down), treatment field modifications, localized control, sites of residual and/or metastatic disease and post therapy response evaluation. The articles in this issue of the seminars provide insights into the current state-of-the-art of functional imaging techniques, mostly centered on the use of 18F-fluorodeoxyglucose PET/CT in image guided oncologic therapies. Because it is a novel science, the future of image-guided functional treatment planning is bright with technologic and biologic innovations, translational research and new clinical applications. [Copyright &y& Elsevier]

Background Stereotactic body radiation therapy (SBRT) is increasingly used to treat early-stage non-small cell lung cancer (NSCLC). A previous report introduced the term size-adjusted biologically effective dose (sBED), which accounts for tumor diameter and biologically effective dose (BED) and may be used to predict the likelihood of local control following SBRT. Here we seek to replicate those findings using a separate dataset. Methods and materials We queried the RSSearch Patient Registry for patients treated with SBRT for stage I NSCLC. Kaplan-Meier survival curves, log-rank testing, and Cox proportional hazards modeling were used to evaluate tumor diameter, BED, and treatment planning algorithm as predictors of local control. sBED was defined as BED minus 10 times the tumor diameter (in centimeters). Tumor control probability (TCP) modeling was performed to characterize the relationship between sBED and the likelihood of local control 2 years after SBRT. Results A total of 928 patients met inclusion criteria. Median BED was 115.5 Gy, and 59% of patients had T1 tumors. Local control rates following treatments planned using a pencil beam algorithm were inferior to those observed following treatments planned using a Monte Carlo algorithm (89% vs 96% at 2 years, log-rank P = .022). In a multivariable Cox model adjusted for tumor diameter and BED, the use of a pencil beam planning algorithm was associated with increased risk of local failure (hazard ratio, 2.39; 95% confidence interval, 1.08-5.29; P = .032). TCP modeling, restricted to patients treated using a Monte Carlo algorithm, demonstrated that sBED values of 60, 80, and 100 Gy yield predicted TCP rates of 91%, 95%, and 97%, respectively. Conclusions Using a large, multi-institutional database, we found a strong association between treatment planning algorithm and local control rates following SBRT for early-stage NSCLC. sBED is a useful tool for predicting the likelihood of local control following SBRT in this setting. [ABSTRACT FROM AUTHOR]

The National Cancer Institute's Radiation Research Program, in collaboration with the Radiosurgery Society, hosted a workshop called Understanding High-Dose, Ultra-High Dose Rate and Spatially Fractionated Radiotherapy on August 20 and 21, 2018 to bring together experts in experimental and clinical experience in these and related fields. Critically, the overall aims were to understand the biological underpinning of these emerging techniques and the technical/physical parameters that must be further defined to drive clinical practice through innovative biologically based clinical trials. [ABSTRACT FROM AUTHOR]

Purpose: Here we explore the prognostic value of baseline step count data captured using wearable devices for patients treated with definitive chemoradiation therapy for locally advanced non-small cell lung cancer (NSCLC).Methods and Materials: Patients with locally advanced NSCLC wore a commercial fitness tracker during a course of definitive, concurrent chemoradiation therapy as part of a clinical trial. Baseline step count average was defined as the average daily step total from study enrollment until completion of the first week of radiation therapy. Based on data from healthy individuals, study subjects were categorized as inactive (below the 25th percentile), moderately active (25th to 75th percentile), or highly active (above the 75th percentile). Fisher's exact test was used to examine activity level as a predictor of hospitalization during radiation therapy and of completing the planned radiation therapy course without delay exceeding 1 week. Median progression-free survival (PFS) and overall survival (OS) durations were estimated using the Kaplan-Meier method. Inactivity was tested as a predictor of PFS and OS using Cox proportional hazards models.Results: Fifty subjects met eligibility criteria. Nine (18%) were categorized as highly active, 23 (46%) were moderately active, and 18 (36%) were inactive. Inactive subjects were more likely to be hospitalized during the radiation therapy course than other subjects (50% vs 9%, P = .004) and less likely to complete radiation therapy without delay exceeding 1 week (67% vs 97%, P = .006). Median PFS duration was 5.3 months for inactive subjects and 18.3 months for others (hazard ratio for inactivity = 5.10, P < .001). Median OS duration was 15.0 months for inactive subjects and not reached for others (hazard ratio = 3.91, P = .004). Performance status was not a significant predictor of PFS or OS.Conclusions: Baseline activity level measured using wearable devices may help identify patients with NSCLC who are fit for concurrent chemoradiation therapy and can predict clinical outcomes in this setting. [ABSTRACT FROM AUTHOR]

Purpose: Understanding the pathways and gateways to leadership and challenges faced by individuals in such roles can inform efforts to promote diversity and equity. We sought to describe the professional experiences and personal characteristics of academic radiation oncology (RO) chairs and to evaluate whether differences exist by gender.Methods and Materials: Anonymous surveys were distributed to 95 chairs of RO departments during the 2016 annual meeting of the Society of Chairs of Academic Radiation Oncology Programs. The surveys included 28 closed-ended questions and the Leadership Practices Inventory. Results were analyzed by gender using χ2 tests, rank-sum, and t tests (significance P < .05).Results: A total of 72 chairs responded (61 male, 10 female, 1 declined to identify gender) for a response rate of 76%. There were no significant gender differences in age, academic rank, publications, or prior leadership positions held at the time of the first chair appointment, but female respondents held significantly greater total direct funding from extramural grants than their male counterparts (median, $1.89 million [interquartile range, $0.5-$5 million] vs $0.25 million [interquartile range, $0-$1.0 million]; P = .006). Women were more likely to have spouses employed outside the home at time of their first chair appointment than men were, with a trend toward women experiencing greater difficulty relocating. Men and women identified budgeting and resource allocation as their greatest professional challenges. There were no gender differences in the Leadership Practices Inventory-identified leadership domains or professional goals.Conclusions: Female RO chairs are as equally qualified as men in terms of productivity or leadership skills, but they face distinct challenges in the context of a gender-structured society. The observation of higher grant funding among women at the time of chair appointment suggests a possible need for interventions such as unconscious bias training to ensure that selection processes do not unnecessarily hold women to a higher standard. [ABSTRACT FROM AUTHOR]

Management of gynecologic brachytherapy(BT) procedural pain or discomfort varies across institutions. Data suggest women experience symptoms of acute stress disorder and post-traumatic stress disorder (PTSD), as high as 30-41%, following BT with spinal/epidural anesthesia (AS)1. We sought to determine the prevalence of post-BT PTSD in our locally advanced cervical cancer (LACC) patients and differences based on the type of AS. We queried an IRB-approved institutional database for eligible women who received HDR-BT for LACC (intracavitary(IC), interstitial(IS), or hybrid intracavitary/interstitial(IC/IS)) from 1/1/2015 to 9/30/2021. Eligibility also included age >= 18 years old, ability to hear and speak well enough to complete the questionnaires in English, and no prior cancer history. Contact was attempted for each eligible patient. Enrolled patients completed two validated questionnaires by phone: 1) Impact of Event Scale-Revised, and 2) EORTC QLQ-CX24. Open commentary was offered. We utilized the Impact Event Scale-Revised with the replacement of the word "event" with "brachytherapy" to assess PTSD symptoms as published by Kirchheiner et al.1 A cutoff score above 33 was chosen to represent probable PTSD.2 Scores ranging from 24-32 were considered probable partial PTSD.3 56 patients met eligibility, and 21 patients aged 30-69 years old enrolled. Reasons for non-enrollment included disinterest, no working phone number, and inability to contact despite multiple attempts. FIGO stage ranged from 1B1-IVA. Five patients identified as Black or African American, 6 Hispanic, 2 Asian, 14 unknown or unavailable race, 9 unknown or unavailable ethnicity. The mean time since treatment was 3.27 years (1.5-6). 17 women were treated for intact CC. 4 patients were treated postoperatively. 9 patients were treated with IC applicators for intact CC, and 5 were treated with IC/IS applicators. 3 patients were treated with an IS implant for intact CC. 12 women were treated for intact CC with oral narcotics and anxiolytics, while 2 women were treated with conscious sedation (SD). 3 patients treated with an IS implant received general AS for implant placement. 4 patients treated with IC BT postoperatively received no SD or AS. The mean Impact of Event Scale score was 16.62 (0-73). 3 women had scores above 33, qualifying for a probable diagnosis of PTSD. 3 women had scores ranging from 24-32, suggesting partial PTSD. 6 women in total had scores above 24, equating to a partial to full PTSD symptom rate of 28.6% (95%CI: 11.3%, 52.2%). Small sample size precluded an analysis of SD technique and its association with PTSD. Open commentary of the BT highlighted the patient experience and emotional state (Table 1). Partial to full PTSD symptoms were present in 28.6% of women treated with HDR-BT for LACC. Challenges included loss to follow-up, successful contact, and recall bias given the retrospective approach. Further prospective study into the relationship between HDR gynecologic BT SD practices and PTSD is warranted.References: 1.doi:10.1016/j.ijrobp.2014.02.0182.doi:10.1016/j.brat.2003.07.0103.doi: 10.1007/978-0-387-70990-1_10 [ABSTRACT FROM AUTHOR]

Purpose: Developing a quantitative decision-support strategy estimating the impact of normal tissue complications from definitive radiation therapy (RT) for head and neck cancer (HNC). We developed this strategy to identify patients with oropharyngeal HNC who may benefit most from receiving proton RT.Methods and Materials: Recent normal tissue complication probability (NTCP) models for dysphagia, esophagitis, hypothyroidism, xerostomia, and oral mucositis were used to estimate NTCP for 33 patients with oropharyngeal HNC previously treated with photon intensity modulated radiation therapy (IMRT). Comparative proton therapy plans were generated using clinical protocols for HNC RT at a collaborating proton center. Organ-at-risk (OAR) doses from photon and proton RT plans were used to calculate NTCPs; Monte Carlo sampling 10,000 times was used for each patient to account for model parameter uncertainty. The latency and duration of each complication were modeled from calculated NTCP, accounting for age-, sex-, smoking- and p16-specific conditional survival probability. Complications were then assigned quality-adjustment factors based on severity to calculate quality-adjusted life years (QALYs) lost from each complication.Results: Based on our institutional-delivered photon IMRT doses and the achievable proton therapy doses, the average QALY reduction from all HNC RT complications for photon and proton therapy was 1.52 QALYs versus 1.15 QALYs, with proton therapy sparing 0.37 QALYs on average (composite 95% confidence interval, 0.27-2.53 QALYs). Long-term complications (dysphagia and xerostomia) contributed most to the QALY reduction. The QALYs spared with proton RT varied considerably among patients, ranging from 0.06 to 0.84 QALYs. Younger patients with p16-positive tumors who smoked ≤10 pack-years may benefit most from proton therapy, although this finding should be validated using larger patient series. A sensitivity analysis reducing photon IMRT doses to all OARs by 20% resulted in no overall estimated benefit with proton therapy with -0.02 QALYs spared, although some patients still had an estimated benefit in this scenario, ranging from -0.50 to 0.43 QALYs spared.Conclusions: This quantitative decision-support strategy allowed us to identify patients with oropharyngeal cancer who might benefit the most from proton RT, although the estimated benefit of proton therapy ultimately depends on the OAR doses achievable with modern photon IMRT solutions. These results can help radiation oncologists and proton therapy centers optimize resource allocation and improve quality of life for patients with HNC. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate whether a response assessment using mid-treatment computed tomography (CT) scans during definitive radiation therapy (RT) for oropharyngeal head and neck cancer can predict for locoregional recurrence (LRR).Methods and Materials: Head and neck cancer patients who receive RT at our institution undergo CT repeat scans at the 15th fraction, with treatment replanning in the case of an inadequate dose to gross disease or an increased dose to organs at risk. A retrospective cohort analysis was performed of 96 consecutive patients with oropharyngeal cancer treated from 2007 to 2015 with mid-treatment repeat CT scans available. The primary disease volume and involved lymph node volume were delineated on the pre- and mid-treatment CT scans. Univariable and multivariable Cox proportional hazards regression analyses were used to evaluate the efficacy of the mid-treatment reduction in tumor volume as a predictor of LRR. Risk stratification was performed by dichotomizing the patients into high- and low-risk groups according to the mid-treatment response and p16 status and smoking history.Results: With a median follow-up of 34 months, 14 patients experienced LRR. The median reduction in the total tumor volume was 18.7% (interquartile range 8.4%-30.9%). A reduction in total tumor volume greater than the median was an independent predictor of LRR (hazard ratio 0.22, 95% confidence interval 0.05-0.89; P = .020). The reduction in primary tumor volume was an even stronger predictor of LRR (hazard ratio 0.11, 95% confidence interval 0.02-0.57; P = .002). Stratifying patients into a high-risk group for those with a reduction in the total tumor volume at mid-treatment at or less than the median, p16 negative status, and smoking status of >10 pack-years and a low-risk group for those without these factors, we found a clear separation in Kaplan-Meier curves, with actuarial 3-year locoregional control, progression-free survival, and overall survival rates for the high-risk patients of 45.7%, 38.2%, and 71.8% compared with 90.7%, 70.6%, and 89.8% for low-risk patients, respectively (P ≤ .021 for all).Conclusions: Our results have shown that the treatment response from an early assessment using mid-treatment CT scans is an independent predictor of LRR and can be used to effectively distinguish high- and low-risk patients, allowing for risk-adaptive treatment stratification at the midway point. [ABSTRACT FROM AUTHOR]

Purpose: To perform a prospective trial examining positron emission tomography (PET)-based, dose-painted intensity modulated radiation therapy (IMRT) in the setting of locally advanced non-small cell lung cancer (NSCLC).Methods and Materials: Patients with stage IIB-III NSCLC were treated with 25 fractions of dose-painted IMRT. Tumors or lymph nodes with metabolic tumor volume exceeding 25 cm3 were deemed "high risk" and received 65 Gy. Smaller lesions were treated with 57 Gy or 52.5 Gy (after November 2014). Patients received concurrent weekly carboplatin (area under the curve = 2) and paclitaxel (45 mg/m2). The primary study endpoint was the absence of high residual metabolic activity (maximum standardized uptake value > 6) in treated lesions on PET 12 to 16 weeks after completion of IMRT.Results: Thirty-five subjects with 116 hypermetabolic lesions were eligible for analysis. The primary endpoint was met for 24 of 30 patients (80%) who underwent posttreatment PET, satisfying our efficacy objective. With a median follow-up duration of 23.8 months for living patients, progression in a lesion targeted with radiation therapy has been observed in 5 patients (14%). Treating progression in other sites and death without progression as competing risks, 2-year cumulative incidence rates of local disease progression in high-risk lesions (n=24) and low-risk lesions (n=92) are 9% and 3%, respectively. The actuarial rate of overall survival at 2 years is 52%.Conclusions: Dose-painted IMRT based on pretreatment PET metrics with concurrent chemotherapy yields high rates of metabolic response and local disease control for locally advanced NSCLC. Future trials should test this approach to maximize the therapeutic ratio of thoracic radiation therapy. [ABSTRACT FROM AUTHOR]

Objective: To determine whether patients with Oropharyngeal Squamous Cell Carcinoma (OPSCC) treated with Transoral Robotic Surgery (TORS) have similar survival to patients treated with definitive RT.Materials and Methods: Using the National Cancer Database (NCDB) registry, we identified patients with newly diagnosed clinical T1-T2, N0-N2b OPSCC between 2010 and 2014. A multivariable logistic regression was utilized to determine the association between chemotherapy use and primary treatment modality (TORS vs definitive RT). Kaplan Meier survival analysis was used to estimate overall survival. Propensity score matching was utilized to address selection bias.Results: We identified 17,150 patients, of which 14,470 (84.4%) received primary RT and 2,680 (15.6%) underwent TORS. The median follow-up for the cohort was 31.4 months. Propensity score matching demonstrated similar 5-year OS for patients treated with either definitive RT or TORS (81% vs 84%, log rank p = 0.10). There was no difference in survival outcomes by treatment selection (TORS or definitive RT) in either HPV positive or HPV negative subtypes. Patients treated with TORS were less likely to receive chemotherapy compared to patients treated with definitive RT and this was also demonstrated in a propensity matched analysis (OR: 0.09, 95%CI 0.078-0.12, p < 0.001). Only 68.4% of TORS treated patients underwent adjuvant RT, compared to 100% of patients in the primary RT cohort (p < 0.001).Conclusions and Relevance: For patients with OPSCC, TORS results in similar OS outcomes and is associated with decreased chemotherapy and RT use compared to definitive RT. Our results demonstrate the feasibility of TORS in a select subgroup of OPSCC patients. [ABSTRACT FROM AUTHOR]

Purpose: A lack of diversity has been observed in radiation oncology (RO), with women and certain racial/ethnic groups underrepresented as trainees, faculty, and practicing physicians. We sought to gain a nuanced understanding of how to best promote diversity, equity, and inclusion (DEI) based on the insights of RO department chairs, with particular attention given to the experiences of the few women and underrepresented minorities (URMs) in these influential positions.Methods and Materials: From March to June 2016, we conducted telephone interviews with 24 RO department chairs (of 27 invited). Purposive sampling was used to invite all chairs who were women (n = 13) or URMs (n = 3) and 11 male chairs who were not URMs. Multiple analysts coded the verbatim transcripts.Results: Five themes were identified: (1) commitment to DEI promotes quality health care and innovation; (2) gaps remain despite some progress with promoting diversity in RO; (3) women and URM faculty continue to experience challenges in various career domains; (4) solutions to DEI issues would be facilitated by acknowledging realities of gender and race; and (5) expansion of the career pipeline is needed.Conclusions: The chairs' insights had policy-relevant implications. Bias training should broach tokenism, blindness, and intersectionality. Efforts to recruit and support diverse talent should be deliberate and proactive. Bridge programs could engage students before their application to medical school. [ABSTRACT FROM AUTHOR]

Purpose: To perform a prospective trial testing the feasibility and utility of acquiring activity data as a measure of health status during concurrent chemoradiotherapy.Methods and Materials: Ambulatory patients who were planned for treatment with concurrent chemoradiotherapy with curative intent for cancers of the head and neck, lung, or gastrointestinal tract were provided with activity monitors before treatment initiation. Patients were asked to wear the devices continuously throughout the radiation therapy course. Step count data were downloaded weekly during radiation therapy and 2 and 4 weeks after radiation therapy completion. The primary objective was to demonstrate feasibility, defined as collection of step counts for 80% of the days during study subjects' radiation therapy courses. Secondary objectives included establishing step count as a dynamic predictor of unplanned hospitalization risk.Results: Thirty-eight enrolled patients were treated with concurrent chemoradiotherapy. Primary diagnoses included head and neck cancer (n=11), lung cancer (n=13), and a variety of gastrointestinal cancers (n=14). Step data were collected for 1524 of 1613 days (94%) during patients' radiation therapy courses. Fourteen patients were hospitalized during radiation therapy or within 4 weeks of radiation therapy completion. Cox regression modeling demonstrated a significant association between recent step counts (3-day average) and hospitalization risk, with a 38% reduction in the risk of hospitalization for every 1000 steps taken each day (hazard ratio 0.62, 95% confidence interval 0.46-0.83, P=.002). Inferior quality of life scores and impaired performance status were not associated with increased hospitalization risk.Conclusion: Continuous activity monitoring during concurrent chemoradiotherapy is feasible and well-tolerated. Step counts may serve as powerful, objective, and dynamic indicators of hospitalization risk. [ABSTRACT FROM AUTHOR]

Background: We previously reported that pretreatment positron emission tomography (PET) identifies lesions at high risk for progression after concurrent chemoradiation therapy (CRT) for locally advanced non-small cell lung cancer (NSCLC). Here we validate those findings and generate tumor control probability (TCP) models.Methods: We identified patients treated with definitive, concurrent CRT for locally advanced NSCLC who underwent staging 18F-fluorodeoxyglucose/PET/computed tomography. Visible hypermetabolic lesions (primary tumors and lymph nodes) were delineated on each patient's pretreatment PET scan. Posttreatment imaging was reviewed to identify locations of disease progression. Competing risks analyses were performed to examine metabolic tumor volume (MTV) and radiation therapy dose as predictors of local disease progression. TCP modeling was performed to describe the likelihood of local disease control as a function of lesion size.Results: Eighty-nine patients with 259 hypermetabolic lesions (83 primary tumors and 176 regional lymph nodes) met the inclusion criteria. Twenty-eight patients were included in our previous report, and the remaining 61 constituted our validation cohort. The median follow-up time was 22.7 months for living patients. In 20 patients, the first site of progression was a primary tumor or lymph node treated with radiation therapy. The median time to progression for those patients was 11.5 months. Data from our validation cohort confirmed that lesion MTV predicts local progression, with a 30-month cumulative incidence rate of 23% for lesions above 25 cc compared with 4% for lesions below 25 cc (P=.008). We found no evidence that radiation therapy dose was associated with local progression risk. TCP modeling yielded predicted 30-month local control rates of 98% for a 1-cc lesion, 94% for a 10-cc lesion, and 74% for a 50-cc lesion.Conclusion: Pretreatment FDG-PET identifies lesions at risk for progression after CRT for locally advanced NSCLC. Strategies to improve local control should be tested on high-risk lesions, and treatment deintensification for low-risk lesions should be explored. [ABSTRACT FROM AUTHOR]

Purpose: To examine associations between radiation therapy (RT) noncompliance and clinical outcomes.Methods and Materials: We reviewed all patients who completed courses of external beam RT with curative intent in our department from the years 2007 to 2012 for cancers of the head and neck, breast, lung, cervix, uterus, or rectum. Patients who missed 2 or more scheduled RT appointments (excluding planned treatment breaks) were deemed noncompliant. Univariate, multivariable, and propensity-matched analyses were performed to examine associations between RT noncompliance and clinical outcomes.Results: Of 1227 patients, 266 (21.7%) were noncompliant. With median follow-up of 50.9 months, 108 recurrences (8.8%) and 228 deaths (18.6%) occurred. In univariate analyses, RT noncompliance was associated with increased recurrence risk (5-year cumulative incidence 16% vs 7%, P<.001), inferior recurrence-free survival (5-year actuarial rate 63% vs 79%, P<.001), and inferior overall survival (5-year actuarial rate 72% vs 83%, P<.001). In multivariable analyses that were adjusted for disease site and stage, comorbidity score, gender, ethnicity, race, and socioeconomic status (SES), RT noncompliance was associated with inferior recurrence, recurrence-free survival, and overall survival rates. Propensity score-matched models yielded results nearly identical to those seen in univariate analyses. Low SES was associated with RT noncompliance and was associated with inferior clinical outcomes in univariate analyses, but SES was not associated with inferior outcomes in multivariable models.Conclusion: For cancer patients being treated with curative intent, RT noncompliance is associated with inferior clinical outcomes. The magnitudes of these effects demonstrate that RT noncompliance can serve as a behavioral biomarker to identify high-risk patients who require additional interventions. Treatment compliance may mediate the associations that have been observed linking SES and clinical outcomes. [ABSTRACT FROM AUTHOR]

Purpose Within a multifraction high-dose-rate vaginal cuff brachytherapy course, we determined if individual variations in organ at risk (OAR) volume and cylinder insertion geometry (CIG) impacted dose and whether planned minus fractional (P − F) differences led to a discrepancy between planned dose and delivered dose. Methods and Materials We analyzed vaginal cuff brachytherapy applications from consecutive patients treated with three fractions of 5 Gy after each undergoing a planning CT and three repeat fractional CTs (fCTs). Rectal and bladder D 2ccs and volumes were recorded in addition to the x (in relationship to midplane) and y (in relationship to the table) angles of CIG. Paired t-tests and multiple regression analyses were performed. Results Twenty-seven patients were identified. In comparing the planning CT vs. mean fCT rectal volumes, bladder volumes, x angles, and y angles, only bladder volume was significantly different (planned volume higher, t = 2.433, p = 0.017). The cumulative mean planned OAR D 2cc vs. delivered D 2cc was only significantly different for the bladder (planned dose lower, t = −2.025, p = 0.053). Regression analysis revealed planned rectal D 2cc ( p < 0.0003) and a positive (posterior) y insertion angle ( p = 0.015) to significantly impact delivered rectal D 2cc . Additionally, P − F rectal volume ( p = 0.037) was significant in determining rectal delivered dose. Conclusions A more posterior y angle of insertion was found to increase rectal D 2cc leading us to believe that angling the vaginal cylinder anteriorly may reduce rectal dose without significantly increasing bladder dose. Although attention should be paid to OAR volume and CIG to minimize OAR dose, the clinical significance of P − F changes remains yet to be shown. [ABSTRACT FROM AUTHOR]

We report our experience of establishing planning objectives to achieve dose coverage, conformity, and dose falloff for spine stereotactic body radiation therapy (SBRT) plans. Patients with spine lesions were treated using SBRT in our institution since September 2009. Since September 2011, we established the following planning objectives for our SBRT spine plans in addition to the cord dose constraints: (1) dose coverage—prescription dose (PD) to cover at least 95% planning target volume (PTV) and 90% PD to cover at least 99% PTV; (2) conformity index (CI)—ratio of prescription isodose volume (PIV) to the PTV < 1.2; (3) dose falloff—ratio of 50% PIV to the PTV (R 50% ); (4) and maximum dose in percentage of PD at 2 cm from PTV in any direction (D 2cm ) to follow Radiation Therapy Oncology Group (RTOG) 0915. We have retrospectively reviewed 66 separate spine lesions treated between September 2009 and December 2012 (31 treated before September 2011 [group 1] and 35 treated after [group 2]). The χ 2 test was used to examine the difference in parameters between groups. The PTV V 100% PD ≥ 95% objective was met in 29.0% of group 1 vs 91.4% of group 2 ( p < 0.01) plans. The PTV V 90% PD ≥ 99% objective was met in 38.7% of group 1 vs 88.6% of group 2 ( p < 0.01) plans. Overall, 4 plans in group 1 had CI > 1.2 vs none in group 2 ( p = 0.04). For D 2cm , 48.3% plans yielded a minor violation of the objectives and 16.1% a major violation for group 1, whereas 17.1% exhibited a minor violation and 2.9% a major violation for group 2 ( p < 0.01). Spine SBRT plans can be improved on dose coverage, conformity, and dose falloff employing a combination of RTOG spine and lung SBRT protocol planning objectives. [ABSTRACT FROM AUTHOR]

An efficient and simple class solution is proposed for hippocampal-avoidance whole-brain radiation therapy (HA-WBRT) planning using the Volumetric Arc Therapy (VMAT) delivery technique following the NRG Oncology protocol NRG-CC001 treatment planning guidelines. The whole-brain planning target volume (PTV) was subdivided into subplanning volumes that lie in plane and out of plane with the hippocampal-avoidance volume. To further improve VMAT treatment plans, a partial-field dual-arc technique was developed. Both the arcs were allowed to overlap on the in-plane subtarget volume, and in addition, one arc covered the superior out-of-plane sub-PTV, while the other covered the inferior out-of-plane subtarget volume. For all plans ( n = 20), the NRG-CC001 protocol dose-volume criteria were met. Mean values of volumes for the hippocampus and the hippocampal-avoidance volume were 4.1 cm 3 ± 1.0 cm 3 and 28.52 cm 3 ± 3.22 cm 3 , respectively. For the PTV, the average values of D 2% and D 98% were 36.1 Gy ± 0.8 Gy and 26.2 Gy ± 0.6 Gy, respectively. The hippocampus D 100% mean value was 8.5 Gy ± 0.2 Gy and the maximum dose was 15.7 Gy ± 0.3 Gy. The corresponding plan quality indices were 0.30 ± 0.01 (homogeneity index), 0.94 ± 0.01 (target conformality), and 0.75 ± 0.02 (confirmation number). The median total monitor unit (MU) per fraction was 806 MU (interquartile range [IQR]: 792 to 818 MU) and the average beam total delivery time was 121.2 seconds (IQR: 120.6 to 121.35 seconds). All plans passed the gamma evaluation using the 5-mm, 4% criteria, with γ > 1 of not more than 9.1% data points for all fields. An efficient and simple planning class solution for HA-WBRT using VMAT has been developed that allows all protocol constraints of NRG-CC001 to be met. [ABSTRACT FROM AUTHOR]

Purpose To quantify the frequency of patient noncompliance in an urban radiation oncology department and identify predictors of noncompliance. Methods and Materials We identified patients treated with external beam radiation therapy (RT) with curative intent in our department from 2007 to 2012 for 1 of 7 commonly treated malignancies. Patients who missed 2 or more scheduled RT appointments were deemed “noncompliant.” An institutional database was referenced to obtain clinical and demographic information for each patient, as well as a quantitative estimate of each patient's socioeconomic status. Logistic regression was used to identify factors associated with RT noncompliance. Results A total of 2184 patients met eligibility criteria. Of these, 442 (20.2%) were deemed “noncompliant.” On multivariate analysis, statistically significant predictors of noncompliance included diagnosis of head-and-neck, cervical, or uterine cancer, treatment during winter months, low socioeconomic status, and use of a long treatment course (all P <.05). Conclusion This is the first large effort examining patient noncompliance with daily RT. We have identified demographic, clinical, and treatment-related factors that can be used to identify patients at high risk for noncompliance. These findings may inform future strategies to improve adherence to prescribed therapy. [ABSTRACT FROM AUTHOR]

Purpose To evaluate, in a gynecologic cancer setting, changes in bowel position, dose-volume parameters, and biological indices that arise between full-bladder (FB) and empty-bladder (EB) treatment situations; and to evaluate, using cone beam computed tomography (CT), the validity of FB treatment presumption. Methods and Materials Seventeen gynecologic cancer patients were retrospectively analyzed. Empty-bladder and FB CTs were obtained. Full-bladder CTs were used for planning and dose optimization. Patients were given FB instructions for treatment. For the study purpose, bowel was contoured on the EB CTs for all patients. Bowel position and volume changes between FB and EB states were determined. Full-bladder plans were applied on EB CTs for determining bowel dose-volume changes in EB state. Biological indices (generalized equivalent uniform dose and normal tissue complication probability) were calculated and compared between FB and EB. Weekly cone beam CT data were available in 6 patients to assess bladder volume at treatment. Results Average (±SD) planned bladder volume was 299.7 ± 68.5 cm 3 . Median bowel shift in the craniocaudal direction between FB and EB was 12.5 mm (range, 3-30 mm), and corresponding increase in exposed bowel volume was 151.3 cm 3 (range, 74.3-251.4 cm 3 ). Absolute bowel volumes receiving 45 Gy were higher for EB compared with FB (mean 328.0 ± 174.8 vs 176.0 ± 87.5 cm 3 ; P =.0038). Bowel normal tissue complication probability increased 1.5× to 23.5× when FB planned treatments were applied in the EB state. For the study, the mean percentage value of relative bladder volume at treatment was 32%. Conclusions Full-bladder planning does not necessarily translate into FB treatments, with a patient tendency toward EB. Given the uncertainty in daily control over bladder volume for treatment, we strongly recommend a “planning-at-risk volume bowel” (PRV_Bowel) concept to account for bowel motion between FB and EB that can be tailored for the individual patient. [ABSTRACT FROM AUTHOR]

Summary: Objectives: Radiation induced cranial nerve palsy (RICNP) involving the lower cranial nerves (CNs) is a serious complication of head and neck radiotherapy (RT). Recommendations for delineating the lower CNs on RT planning studies do not exist. The aim of the current study is to develop a standardized methodology for contouring CNs IX–XII, which would help in establishing RT limiting doses for organs at risk (OAR). Methods: Using anatomic texts, radiologic data, and guidance from experts in head and neck anatomy, we developed step-by-step instructions for delineating CNs IX–XII on computed tomography (CT) imaging. These structures were then contoured on five consecutive patients who underwent definitive RT for locally-advanced head and neck cancer (LAHNC). RT doses delivered to the lower CNs were calculated. Results: We successfully developed a contouring atlas for CNs IX–XII. The median total dose to the planning target volume (PTV) was 70Gy (range: 66–70Gy). The median CN (IX–XI) and (XII) volumes were 10c.c (range: 8–12c.c) and 8c.c (range: 7–10c.c), respectively. The median V50, V60, V66, and V70 of the CN (IX–XI) and (XII) volumes were (85, 77, 71, 65) and (88, 80, 74, 64) respectively. The median maximal dose to the CN (IX–XI) and (XII) were 72Gy (range: 66–77) and 71Gy (range: 64–78), respectively. Conclusions: We have generated simple instructions for delineating the lower CNs on RT planning imaging. Further analyses to explore the relationship between lower CN dosing and the risk of RICNP are recommended in order to establish limiting doses for these OARs. [ABSTRACT FROM AUTHOR]

Purpose: Large randomized trials have demonstrated significant survival benefits with the use of adjuvant chemotherapy or chemoradiation therapy for gastric cancer. The importance of adjuvant radiation therapy (RT) remains unclear. We performed an up-to-date meta-analysis of randomized trials testing the use of RT for resectable gastric cancer. Methods and Materials: We searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials for randomized trials testing adjuvant (including neoadjuvant) RT for resectable gastric cancer. Hazard ratios describing the impact of adjuvant RT on overall survival (OS) and disease-free survival (DFS) were extracted directly from the original studies or calculated from survival curves. Pooled estimates were obtained using the inverse variance method. Subgroup analyses were performed to determine whether the efficacy of RT varies with chemotherapy use, RT timing, geographic region, type of nodal dissection performed, or lymph node status. Results: Thirteen studies met all inclusion criteria and were used for this analysis. Adjuvant RT was associated with a significant improvement in both OS (HR = 0.78, 95% CI: 0.70-0.86, P<.001) and DFS (HR = 0.71, 95% CI: 0.63-0.80, P<.001). In the 5 studies that tested adjuvant chemoradiation therapy against adjuvant chemotherapy, similar effects were seen for OS (HR = 0.83, 95% CI: 0.67-1.03, P=.087) and DFS (HR = 0.77, 95% CI: 0.91-0.65, P=.002). Available data did not reveal any subgroup of patients that does not benefit from adjuvant RT. Conclusion: In randomized trials for resectable gastric cancer, adjuvant RT provides an approximately 20% improvement in both DFS and OS. Available data do not reveal a subgroup of patients that does not benefit from adjuvant RT. Further study is required to optimize the implementation of adjuvant RT for gastric cancer with regard to patient selection and integration with systemic therapy. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effects of breast size on dose-volume histogram parameters and clinical toxicity in whole-breast hypofractionated radiation therapy using intensity modulated radiation therapy (IMRT). Materials and Methods: In this retrospective study, all patients undergoing breast-conserving therapy between 2005 and 2009 were screened, and qualifying consecutive patients were included in 1 of 2 cohorts: large-breasted patients (chest wall separation >25 cm or planning target volume [PTV] >1500 cm3) (n=97) and small-breasted patients (chest wall separation <25 cm and PTV <1500 cm3) (n=32). All patients were treated prone or supine with hypofractionated IMRT to the whole breast (42.4 Gy in 16 fractions) followed by a boost dose (9.6 Gy in 4 fractions). Dosimetric and clinical toxicity data were collected and analyzed using the R statistical package (version 2.12). Results: The mean PTV V95 (percentage of volume receiving >= 95% of prescribed dose) was 90.18% and the mean V105 percentage of volume receiving >= 105% of prescribed dose was 3.55% with no dose greater than 107%. PTV dose was independent of breast size, whereas heart dose and maximum point dose to skin correlated with increasing breast size. Lung dose was markedly decreased in prone compared with supine treatments. Radiation Therapy Oncology Group grade 0, 1, and 2 skin toxicities were noted acutely in 6%, 69%, and 25% of patients, respectively, and at later follow-up (>3 months) in 43%, 57%, and 0% of patients, respectively. Large breast size contributed to increased acute grade 2 toxicity (28% vs 12%, P=.008). Conclusions: Adequate PTV coverage with acceptable hot spots and excellent sparing of organs at risk was achieved by use of IMRT regardless of treatment position and breast size. Although increasing breast size leads to increased heart dose and maximum skin dose, heart dose remained within our institutional constraints and the incidence of overall skin toxicity was comparable to that reported in the literature. Taken together, these data suggest that hypofractionated radiation therapy using IMRT is a viable and appropriate therapeutic modality in large-breasted patients. [Copyright &y& Elsevier]

Abstract: Purpose: To study the influence of timing of postseed implant imaging on rectal dose–volume parameters for cesium-131 (131Cs) seed prostate implants. Methods and Materials: Fifteen patients were treated in our institution with combination 131Cs brachytherapy followed by pelvic external beam radiation therapy for intermediate to high-risk prostate cancers. For all patients, CT scans were scheduled at 7 days (CT7) and again at 2 months for external beam radiation therapy simulation purpose (CT60) postseed implantation. Comprehensive postseed implant dosimetry was performed for both CT7 and CT60 scans. In each case, dose–volume histogram parameters, rectal separation (the distance between the center of posterior most seed and most anterior rectal wall), and posterior row activity (the total activity implanted within 2–4mm anterior to the posterior wall of the prostate) data were collected. The absolute rectal volumes receiving 100% and 110% prescription dose were also collected. Results: Rectal dose correlated strongly with rectal separation (p <0.001). The mean change in rectal separation between CT7 and CT60 scans was 1.1 (±1.7) mm, and the corresponding change in 0.1-cc rectal dose was 18 (±26.5) Gy. Posterior row activity did not correlate with rectal dose (p =0.51). The mean volume of rectum that receives between 100% and 110% of the prescription dose (RV100 and RV110) increased twofold, between CT7 and CT60 evaluations (0.03 [±0.06] cc vs. 0.07 (±0.05) cc, respectively, p =0.06). Conclusions: Our study has demonstrated that rectal doses after 131Cs seed implants are influenced by the timing of postseed imaging. This may be a consequence of prostatic and periprostatic edema resolution. [Copyright &y& Elsevier]

Purpose: Anatomic changes and positional variability during intensity-modulated radiation therapy (IMRT) for head and neck cancer can lead to clinically significant dosimetric changes. We report our single-institution experience using an adaptive protocol and correlate these changes with anatomic and positional changes during treatment. Methods and Materials: Twenty-three sequential head and neck IMRT patients underwent serial computed tomography (CT) scans during their radiation course. After undergoing the planning CT scan, patients underwent planned rescans at 11, 22, and 33 fractions; a total of 89 scans with 129 unique CT plan combinations were thus analyzed. Positional variability and anatomic changes during treatment were correlated with changes in dosimetric parameters to target and avoidance structures between planning CT and subsequent scans. Results: A total of 15/23 patients (65%) benefited from adaptive planning, either due to inadequate dose to gross disease or to increased dose to organs at risk. Significant differences in primary and nodal targets (planning target volume, gross tumor volume, and clinical tumor volume), parotid, and spinal cord dosimetric parameters were noted throughout the treatment. Correlations were established between these dosimetric changes and weight loss, fraction number, multiple skin separations, and change in position of the skull, mandible, and cervical spine. Conclusions: Variations in patient positioning and anatomy changes during IMRT for head and neck cancer can affect dosimetric parameters and have wide-ranging clinical implications. The interplay between random positional variability and gradual anatomic changes requires careful clinical monitoring and frequent use of CT- based image-guided radiation therapy, which should determine variations necessitating new plans. [ABSTRACT FROM AUTHOR]

Abstract: Intensity-modulated radiation therapy (IMRT) has been applied for treatments of primary head with neck nodes, lung with supraclavicular nodes, and high-risk prostate cancer with pelvis wall nodes, all of which require large fields. However, the design of the Varian multileaf collimator requires fields >14 cm in width to be split into 2 or more carriage movements. With the split-field technique, both the number of monitor units (MUs) and total treatment time are significantly increased. Although many different approaches have been investigated to reduce the MU, including introducing new leaf segmentation algorithms, none have resulted in widespread success. In addition, for most clinics, writing such algorithms is not a feasible solution, particularly with commercial treatment planning systems. We introduce a new approach that can minimize the number of split fields and reduce the total MUs, thereby reducing treatment time. The technique is demonstrated on the Eclipse planning system V7.3, but could be generalized to any other system. [Copyright &y& Elsevier]

Abstract: The purpose of this study was to evaluate normal tissue dose constraints while maintaining planning target volume (PTV) prescription without reducing PTV margins. Sixteen patients with oral cavity carcinoma (group I), 27 patients with oropharyngeal carcinoma (group II), and 28 patients with laryngeal carcinoma (group III) were reviewed. Parotid constraints were a mean dose to either parotid < 26 Gy (PP1), 50% of either parotid < 30 Gy (PP2), or 20 cc of total parotid < 20 Gy (PP3). Treatment was intensity modulated radiation therapy (IMRT) with simultaneous integrated boost (SIB). All patients met constraints for cord and brain stem. The mandibular constraints were met in 66%, 29%, and 57% of patients with oral, oropharyngeal, and laryngeal cancers, respectively. Mean dose of 26 Gy (PP1) was achieved in 44%, 41%, and 38% of oral, oropharyngeal, and laryngeal patients. PP2 (parotid constraint of 30 Gy to less than 50% of one parotid) was the easiest to achieve (group I, II, and III: 82%, 76%, and 78%, respectively). PP3 (20 cc of total parotid < 20 Gy) was difficult, and was achieved in 25%, 17%, and 35% of oral, oropharyngeal, and laryngeal patients, respectively. Mean parotid dose of 26 Gy was met 40% of the time. However, a combination of constraints allowed for sparing of the parotid based on different criteria and was met in high numbers. This was accomplished without reducing PTV-parotid overlap. What dose constraint best correlates with subjective and objective functional outcomes remains a focus for future study. [Copyright &y& Elsevier]

Purpose: After breast-conserving surgery, a seroma often forms in the surgical cavity. If not drained, it may affect the volume of tumor bed requiring a boost after whole-breast radiation therapy (WBRT). Our objective was to evaluate the change in seroma volume that occurs during WBRT, before boost planning. Methods and Materials: A retrospective review was performed of women receiving breast-conserving therapy with evidence of seroma at the time of WBRT planning. Computed tomography (CT) simulation was performed before WBRT and before the tumor bed boost. All patients received either a hypofractionated (42.4 Gy/16 fraction + 9.6 Gy/4 fraction boost) or standard fractionated (50.4 Gy/28 fraction + 10 Gy/5 fraction boost) regimen. Seroma volumes were contoured and compared on CT at the time of WBRT simulation and tumor bed boost planning. Results: Twenty-four patients with evidence of seroma were identified and all patients received WBRT without drainage of the seroma. Mean seroma volume before WBRT and at boost planning were significantly different at 65.7 cm3 (SD, 50.5 cm3) and 35.6 cm3 (SD, 24.8 cm3), respectively (p < 0.001). Mean and median reduction in seroma volume during radiation were 39.6% (SD, 23.8%) and 46.2% (range, 10.7–76.7%), respectively. Fractionation schedule was not correlated with change in seroma volume. Length of time from surgery to start of radiation therapy showed an inverse correlation with change in seroma volume (Pearson correlation r = –0.53, p < 0.01). Conclusions: The volume of seroma changes significantly during WBRT. Consequently, the accuracy of breast boost planning is likely affected, as is the volume of normal breast tissue irradiated. CT-based boost planning before boost irradiation is suggested to ensure appropriate coverage. [Copyright &y& Elsevier]

Purpose: With 54° of freedom from the skull to mandible to C7, ensuring adequate immobilization for head-and-neck radiotherapy (RT) is complex. We quantify variations in skull, mandible, and cervical spine movement between RT sessions. Methods and Materials: Twenty-three sequential head-and-neck RT patients underwent serial computed tomography. Patients underwent planned rescanning at 11, 22, and 33 fractions for a total of 93 scans. Coordinates of multiple bony elements of the skull, mandible, and cervical spine were used to calculate rotational and translational changes of bony anatomy compared with the original planning scan. Results: Mean translational and rotational variations on rescanning were negligible, but showed a wide range. Changes in scoliosis and lordosis of the cervical spine between fractions showed similar variability. There was no correlation between positional variation and fraction number and no strong correlation with weight loss or skin separation. Semi-independent rotational and translation movement of the skull in relation to the lower cervical spine was shown. Positioning variability measured by means of vector displacement was largest in the mandible and lower cervical spine. Conclusions: Although only small overall variations in position between head-and-neck RT sessions exist on average, there is significant random variation in patient positioning of the skull, mandible, and cervical spine elements. Such variation is accentuated in the mandible and lower cervical spine. These random semirigid variations in positioning of the skull and spine point to a need for improved immobilization and/or confirmation of patient positioning in RT of the head and neck. [Copyright &y& Elsevier]

Abstract: Background and Purpose: IMRT clinical trials lack dose prescription and specification standards similar to ICRU standards for two- and three-dimensional external beam planning. In this study, we analyzed dose distributions for patients whose treatment plans incorporated IMRT, and compared the dose determined at the ICRU reference point to the PTV doses determined from dose–volume histograms. Additionally, we evaluated if ICRU reference type single-point dose prescriptions are suitable for IMRT dose prescriptions. Materials and methods: For this study, IMRT plans of 117 patients treated at our institution were randomly selected and analyzed. The treatment plans were clinically applied to the following disease sites: abdominal (11), anal (10), brain (11), gynecological (15), head and neck (25), lung (15), male pelvis (10) and prostate (20). The ICRU reference point was located in each treatment plan following ICRU Report 50 guidelines. The reference point was placed in the central part of the PTV and at or near the isocenter. In each case, the dose was calculated and recorded to this point. For each patient – volume and dose (PTV, PTV mean, median and modal) information was extracted from the planned dose–volume histogram. Results: The ICRU reference dose vs PTV mean dose relationship in IMRT exhibited a weak positive association (Pearson correlation coefficient 0.63). In approximately 65% of the cases studied, dose at the ICRU reference point was greater than the corresponding PTV mean dose. The dose difference between ICRU reference and PTV mean doses was ⩽2% in approximately 79% of the cases studied (average 1.21% (±1.55), range −4% to +4%). Paired t-test analyses showed that the ICRU reference doses and PTV median doses were statistically similar (p =0.42). The magnitude of PTV did not influence the difference between ICRU reference and PTV mean doses. Conclusions: The general relationship between ICRU reference and PTV mean doses in IMRT is similar to that in 3D CRT distributions. Point doses in IMRT are influenced by the degree of intensity modulation as well as calculation grid size utilized. Although the ICRU reference point type prescriptions conceptually may be extended for IMRT dose prescriptions and used as a representative of tumor dose, new universally acceptable dose prescription and specification standards for IMRT based on RTOG IMRT prescription model incorporating dose–volume specification would likely lead to greater consistency among treatment centers. [Copyright &y& Elsevier]

Abstract: Purpose: We correlated rectal and bladder point and volumetric dose data in patients treated for advanced cervix cancers with combined intracavitary-interstitial high-dose-rate (HDR) brachytherapy (BT). The results are compared with published Vienna applicator data. Methods and Materials: We retrospectively analyzed 30 individual combined intracavitary plus interstitial implants from 10 patients treated with external beam radiation therapy (EBRT) followed by HDR BT for locally advanced cervix carcinoma. EBRT consisted of 45Gy to the pelvis followed by 9–14.4Gy boost to involved parametria. BT consisted of a total dose of 21Gy delivered in 7Gy fraction. For each implant, CT-image-based simulation and image-guided BT treatment planning was performed. Bladder and rectal doses were evaluated and analyzed using both International commission on Radiation Units and Measurements (ICRU) reference points and dose–volume histograms. The cumulative doses to the rectum and bladder were calculated by combining contributions from external beam therapy and BT. To facilitate comparison with published literature, the total doses were normalized to equivalent dose in 2-Gy fractions (EQD2) using the equation EQD2total =EQD2EBRT +EQD2BT. Results: For the patient population considered, the mean ICRU bladder dose was 75 (±4) Gy3 compared to bladder D 0.1 cc and D 2 cc doses of 84 (±4) and 78 (±3) Gy3, respectively. The mean ICRU rectal dose was 73 (±4) Gy3 compared to rectal D 0.1 cc and D 2 cc doses of 79 (±5) and 74 (±4) Gy3, respectively. For rectum, the mean dose ratios (D 0.1 cc/D ICRU) and (D 2 cc/D ICRU) were 1.08 and 1.01, respectively, compared to Vienna applicator study mean dose ratios of 1.08 and 0.93, respectively. ICRU rectal dose correlated with volumetric rectal doses and best with volumetric D 2 cc dose (r S =0.91, p =0.0003); however, ICRU bladder dose did not correlate with volumetric bladder dose. Conclusions: Our study findings reveal a strong correlation between ICRU rectal reference dose and volumetric rectal D 2 cc dose in combined intracavitary-interstitial HDR brachytherapy. This surrogate rectal–dose relationship is valuable in establishing rectal tolerance dose levels in transitioning from traditional two-dimensional to image-based three-dimensional dose planning. [Copyright &y& Elsevier]

Purpose: To measure respiration-induced abdominal organ motion using four-dimensional computed tomography (4D CT) scanning and to examine the organ paths. Methods and Materials: During 4D CT scanning, consecutive CT images are acquired of the patient at each couch position. Simultaneously, the patient's respiratory pattern is recorded using an external marker block taped to the patient's abdomen. This pattern is used to retrospectively organize the CT images into multiple three-dimensional images, each representing one breathing phase. These images are analyzed to measure organ motion between each phase. The displacement from end expiration is compared to a displacement limit that represents acceptable dosimetric results (5 mm). Results: The organs measured in 13 patients were the liver, spleen, and left and right kidneys. Their average superior to inferior absolute displacements were 1.3 cm for the liver, 1.3 cm for the spleen, 1.1 cm for the left kidney, and 1.3 cm for the right kidney. Although the organ paths varied among patients, 5 mm of superior to inferior displacement from end expiration resulted in less than 5 mm of displacement in the other directions for 41 of 43 organs measured. Conclusions: Four-dimensional CT scanning can accurately measure abdominal organ motion throughout respiration. This information may result in greater organ sparing and planning target volume coverage. [ABSTRACT FROM AUTHOR]

Purpose: To prospectively study the impact on tumor and normal tissue delineation for RT planning by use of hybrid PET-CT simulation for patients with head-and-neck cancer. Methods and Materials: Twenty-one patients were simulated in treatment position on a hybrid PET-CT scanner. Images were transferred to the Varian Eclipse planning system. Abnormal areas of fluorodeoxyglucose (FDG) uptake were contoured on PET for the gross tumor volume of primaries (GTVp) and abnormal nodal region of primaries (ABNp) then compared with the same CT gross tumor volumes (GTVc) and abnormal nodal region (ABNc). A statistical analysis was performed to evaluate the correlation of PET and CT volumes. Results: Positron emission tomography demonstrated the primary in all cases, whereas CT did not find the primary in 3 cases. In 8 patients, additional areas of disease were seen only in PET. The average ratio of GTVc/GTVp was 3.1 (range, 0.3-23.6), whereas for ABNc/ABNp was 0.7 (range, 0-4). Volumes for the primaries were significantly larger on CT than on PET (p = 0.002) but not for nodal regions (p = 0.5). Conclusions: Hybrid PET-CT simulation is feasible and provides valuable information that results in greater delineation of normal tissues from tumor bearing areas at high risk for recurrence. This finding may further improve therapeutic window for IMRT for head-and-neck cancers. [ABSTRACT FROM AUTHOR]