CASE OF THE WEEK – "The value of whole body scintigraphy using (99M)Tc-HYNIC-TOC (Tektrotyd) and with single photon emission computerized tomography (SPECT/CT hybrid imaging) in the detection of primary and metastatic neuroendrocrine tumor (nets)" by Dr ShekharShikare, HOD & Consultant, Nuclear Medicine and Dr Piyush Somani, HOD & Specialist, Gastroenterology, NMC Royal Hospital Sharjah

Introduction

Neuroendocrine tumors include such tumors as adenomas from the pituitary gland, islet cell tumors from the pancreas, pheochromocytoma and neuroblastoma from the adrenal medulla, medullary thyroid carcinoma from the C-cells of the thyroid gland, carcinoid tumors from the gastrointestinal tract (or less often from the lung), and paragangliomas.

Generally, anatomic and/or physiologic-functional imaging for neuroendocrine tumors is reserved for patients who present with a clinical history that is suspicious for a neuroendocrine tumor, supported by elevated levels of primary hormones and/or metabolites in the plasma and/or urine. These patients can be evaluated by anatomical imaging studies, such as computed tomography (CT) or magnetic resonance imaging (MRI), and the functional status of these tumors can be assessed by physiologic imaging via scintigraphy, with radiolabeled octreotide (Octreoscan). These imaging techniques should be considered as complementary studies, rather than competitive modalities, as each provides important aspects in the evaluation of these underlying tumors for patient management.

 In addition to localizing sites of disease, scintigraphy of neuroendocrine tumors can provide a functional assessment of the disease state. With whole-body SPECT-CT hybrid imaging capability, nuclear imaging is an excellent technique for searching for distant metastases or multifocal disease (as shown in this case) Scintigraphy can also evaluate for tumor recurrence, for example, in evaluating abnormalities such as suspected scar tissue versus a recurrent tumor at or near a postoperative site and can also evaluate the efficacy of therapeutic interventions. Finally, scintigraphy can be performed to evaluate tracer uptake characteristics of a tumor when there is consideration of radionuclide therapy,

Case

39 years old gentleman with history of recurrent epigastric pain, anorexia, weight loss and jaundice.

CT SCAN ABDOMEN

Large pancreatic mass lesion in head/uncinate process of pancreas of around 75*58 mm with grossly dilated Common bile duct, common hepatic duct with dilated IHBR with few ill-defined focal lesions 17*12 mm in segment 8, suspicious of metastasis.

MRI OF ABDOMEN

Large pancreatic mass lesion in head/uncinate process of pancreas of around 63*53*46 mm with grossly dilated common bile duct, common hepatic duct with dilated IHBR with mildly dilated pancreatic duct. Few ill-defined focal lesion, largest 15 mm seen in segment 8 suspicious of liver metastasis. Common bile duct is compressed by the mass in the distal end close to the ampulla.

Underwent endoscopic ultrasound guided biopsy of the mass.

large ulcerated necrotic heterogenous subepithelial duodenal mass involving second/third part of duodenum.

Histopathology/immunochemistry revealed Grade II Neuroendocrine Tumour

Referred for whole body octreoscan (99mTc Tektrotyed) for the staging of the disease process

The value of whole body scintigraphy using (99M)Tc-HYNIC-TOC (Tektrotyd) and with single photon emission computerized tomography (SPECT/CT hybrid imaging) in the detection of primary and metastatic neuroendrocrine tumor (nets) The value of whole body scintigraphy using (99M)Tc-HYNIC-TOC (Tektrotyd) and with single photon emission computerized tomography (SPECT/CT hybrid imaging) in the detection of primary and metastatic neuroendrocrine tumor (nets) The value of whole body scintigraphy using (99M)Tc-HYNIC-TOC (Tektrotyd) and with single photon emission computerized tomography (SPECT/CT hybrid imaging) in the detection of primary and metastatic neuroendrocrine tumor (nets)
The value of whole body scintigraphy using (99M)Tc-HYNIC-TOC (Tektrotyd) and with single photon emission computerized tomography (SPECT/CT hybrid imaging) in the detection of primary and metastatic neuroendrocrine tumor (nets) The value of whole body scintigraphy using (99M)Tc-HYNIC-TOC (Tektrotyd) and with single photon emission computerized tomography (SPECT/CT hybrid imaging) in the detection of primary and metastatic neuroendrocrine tumor (nets)

MULTIPLE SRS LESIONS IN LIVER (METS)

The value of whole body scintigraphy using (99M)Tc-HYNIC-TOC (Tektrotyd) and with single photon emission computerized tomography (SPECT/CT hybrid imaging) in the detection of primary and metastatic neuroendrocrine tumor (nets) The value of whole body scintigraphy using (99M)Tc-HYNIC-TOC (Tektrotyd) and with single photon emission computerized tomography (SPECT/CT hybrid imaging) in the detection of primary and metastatic neuroendrocrine tumor (nets)

MULTIPLE SRS LESIONS IN LIVER (METS)

The value of whole body scintigraphy using (99M)Tc-HYNIC-TOC (Tektrotyd) and with single photon emission computerized tomography (SPECT/CT hybrid imaging) in the detection of primary and metastatic neuroendrocrine tumor (nets) The value of whole body scintigraphy using (99M)Tc-HYNIC-TOC (Tektrotyd) and with single photon emission computerized tomography (SPECT/CT hybrid imaging) in the detection of primary and metastatic neuroendrocrine tumor (nets)

MULTIPLE SRS LESIONS IN LIVER (METS)

99mTc- LABELLED-TEKTROTYED {HYNIC OCTEREOSCAN WHOLE BODY SCAN (SOMATOSTATIN RECEPTOR IMAGING)}.

H/O LARGE DUODENAL MASS INVOLVING SECOND/THIRD PART OF THE DUODENUM & BIOPSY SUGGESTIVE OF GRADE 2 NEURO-ENDOCRINE TUMOR.

SOMATOSTATIN RECEPTOR EXPRESSION (SRS) LESIONS ARE SEEN IN

  1. LARGE DUODENAL MASS (VERY AVID TRACER UPTAKES)- PRIMARY NET.
  2. MULTIPLE IN RIGHT LOBE OF LIVER SEGMENTS 4,5,6,7 & 8 respectively) with varying tracer uptake intensities- MESTASTASIS.
  3. ANTERIOR SEGMENT OF UPPER LOBE OF RIGHT LUNG LATERALLY -METASTASIS.

All abnormalities are better appreciated on SPECT-CT fused images

WHAT IS THE CLINICAL RELEVANCE OF SOMATOSTATIN RECEPTOR SCINTIGRAPHY?

A positive scan predicts the suppressive effect of Somatostatin analogues on hormone secretion from endocrine active tumours.

THE 99mTc-TEKTROTYED WHOLE BODY AND SPECT/CT HYBRID IMAGING HAS HIGH SENSITIVITY, AND IT MAKES IT A SUITABLE, EASILY ACCESSIBLE NUCLEAR IMAGING METHOD TO DETECT NEUROENDOCRINE TUMORS AND STAGING OF THE DISEASE PROCESS AS HIGHLIGHTED IN THIS CASE.

The value of whole body scintigraphy using (99M)Tc-HYNIC-TOC (Tektrotyd) and with single photon emission computerized tomography (SPECT/CT hybrid imaging) in the detection of primary and metastatic neuroendrocrine tumor (nets) The value of whole body scintigraphy using (99M)Tc-HYNIC-TOC (Tektrotyd) and with single photon emission computerized tomography (SPECT/CT hybrid imaging) in the detection of primary and metastatic neuroendrocrine tumor (nets) The value of whole body scintigraphy using (99M)Tc-HYNIC-TOC (Tektrotyd) and with single photon emission computerized tomography (SPECT/CT hybrid imaging) in the detection of primary and metastatic neuroendrocrine tumor (nets)

Figure 3

SPECT-CT FUSED images corresponds to D12 left costovertebral joint ( figure 3).

A fluoroscopy guided D12 left costovertebral joint corticosteroid injection was performed and subsequently patient becomes pain free since then (more than two years).

Discussion

The increased 99mTc MDP activity at the costovertebral joint on SPECT-CT is highly predictive of pain or positive response to percutaneous injection. Patients may have corresponding thoracic back pain, with increasing use of combined imaging such as SPECT-CT, specific localization of activity to these articulations may become more common. Therefore, it is important to report these findings to help establish the prevalence and significance of 99mTc MDP activity at these joints.

99mTc MDP SPECT is often performed for the purpose of identifying the cause of back pain, but its utility in degenerative conditions remains unclear. Previous reports addressing the significance of SPECT-CT activity in the costovertebral and costotransverse joints are limited, but studies have been performed to evaluate the significance of radiotracer activity in facet joints. Prior studies suggest that injection of facet joints with increased 99mTc MDP activity results in clinical improvement

Degenerative changes of the costovertebral joints are present in approximately half of all people on postmortem examination. They may be asymptomatic in most instances, but there are numerous reports of both localized pain and referred patterns such as chest pain . Indeed, pain reduction with administration of local anesthetic and corticosteroid as a criterion to direct resection arthroplasty of these joints has been reported. Additionally, pain related to these joints reportedly can be present in the absence of anatomic degenerative changes. Identification of both an imaging marker of this pain and effective minimally invasive treatment is desirable. Physiologic imaging markers such as 99mTc MDP are attractive prospects because they may identify joints with inflammation, and presumably associated pain, that could in principle be ameliorated with local anti-inflammatory medication.

In conclusion, our results indicate that 99mTc MDP activity at the costovertebral and costotransverse joints on SPECT-CT is highly predictive of corresponding thoracic back pain or positive response to percutaneous injection. Patients may have corresponding thoracic back pain, but more than half did not. When corresponding thoracic back pain was present, there was often relief with percutaneous injection. Given the retrospective design and small number of patients in the study, future prospective investigation with a larger number of patients is necessary to further define the significance of costovertebral and costotransverse joint 99mTc MDP activity on SPECT-CT.

Main points

Costovertebral and costotransverse joints are potential pain generators in the thoracic spine.

99mTc MDP activity at the costovertebral and costotransverse joints on SPECT-CT is not uncommon.

99mTc MDP activity at the costovertebral on SPECT-CT is highly predictive of corresponding pain as shown in this case and subsequent resolution of the pain completely post fluoroscopy guided corticosteroid injection.