Pulmonary nodule detection in oncological patients - Value of respiratory-triggered, periodically rotated overlapping parallel T2-weighted imaging evaluated with PET/CT-MR.

PURPOSE: To prospectively evaluate the detection and conspicuity of pulmonary nodules in an oncological population, using a tri-modality PET/CT-MR protocol including a respiration-gated T2-PROPELLER sequence for possible integration into a simultaneous PET/MR protocol. METHODS: 149 patients referred for staging of malignancy were prospectively enrolled in this single-center study. Imaging was performed on a tri-modality PET/CT-MR setup and was comprised of PET/CT and 3T-MR imaging with 3D dual-echo GRE pulse sequence (Dixon) and an axial respiration-gated T2-weighted PROPELLER (T2-P) sequence. Images were assessed for presence, conspicuity, size and interpretation of the pulmonary parenchymal nodules. McNemar's test was used to evaluate paired differences in nodule detection rates between MR and CT from PET/CT. The correlation of pulmonary nodule size in CT and MR imaging was assessed using Pearson correlation coefficient. RESULTS: 299 pulmonary nodules were detected on PET/CT. The detectability was significantly higher on T2-P (60%, p<0.01) compared to T1-weighted Dixon-type sequences (16.1-37.8%). T2-P had a significantly higher detection rate among FDG-positive (92.4%) and among confirmed malignant nodules (75.9%) compared to T1-Dixon. Nodules <10mm were detected less often by MR sequences than by CT (p < 0.01). However, nodules >10mm were detected equally well with T2-P (92.2%) and CT (p >0.05). In a per-patient analysis, there was no significant change in the clinical interpretation of the nodules detected with T2-P and CT. CONCLUSION: Despite the overall lower detection rate compared with CT, the free-breathing respiratory gating T2-w sequence showed higher detectability in all evaluated categories compared to breath-hold T1-weighted MR sequences. Specifically, the T2-P was found to be not statistically different from CT in FDG-positive nodules, in detection of nodules >10mm and concerning conspicuity of pulmonary nodules. Overall, the additional time investment into T2-P seems to be justified since clinical relevant assessment of pulmonary lung nodules can mostly be done by T2-P in a whole body PET/MR staging of oncologic patients.

Adult langerhans cell histiocytosis of bones : a rare cancer network study.

Langerhans Cell Histiocytosis (LCH) is an uncommon benign bone tumour typically seen in children. LCH of bones in adults has been reported as solitary cases. The aim of the current study is to analyze different treatment approaches and the role of radiotherapy (RT) in adult LCH. Thirty patients from five Rare Network Cancer centers were included in this retrospective study. Median age was 30 years. The localization of tumours was skull bones in 12 (40%), lower extremity in 6 (20%), thoracic bones in 4 (133%), spine in 3 (10%), pelvis in 2 (6.7%) and multiple sites in 3 (10%) patients. Primary treatment was surgery in 1 (33%), surgery+ radiotherapy (RT) in 15 (50%), RT in 12 (40%), RT + CHT in 1 (33%) and corticosteroids in 1 (33%) patient. Median follow-up was 58 months. Complete remission was obtained in 21 (70%), partial remission in 4 (133%); 2 lesions were stable (6.7%) and progression was noted in 2 (6.7%) of the patients. Nine patients (30%) had recurrent disease. Recurrence rates were significantly lower in patients who were treated with surgery and RT (p < 0.003). Surgery plays a major role in the treatment of adult LCH of bones ; radiotherapy should be considered in the adjuvant setting and palliation.

Radiation recall dermatitis with soft tissue necrosis following pemetrexed therapy: a case report.

INTRODUCTION: Radiation recall dermatitis is a well known but still poorly understood inflammatory reaction. It can develop in previously irradiated areas and has been shown to be triggered by a variety of different drugs, including cytostatic agents. Pemetrexed may cause radiation recall dermatitis in pre-irradiated patients. CASE PRESENTATION: We present the case of a 49-year-old Caucasian woman with non-small cell lung cancer who was initially treated with carboplatin and paclitaxel concomitant with radiotherapy after suffering a painful plexus brachialis infiltration. Due to disease progression, a second-line treatment with pemetrexed was started. A severe soft tissue necrosis developed despite steroid treatment and plastic surgery. CONCLUSION: To the best of our knowledge, we present the first case of a patient with severe soft tissue necrosis in a pre-irradiated area after pemetrexed therapy. We believe that physicians treating patients with pemetrexed should be aware of the severe, possibly life-threatening effects that may be induced by pemetrexed after previous radiation therapy.