Interobserver agreement on definition of the target volume in stereotactic radiotherapy for pancreatic adenocarcinoma using different imaging modalities.

PURPOSE: The aim of this study was to evaluate interobserver agreement (IOA) on target volume definition for pancreatic cancer (PACA) within the Radiosurgery and Stereotactic Radiotherapy Working Group of the German Society of Radiation Oncology (DEGRO) and to identify the influence of imaging modalities on the definition of the target volumes. METHODS: Two cases of locally advanced PACA and one local recurrence were selected from a large SBRT database. Delineation was based on either a planning 4D CT with or without (w/wo) IV contrast, w/wo PET/CT, and w/wo diagnostic MRI. Novel compared to other studies, a combination of four metrics was used to integrate several aspects of target volume segmentation: the Dice coefficient (DSC), the Hausdorff distance (HD), the probabilistic distance (PBD), and the volumetric similarity (VS). RESULTS: For all three GTVs, the median DSC was 0.75 (range 0.17-0.95), the median HD 15 (range 3.22-67.11) mm, the median PBD 0.33 (range 0.06-4.86), and the median VS was 0.88 (range 0.31-1). For ITVs and PTVs the results were similar. When comparing the imaging modalities for delineation, the best agreement for the GTV was achieved using PET/CT, and for the ITV and PTV using 4D PET/CT, in treatment position with abdominal compression. CONCLUSION: Overall, there was good GTV agreement (DSC). Combined metrics appeared to allow a more valid detection of interobserver variation. For SBRT, either 4D PET/CT or 3D PET/CT in treatment position with abdominal compression leads to better agreement and should be considered as a very useful imaging modality for the definition of treatment volumes in pancreatic SBRT. Contouring does not appear to be the weakest link in the treatment planning chain of SBRT for PACA.

SBRT for centrally localized NSCLC - What is too central?

PURPOSE: Current guidelines recommend stereotactic body radiotherapy (SBRT) for stage I non-small-cell lung cancer (NSCLC) in medically inoperable patients. There are excellent outcome and toxicity data for SBRT of peripheral lung tumors. However, the discussion on SBRT for centrally located tumors is controversial. This study evaluated current clinical practice regarding SBRT of centrally located lung tumors, to identify common fractionation schedules and commonly accepted contraindications for SBRT. METHODS: A questionnaire consisting of two parts was introduced at the annual meeting of the DEGRO working group on stereotactic radiotherapy, representing centers in Germany and Switzerland. The first part of the questionnaire covered general information about the centers, whereas the second part specifically addressed SBRT of centrally located lung tumors, using case examples of nine primary NSCLC patients. Reconstructions of a contrast enhanced CT, as well as PET-Imaging for each case were demonstrated to the participants. RESULTS: Twenty-six centers participated in the meeting. The majority was academic (73%), participated in interdisciplinary thoracic oncology tumorboards (88%) and offered SBRT for lung tumors (96%). Two centers questioned the indication of SBRT for central lung tumors because of lack of evidence. The majority of centers had experience in SBRT for central lung tumors (88%) and half of the centers reported more than ten cases treated during a median period of five years. Most fractionation schedules used PTV encompassing doses of 48-60 Gy in eight fractions with maximum doses of 125-150%. A clear indication for SBRT treatment was seen by more than 85% of centers in three of the nine patients in whom tumors were small and not closer than 2 cm to the main bronchus. Prior pneumonectomy or immediate adjacency to hilar/mediastinal structures were not considered as contraindications for SBRT. In cases where the tumor exceeded 4 cm in diameter or was located closer than 4 cm to the carina 50-80% of centers saw an indication for SBRT. One case, with a 7 cm tumor reaching to the carina would have been treated with SBRT only by one center. CONCLUSION: Within DEGRO working group on stereotactic radiotherapy, SBRT for small (<4 cm) early stage NSCLC is a common indication, if the minimal distance to the main bronchi is at least 2 cm. The controversy on the treatment of larger and more central tumors will hopefully be solved by ongoing prospective clinical trials.

[Pain staging, gender, and rehabilitation outcome in chronic low back pain. A pilot study]. / Schmerzchronifizierung, Geschlecht und Rehabilitationserfolg bei chronischem Rückenschmerz. Eine Pilotstudie.

BACKGROUND: Current biopsychosocial models of the etiology and chronicity of back pain postulate a major impact of psychological factors in the process of back pain chronicity. PARTICIPANTS AND METHODS: Effects of gender and pain staging on rehabilitation outcome were examined immediately after and 3 and 6 months after rehabilitation in 121 patients with chronic low back pain (43 women, 78 men; M=48 years; ICD-10 diagnoses M54.4/M54.5). Pain was staged using the Mainz Pain Staging System. RESULTS: In the short and mid term, patients in stage I and women benefited from rehabilitation. Rehabilitation outcomes tended not to be improved for men in stage III. CONCLUSIONS: Results support the notion that rehabilitation outcome is significantly influenced by pain staging and gender. Thus, clinical-psychological and gender-specific interventions should be incorporated in future therapeutic regimens to increase the rehabilitation outcomes in patients with higher chronicity of back pain.

[Influence of depressive symptoms and gender in chronic low back pain rehabilitation outcome: a pilot study]. / Der Einfluss von Depressivität und Geschlecht auf den Rehabilitationserfolg bei chronischem Rückenschmerz: Eine Pilotstudie.

Currently, little is known about the influence of depressive symptoms and gender-specific aspects in rehabilitation outcome of patients with chronic low back pain. Effects of gender and depressive symptoms on rehabilitation outcome were examined immediately after rehabilitation, as well as three and six months after rehabilitation in 116 patients with chronic low back pain (43 women, 73 men; M=48 yrs.; ICD-10 diagnoses: M45.4/M45.5, M54.4/M54.5). Immediately after rehabilitation, general improvements with medium effect sizes in all rehabilitation measures were found. In contrast, six months after rehabilitation, only pain-related measures showed moderate improvements. Additionally, the mid-term outcomes were influenced by gender and depressive symptoms; women showed more stable rehabilitation outcomes in pain intensity, in the impaired function related to family/leisure, and the coping with pain strategies of "perceived self-competence" and "relaxation". In contrast, especially male patients with severe depressive symptoms revealed regressive rehabilitation outcomes, both in pain-related variables as well as marginally in the coping with pain strategy of "cognitive restructuring". In post-hoc analyses, in the mid-term, they even showed a deterioration of functional capacity and somatisation compared to prior to rehabilitation. Our results suggest that the outcome of orthopaedic rehabilitation may be persistently improved by implementing gender-specific treatments in general and elements of depression treatments for the patients with severe but sub-clinical depressive symptoms.