Multi-centre evaluation of variation in cumulative dose assessment in reirradiation scenarios.

BACKGROUND AND PURPOSE: Safe reirradiation relies on assessment of cumulative doses to organs at risk (OARs) across multiple treatments. Different clinical pathways can result in inconsistent estimates. Here, we quantified the consistency of cumulative dose to OARs across multi-centre clinical pathways. MATERIAL AND METHODS: We provided DICOM planning CT, structures and doses for two reirradiation cases: head & neck (HN) and lung. Participants followed their standard pathway to assess the cumulative physical and EQD2 doses (with provided α/ß values), and submitted DVH metrics and a description of their pathways. Participants could also submit physical dose distributions from Course 1 mapped onto the CT of Course 2 using their best available tools. To assess isolated impact of image registrations, a single observer accumulated each submitted spatially mapped physical dose for every participating centre. RESULTS: Cumulative dose assessment was performed by 24 participants. Pathways included rigid (n = 15), or deformable (n = 5) image registration-based 3D dose summation, visual inspection of isodose line contours (n = 1), or summation of dose metrics extracted from each course (n = 3). Largest variations were observed in near-maximum cumulative doses (25.4 - 41.8 Gy for HN, 2.4 - 33.8 Gy for lung OARs), with lower variations in volume/dose metrics to large organs. A standardised process involving spatial mapping of the first course dose to the second course CT followed by summation improved consistency for most near-maximum dose metrics in both cases. CONCLUSION: Large variations highlight the uncertainty in reporting cumulative doses in reirradiation scenarios, with implications for outcome analysis and understanding of published doses. Using a standardised workflow potentially including spatially mapped doses improves consistency in determination of accumulated dose in reirradiation scenarios.

Clinical outcomes and lung toxicities after lung SABR using dynamic conformal arc therapy: a single-institution cohort study.

BACKGROUND: Stereotactic ablative radiotherapy (SABR) is a validated treatment for early stage lung cancer and pulmonary metastases. It provides a high local control rate with low symptomatic toxicities. Recently, Dynamic Conformal Arc Therapy (DCAT), a delivery option that differs from conventional DCA, has been implemented in the Monaco Treatment Planning System for SABR. The aim of the study was to report clinical outcomes and toxicities for patients treated for lung SABR with this new technique. METHODS: We retrospectively identified adult patients treated for primary or secondary lung tumors with DCAT-SABR and reported their clinical, radiological, histological characteristics and dosimetric parameters. Total dose was delivered in 3 or 5 fractions for 95% of patients and prescribed on the 80% isodose line to the PTV periphery. RESULTS: 145 patients met inclusion criteria for a total of 152 lesions with a median follow up of 12 months. Local control for the irradiated site was 96.7% at 1 year. Overall survival was 93.1% at 1 year. Mean prescription dose in BED10 was 110 Gy. 92% of patients had a prescribed dose superior to 100 Gy BED10. Mean PTV coverage was 95.1%. There were 66 cases of grade 1 radiation pneumonitis (RP) (43%) and only 7 cases of symptomatic grade 2 RP (4.6%). CONCLUSION: Lung SABR for primary or metastatic lung tumors using dynamic conformal arc therapy provides efficient results of local control and low lung toxicities, similar to other SABR techniques. ADVANCES IN KNOWLEDGE: SABR using DCAT is a safe technique to treat lung lesions, allowing intra-fraction motion limitation, potentially higher OARs protection and a shortened beam delivery.

Management of reirradiations: A clinical and technical overview based on a French survey.

INTRODUCTION: The reirradiation number increased due to systemic therapies and patient survival. Few guidelines regarding acceptable cumulative doses to organs at risk (OARs) and appropriate dose accumulation tools need, made reirradiation challenging. The survey objective was to present the French current technical and clinical practices in reirradiations. METHODS: A group of physician and physicists developed a survey gathering major issues of the topic. The questionnaire consisted in 4 parts: data collection, demographic, clinical and technical aspects. It was delivered through the SFRO and the SFPM. Data collection lasted 2 months and were gathered to compute statistical analysis. RESULTS: 48 institutions answered the survey. Difficulties about patient data collection were related to patient safety, administrative and technical limitations. Half of the institutions discussed reirradiation cases during a multidisciplinary meeting. It mainly aimed at discussing the indication and the new treatment total dose (92%). 79% of the respondents used various references but only 6% of them were specific to reirradiations. Patients with pain and clinical deficit were ranked as best inclusion criteria. 54.2% of the institutions considered OARs recovery, especially for spinal cord and brainstem. A commercial software was used for dose accumulation for 52% of respondents. Almost all institutions performed equivalent dose conversion (94%). A quarter of the institutions estimated not to have the appropriate equipment for reirradiation. CONCLUSION: This survey showed the various approaches and tools used in reirradiation management. It highlighted issues in collecting data, and the guidelines necessity for safe practices, to increase clinicians confidence in retreating patients.

Evaluation of a dedicated software for semi-automated VMAT planning of spine Stereotactic Body Radiotherapy (SBRT).

PURPOSE: To determine whether SBRT of spinal metastasis using a dedicated treatment planning system (TPS) and delivered with a gantry-based LINAC could provide plans of similar quality to the Cyberknife technology. Additional comparison was also done with other commercial TPS used for volumetric modulated arc therapy (VMAT) planning. MATERIALS AND METHODS: Thirty Spine SBRT patients, previously treated in our institution with CyberKnife (Accuray, Sunnyvale) using Multiplan TPS, were replanned in VMAT with an dedicated TPS (Elements Spine SRS, Brainlab, Munich) and our clinical TPS (Monaco, Elekta LTD, Stockholm), using exactly the same arc geometry. The comparison was done by assessing differences in dose delivered to PTV, CTV and spinal cord, calculating modulation complexity scores (MCS) and performing quality control (QA) of the plans. RESULTS: Regardless of the vertebra level, in general, no statistical difference was found in PTV coverage between all TPS. Conversely, PTV and CTV D50% were found significantly higher for the dedicated TPS compared to others. In addition, the dedicated TPS also resulted in better gradient index (GI) than clinical VMAT TPS, whatever the vertebral level, and better GI than Cyberknife TPS for the thoracic level only. The D2% to the spinal cord was generally significantly lower with the dedicated TPS compared with others. No significant difference was found in the MCS between both VMAT TPS. All QA were clinically acceptable. CONCLUSION: The Elements Spine SRS TPS offers very effective and user-friendly semi-automated planning tools and is secure and promising for gantry-based LINAC spinal SBRT.

Comparison among four immobilization devices for whole breast irradiation with Helical Tomotherapy.

PURPOSE: To evaluate the repositioning accuracy of 4 immobilization devices (ID) used for whole breast Helical Tomotherapy treatments: arm float with VacFix® (Par Scientific, Denmark), all-in-one® (AIO®) system (Orfit, Belgium), MacroCast thermoplastic mask (Macromedics, The Netherlands) and BlueBag® system with Arm-Shuttle (Elekta, Sweden). MATERIALS AND METHODS: Twenty four women with breast cancer with PTV including the breast/chest wall and lymph nodes were involved in this study (6 women per group). Pretreatment registration results were first collected using automatic bone registration + manual adjustment on the vertebra followed by independent registrations on different ROIs representing each treated area (axillary, mammary chain, clavicular, breast/chest wall). The differences in translations and rotations between reference registration and the above mentionned ROIs were calculated. A total of 120 MVCT images were analyzed. RESULTS: Significant differences were found between IDs (p < 0.0001), ROIs (p = 0.0002) and the session number (p < 0.0001) on the observed shifts, when examining 3D translation vectors. 3D-vectors were significantly lower for the BlueBag® than for the VacFix® or for the AIO® (p < 0.0001), but differences were not significant compared to the mask (p = 0.674). Finally, setup margins were overall smaller for the BlueBag® than for other IDs, with values ranging from 1.53 to 1.91 mm on the mammary chain area, 4.52-6.07 mm on the clavicular area, 2.71-4.62 mm on the axillary area, and 3.39-5.10 mm on the breast. CONCLUSION: We demonstrated in this study that the BlueBag® combined with arm shuttle is a robust solution for breast and nodes immobilization during HT treatments.

Increasing emotional competence improves psychological and physical well-being, social relationships, and employability.

This study builds on earlier work showing that adult emotional competencies (EC) could be improved through a relatively brief training. In a set of 2 controlled experimental studies, the authors investigated whether developing EC could lead to improved emotional functioning; long-term personality changes; and important positive implications for physical, psychological, social, and work adjustment. Results of Study 1 showed that 18 hr of training with e-mail follow-up was sufficient to significantly improve emotion regulation, emotion understanding, and overall EC. These changes led in turn to long-term significant increases in extraversion and agreeableness as well as a decrease in neuroticism. Results of Study 2 showed that the development of EC brought about positive changes in psychological well-being, subjective health, quality of social relationships, and employability. The effect sizes were sufficiently large for the changes to be considered as meaningful in people's lives.