Purpose: To evaluate a new, automated brain metastases planning software designed to treat up to ten brain metastases simultaneously. Methods: We treated 61 patients with multiple brain metastases using the Elements software by BrainLab (Munich, Germany). Patients had between 2–10 metastases ranging from 0.01–8.64 cc. Dose prescription was 18–24 Gy. Plans use up to 5 non-coplanar arcs with a single isocenter at the metastases’ center of mass. The high degree of automation shortens the planning time to 15–20 minutes per patient.For comparison we planned 21 of the patients using Rapid Arc (Varian, Palo Alto CA) (RA). We used two coplanar arcs so as to keep planning times comparable to the Elements. We also planned 8 patients using iPlan software (BrainLab). We compared conformity index (CI), volume of brain receiving over 12 Gy (V12) and mean brain dose (MBD) for the three different planning systems (TPSs). Results: Plans from all TPSs were judged clinically acceptable. V12 and MBD were not statistically significantly different between TPSs.CI between RA and Elements was similar, however for iPlan CI was significantly worse compared to both RA and Elements (p<0.001). RA plans took approximately 40 minutes to plan (despite fusion and contouring being done in the Elements), and iPlan plans over an hour each. Delivery times were approximately 30 minutes for Elements, 10 minutes for RA, and up to 300 minutes for iPlan. Conclusion: Elements plans had good CI values and low brain doses. While treatment times for Elements were longer than for RA, 30 minutes is a significant improvement over conventional radiosurgery techniques where each metastasis is treated individually and delivery times to 10 metastases are close to 300 minutes.BrainLab Elements is a novel software allowing fast, automated planning and efficient irradiation of multiple brain metastases with minimal dose to healthy brain.

We compared 3D standard tangential plans before and after contouring LAD in terms of target coverage and doses to organs at risk (OARs). Thirty patients with left-sided breast cancer were treated using deep inspiration breath hold technique with simultaneous integrated boost delivered with conformal (non IMRT) fields. Breast and tumor bed (TB) PTVs, lungs, and heart were contoured. We subsequently contoured the LAD and when necessary plans were revised to decrease the dose to the LAD while maintaining PTV coverage to deliver simultaneously 50 Gy (2 Gy/fx) to breast PTV and 60 Gy (2.4 Gy/fx) to TB PTV. Plans were normalized for 95% dose to cover 95% breast PTV, with maximum dose below 107%. OAR doses were based on QUANTEC: mean lung dose (MLD) < 20 Gy, V20 < 30%, V5 < 70%; Heart: V25 < 10%, D2% (a measure of maximal heart dose) ALARA; LAD dose: ALARA. The Mann-Whitney Rank-Sum test was used to determine statistical significance between treated and revised plans. Contouring the LAD required revision of 14 plans (47%). Two physicians contoured the PTVs and OARs prior to contouring LAD. Physician A contoured the heart according to RTOG atlas guidelines, thus the LAD was usually included in the heart contour, while physician B contoured the heart minimally, so the LAD was outside the contoured heart. Twenty-five percent of physician A plans and 90% of physician B plans had to be revised. The difference can be explained by how the heart was contoured. Breast and TB coverage were similar for treated and revised plans: PTV breast: mean dose 51.63±0.78 and 51.56±0.65 (Gy), TB mean dose 58.69±0.46 and 58.89±0.406 (Gy) for treated and revised plans, respectively. Lung metrics were also similar: MLD (Gy) 3.086±0.9 vs 3.014±0.94, V20(%) 4.39±1.89 vs 4.13±0.81, and V5(%) 12±3.53 vs 12.75±4.03 for treated vs revised plans, respectively. LAD mean dose was significantly different (p < 0.01) between treated and revised plans: 6.67±3.44 vs 3.96±1.11 (Gy) respectively. For heart, mean dose and D2% were significantly different between treated and revised plans: 1.44±0.34 vs 1.22±0.25 (p < 0.05) and 4.54±1.38 vs 3.55±0.59 (p < 0.02) between the treated revised plans respectively. Overall LAD doses were lower than those reported in published studies using IMRT. Thus, we recommend 3D plans over advanced techniques in the case of left breast treatments. When RTOG heart contouring guidelines are not followed, 90% of plans required revision in order to decrease LAD dose (this was statistically significant). When following RTOG guidelines 25% of plans required revision, with no significant difference in LAD or heart dose. Thus, if RTOG guidelines are followed, it is not necessary to contour the LAD separately.

Radiotherapy (RT) is a key component of the management of older cancer patients. Level I evidence in older patients is limited. The International Society of Geriatric Oncology (SIOG) established a task force to make recommendations for curative RT in older patients and to identify future research priorities. Evidence-based guidelines are provided for breast, lung, endometrial, prostate, rectal, pancreatic, oesophageal, head and neck, central nervous system malignancies and lymphomas. Patient selection should include comorbidity and geriatric evaluation. Advances in radiation planning and delivery improve target coverage, reduce toxicity and widen eligibility for treatment. Shorter courses of hypofractionated whole breast RT are safe and effective. Conformal RT and involved-field techniques without elective nodal irradiation have improved outcomes in non-small-cell lung cancer (NSCLC) without increasing toxicity. Where comorbidities preclude surgery, stereotactic body radiotherapy (SBRT) is an option for early-stage NSCLC and pancreatic cancer. Modern involved-field RT for lymphoma based on pre-treatment positron emission tomography data has reduced toxicity. Significant comorbidity is a relative contraindication to aggressive treatment in low-risk prostate cancer (PC). For intermediate-risk disease, 4-6 months of hormones are combined with external beam radiotherapy (EBRT). For high-risk PC, combined modality therapy (CMT) is advised. For high-intermediate risk, endometrial cancer vaginal brachytherapy is recommended. Short-course EBRT is an alternative to CMT in older patients with rectal cancer without significant comorbidities. Endorectal RT may be an option for early disease. For primary brain tumours, shorter courses of postoperative RT following maximal debulking provide equivalent survival to longer schedules. MGMT methylation status may help select older patients for temozolomide alone. Stereotactic RT provides an alternative to whole-brain RT in patients with limited brain metastases. Intensity-modulated radiation therapy provides an excellent technique to reduce dose to the carotids in head and neck cancer and improves locoregional control in oesophageal cancer. Best practice and research priorities are summarised.

Purpose: To evaluate dosimetric differences between standard tangential and volumetric modulated arc (VMAT) plans for synchronous bilateral breast patients treated with simultaneous integrated boost (SIB). Methods: For 10 bilateral breast patients we created separate left and right tangential plans and a single VMAT plan encompassing both breasts and tumor beds as target volumes. Patients were prescribed to 50 and 60 Gy in 2 and 2.4 Gy daily fractions to breasts and tumor beds respectively. For 3D plans each breast was planned independently. A sum of the independent plans was generated to ensure no dose overlaps, and for comparison with the VMAT plan. VMAT plans were normalized to 95% dose covering 95% breast volume. Optimization objectives for lungs, heart, and spine were based on QUANTEC data. Conformity index (CI) was calculated for all plans. Data were analyzed using the Mann‐Whitney Rank‐Sum test. Results: Tumor bed and breast coverage was similar for 3D and VMAT plans. However, CI for VMAT was significantly better (p<0.001) for both breast and tumor bed. All organ at risk (OAR) metrics (Mean Lung Dose, V20, V5, maximal heart and spine doses) were significantly better (p<0.001) in the 3D plans. Conclusion: Conformity in VMAT plans was superior to 3D plans, indicating that in 3D plans larger volumes of non‐target tissue received high doses. In addition, VMAT treatment setup is much simpler than for 3D plans, where treatment is delivered sequentially to each breast, necessitating separate setups for each side. Thus, VMAT treatment is faster, and much easier for patients. However, 3D plans are overwhelmingly superior to VMAT in terms of doses to OARs. Thus, possibly because the breast is a peripheral organ, it appears to be a unique site, where OARs are better spared by a ‘simple’ tangential plan rather than a more sophisticated VMAT technique.

PURPOSE To evaluate dosimetric differences between standard tangential and volumetric modulated arc (VMAT) plans for synchronous bilateral breast patients treated with simultaneous integrated boost (SIB). METHODS For 10 bilateral breast patients we created separate left and right tangential plans and a single VMAT plan encompassing both breasts and tumor beds as target volumes. Patients were prescribed to 50 and 60 Gy in 2 and 2.4 Gy daily fractions to breasts and tumor beds respectively. For 3D plans each breast was planned independently. A sum of the independent plans was generated to ensure no dose overlaps, and for comparison with the VMAT plan. VMAT plans were normalized to 95% dose covering 95% breast volume. Optimization objectives for lungs, heart, and spine were based on QUANTEC data. Conformity index (CI) was calculated for all plans. Data were analyzed using the Mann-Whitney Rank-Sum test. RESULTS Tumor bed and breast coverage was similar for 3D and VMAT plans. However, CI for VMAT was significantly better (p<0.001) for both breast and tumor bed. All organ at risk (OAR) metrics (Mean Lung Dose, V20, V5, maximal heart and spine doses) were significantly better (p<0.001) in the 3D plans. CONCLUSION Conformity in VMAT plans was superior to 3D plans, indicating that in 3D plans larger volumes of non-target tissue received high doses. In addition, VMAT treatment setup is much simpler than for 3D plans, where treatment is delivered sequentially to each breast, necessitating separate setups for each side. Thus, VMAT treatment is faster, and much easier for patients. However, 3D plans are overwhelmingly superior to VMAT in terms of doses to OARs. Thus, possibly because the breast is a peripheral organ, it appears to be a unique site, where OARs are better spared by a 'simple' tangential plan rather than a more sophisticated VMAT technique.

Purpose/Objective(s)Magnetic Resonance guided Focused Ultrasound (MRgFUS) is a non-invasive, non-ionizing treatment producing thermal ablation using high intensity focused ultrasound and MR thermometry to denervate pain from bone metastases. We performed a retrospective analysis of factors contributing to successful treatment on a phase III study.Materials/MethodsOne hundred twenty-two patients underwent MRgFUS in 17 medical centers worldwide as part of a randomized phase III study comparing MRgFUS to sham treatment for a painful bone metastasis previously irradiated or unsuitable for radiation therapy (RT). Patients were followed for 3 months. Response was defined as a combination of a standard numerical rating scale and monitoring changes in analgesic medication at 3 months follow-up. A patient exhibiting a reduction of 2 points or more without a significant increase in pain medications (<25% difference from baseline) was considered a responder. A patient who failed either or both criteria was categorized as a non-responder. Univariate and multivariate analyses were performed to identify clinical and technical factors predictive of response. Linear regression was performed to evaluate factors associated with a change in pain score at 3 month follow-up.ResultsOne hundred twenty-five procedures were performed, targeting 125 lesions in 122 patients. Three patients were treated to a second lesion. Eighty-seven treatments produced responses and 38 did not. Univariate analysis showed 5 factors related to response rate: sex (p < 0.001), history of prior RT (p = 0.001), primary tumor site (p = 0.009), treated tumor location (p = 0.021), and treatment energy (p < 0.001), with a trend toward an association with osteoblastic tumor type (OTT) (p = 0.12). Metastases from breast cancer (n = 46) showed the best response rate (87%). Multivariate logistic regression showed a higher likelihood of response associated with female sex (OR = 4.55, 95% CI, 1.63-12.68) and OTT (OR = 4, 95% CI, 1.13-14.2). Prior RT was associated with a decreased chance of response (OR = 0.33, 95% CI, 0.12-0.91). An increase in energy density (ED) of 1 J/mm2 trended toward an increased chance of a response (OR = 1.25, 95% CI, 0.99-1.57); when over 3.49 J/mm2 was delivered, the chance of response increased (OR = 3.65, 95% CI, 1.31-10.19). Linear regression of the delta pain score including all factors showed higher ED (p = 0.004), female sex (p = 0.043) and OTT (p = 0.001) were associated improved pain relief.ConclusionsIn this retrospective analysis of a prospective study, female sex and OTT were associated with an increased rate of response, while prior RT decreased the response rate. ED over 3.49 J/mm2 was associated with an increased response rate. These findings may have bearing on patient selection and treatment decisions for MRgFUS. Purpose/Objective(s)Magnetic Resonance guided Focused Ultrasound (MRgFUS) is a non-invasive, non-ionizing treatment producing thermal ablation using high intensity focused ultrasound and MR thermometry to denervate pain from bone metastases. We performed a retrospective analysis of factors contributing to successful treatment on a phase III study. Magnetic Resonance guided Focused Ultrasound (MRgFUS) is a non-invasive, non-ionizing treatment producing thermal ablation using high intensity focused ultrasound and MR thermometry to denervate pain from bone metastases. We performed a retrospective analysis of factors contributing to successful treatment on a phase III study. Materials/MethodsOne hundred twenty-two patients underwent MRgFUS in 17 medical centers worldwide as part of a randomized phase III study comparing MRgFUS to sham treatment for a painful bone metastasis previously irradiated or unsuitable for radiation therapy (RT). Patients were followed for 3 months. Response was defined as a combination of a standard numerical rating scale and monitoring changes in analgesic medication at 3 months follow-up. A patient exhibiting a reduction of 2 points or more without a significant increase in pain medications (<25% difference from baseline) was considered a responder. A patient who failed either or both criteria was categorized as a non-responder. Univariate and multivariate analyses were performed to identify clinical and technical factors predictive of response. Linear regression was performed to evaluate factors associated with a change in pain score at 3 month follow-up. One hundred twenty-two patients underwent MRgFUS in 17 medical centers worldwide as part of a randomized phase III study comparing MRgFUS to sham treatment for a painful bone metastasis previously irradiated or unsuitable for radiation therapy (RT). Patients were followed for 3 months. Response was defined as a combination of a standard numerical rating scale and monitoring changes in analgesic medication at 3 months follow-up. A patient exhibiting a reduction of 2 points or more without a significant increase in pain medications (<25% difference from baseline) was considered a responder. A patient who failed either or both criteria was categorized as a non-responder. Univariate and multivariate analyses were performed to identify clinical and technical factors predictive of response. Linear regression was performed to evaluate factors associated with a change in pain score at 3 month follow-up. ResultsOne hundred twenty-five procedures were performed, targeting 125 lesions in 122 patients. Three patients were treated to a second lesion. Eighty-seven treatments produced responses and 38 did not. Univariate analysis showed 5 factors related to response rate: sex (p < 0.001), history of prior RT (p = 0.001), primary tumor site (p = 0.009), treated tumor location (p = 0.021), and treatment energy (p < 0.001), with a trend toward an association with osteoblastic tumor type (OTT) (p = 0.12). Metastases from breast cancer (n = 46) showed the best response rate (87%). Multivariate logistic regression showed a higher likelihood of response associated with female sex (OR = 4.55, 95% CI, 1.63-12.68) and OTT (OR = 4, 95% CI, 1.13-14.2). Prior RT was associated with a decreased chance of response (OR = 0.33, 95% CI, 0.12-0.91). An increase in energy density (ED) of 1 J/mm2 trended toward an increased chance of a response (OR = 1.25, 95% CI, 0.99-1.57); when over 3.49 J/mm2 was delivered, the chance of response increased (OR = 3.65, 95% CI, 1.31-10.19). Linear regression of the delta pain score including all factors showed higher ED (p = 0.004), female sex (p = 0.043) and OTT (p = 0.001) were associated improved pain relief. One hundred twenty-five procedures were performed, targeting 125 lesions in 122 patients. Three patients were treated to a second lesion. Eighty-seven treatments produced responses and 38 did not. Univariate analysis showed 5 factors related to response rate: sex (p < 0.001), history of prior RT (p = 0.001), primary tumor site (p = 0.009), treated tumor location (p = 0.021), and treatment energy (p < 0.001), with a trend toward an association with osteoblastic tumor type (OTT) (p = 0.12). Metastases from breast cancer (n = 46) showed the best response rate (87%). Multivariate logistic regression showed a higher likelihood of response associated with female sex (OR = 4.55, 95% CI, 1.63-12.68) and OTT (OR = 4, 95% CI, 1.13-14.2). Prior RT was associated with a decreased chance of response (OR = 0.33, 95% CI, 0.12-0.91). An increase in energy density (ED) of 1 J/mm2 trended toward an increased chance of a response (OR = 1.25, 95% CI, 0.99-1.57); when over 3.49 J/mm2 was delivered, the chance of response increased (OR = 3.65, 95% CI, 1.31-10.19). Linear regression of the delta pain score including all factors showed higher ED (p = 0.004), female sex (p = 0.043) and OTT (p = 0.001) were associated improved pain relief. ConclusionsIn this retrospective analysis of a prospective study, female sex and OTT were associated with an increased rate of response, while prior RT decreased the response rate. ED over 3.49 J/mm2 was associated with an increased response rate. These findings may have bearing on patient selection and treatment decisions for MRgFUS. In this retrospective analysis of a prospective study, female sex and OTT were associated with an increased rate of response, while prior RT decreased the response rate. ED over 3.49 J/mm2 was associated with an increased response rate. These findings may have bearing on patient selection and treatment decisions for MRgFUS.

Osseous metastases are a daunting problem in oncology. Radiation therapy (RT) is the primary treatment for most patients with painful bone metastases; however, about one-third do not get pain relief and others may have pain recurrence or not be candidates for RT. Magnetic resonance guided focused ultrasound surgery (MRgFUS) combines non-invasive focused ultrasound with MR guidance. Phase I-II studies demonstrated that MRgFUS resulted in high rates of pain relief with an excellent safety profile. A multi-center phase III trial, the first to assess a role for MRgFUS in oncology, was done to definitively assess efficacy of MRgFUS for treatment of painful bone metastases in patients for whom RT was not considered an appropriate option. Patients with a painful bone metastasis amenable to MRgFUS treatment and NRS pain score ≥4 for whom RT was not considered appropriate (e.g., prior RT to painful site) were randomized 3:1 to MRgFUS or sham treatment. Study subjects were followed for 3 months. Sham subjects who were non-responders after 2 weeks were allowed to opt for crossover MRgFUS treatment. Significant pain response was defined as decrease in worst pain NRS score ≥2 from baseline without increase in pain medication. Quality of life (QOL) measured by BPI-QOL, self-assessed overall treatment effect (OTE) measured items, and self-assessed EQ-5D for function and well-being subscales, as well as safety were also evaluated. One hundred thirty-four subjects were included in an intent-to-treat analysis. Blinding of sham subjects was excellent. Ninety-four percent of MRgFUS and 88% of sham subjects indicated belief they had received MRgFUS treatment. MRgFUS resulted in significant pain reduction. Sixty-seven percent (95% CI 57-76%) of 100 subjects in the MRgFUS arm had significant pain relief at 3 months compared to 21% of 34 sham subjects (p < 0.0001) Median baseline and 3 month NRS scores in the MRgFUS and sham arms were 7.0 and 2.0 versus 7.0 and 6.5 respectively. Clinically and statistically significant durable improvement in average BPI-QOL score: 2.4 at 3 months (p < 0.0001), patient assessed wellbeing, and function with MRgFUS but not sham treatment were noted. MRgFUS was well tolerated with transient treatment related pain the most commonly reported toxicity. MRgFUS results in excellent rates of durable pain relief, improvement in QOL, and subject-assessed wellbeing and function for patients with metastatic bone pain who are not candidates for RT. Given these excellent results coupled with a favorable side effect profile, MRgFUS should be considered a primary choice for eligible patients when RT is contraindicated in treatment of painful bone metastases.

Bronchioloalveolar carcinoma (BAC) is a distinct form of lung cancer characterized by non-invasive 'lepidic' spreading, high response rates to tyrosine-kinase inhibitors and a comparatively good prognosis. The role of RT in the treatment of BAC has not been defined. We hypothesized that RT improves the outcome of patients with non-resected non-metastatic BAC. We tested this hypothesis by performing a population-based investigation within the Surveillance, Epidemiology, and End Results (SEER) registry, which currently covers 26% of the U.S. population. Subjects diagnosed with BAC between 2001 and 2007 were included in the analysis. We excluded subjects diagnosed at the time of autopsy. Age was analyzed as a categorical variable. Information regarding systemic treatments and second-line therapies was not available through the SEER database. Survival was analyzed using the Kaplan-Meier, and log-rank techniques. The Cox proportional hazard model was used for multivariate survival analysis. Statistical analysis was performed using Stata/IC 11.1 (StataCorp). A total of 10018 subjects with BAC were included in the analysis. The median age at diagnosis was 71 years (range 10 - 104). There were 5198, 332, 1481, and 1918 Stage I, II ,III and IV cancers respectively (58%, 4%, 17%, 21%). Surgical treatment was highly variable, with 3091 (31%) undergoing no resection and 5174 (52%) undergoing at least a lobectomy. Overall only 1119 patients (11.4%) received RT, rising to 31.0% in the subset of patients with non-resected non-Stage IV disease. Median survival was 30, 22, 18 and 8 months for Stage I, II, III and IV disease respectively. Factors associated with improved survival on both univariate and multivariate analysis included younger age, female sex, later year of diagnosis, more radical resection, lower grade and stage. Although RT was not beneficial for the overall population, there was a distinct survival advantage in those with non-resected, non-metastatic disease: Stage I 14m vs 19.5m (n = 181, p = 0.06), Stage II 12m vs 15m (n = 16, NS), Stage III 9m vs 14m (n = 405, p<0.003). RT appears to improve prognosis in unresected BAC Stage I-III. Less than a third of patients who could have benefited from this treatment received it. If confirmed, our findings define a new standard of care for unresected BAC.

Purpose: The submillimeter accuracy of a novel gantry‐mounted radioactive fiducial tracking system has been reported previously in a number of semi‐clinical scenarios. These have included tissue equivalent phantoms without bones, and antomical phantoms including bones, but with measurements being made from a single gantry angle that does not include potential interference from the bones and the patient couch and potential tracking system alignment inaccuracy due to gantry and collimator rotation. In this study the gantry‐mounted tracking system is tested in a more realistic clinical scenario. This study used an anatomical phantom with bones placed at multiple positions about the isocenter and made localization measurements with the gantry and collimator at various angles. Method and Materials: The tracking device was installed on a Varian Trilogy® linac gantry. The radioactive marker was located at the approximate position of the prostate in an anatomical tissue equivalent phantom on the patient couch. Actual marker location was measured using a Microscribe MLX coordinate measuring machine (CMM) arm (certified spatial accuracy of 0.08 mm). The marker was attached to the tip of the CMM arm, which was inserted into a hole in the phantom, and its location was measured simultaneously by the CMM and the tracking system. 102 localization accuracy measurements were made at locations covering a 10cm diameter sphere centered at the linac iso‐center with varying gantry and collimator angles including those that would potentially induce interference due to bones and the patient couch. Results: The mean localization error for all measured positions and gantry and collimator angles was less than 1mm. Conclusion: The gantry‐mounted radioactive tracking system maintains sufficient accuracy for radiation therapy patient localization and monitoring in a real clinical environment even in the presence of bones and patient couch interference. Conflict of Interest: Research sponsored by Navotek Medical Ltd.

Purpose: To examine the robustness of a gantry mounted radioactive tracking system in 6MV and 10MV clinical radiation therapy environments. Method and Materials: The gantry‐mounted tracking system was installed in several radiation therapy treatment rooms. Total dose equivalent to 20 treatment sessions was delivered at 6MV or 10MV in a few fractions (within 1 hour) to a phantom containing a radioactive marker (Ir192). During irradiation the tracking system was operating and system parameters were recorded before, during and immediately after irradiation. Recorded data was analyzed to assess system performance and the accumulated effects of radiation on the system. The radioactive marker location measured by the tracking system was monitored during and after irradiation to test for accuracy and stability. The spectra of the signals from the radioactive marker before and after irradiation were compared to see if any shift in spectrum is observed. After 10MV irradiation, background signal level was monitored to analyze the halflives of the isotopes resulting from neutron activation. Results: There was no significant change in signal spectrum after irradiation and no cumulative influence on system performance was observed. Tracking is temporarily interrupted during 10MV irradiation and is resumed within a few seconds after irradiation despite the increased background noise resulting from neutron activation which decays with a half life of approximately 105 seconds. At 6MV, the system maintains tracking accuracy and performance throughout irradiation despite an increased background noise level. The system adjusts to the changes in background noise level at the beginning and end of irradiation in under 3 seconds. Conclusion: The radioactive tracking system is robust in the radiation environment. There is no observable effect or malfunction after exposure to radiation. The system is capable of tracking a radioactive marker during irradiation at 6MV. Conflict of Interest: Research sponsored by Navotek Medical Ltd.

The accuracy of a novel gantry-mounted radioactive tracking system for patient positioning and monitoring in external beam radiation therapy of the prostate in phantoms has previously been reported where it was compared to Elekta Synergy cone beam CT. As this is a gantry-mounted system, accuracy may be dependent on the linac on which it is mounted. The purpose of this study is to evaluate the localization accuracy of this radioactive tracking system mounted on a Varian Trilogy linac. A 100 uCi Ba133 radioactive marker was located inside a tissue equivalent pelvic phantom in the approximate location of the prostate. The phantom was scanned in a wide bore treatment planning CT. The radioactive fiducial was identified in the CT image and its position relative to the target isocenter was recorded. The tracking system was installed on a Varian Trilogy linac and the tracker coordinate system was aligned with the treatment room fixed coordinate system by measuring known locations in an alignment phantom in both coordinate systems. The pelvic phantom containing the radioactive fiducial was placed on the treatment couch and positioned approximately at isocenter using lasers. The required positioning correction was then measured using the radioactive tracking system and using the cone beam CT imaging and the corrections recommended by the two systems were compared. The overall mean error between the 3-dimensional corrections recommended by the tracking system and by the cone beam CT was smaller than 1.5mm. This error includes the tracking system error, fiducial identification in CT planning error, cone beam CT 3D matching errors, and the Varian position correction round-off error. The radioactive tracking system is accurate and objective and is appropriate for patient positioning in the Varian Trilogy environment.

Objective Examination of the rate of grade III or grade IV radiation dermatitis during treatment of head and neck cancer (HNC) with radiotherapy (RT) and concurrent cetuximab in EORTC centres. Materials and method A questionnaire was sent to all members of the EORTC Radiation Oncology Group and Head and Neck Group (111 institutions) to evaluate the widespread use of cetuximab and radiotherapy in HNC and to estimate the frequency of grades III and IV skin reactions in the radiation portals associated with this protocol. Co-morbidities, RT schedules and co-medications were also recorded. Results We received responses from 28 institutions in 11 countries. A total of 125 HNC patients from 15 institutions were treated with cetuximab and concurrent RT. Information about the skin reactions was available from 71 patients. Of these 36 had no grade III/IV adverse effects in the RT field, 15 had a grade III and 20 had grade IV radiation dermatitis. No detectable relation of grades III and IV radiation dermatitis with co-morbidities such as liver insufficiency or renal dysfunction was found. Conclusion According to the results of the questionnaire, grade III/IV radiation dermatitis is observed in 49% of HNC patients treated with cetuximab and concurrent RT. A systematic clinical monitoring of cutaneous side effects during RT plus cetuximab is advised to ensure the safety of this protocol.

Purpose/Objective(s)There is mounting evidence that for prostate cancer patients treated with EBRT, dose escalation to prostate increases local control. Also, restricting the dose to normal tissue reduces toxicity. To achieve these goals, precise targeting and treatment delivery are necessary; hence, the need for real-time tracking and adjusting to organ motion. Tracking systems traditionally use fiducial markers implanted inside the target as surrogates for target location. A novel radioactive marker (Platinum/Iridium) is being developed for radiographic and/or radioactive real-time target localization. Our purpose in this study is to investigate the accuracy and consistency with which experienced treatment planning physicists can identify and localize these markers in a series of CT images.Materials/MethodsThis multi-center study used 3 CT datasets of the new markers. The first dataset consisted of 3 markers in a plastic jar filled with chicken livers. The slice thickness of the phantom images was 2 mm. The second and third datasets were CT images of 3 markers implanted in the prostate of a dog with 3 mm and 0.8 mm slice thicknesses, respectively. The datasets were imported into a TPS (Pinnacle, Philips Medical Systems). Five planners from each of 3 institutions identified the markers on each dataset and recorded their coordinates. Each planner repeated the coordinate's extraction process 3 times. No specific instructions were given to the physicists on how to identify the markers.ResultsThe coordinates of each marker were recorded for each dataset. The results from all physicists, for all attempts, from all institutions, were combined. The mean coordinates and standard deviations were computed and analyzed. The planners, working independently, were all able to pinpoint the position of the markers in 3D with inter-observer variability of less than 0.9mm for the 1st dataset, 1.3 mm for the 2nd dataset, and 0.4mm for the last dataset. The variability decreases with CT slice thickness.ConclusionsThis study shows that these novel fiducial markers can be easily identified on CT images. Results show consistency in localizing the markers amongst different planners at different centers. Purpose/Objective(s)There is mounting evidence that for prostate cancer patients treated with EBRT, dose escalation to prostate increases local control. Also, restricting the dose to normal tissue reduces toxicity. To achieve these goals, precise targeting and treatment delivery are necessary; hence, the need for real-time tracking and adjusting to organ motion. Tracking systems traditionally use fiducial markers implanted inside the target as surrogates for target location. A novel radioactive marker (Platinum/Iridium) is being developed for radiographic and/or radioactive real-time target localization. Our purpose in this study is to investigate the accuracy and consistency with which experienced treatment planning physicists can identify and localize these markers in a series of CT images. There is mounting evidence that for prostate cancer patients treated with EBRT, dose escalation to prostate increases local control. Also, restricting the dose to normal tissue reduces toxicity. To achieve these goals, precise targeting and treatment delivery are necessary; hence, the need for real-time tracking and adjusting to organ motion. Tracking systems traditionally use fiducial markers implanted inside the target as surrogates for target location. A novel radioactive marker (Platinum/Iridium) is being developed for radiographic and/or radioactive real-time target localization. Our purpose in this study is to investigate the accuracy and consistency with which experienced treatment planning physicists can identify and localize these markers in a series of CT images. Materials/MethodsThis multi-center study used 3 CT datasets of the new markers. The first dataset consisted of 3 markers in a plastic jar filled with chicken livers. The slice thickness of the phantom images was 2 mm. The second and third datasets were CT images of 3 markers implanted in the prostate of a dog with 3 mm and 0.8 mm slice thicknesses, respectively. The datasets were imported into a TPS (Pinnacle, Philips Medical Systems). Five planners from each of 3 institutions identified the markers on each dataset and recorded their coordinates. Each planner repeated the coordinate's extraction process 3 times. No specific instructions were given to the physicists on how to identify the markers. This multi-center study used 3 CT datasets of the new markers. The first dataset consisted of 3 markers in a plastic jar filled with chicken livers. The slice thickness of the phantom images was 2 mm. The second and third datasets were CT images of 3 markers implanted in the prostate of a dog with 3 mm and 0.8 mm slice thicknesses, respectively. The datasets were imported into a TPS (Pinnacle, Philips Medical Systems). Five planners from each of 3 institutions identified the markers on each dataset and recorded their coordinates. Each planner repeated the coordinate's extraction process 3 times. No specific instructions were given to the physicists on how to identify the markers. ResultsThe coordinates of each marker were recorded for each dataset. The results from all physicists, for all attempts, from all institutions, were combined. The mean coordinates and standard deviations were computed and analyzed. The planners, working independently, were all able to pinpoint the position of the markers in 3D with inter-observer variability of less than 0.9mm for the 1st dataset, 1.3 mm for the 2nd dataset, and 0.4mm for the last dataset. The variability decreases with CT slice thickness. The coordinates of each marker were recorded for each dataset. The results from all physicists, for all attempts, from all institutions, were combined. The mean coordinates and standard deviations were computed and analyzed. The planners, working independently, were all able to pinpoint the position of the markers in 3D with inter-observer variability of less than 0.9mm for the 1st dataset, 1.3 mm for the 2nd dataset, and 0.4mm for the last dataset. The variability decreases with CT slice thickness. ConclusionsThis study shows that these novel fiducial markers can be easily identified on CT images. Results show consistency in localizing the markers amongst different planners at different centers. This study shows that these novel fiducial markers can be easily identified on CT images. Results show consistency in localizing the markers amongst different planners at different centers.