Objective criteria for MRI evaluation of the effectiveness of treatment of bone metastases in patients with prostate cancer and breast cancer: systematic review and meta-analysis

Objectives. The possibility of a personalized approach to the treatment of metastatic prostate cancer and breast cancer requires objective methods for evaluation of response of foci treatment in the skeleton. The proven high efficiency of MRI in detecting bone metastases, in combination with the absence of ionizing radiation, has laid the groundwork for using this method in monitoring the treatment course based on objective criteria for evaluation of the therapeutic outcome. Aim. To analyze quantitative and semi-quantitative parameters of MRI-evaluation of treatment efficacy (radiation, chemotherapy, hormone therapy, and targeted therapy) of bone metastases that were used in prostate and breast cancer clinical trials. Materials and methods. The databases Embase, PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), eLibrary were searched until April 1, 2021, using the following keywords: magnetic resonance imaging, MRI, DWI, treatment response, prostate cancer or breast cancer, and bone metastasis. Only studies related to the MRI-evaluation of treatment efficacy of any type of therapeutic intervention (with the exception of surgery) for metastatic skeletal lesions have been included in this review. Results. Of the 312 sources found as a result of the search, 11 studies were selected and analyzed. It allowed us to identify four groups of objective MRI-criteria for evaluating the therapeutic effect in metastatic bone lesions in patients with prostate and breast cancer that include the dynamics of: a) sizes; b) signal intensity on DWI; c) ADC; d) tumor total diffusion volume (tDV). Changes in these quantitative and semi-quantitative indicators, with only one exception, had the same direction, although they differed in numerical values. Conclusion. MRI is an informative technique for the objective evaluation of the response of bone metastases to therapy in patients with prostate cancer and breast cancer based on quantitative and semi-quantitative parameters. It has significant potential as a diagnostic test instrument for monitoring the effectiveness of treatment of metastatic skeletal lesions.

Multifocal Osseous Tuberculosis Mimicking Langerhans’ Cell Histiocytosis: A Case Series

Langerhans cell histiocytosis (LCH) is a common cause of multifocal lytic skeletal lesions in children. However, multifocal osseous tuberculosis can affect children and mimics LCH on imaging, especially in endemic regions. We report cases with atypical manifestations of multifocal osseous tuberculosis which were presumptively diagnosed as LCH. The findings of our series of cases suggest that on computed tomography (CT) irregular sclerotic margins, abscess formation, sclerosis of involved bone, and button sequestrum point toward a diagnosis of multifocal osseous tuberculosis, especially in endemic regions.

Skeletal sarcoidosis; an uncommon mimic of metastatic disease

A 66-year-old man with pulmonary sarcoidosis was referred to the urology team for assessment of troublesome lower urinary tract symptoms. An elevated blood serum prostate-specific antigen raised concern for prostate cancer. An MRI of the prostate demonstrated a potentially aggressive prostate lesion, along with low T1 signal skeletal lesions, suggestive of metastatic disease. Subsequent bone scan and MRI whole spine demonstrated further skeletal lesions. In cases of known prostate cancer, sometimes a presumptive diagnosis of skeletal metastases is made without histological diagnosis from the skeletal lesions. However, there were certain factors in this case whereby skeletal biopsy was deemed prudent prior to further therapy. Factors included atypical MRI signal characteristics for metastatic disease, absence of a positive tissue diagnosis from the prostate and the clinical background of sarcoidosis. The biopsy confirmed skeletal sarcoid rather than metastatic disease, thereby avoiding inappropriate and potentially toxic treatment for the patient.

Usefulness of 68Ga-DOTATOC PET/CT to localize the culprit tumor inducing osteomalacia

Tumor-induced osteomalacia (TIO) is an uncommon paraneoplastic syndrome presenting with sustained hypophosphatemia. Treatment of choice is removal of the tumor causing the TIO, but identification of the culprit tumor by routine imaging is challenging. This study aimed to assess the usefulness of somatostatin receptor imaging, called 68Ga-DOTATOC PET/CT, in the management of patients with TIO. Twelve patients who were suspected of having TIO underwent 68Ga-DOTATOC PET/CT. Lesion detectability and maximum standardized uptake value (SUVmax) were determined and retrospectively compared with the clinical/imaging surveillance and histopathologic diagnosis. The median duration of suspected TIO with hypophosphatemia was 7.8 years (range 2.1–21.0). Conventional radiologic and/or nuclear medicine images failed to identify the culprit tumors. However, 68Ga-DOTATOC PET/CT scans showed that 8 of the 12 patients had positive lesions, suggesting the presence of focal culprit tumors. The SUVmax of positive tumors was 1.9–45.7 (median: 11.5). Six skeletal lesions and two extra-skeletal lesions were identified. Seven of the lesions were pathologically confirmed as potential culprits of TIO. Hypophosphatemia was resolved in five patients who underwent lesion excision. The 68Ga-DOTATOC PET/CT is a useful whole-body imaging modality for the detection of causative tumors in patients with suspected TIO.

A new investigative strategy to diagnose β-thalassemia syndrome in past human populations

The study of thalassaemia syndromes in archeological human remains is of growing interest in the field of paleopathology. However, a definitive diagnosis of the disease in skeletonized individuals remains difficult. Several non-specific bone lesions have been suggested as the most likely evidence of β-thalassaemia syndrome. In particular, skull lesions have been considered by several scholars as the most indicative of this hematopoietic disorder, while other authors have identified postcranial lesions as the best evidence of β-thalassemia. In this study, we reviewed the main features that have been identified in β-thalassaemia patients thanks to an extensive bibliographic research of clinical cases, radiological and microscopic analyses. Our aim was to discern between those skeletal lesions that can be considered “indicative/diagnostic” and those that are “indicative/non-diagnostic” of β-thalassaemia syndrome. With this knowledge, we developed a new evaluation form (Eva-BeTa) and tested it on previously published archeological cases. Based on our results, we believe that Eva-BeTa can be a valid diagnostic tool for the identification of ancient individuals potentially affected by β-thalassemia for further genetic confirmation.