Automated detection of skeletal metastasis of lung cancer with bone scans using convolutional nuclear network

Bone scan is widely used for surveying bone metastases caused by various solid tumors. Scintigraphic images are characterized by inferior spatial resolution, bringing a significant challenge to manual analysis of images by nuclear medicine physicians. We present in this work a new framework for automatically classifying scintigraphic images collected from patients clinically diagnosed with lung cancer. The framework consists of data preparation and image classification. In the data preparation stage, data augmentation is used to enlarge the dataset, followed by image fusion and thoracic region extraction. In the image classification stage, we use a self-defined convolutional neural network consisting of feature extraction, feature aggregation, and feature classification sub-networks. The developed multi-class classification network can not only predict whether a bone scan image contains bone metastasis but also tell which subcategory of lung cancer that a bone metastasis metastasized from is present in the image. Experimental evaluations on a set of clinical bone scan images have shown that the proposed multi-class classification network is workable for automated classification of metastatic images, with achieving average scores of 0.7392, 0.7592, 0.7242, and 0.7292 for accuracy, precision, recall, and F-1 score, respectively.

PREDICTIVE VALUE OF SERUM PROSTATE SPECIFIC ANTIGEN IN DETECTING BONE METASTASIS IN PROSTATE CANCER

Objective: We determine the utility of Prostate Specific Antigen (PSA) for predicting the presence of skeletal metastasis on Bone Scan (BS) in prostate cancer patients. Material & Methods: Retrospective analysis of medical records of 70 consecutive prostate cancer patients subjected to bone scan during the last 2 years was done. 5 cases were excluded due to the following reasons: Serum PSA not available, hormonal or other therapy given prior to serum PSA measurement, and/or Bone Scan, and symptomatic for bone metastasis. In remaining 65 cases, PSA value and bone scan were evaluated. Results: BS was found to be positive in 20/65 (31%) and negative in 45(69%) patients. 24 (37%) had serum PSA > 100 ng/ml, 25 (38.5%) had PSA of 20‐100 ng/ml and only 16 (24.5%) had PSA < 20 ng/ml. Conclusion: Serum PSA < 20 ng/ml have high predictive value in ruling out skeletal metastasis. Our data are in corroboration with results from previous studies that BS should be performed only if PSA > 20 ng/ml. Using this cut‐off, unnecessary investigation can be avoided. Avoiding BS asymptomatic in this group of patients would translate into a significant cost‐saving and reduction in their psychological and physical burden.

Brown tumour mimicking skeletal metastasis

Brown tumours of bone are highly vascular osteolytic lesions that depict a reparative cellular process instead of a neoplastic process in hyperparathyroidism (HPT) patients. These tumours have the potential to be aggressive and destructive. We report a case of a 30-year-old woman who presented with left thigh and lower back pain. The radiological evaluation showed multiple bony lesions in the pelvis and the spine, which mimicked multiple metastatic tumours. However, on biochemistry evaluation, serum calcium, alkaline phosphatase, and parathyroid hormone were all high, while serum phosphate was low, indicating primary HPT (PHPT), which was confirmed by parathyroid scintigraphy showing left parathyroid adenoma. Hence, the bony lesions were diagnosed as brown tumours secondary to PHPT. The patient underwent parathyroidectomy and developed severe hungry bone syndrome requiring parenteral calcium infusion along with oral calcium and active vitamin D supplementation. The clinical symptoms of bone pain improved after surgery.

338 Biceps Metastasis Presenting as A Presumed Abscess in Patient with An Undiagnosed Non-Small Cell Lung Cancer - An Unusual Presentation

Lung cancer is the most common cancer worldwide and has highest cancer mortality. Around 50% of cases present with metastasis, however skeletal muscle metastasis is rarely reported. In this case we describe a fifty-nine-year-old male patient who presented complaining of fever and a mass on the distal biceps and proximal forearm over a five-month period, with no reported improvement despite debridement and antibiotics spanning three presentations to the emergency department. Subsequent biopsy at various anatomical sites showed adenocarcinoma, later identified as metastatic from a primary non squamous-cell lung cancer (NSCLC). Metastases from lung cancer are more commonly limited to liver and adrenal glands. Presentation of such a mass in skeletal muscle would raise suspicion for the more-commonly seen soft-tissue sarcoma or hemangiomas. This case illustrates a rare example of lung cancer metastatic to skeletal muscle, more specifically, the biceps. Presentation of the mass was also unique in its morphology of an abscess with purulent discharge, raising the importance of cytology and suspicion for malignancy in an abscess unresponsive to antibiotics. Non-small cell lung cancer can present with skeletal metastasis. A work-up of a mass or abscess of the muscle should include the possibility of soft tissue metastasis.

Pelvic Kidney Mimicking Skeletal Metastasis on Bone Scan- Interesting Image

A 57-year-old female patient underwent left breast-conserving surgery with sentinel lymph node biopsy for Left breast carcinoma (stage IIA). The patient had hypertension and diabetes mellitus. Other findings include multiple hepatic cyst, bilateral renal cysts and uterine myoma. She had no significant renal symptoms and her liver &renal function test were normal.She was sent for Technetium-99m-methylene diphosphonate (99mTc-MDP) bone scan. There was a large area of intense tracer concentration in the region of right sacro-iliac (SI) joint which appeared like an osteoblastic metastasis at first glance. However, absence of uptake in the right renal fossa with the left kidney being normal in position contemplated the probability of right-sidedpelvickidneywhich was confirmed later by a contrast enhanced computerized tomography (CT) scan of abdomen that showed a pelvic right kidney overlying the sacrum. Bangladesh J. Nuclear Med. 22(2): 155-156, Jul 2019