Results:
Patient 1 is a 23-month old toddler who presented with lower back pain, gradually worsening ataxia and leg weakness over the previous 5 days. Physical examination was initially non-suggestive, but quickly progressed to lower limb weakness and frank paraplegia. His blood investigation were normal and chest X-Ray was suggestive of a soft tissue paravertebral mass at the level of upper thoracic vertebrae. This was followed by MRI scan that demonstrated a paravertebral mass at the level of T2-T4 vertebrae, causing spinal cord compression and edema. He underwent emergency laminotomy and laminoplasty by the neurosurgeons and a de-bulking procedure, which relieved pressure on the spinal cord resulting in return of lower limb function over the next 48 hours. His urinary Vanillylmandellic Acid (VMA)/creatinine ratio and Homovanillic Acid (HVA)/creatinine ratio were mildly elevated. Histopathology of the resected tissue showed poorly differentiated Neuroblastoma. Tumor cytogenetics did not reveal any high-risk features.
On 68Ga-DOTATATE PET/CT scan, increased DOTATATE uptake was seen in the left paravertebral mass extending into the posterior mediastinum and posterior chest wall and crossing the midline. Another focus of increased DOTATATE uptake was noted along the right paravertebral aspect of thoracic vertebrae at the level of T2 and T3. Additionally, a calcified distinct posterior mediastinal node with increased DOTATATE uptake was also noted. These findings are summarized in Table 1 and 68Ga-DOTATATE imaging is shown in (Fig 1).
Patient 2 is a six-year old girl who presented with a mild intermittent limp over the previous 2 months. She did not have any other symptoms. On physical examination, she was unable to stand straight due to left leg pain and had a mildly tender left side of lower abdomen. X-Ray of her pelvis demonstrated 2 radiolucent lesions in her left femur. Further imaging studies including MRI scan of her abdomen and pelvis demonstrated a large left supra-renal mass and numerous bony metastatic lesions in addition to several enlarged retroperitoneal lymph nodes. Her urinary VMA/Creatinine ratio and HVA/Creatinine ratio were moderately elevated. A core biopsy from the suprarenal mass was carried out under ultrasound guidance. Histopathology of the mass confirmed the diagnosis of poorly differentiated Neuroblastoma, which did not have any high-risk cytogenetic features. Her bone marrow was infiltrated by Neuroblastoma.
On 68Ga-DOTATATE PET/CT scan, intense DOTATATE uptake was noted in the large left suprarenal mass with areas of photopenia corresponding to necrosis and calcifications. Uptake was also noted in the right adrenal bed as well as in the right retrocrural region. A few bony skull lesions with increased uptake were noted including the skull base most consistent with disease involvement. Extensive skeletal metastasis along the axial and appendicular skeleton were noted with evidence of bone marrow infiltration. These findings are summarized in Table 1 and 68Ga-DOTATATE imaging is shown in (Fig 2).
Patient 3 is a 3.5-year old girl who presented with weight loss, left eye swelling, body aches and constitutional symptoms over several months. She was cachectic, severely malnourished and had left sided proptosis. MRI scan showed a right upper abdominal mass arising from the adrenal gland. She also had numerous liver metastases, enlarged lymph nodes along the lower pole of the left kidney and multiple vertebral lesions. It also showed enlarged mediastinal lymph nodes at the level of tracheal bifurcation and left posterior mediastinum. Her bone marrow was infiltrated by malignant cells. Urinary VMA/Creatinine ratio and HVA/Creatinine ratio were grossly elevated. In the presence of elevated catecholamines and highly suggestive bone marrow results, we elected not to carry out tumor biopsy.
68Ga-DOTATATE PET/CT scan demonstrated intense heterogeneous uptake in the right adrenal mass with skeletal metastatic deposits and diffuse bone marrow infiltration. It also demonstrated uptake in the thoracic and abdominal lymph nodes seen on MRI scan. Additionally, there were two bony lesions in the skull vault. These findings are summarized in Table 1 and selected representative images on68Ga-DOTATATE imaging are shown in (Fig 3).