Does Bone Scintigraphy Change Clinical Management in Patients with Lung Cancer?

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Introduction: Lung cancer is the third most common cancer in South Africa men, with a lifetime risk of 1 in 98. According to the ESMO cancer guidelines, the standard work-up includes computed tomography, X-rays, PET/CT, and bone scintigraphy.

Phosphate analogues labeled with technetium are used to evaluate presence and distribution of active bone remodeling (osteoclastic and osteoblastic skeletal activity) related to benign and nonbenign processes. Phosphonates have an affinity for the mineral part of the bone; a third concentrates in the calcium phosphate and two-thirds in the hydroxyapatite crystal of the bone. This occurs in relation to local blood flow and extraction efficiency. Skeletal scintigraphy provides a highly sensitive evaluation tool for the assessment of osteoblastic skeletal activity, however the specificity is low.

Bone scintigraphy is commonly used in oncology for assessment of primary and secondary skeletal malignancies. In cancers that are classically characterized by osteoblastic skeletal metastases, bone scintigraphy is known to have high sensitivity for skeletal metastases. This is in contrast to other malignancies that typically have osteolytic bone metastasis or mixed osteolytic/osteoblastic skeletal lesions such as lung carcinoma. The diagnostic yield for these scans is lower on bone scintigraphy.

The aim of this retrospective review is to evaluate the utility of bone scintigraphy in management of patients with lung carcinoma.

Methods: A review was performed from patient records at Inkosi Albert Luthuli Central Hospital, Nuclear Medicine department from the years 2017 to 2022. The study was done as retrospective analysis of patients with biopsy proven lung cancer who were referred for bone scan. Patients all underwent bone scintigraphy in the nuclear medicine department at Inkosi Albert Luthuli Central Hospital.

Image acquisition was performed on a Siemens biograph SPECT/CT camera. The CT scan was unenhanced and CT parameters were 120 keV 50mAs. The bone scan was acquired 2 to 4 hours after an injected dose of 20 mCi of ^99mTc-MDP. Regional SPECT/CT of the area of interest was acquired at 3 min/bed position.

Results: The study had 40 participants, 33 males and 7 females, with an age ranging from 45 to 83 years. Histology demonstrated non-small cell carcinoma for all of the participants, with the exception of two patients (who demonstrated adenocarcinoma). Our results demonstrated that bone scintigraphy influenced patient staging in 25% of cases and changed management in 17.5% of the cases. Serum ALP results were available in only 8/40 (20%) patients and was increased in all of these patients (detailed statistical analysis to follow).

Conclusion: In our study population, bone scintigraphy changed staging in 25% of patients with lung cancer and influenced management in 17.5%. Bone scintigraphy may not be the optimal nuclear medicine study and further studies are needed to compare the use of bone scintigraphy to that of ¹⁸F-FDG PET/CT in lung cancer patients.

Publication History

Article published online:
25 May 2023