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Aim/objectives/background The American College of Radiology (ACR) and the American Society for Radiation Oncology (ASTRO) have jointly developed the following practice parameter for image-guided radiation therapy (IGRT). IGRT is radiation therapy that employs imaging to maximize accuracy and precision throughout the entire process of treatment delivery with the goal of optimizing accuracy and reliability of radiation therapy to the target, while minimizing dose to normal tissues. Methods The ACR-ASTRO Practice Parameter for IGRT was revised according to the process described on the ACR website ("The Process for Developing ACR Practice Parameters and Technical Standards," www.acr.org/ClinicalResources/Practice-Parametersand-Technical-Standards) by the Committee on Practice Parameters of the ACR Commission on Radiation Oncology in collaboration with the ASTRO. Both societies then reviewed and approved the document. Results This practice parameter is developed to serve as a tool in the appropriate application of IGRT in the care of patients with conditions where radiation therapy is indicated. It addresses clinical implementation of IGRT including personnel qualifications, quality assurance standards, indications, and suggested documentation. Conclusions This practice parameter is a tool to guide clinical use of IGRT and does not make recommendations on site-specific IGRT directives. It focuses on the best practices and principles to consider when using IGRT effectively, especially with the significant increase in imaging data that is now available with IGRT. The clinical benefit and medical necessity of the imaging modality and frequency of IGRT should be assessed for each patient.

Purpose Although stereotactic body radiation therapy (SBRT) is an attractive noninvasive approach for liver irradiation, it presents specific challenges associated with respiration-induced liver motion, daily tumor localization due to liver deformation, and poor visualization of target with respect to adjacent normal liver in computed tomography (CT). We aim to identify potential hazards and develop a set of mitigation strategies to improve the safety of our liver SBRT program, using failure mode and effect analysis (FMEA). Materials and methods A multidisciplinary group consisting of two physicians, three physicists, two dosimetrists, and two therapists was formed. A process map covering ten major stages of the liver SBRT program from the initial diagnosis to posttreatment follow-up was generated. A total of 102 failure modes (FM), together with their causes and effects, were identified. The occurrence (O), severity (S), and lack of detectability (D) were independently scored using a scale from 1 (lowest risk) to 10 (largest risk). The ranking was done using the risk probability number (RPN) defined as the product of average O, S, and D numbers for each mode. Two fault tree analyses were performed. The failure modes with the highest RPN values as well as highest severity score were considered for investigation and a set of mitigation strategies was developed to address these. Results The median RPN (RPNmed ) values for all modes ranged from of 9 to 105 and the highest median S score (Smed ) was 8. Fourteen FMs were identified to be significant by both RPNmed and Smed (top ten RPNmed ranked and highest Smed FMs) and 12 of them were considered for risk mitigation efforts. The remaining two were omitted due to either sufficient checks already in place, or lack of practical mitigation strategies. Implemented measures consisted of five physics tasks, two physician tasks, and three workflow changes. Conclusions The application of FMEA to our liver SBRT program led to the identification of potential FMs and allowed improvement measures to enhance the safety of our clinical practice.

Purpose Our peer-review program previously consisted of weekly chart rounds performed before the end of the first week of treatment. In order to perform peer review before the start of treatment when possible, we implemented daily prospective contouring and planning rounds (CPR). Methods and materials At the time of computed tomography simulation, patients were categorized by the treating physician into 5 treatment groups based on urgency and complexity (ie, standard, urgent, palliative nonemergent, emergent, and special procedures). A scoring system was developed to record the outcome of case presentations, and the results of the CPR case presentations were compared with the time period 2.5 years before CPR implementation, for which peer review was performed retrospectively. Results CPR was implemented on October 1, 2015, and a total of 4759 patients presented for care through May 31, 2018. The majority were in the standard care path (n = 3154; 66.3%). Among the remainder of the charts, 358 (7.5%), 430 (9.0%), and 179 (3.8%) cases were in the urgent, nonemergent palliative, and emergent care paths, respectively. The remaining patients were in the special procedures group, representing brachytherapy and stereotactic radiosurgery. A total of 125 patients (2.6%) required major changes and were re-presented after the suggested modifications, 102 patients (2.1%) had minor recommendations that did not require a repeat presentation, and 247 cases (5.2%) had minor documentation-related recommendations that did not require editing of the contours. In the 2.5 years before the implementation, records of a total of 1623 patients were reviewed, and only 9 patients (0.6%) had minor recommendation for change. The remainder was noted as complete agreement. Conclusions Contouring and planning rounds were successfully implemented at our clinic. Pretreatment and, most often, preplanning review of contours and directives allows for a more detailed review and changes to be made early on in the treatment planning process. When compared with historical case presentations, the CPR method made our peer review more thorough and improved standardization.

Purpose/Objective(s) Symptomatic radiation pneumonitis (RP) is a common cause of treatment related toxicity in patients receiving radiation therapy for lung cancer. Machine learning techniques have been utilized to determine predictors of RP, but most of these models have used dosimetric features to generate results. The identification of pretreatment factors related to the development of symptomatic RP and implementation of these factors into a machine learning model would be clinically useful to guide treatment decisions, risk estimation, and risk reduction of development of symptomatic RP. Materials/Methods We retrospectively reviewed data from 278 lung cancer patients that underwent stereotactic body radiation therapy (SBRT). Pretreatment factors including patient demographics, pulmonary function data, and tumor characteristics were previously analyzed for the development of symptomatic RP, defined as CTCAE v4.0 ≥ Grade 2. A programming environment was used to generate classification machine learning models based on this dataset. Models were tested for accuracy in classification, area-under-the-curve (AUC), and special attention was paid to the false negative rate. The performance of several different algorithms using various combinations of predictors was evaluated including Decision Trees, Discriminant Analysis, Logistic Regression, Naive Bayes Classifiers, Support Vector Machines, Nearest Neighbor Classifiers and Ensemble Classifiers. Each model utilized 5-fold cross-validation to prevent overfitting. Results Of the 278 patients receiving SBRT, 42 patients (15.1%) developed symptomatic RP. A RUSBoosted Trees Ensemble Classifier was found to be the most accurate model tested. Features identified as significant risk factors for symptomatic RP in prior univariate and multivariate analyses were found to be the most important predictors in the machine learning models tested. These features included prior radiation treatment to the thorax or lung resection, location of tumor in the right lower lobe, a higher T Stage and age. When this model was used to classify cases of symptomatic RP, it had an AUC of 0.86 and an accuracy of 87%, correctly predicting 36 out of 42 pneumonitis cases. The model had a false negative rate of 14% and false positive rate of 13%. Conclusion A machine learning model was developed to identify pretreatment factors predictive of symptomatic RP. The advantage of this model when compared to others with a similar goal is that it depends solely on pretreatment factors, and therefore could be applied in a clinical setting prior to radiation therapy. Next steps include testing with an independent dataset to confirm the model's accuracy and prospective studies to verify the model's clinical utility.

While some institutions deliver multiple fractions per implant for MRI-based planning, it is common for only one fraction to be delivered per implant with CT-based cervical brachytherapy. The purpose of this study was to compare physician costs, hospital costs, and overall costs for cervical cancer patients treated with either CT-based or MRI-based high-dose-rate (HDR) cervical brachytherapy to determine if MRI-based brachytherapy as described can be financially feasible.We identified 40 consecutive patients treated with curative intent cervical brachytherapy. Twenty patients underwent CT-based HDR brachytherapy with five fractions delivered in five implants on nonconsecutive days in an outpatient setting with the first implant placed with a Smit sleeve under general anesthesia. Twenty patients received MRI-based HDR brachytherapy with four fractions delivered in two implants, each with MRI-based planning, performed 1-2 weeks apart with an overnight hospital admission for each implant. We used Medicare reimbursements to assess physician costs, hospital costs, and overall cost.The median cost of MRI-based brachytherapy was $14,248.75 (interquartile range [IQR]: $13,421.32-$15,539.74), making it less costly than CT-based brachytherapy with conscious sedation (i.e., $18,278.85; IQR: $17,323.13-$19,863.03, p0.0001) and CT-based brachytherapy with deep sedation induced by an anesthesiologist (i.e., $27,673.44; IQR: $26,935.14-$29,511.16, p0.0001). CT-based brachytherapy with conscious sedation was more costly than CT-based brachytherapy with deep sedation (p0.001).MRI-based brachytherapy using the described treatment course was less costly than both methods of CT-based brachytherapy. Cost does not need to be a barrier for MRI-based cervical brachytherapy, especially when delivering multiple fractions with the same application.

Purpose Radiation therapy (RT)–specific aspects of a patient’s cancer care commonly are documented and scheduled through a radiation oncology electronic health record (rEHR). However, patients who receive RT also receive multidisciplinary care from providers who use the hospital EHR (hEHR). We created an electronic interface to integrate our hEHR and rEHR to improve communication of the RT aspects of care between our department and the rest of the hospital. The objective of this study was to assess the impact of rEHR and hEHR integration on the accessibility of the RT-specific aspects of patient care to providers. Methods and Materials We performed a preintegration and postintegration survey of 175 staff members at our academic cancer center. Respondents rated the importance and accessibility of several RT encounters and documents on a Likert scale. The Wilcoxon-Mann-Whitney, χ2, and Fisher’s exact tests were used to compare preintegration and postintegration responses. Results There were 32 and 19 responses to the pre- and postintegration surveys, respectively. rEHR items most commonly reported to be at least moderately important were the dates of first treatment (n = 29 [91%]), last treatment (n = 29 [91%]), brachytherapy (n = 22 [69%]), radiosurgery (n = 22 [69%]), and computed tomography simulation (n = 21 [66%]). A drastic improvement was found in most items made visible in the hEHR through the interface. Conclusion By integrating our hEHR and rEHR, we improved the communication of patient care between the RT department and the multidisciplinary team. Institutions should pursue and support integration of the EHRs to improve the quality of care provided to patients with cancer.

Purpose : Adaptive magnetic resonance imaging (MRI)-based brachytherapy results in improved local control and decreased high-grade toxicities compared to historical controls. Incorporating MRI into the workflow of a department can be a major challenge when initiating an MRI-based brachytherapy program. This project aims to describe the goals, challenges, and solutions when initiating an MRI-based cervical cancer brachytherapy program at our institution. Material and methods : We describe the 6-month multi-disciplinary planning phase to initiate an MRI-based brachytherapy program. We describe the specific challenges that were encountered prior to treating our first patient. Results : We describe the solutions that were realized and executed to solve the challenges that we faced to establish our MRI-based brachytherapy program. We emphasize detailed coordination of care, planning, and communication to make the workflow feasible. We detail the imaging and radiation physics solutions to safely deliver MRI-based brachytherapy. The focus of these efforts is always on the delivery of optimal, state of the art patient care and treatment delivery within the context of our available institutional resources. Conclusions : Previous publications have supported a transition to MRI-based brachytherapy, and this can be safely and efficiently accomplished as described in this manuscript.

Objective: To investigate the effects of adaptive radiotherapy on dosimetric, clinical, and toxicity outcomes for patients with head and neck cancer undergoing chemoradiotherapy with intensity-modulated radiotherapy. Methods: Fifty-one patients with advanced head and neck cancer underwent definitive chemoradiotherapy with the original plan optimized to deliver 70.2 Gy. All patients were resimulated at a median dose of 37.8 Gy (range, 27.0-48.6 Gy) due to changes in tumor volume and/or patient weight loss (>15% from baseline). Thirty-four patients underwent adaptive replanning for their boost planning (21.6 Gy). The dosimetric effects of the adaptive plan were compared to the original plan and the original plan copied on rescan computed tomography. Acute and late toxicities and tumor local control were assessed. Gross tumor volume reduction rate was calculated. Results: With adaptive replanning, the maximum dose to the spinal cord, brain stem, mean ipsilateral, and contralateral parotid had a median reduction of −4.5%, −3.0%, −6.2%, and −2.5%, respectively (median of 34 patients). Median gross tumor volume and boost planning target volume coverage improved by 0.8% and 0.5%, respectively. With a median follow-up time of 17.6 months, median disease-free survival and overall survival was 14.8 and 21.1 months, respectively. Median tumor volume reduction rate was 35.2%. For patients with tumor volume reduction rate ≤35.2%, median disease-free survival was 8.7 months, whereas it was 16.9 months for tumor volume reduction rate >35.2%. Four patients had residual disease after chemoradiotherapy, whereas 64.7% (20 of 34) of patients achieved locoregional control. Conclusion: Implementation of adaptive radiotherapy in head and neck cancer offers benefits including improvement in tumor coverage and decrease in dose to organs at risk. The tumor volume reduction rate during treatment was significantly correlated with disease-free survival and overall survival.

Purpose We transitioned from a low-dose-rate (LDR) to a high-dose-rate (HDR) prostate brachytherapy program. The objective of this study was to describe our experience developing a prostate HDR program, compare the LDR and HDR dosimetry, and identify the impact of several targeted interventions in the HDR workflow to improve efficiency. Methods and Materials We performed a retrospective cohort study of patients treated with LDR or HDR prostate brachytherapy. We used iodine-125 seeds (145 Gy as monotherapy, and 110 Gy as a boost) and preoperative planning for LDR. For HDR, we used iridium-192 (13.5 Gy × 2 as monotherapy and 15 Gy × 1 as a boost) and computed tomography–based planning. Over the first 18 months, we implemented several targeted interventions into our HDR workflow to improve efficiency. To evaluate the progress of the HDR program, we used linear mixed-effects models to compare LDR and HDR dosimetry and identify changes in the implant procedure and treatment planning durations over time. Results The study cohort consisted of 122 patients (51 who received LDR and 71 HDR). The mean D90 was similar between patients who received LDR and HDR (P = .28). HDR mean V100 and V95 were higher (P < .0001), but mean V200 and V150 were lower (P < .0001). HDR rectum V100 and D1cc were lower (P < .0001). The HDR mean for the implant procedure duration was shorter (54 vs 60 minutes; P = .02). The HDR mean for the treatment planning duration dramatically improved with the implementation of targeted workflow interventions (3.7 hours for the first quartile to 2.0 hours for the final quartile; P < .0001). Conclusions We successfully developed a prostate HDR brachytherapy program at our institution with comparable dosimetry to our historic LDR patients. We identified several targeted interventions that improved the efficiency of treatment planning. Our experience and workflow interventions may help other institutions develop similar HDR programs.

Objective: To develop decision trees predicting for tumor volume reduction in patients with head and neck (H&N) cancer using pretreatment clinical and pathological parameters. Methods: Forty-eight patients treated with definitive concurrent chemoradiotherapy for squamous cell carcinoma of the nasopharynx, oropharynx, oral cavity, or hypopharynx were retrospectively analyzed. These patients were rescanned at a median dose of 37.8 Gy and replanned to account for anatomical changes. The percentages of gross tumor volume (GTV) change from initial to rescan computed tomography (CT; %GTVΔ) were calculated. Two decision trees were generated to correlate %GTVΔ in primary and nodal volumes with 14 characteristics including age, gender, Karnofsky performance status (KPS), site, human papilloma virus (HPV) status, tumor grade, primary tumor growth pattern (endophytic/exophytic), tumor/nodal/group stages, chemotherapy regimen, and primary, nodal, and total GTV volumes in the initial CT scan. The C4.5 Decision Tree induction algorithm was implemented. Results: The median %GTVΔ for primary, nodal, and total GTVs was 26.8%, 43.0%, and 31.2%, respectively. Type of chemotherapy, age, primary tumor growth pattern, site, KPS, and HPV status were the most predictive parameters for primary %GTVΔ decision tree, whereas for nodal %GTVΔ, KPS, site, age, primary tumor growth pattern, initial primary GTV, and total GTV volumes were predictive. Both decision trees had an accuracy of 88%. Conclusions: There can be significant changes in primary and nodal tumor volumes during the course of H&N chemoradiotherapy. Considering the proposed decision trees, radiation oncologists can select patients predicted to have high %GTVΔ, who would theoretically gain the most benefit from adaptive radiotherapy, in order to better use limited clinical resources.

Purpose: We evaluated the performance of organ contour propagation from a planning computed tomography to cone-beam computed tomography with deformable image registration by comparing contours to manual contouring. Materials and Methods: Sixteen patients were retrospectively identified based on showing considerable physical change throughout the course of treatment. Multiple organs in the 3 regions (head and neck, prostate, and pancreas) were evaluated. A cone-beam computed tomography from the end of treatment was registered to the planning computed tomography using rigid registration, followed by deformable image registration. The contours were copied on cone-beam computed tomography image sets using rigid registration and modified by 2 radiation oncologists. Contours were compared using Dice similarity coefficient, mean surface distance, and Hausdorff distance. Results: The mean physician-to-physician Dice similarity coefficient for all organs was 0.90. When compared to each physician’s contours, the overall mean for rigid was 0.76 (P < .001), and it was improved to 0.79 (P < .001) for deformable image registration. Comparing deformable image registration to physicians resulted in a mean Dice similarity coefficient of 0.77, 0.74, and 0.84 for head and neck, prostate, and pancreas groups, respectively; whereas, the physician-to-physician mean agreement for these sites was 0.87, 0.90, and 0.93 (P < .001, for all sites). The mean surface distance for physician-to-physician contours was 1.01 mm, compared to 2.58 mm for rigid-to-physician contours and 2.24 mm for deformable image registration-to-physician contours. The mean physician-to-physician Hausdorff distance was 11.32 mm, and when compared to any physician’s contours, the mean for rigid and deformable image registration was 12.1 mm and 12.0 mm (P < .001), respectively. Conclusion: The physicians had a high level of agreement via the 3 metrics; however, deformable image registration fell short of this level of agreement. The automatic workflows using deformable image registration to deform contours to cone-beam computed tomography to evaluate the changes during treatment should be used with caution.

For radiation delivery tracking systems that monitor intrafraction prostate motion, generalized departmental threshold protocols may be used. The purpose of this study is to determine whether predefined action thresholds can be generally applied or if patient-specific action thresholds may be required. Software algorithms were developed in the MatLab (The Mathworks Inc., Natick, MA) software environment to simulate shifts of the patient structure set consisting of prostate, bladder, and rectum. These structures were shifted by +/- 10 mm in each direction in 1 mm increments to simulate displacements during treatment, without taking into consideration organ deformity. Dose-volume data at each shift were plotted and analyzed. A linear relationship was observed between planning dose-volume parameters and shifted dose-volume parameters. For a 5 mm anterior shift, it was observed that individual rectal V70 values increased by absolute magnitudes of 6–15%, dependent on the planning rectal V70 of each patient. Likewise, for a 5 mm inferior shift, individual bladder V70 values increased by 1–14%, dependent on planning bladder V70. This linear relationship was observed for all levels of shifts up to 10 mm. Since rectum and bladder dose-volume changes due to patient shifts are dependent on dose-volume parameters, this study suggests that patient-specific action thresholds may be necessary.

To determine factors predictive for hematologic toxicity (HT) associated with concurrent chemoradiation for Stage II through IV cervical cancer.The medical records of 40 women receiving concurrent chemoradiation for cervical cancer were reviewed. Hematologic toxicity was defined by use of Common Terminology Criteria for Adverse Events (version 3.0). Variables predicting for HT including age, body mass index, transfusions, and bone marrow volumes irradiated were included in the data analysis.Of the patients, 13 (32.5%) had Grade 0 or 1 HT and 27 (67.5%) had Grade 2 through 4 HT (HT2+). Multiple logistic regression analysis of potential predictors showed that only the volume of bone receiving 20 Gy (V20) for whole pelvic bone tended toward significance for predicting HT2+. A strong correlation was noted between HT2+ and V20 (r = 0.8, p0.0001). A partitioning analysis to predict HT2+ showed a cutoff value of 79.42% (approximately 80%) for V20 of whole pelvic bone. That is, if the V20 of the whole pelvis exceeds 80%, the risk of HT2+ developing increases by a factor (odds ratio) of 4.5 (95%, confidence interval, 1.08-18.69) (p0.05).We have shown a correlation between bone marrow volume radiated and development of HT. This has implications for use of pelvic intensity-modulated radiation therapy, which can potentially decrease the volume of bone marrow radiated.

Using previous dosimetric analysis methods, we identified the volume of bowel receiving 30Gy ( V 30 ) correlated with acute gastrointestinal (GI) toxicity in anal cancer patients treated with intensity-modulated radiation therapy and concurrent chemotherapy. For V 30 >450cc and⩽450cc, acute GI toxicity was 33% and 8%, respectively ( p =0.003).

Purpose: To test the hypothesis that the volume of pelvic bone marrow (PBM) receiving 10 and 20 Gy or more (PBM-V{sub 10} and PBM-V{sub 20}) is associated with acute hematologic toxicity (HT) in anal cancer patients treated with concurrent chemoradiotherapy. Methods and Materials: We analyzed 48 consecutive anal cancer patients treated with concurrent chemotherapy and intensity-modulated radiation therapy. The median radiation dose to gross tumor and regional lymph nodes was 50.4 and 45 Gy, respectively. Pelvic bone marrow was defined as the region extending from the iliac crests to the ischial tuberosities, including the os coxae, lumbosacral spine, and proximal femora. Endpoints included the white blood cell count (WBC), absolute neutrophil count (ANC), hemoglobin, and platelet count nadirs. Regression models with multiple independent predictors were used to test associations between dosimetric parameters and HT. Results: Twenty patients (42%) had Stage T3-4 disease; 15 patients (31%) were node positive. Overall, 27 (56%), 24 (50%), 4 (8%), and 13 (27%) experienced acute Grade 3-4 leukopenia, neutropenia, anemia, and thrombocytopenia, respectively. On multiple regression analysis, increased PBM-V{sub 5}, V{sub 10}, V{sub 15}, and V{sub 20} were significantly associated with decreased WBC and ANC nadirs, as were female gender, decreased body mass index, andmore » increased lumbosacral bone marrow V{sub 10}, V{sub 15}, and V{sub 20} (p < 0.05 for each association). Lymph node positivity was significantly associated with a decreased WBC nadir on multiple regression analysis (p < 0.05). Conclusion: This analysis supports the hypothesis that increased low-dose radiation to PBM is associated with acute HT during chemoradiotherapy for anal cancer. Techniques to limit bone marrow irradiation may reduce HT in anal cancer patients.« less

Purpose To report a multicenter experience treating anal canal cancer patients with concurrent chemotherapy and intensity-modulated radiation therapy (IMRT). Patients and Methods From October 2000 to June 2006, 53 patients were treated with concurrent chemotherapy and IMRT for anal squamous cell carcinoma at three tertiary-care academic medical centers. Sixty-two percent were T1-2, and 67% were N0; eight patients were HIV positive. Forty-eight patients received fluorouracil (FU)/mitomycin, one received FU/cisplatin, and four received FU alone. All patients underwent computed tomography–based treatment planning with pelvic regions and inguinal nodes receiving a median of 45 Gy. Primary sites and involved nodes were boosted to a median dose of 51.5 Gy. All acute toxicity was scored according to the Common Terminology Criteria for Adverse Events, version 3.0. All late toxicity was scored using Radiation Therapy Oncology Group criteria. Results Median follow-up was 14.5 months (range, 5.2 to 102.8 months). Acute grade 3+ toxicity included 15.1% GI and 37.7% dermatologic toxicity; all acute grade 4 toxicities were hematologic; and acute grade 4 leukopenia and neutropenia occurred in 30.2% and 34.0% of patients, respectively. Treatment breaks occurred in 41.5% of patients, lasting a median of 4 days. Forty-nine patients (92.5%) had a complete response, one patient had a partial response, and three had stable disease. All HIV-positive patients achieved a complete response. Eighteen-month colostomy-free survival, overall survival, freedom from local failure, and freedom from distant failure were 83.7%, 93.4%, 83.9%, and 92.9%, respectively. Conclusion Preliminary outcomes suggest that concurrent chemotherapy and IMRT for anal canal cancers is effective and tolerated favorably compared with historical standards.

The purpose of this study was to survey current departmental policies on treatment couch overrides and the values of table tolerances used clinically. A 25‐question electronic survey on couch overrides and tolerances was sent to full members of the American Association of Physicists in Medicine (AAPM). The first part of the survey asked participants if table overrides were allowed at their institution, who was allowed to perform these overrides, and if imaging was required with overrides. The second part of the survey asked individuals to provide table tolerance data for the following treatment sites: brain/head and neck (H&N), lung, breast, abdomen/pelvis and prostate. Each site was further divided into IMRT/VMAT and 3D conformal techniques. Spaces for free‐text were provided, allowing respondents to enter any table tolerance data they were unable to specify under the treatment sites listed. A total of 361 individuals responded, of which approximately half participated in the couch tolerances portion of the survey. Overall, 86% of respondents’ institutions allow couch tolerance overrides at treatment. Therapists were the most common staff members permitted to perform overrides, followed by physicists, dosimetrists, and physicians, respectively. Of the institutions allowing overrides, 34% reported overriding daily. More than half of the centers document the override and/or require a setup image to radiographically verify the treatment site. With respect to table tolerances, SRS/SBRT table tolerances were the tightest, while clinical setup table tolerances were the largest. There were minimal statistically significant differences between IMRT/VMAT and 3D conformal table tolerances. Our results demonstrated that table overrides are relatively common in radiotherapy despite being a potential safety concern. Institutions should review their override policy and table tolerance values in light of the practices of other institutions. Careful attention to these matters is crucial in ensuring the safe and accurate delivery of radiotherapy. PACS number(s): 87.55.N‐, 87.55.Qr, 87.55.T‐

Intensity-modulated whole pelvic radiation therapy (IM-WPRT) has decreased the incidence of gastrointestinal complications by reducing the volume of normal tissue irradiated in gynecologic patients. However, IM-WPRT plans result in steep dose gradients around the target volume, and thus accurate patient setup is essential. To quantify the accuracy of our patient positioning, we examined the weekly portal films of 46 women treated with IM-WPRT at our institution. All patients were positioned using a customized immobilization device that was indexed to the treatment table. Setup errors were evaluated by comparing portal images to simulation images using an algorithm that registers user-defined open curve segments drawn on both sets of film. The setup errors, which were separated into systematic and random components, ranged from 1.9 to 3.7 mm for the translations and 1.3 degrees to 4.4 degrees for the 2 in-plane translations. The systematic errors were all less than the respective random errors, with the largest error in the anterior/posterior direction. In addition, there was no correlation between the magnitude of these errors and patient-specific factors (age, weight, height). In the future, we will investigate the effect of these setup errors on the delivered dose distribution.

Purpose To assess the efficacy and toxicity of intensity-modulated radiotherapy (IMRT) in pancreatic and bile duct (cholangiocarcinoma) malignancies. Methods and materials Twenty-five patients with pancreatic and bile duct cancer were treated with IMRT. Twenty-three received concurrent 5-fluoruracil. One patient with a pancreatic primitive neuroectodermal tumor received concurrent etoposide and ifosfamide. Eight patients had resected tumors, and 17 had unresectable primary ( n = 14) or recurrent ( n = 3) tumors. Six patients underwent treatment planning with conventional three-dimensional four-field techniques for dosimetric comparison with IMRT. Results Compared with conventional RT, IMRT reduced the mean dose to the liver, kidneys, stomach, and small bowel. IMRT was well tolerated, with 80% experiencing Grade 2 or less acute upper GI toxicity. At a median follow-up of 10.2 months, no resected patients had local failure, and only 1 of 10 assessable patients with unresectable cancer had local progression. The median survival and distant metastasis-free survival of the 24 patients with adenocarcinoma was 13.4 and 7.3 months, respectively. Grade 4 late liver toxicity occurred in 1 patient surviving >5 years. The remainder of the assessable patients experienced no ( n = 9) or Grade 1 ( n = 4) late toxicity. Conclusion In this hypothesis-generating analysis, the acute and chronic toxicity profile with IMRT in the treatment of pancreatic and bile duct cancer was encouraging. Local control was not compromised, despite efforts to increase conformality and avoid doses to normal structures. Distant failure remains a major obstacle in pancreatic cancer.

Radiation therapy occupies an important role in the treatment of gynecologic malignancies. Unfortunately, traditional approaches result in the irradiation of large volumes of normal tissues exposing patients to many toxicities and precluding dose escalation in select patients. A novel approach to the planning and delivery of radiation therapy, known as intensity-modulated radiation therapy (IMRT), has been introduced. Unlike conventional approaches, IMRT conforms the prescription dose to the shape of the target in three dimensions, thus sparing the surrounding normal tissues. Multiple studies have demonstrated the clear superiority of IMRT planning in these patients in terms of normal tissue sparing. Promising clinical results have also been published, suggesting that IMRT reduces the incidence of acute and chronic toxicity in these women. Ongoing studies are focusing on tumor control and patient outcome. Although further work is needed, these results suggest that IMRT may represent a major advancement in the planning and delivery of radiation therapy in patients with gynecologic malignancies.

BACKGROUND The objective of the current study was to evaluate the content and quality of patient-oriented information regarding intensity-modulated radiotherapy (IMRT) on the Internet. METHODS IMRT websites were identified by reviewing the first 50 uniform resource locators on 5 search engines using the search terms IMRT and intensity modulated radiation therapy. Each site was evaluated by three observers for informational content, presentation, accuracy, and balance. A score of low, moderate, or high was assigned to each category based on a predefined scoring system. An overall score was assigned to each site, ranging from −35 to 100 points. RESULTS Seventy-seven patient-oriented IMRT websites were identified (45% private, 21% academic, and 18% commercial). Most sites (58%) had a low level of informational content, with information on fundamental aspects of IMRT planning (target delineation and inverse planning) appearing on < 50% of sites. The most commonly discussed tumors were genitourinary (65%) and head and neck (53%) lesions. Few sites, however, described the potential benefits of IMRT (toxicity and tumor control). Most sites (82%) used patient-appropriate language. False and/or misleading information was seen on 42% of sites and was equally common on academic, private, and commercial sites. Balance statements were present on 24% of sites (most of which were commercial). The median overall score was 20 points (range, −25 to 70 points). The median overall scores for academic, private, commercial, and other sites were 10, 20, 25, and 20 points, respectively (P = 0.26). CONCLUSIONS In general, the content and quality of patient-oriented information regarding IMRT on the Internet were poor. Patients and their physicians need to be aware of these problems when selecting treatment courses. Cancer 2004. © 2004 American Cancer Society.

Purpose : To identify dosimetric factors correlated with acute gastrointestinal (GI) toxicity in gynecology patients undergoing intensity-modulated whole pelvic radiation therapy (IM-WPRT). Material and methods : Fifty gynecology patients received IM-WPRT (45–1.8Gy/fraction) between 2/00 and 3/02. All patients were treated to a clinical target volume (CTV) consisting of the upper vagina, parametria, uterus, presacral region and pelvic lymph nodes. Grade 2 acute GI toxicity requiring frequent medications and grade 3–5 toxicities were designated as clinically significant and analyzed as a function of patient and dosimetric variables. The most significant volumetric factors were fit to a normal tissue complication probability (NTCP) function. Results : Fourteen women (28%) developed clinically significant acute GI toxicity. None of the patient factors were correlated with acute GI toxicity. In addition, the volume of rectum receiving 25, 50, 75, 90, 100 and 110% of the prescription dose did not reach statistical significance. In contrast, a correlation was observed between the volume of small bowel (SB) irradiated and acute GI toxicity, particularly the SB volumes receiving 90 and 100% of the prescription dose ( p =0.009 and p =0.009, respectively). Controlling for patient and other dosimetric factors, the SB volume receiving the 100% (Vol SB,100 ) of the prescription dose remained the sole significant factor on multivariate analysis ( p =0.012). Subsequently, a NTCP curve, quantifying the risk of acute GI toxicity, was generated based on the Vol SB,100 . Conclusions : The most significant factor correlated acute GI toxicity in gynecology patients undergoing IM-WPRT is Vol SB,100 .

Prostate cancer is among the most common solid malignancies. A number of treatment alternatives exist for localized prostate cancer, including observation, prostatectomy, brachytherapy, and externalbeam radiation therapy (EBRT). External-beam radiation therapy has changed dramatically during the past several years. Older techniques paved the way for 3-dimensional conformal radiation therapy (CRT), which in turn facilitated the introduction of intensity-modulated radiation therapy (IMRT). The prostate has served as a model disease site for the implementation of IMRT. As indicated by a growing body of experience, IMRT for prostate cancer represents a major technologic and clinical advance for radiation therapy. In this article, a review is provided of the evolution of EBRT leading to IMRT, the unique features making the prostate an ideal disease site for employing IMRT, the details of the clinical implementation of prostate IMRT and supporting technologic advancements, and the currently reported clinical outcomes of IMRT in prostate cancer. In addition, future directions of prostate IMRT, both technologic and clinical, are discussed.

Objective. Our goal in this article to describe our initial experience with intensity-modulated whole-pelvis radiation therapy (IM-WPRT) in gynecologic malignancies. Methods. Between February and August 2000, 15 women with cervical (9) or endometrial (6) cancer received IM-WPRT. All patients received a treatment planning computed tomography (CT) scan. On each scan, the target volume (upper vagina, parametrial tissues, presacral region, uterus, and regional lymph nodes) and normal tissues (small bowel, bladder, and rectum) were identified. Using commercially available software, an IM-WPRT plan was generated for each patient. The goal was to provide coverage of the target with the prescription dose (45 Gy) while minimizing the volume of small bowel, bladder, and rectum irradiated. Acute gastrointestinal (GI) and genitourinary (GU) toxic effects in these women were compared with those seen in 25 patients treated with conventional WPRT. Results. IM-WPRT plans provided excellent coverage of the target structures in all patients and were highly conformal, providing considerable sparing of the bladder, rectum, and small bowel. Treatment was well tolerated, with grade 0–1 GI and GU toxicity in 46 and 93% of patients, respectively. IM-WPRT patients had a lower rate of grade 2 GI toxicity (53.4% vs 96%, P = 0.001) than those treated with conventional WPRT. Moreover, the percentage of women requiring no or only infrequent antidiarrheal medications was lower in the IM-WPRT group (73.3% vs 20%, P = 0.001). While grade 2 GU toxicity was also lower in the IM-WPRT patients (6.7% vs 16%), this difference did not reach statistical significance ( P = 0.38). Conclusion. IM-WPRT provides excellent coverage of the target structures while sparing critical neighboring structures in gynecology patients. Treatment is well tolerated with less acute GI toxicity than conventional WPRT. More patients and longer follow-up are needed to evaluate the full merits of this approach.

Cancer comprises a group of diseases characterized by the uncontrolled growth of abnormal cells that spread from the anatomical site of origin. For many types of cancer, surgery alone has proven inadequate, necessitating a broader approach to treatment incorporating chemotherapy and radiotherapy. Of particular recent interest has been the use of α-emitters in the treatment of microscopic carcinoma. The effective application of these materials requires an understanding of the physical and biological bases of radiation therapy. In addition, both radiochemical and radionuclidic purity are essential in all clinical applications. Recent work with the α-emitting radionuclide bismuth-212 offers considerable promise in the treatment of microscopic ovarian carcinoma resistant to conventional treatment modalities. Ongoing improvements in methods for its preparation are expected to further improve its therapeutic utility.

Purpose: This study attempted to correlate patient, treatment, and dosimetric factors with the risk of late rectal sequelae in patients treated with radiation therapy (RT) for cervical carcinoma. Methods and Materials: A total of 183 patients with cervical carcinoma (67 Stage I, 93 Stage II, and 23 Stage III) treated with definitive RT with a minimum of 2 years follow-up were evaluated. Treatment consisted of external beam pelvic RT (EBRT) followed by intracavitary RT (ICRT) consisting of one or two insertions. Complications were scored and analyzed as a function of 25 patient and treatment factors. Conventional total rectal doses were obtained by adding together the EBRT and ICRT rectal doses. To account for differences in dose rate between the ICRT and EBRT, and variations in EBRT fractionation schemes, biologically equivalent rectal doses (BED) were calculated using a linear quadratic model. In addition, the influence of the varying proportions of EBRT and ICRT rectal doses were evaluated. Results: Twenty-eight patients (15.3%) developed late rectal sequelae (13 Grade 1,3 Grade 2, and 12 Grade 3). Diabetes (p = 0.03), Point A dose (p = 0.04), and conventional EBRT dose (p = 0.03) were the most significant factors on multivariate analysis. Logistic regression analysis demonstrated a low risk (~10%) of late rectal sequelae below conventional and biological rectal doses of 75 Gy and 135 BED, respectively. The percentage of rectal dose delivered by the EBRT significantly influenced the dose-response relationship. A defined threshold percentage above which rectal sequelae were more common was identified over the range of doses evaluated. This threshold was 87% at a total rectal dose of 60 Gy and decreased to 60% at 80 Gy. Conclusion: Diabetes, Point A, and EBRT doses are the most significant factors associated with the risk of late rectal sequelae in patients treated with RT for cervical carcinoma. The percentage of rectal dose delivered by the EBRT significantly affects the conventional and biological dose-response relationship. This suggests that the volume of rectum irradiated is an important and independent parameter in the development of late rectal sequelae. 0 1997 Elsevier Science Inc.

A prospective feasibility study was conducted to investigate the utility of dual-energy (DE) imaging compared to conventional x-ray imaging for patients undergoing kV-based image guided radiation therapy (IGRT) for lung cancer.An institutional review board-approved feasibility study enrolled patients with lung cancer undergoing IGRT and was initiated in September 2011. During daily setup, 2 sequential respiration-gated x-ray images were obtained using an on-board imager. Imaging was composed of 1 standard x-ray image at 120 kVp (1 mAs) and a second image obtained at 60 kVp (4 mAs). Weighted logarithmic subtraction of the 2 images was performed offline to create a soft tissue-selective DE image. Conventional and DE images were evaluated by measuring relative contrast and contrast-to-noise ratios (CNR) and also by comparing spatial localization, using both approaches. Imaging dose was assessed using a calibrated ion chamber.To date, 10 patients with stage IA to IIIA lung cancer were enrolled and 57 DE images were analyzed. DE subtraction resulted in complete suppression of overlying bone in all 57 DE images, with an average improvement in relative contrast of 4.7 ± 3.3 over that of 120 kVp x-ray images (P.0002). The improvement in relative contrast with DE imaging was seen for both smaller (gross tumor volume [GTV] ≤5 cc) and larger tumors (GTV5 cc), with average relative contrast improvement ratios of 3.4 ± 4.1 and 5.4 ± 3.6, respectively. Moreover, the GTV was reliably localized in 95% of the DE images versus 74% of the single energy (SE images, (P=.004). Mean skin dose per DE image set was 0.44 ± 0.03 mGy versus 0.43 ± 0.03 mGy, using conventional kV imaging parameters.Initial results of this feasibility study suggest that DE thoracic imaging may enhance tumor localization in lung cancer patients receiving kV-based IGRT without increasing imaging dose.

Purpose : To document the size and location of the prostate, seminal vesicles, bladder, and rectum throughout the course of external beam radiotherapy. The frequency and range of motion of these organs are quantified. Methods and Materials : Ten patients with localized carcinoma of the prostate had conventional simulation followed immediately by a treatment planning computed tomography scan (TPCT 0 ). Once treatment was initiated, each patient had a weekly CT (TPCT 1-N ) before or after his daily treatment. Anatomical structures from CT were delineated on a computer workstation for analysis. The serial CT sets were spatially registered to the initial scan using image correlation software that brings into congruence the bony pelvis of the different scans. The location of the prostate, seminal vesicles, bladder, and rectum on subsequent scans were compared to TPCT 0 , as well as to each other. Results : Prostate volumes were observed to vary by an average of ±10% during the course of radiation therapy, while the seminal vesicle volumes varied by as much as 100%. Bladder and rectal volumes varied by ±30%. Compared to TPCT 0 , movement of the prostate was demonstrated in all patients. Quantitation of the center-of-mass (CM) showed motion of less than 1 mm in the left-right direction, while motion ranging from 0 to ± 1 cm was observed in the anterior-posterior and superior-inferior directions. The individual standard deviations of these motions varied from approximately 1-5 mm. These variations were correlated to changes in the dimensions of the bladder and rectum. Conclusions : Changes in the location of the prostate, seminal vesicles, and normal tissue volumes during the course of radiation therapy occur and have dosimetric consequences that may impact tumor control and normal tissue complication probabilities. Conformal therapy for prostate cancer will require the incorporation of knowledge of the anatomic relationships of these structures as a function of time. Therefore, these uncertainties must be taken into account when designing treatment plans and in considering dose escalation trials.

152 Background: We are working to electronically integrate our radiation oncology EMR and our hospital EMR to improve communication and facilitate patient care. To guide integration, we surveyed providers and support staff at our academic cancer center to identify the important encounters/documents and how well these are currently communicated. Methods: We sent an email survey to 182 MDs, nurses, and administrative staff at our cancer center. Respondents identified their role in the patient care team, and rated how important several radiation oncology-specific encounters/documents from “not important at all” to “extremely important” and rated the accessibility of these encounters/documents from “not at all accessible” to “exceptionally accessible.” Encounters/documents are listed in the table. Descriptive statistics were then performed to identify opportunities to improve communication. Results: There were 32 responses to our survey from staff outside of our department, including 18 physicians, 2 APN/PAs, 8 nurses, 2 nutritionists, 1 receptionist, and 1 social worker. Of the physicians, there were 8 medical oncologists, 2 neurosurgeons, 5 urologists, 1 breast surgeon, 1 gynecologic oncologist, and 1 reconstructive surgeon. The table describes the number of respondents who felt the encounter/document was “moderately,” “very,” or “extremely important”, and within this group of respondents, what percent thought each item was “very” or “exceptionally accessible.” Conclusions: We prioritized the importance of encounters/documents for integration between EMRs and identified deficiencies in communication. We will use the results of this study to guide our electronic integration of our two EMR systems. We will repeat the survey after integration is complete to identify improvement. [Table: see text]

To implement the "plan-do-check-act" (PDCA) cycle for the continual quality improvement of normal tissue contours used for radiation therapy treatment planning.The CT scans of patients treated for tumors of the brain, head and neck, thorax, pancreas and prostate were selected for this study. For each scan, a radiation oncologist and a diagnostic radiologist, outlined the normal tissues ("gold" contours) using Radiation Therapy Oncology Group (RTOG) guidelines. A total of 30 organs were delineated. Independently, 5 board-certified dosimetrists and 1 trainee then outlined the same organs. Metrics used to compare the agreement between the dosimetrists' contours and the gold contours included the Dice Similarity Coefficient (DSC), and a penalty function using distance to agreement. Based on these scores, dosimetrists were re-trained on those organs in which they did not receive a passing score, and they were subsequently re-tested.Passing scores were achieved on 19 of 30 organs evaluated. These scores were correlated to organ volume. For organ volumes8 cc, the average DSC was 0.61 vs organ volumes ≥8 cc, for which the average DSC was 0.91 (P=.005). Normal tissues that had the lowest scores included the lenses, optic nerves, chiasm, cochlea, and esophagus. Of the 11 organs that were considered for re-testing, 10 showed improvement in the average score, and statistically significant improvement was noted in more than half of these organs after education and re-assessment.The results of this study indicate the feasibility of applying the PDCA cycle to assess competence in the delineation of individual organs, and to identify areas for improvement. With testing, guidance, and re-evaluation, contouring consistency can be obtained across multiple dosimetrists. Our expectation is that continual quality improvement using the PDCA approach will ensure more accurate treatments and dose assessment in radiotherapy treatment planning and delivery.

Purpose To evaluate disease outcomes and toxicity in cervical cancer patients treated with pelvic intensity-modulated radiation therapy (IMRT). Methods and Materials We included all patients with Stage I–IVA cervical carcinoma treated with IMRT at three different institutions from 2000–2007. Patients treated with extended field or conventional techniques were excluded. Intensity-modulated radiation therapy plans were designed to deliver 45 Gy in 1.8-Gy daily fractions to the planning target volume while minimizing dose to the bowel, bladder, and rectum. Toxicity was graded according to the Radiation Therapy Oncology Group system. Overall survival and disease-free survival were estimated by use of the Kaplan-Meier method. Pelvic failure, distant failure, and late toxicity were estimated by use of cumulative incidence functions. Results The study included 111 patients. Of these, 22 were treated with postoperative IMRT, 8 with IMRT followed by intracavitary brachytherapy and adjuvant hysterectomy, and 81 with IMRT followed by planned intracavitary brachytherapy. Of the patients, 63 had Stage I–IIA disease and 48 had Stage IIB–IVA disease. The median follow-up time was 27 months. The 3-year overall survival rate and the disease-free survival rate were 78% (95% confidence interval [CI], 68–88%) and 69% (95% CI, 59–81%), respectively. The 3-year pelvic failure rate and the distant failure rate were 14% (95% CI, 6–22%) and 17% (95% CI, 8–25%), respectively. Estimates of acute and late Grade 3 toxicity or higher were 2% (95% CI, 0–7%) and 7% (95% CI, 2–13%), respectively. Conclusions Intensity-modulated radiation therapy is associated with low toxicity and favorable outcomes, supporting its safety and efficacy for cervical cancer. Prospective clinical trials are needed to evaluate the comparative efficacy of IMRT vs. conventional techniques.

The potential of alpha-particle emitters to treat cancer has been recognized since the early 1900s. Advances in the targeted delivery of radionuclides and radionuclide conjugation chemistry, and the increased availability of alpha-emitters appropriate for clinical use, have recently led to patient trials of radiopharmaceuticals labeled with alpha-particle emitters. Although alpha-emitters have been studied for many decades, their current use in humans for targeted therapy is an important milestone. The objective of this work is to review those aspects of the field that are pertinent to targeted alpha-particle emitter therapy and to provide guidance and recommendations for human alpha-particle emitter dosimetry.

Purpose To test the hypothesis that increased pelvic bone marrow (BM) irradiation is associated with increased hematologic toxicity (HT) in cervical cancer patients undergoing chemoradiotherapy and to develop a normal tissue complication probability (NTCP) model for HT. Methods and Materials We tested associations between hematologic nadirs during chemoradiotherapy and the volume of BM receiving ≥10 and 20 Gy (V 10 and V 20 ) using a previously developed linear regression model. The validation cohort consisted of 44 cervical cancer patients treated with concurrent cisplatin and pelvic radiotherapy. Subsequently, these data were pooled with data from 37 identically treated patients from a previous study, forming a cohort of 81 patients for normal tissue complication probability analysis. Generalized linear modeling was used to test associations between hematologic nadirs and dosimetric parameters, adjusting for body mass index. Receiver operating characteristic curves were used to derive optimal dosimetric planning constraints. Results In the validation cohort, significant negative correlations were observed between white blood cell count nadir and V 10 (regression coefficient (β) = −0.060, p = 0.009) and V 20 (β = −0.044, p = 0.010). In the combined cohort, the (adjusted) β estimates for log (white blood cell) vs. V 10 and V 20 were as follows: −0.022 ( p = 0.025) and −0.021 ( p = 0.002), respectively. Patients with V 10 ≥ 95% were more likely to experience Grade ≥3 leukopenia (68.8% vs. 24.6%, p 20 > 76% (57.7% vs. 21.8%, p = 0.001). Conclusions These findings support the hypothesis that HT increases with increasing pelvic BM volume irradiated. Efforts to maintain V 10 20

The standard treatment technique used for whole-breast irradiation can result in undesirable dose distributions in the treatment site, leading to skin reaction/fibrosis and pulmonary and cardiac toxicities. Hence, the technique has evolved from conventional wedged technique (CWT) to segment intensity-modulated radiation therapy (SIMRT) and beamlet IMRT (IMRT). However, these newer techniques feature more highly modulated dose distributions that may be affected by respiration. The purpose of this work was to conduct a simple study of the clinical impact of respiratory motion on breast radiotherapy dose distributions for the three treatment planning techniques. The ultimate goal was to determine which patients would benefit most from the use of motion management. Eight patients with early-stage breast cancer underwent a free-breathing (FB) computed tomography (CT) simulation, with medial and lateral markers placed on the skin. Two additional CT scans were obtained at the end of inspiration (EI) and the end of expiration (EE). The FB-CT scan was used to develop treatment plans using each technique. Each plan was then applied to EI and EE-CT scans. Compared with the FB CT scan, the medial markers moved up to 1.8 cm in the anterior-superior direction at the end of inspiration (EI-scan), and on average 8 mm. The CWT and SIMRT techniques were not "sensitive" to respiratory motion, because the % clinical target volume (CTV) receiving 95% of the prescription dose (V(95%)) remained constant for both techniques. For patients that had large respiratory motion indicated by marker movement >0.6 cm, differences in coverage of the CTV at the V100% between FB and EI for beamlet IMRT plans were on the order of >10% and up to 18%. A linear model was developed to relate the dosimetric coverage difference introduced by respiration with the motion information. With this model, the dosimetric coverage difference introduced by respiratory motion could be evaluated during patient CT simulation. An appropriate treatment method can be chosen after the simulation.

Purpose: To compare bone marrow-sparing intensity-modulated pelvic radiotherapy (BMS-IMRT) with conventional (four-field box and anteroposterior‐posteroanterior [AP‐PA]) techniques in the treatment of cervical cancer. Methods and Materials: The data from 7 cervical cancer patients treated with concurrent chemotherapy and IMRTwithout BMS were analyzed and compared with data using four-field box and AP‐PA techniques. All plans were normalized to cover the planning target volume with the 99% isodose line. The clinical target volume consisted of the pelvic and presacral lymph nodes, uterus and cervix, upper vagina, and parametrial tissue. Normal tissues included bowel, bladder, and pelvic bone marrow (PBM), which comprised the lumbosacral spine and ilium and the ischium, pubis, and proximal femora (lower pelvis bone marrow). Dose‐volume histograms for the planning target volume and normal tissues were compared for BMS-IMRT vs. four-field box and AP‐PA plans. Results: BMS-IMRT was superior to the four-field box technique in reducing the dose to the PBM, small bowel, rectum, and bladder. Compared with AP‐PA plans, BMS-IMRT reduced the PBM volume receiving a dose >16.4 Gy. BMS-IMRT reduced the volume of ilium, lower pelvis bone marrow, and bowel receiving a dose >27.7, >18.7, and >21.1 Gy, respectively, but increased dose below these thresholds compared with the AP‐PA plans. BMS-IMRT reduced the volume of lumbosacral spine bone marrow, rectum, small bowel, and bladder at all dose levels in all 7 patients. Conclusion: BMS-IMRTreduced irradiation of PBM compared with the four-field box technique. Compared with theAP‐PAtechnique,BMS-IMRTreduced lumbosacral spine bonemarrowirradiationand reduced thevolumeof PBM irradiated to high doses. ThereforeBMS-IMRT might reduce acute hematologic toxicity comparedwith conventional techniques. 2008 Elsevier Inc. Bone marrow, Bone marrow-sparing, Intensity-modulated radiotherapy, IMRT, Cervical cancer.