Vol 26 (2023): Continuous Publishing
Clinical vignette
Published online: 2023-05-25

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A case of a patient with biochemical recurrence and inadequate results of suspected bone metastases in imaging methods — will [68Ga]Ga-PSMA-11 PET/CT give us an answer?

Kacper Pelka12, Aleksandra Bodys-Pelka34, Elżbieta Świątek-Rawa5, Krzysztof Toth5, Jolanta Kunikowska1
Pubmed: 37381790
Nucl. Med. Rev 2023;26:74-76.

Abstract

We present a case of a 79-year-old asymptomatic patient with prostate adenocarcinoma, Gleason score 9 (4 + 5), with the initial prostate-specific antigen (PSA) level of 17 ng/mL, treated with radiotherapy and hormonotherapy, who was diagnosed with the rapid growth of PSA levels up to 78.8 ng/mL. Due to suspected bone metastases, first, bone scintigraphy was performed. However, it showed only one intense “hot” lesion in the Th7 projection. This image was not consistent with a high level of PSA, for which reason a computed tomography (CT) scan was performed. It revealed lytic metastasis in Th7 and one more suspicious change in L2, which still was inconsistent with the patient’s clinical picture. The patient was referred for [68Ga]Ga-PSMA-11 PET/CT. It showed an uncountable number of foci of increased marker accumulation in bones, mostly without visible change in CT examination. This case showed that the clinical results and suspicions of the advancement of a patient’s disease are still the most important data in care and therapy planning.

Clinical vignette

Nuclear Medicine Review 2023, 26, 74–76

DOI: 10.5603/NMR.2023.0009

Copyright © 2023 Via Medica

ISSN 1506–9680, e-ISSN 1644–4345

A case of a patient with biochemical recurrence and inadequate results of suspected bone metastases in imaging methods — will [68Ga]Ga-PSMA-11 PET/CT give us an answer?

Kacper Pelka12Aleksandra Bodys-Pelka34Elżbieta Swiatek-Rawa5Krzysztof Toth5Jolanta Kunikowska1
1Department of Nuclear Medicine, Medical University of Warsaw, Warsaw, Poland
2Department of Methodology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
31st Department of Cardiology, Medical University of Warsaw, Warsaw, Poland
4Doctoral School, Medical University of Warsaw, Warsaw, Poland
5Nuclear Medicine Laboratory Nukleomed, Warsaw, Poland

[Received 22 XI 2022; Accepted 23 IV 2023]

Correspondence to: Aleksandra Bodys-Pelka, 1st Department of Cardiology, Medical University of Warsaw, Banacha 1a, 02–097 Warsaw, Poland; phone: +48 22 599 22 70, fax: +48 22 599 11 70; e-mail: aleksandra.bodys-pelka@wum.edu.pl

This article is available in open access under Creative Common Attribution-Non-Commercial-No Derivatives 4.0 International (CC BY-NC-ND 4.0) license, allowing to download articles and share them with others as long as they credit the authors and the publisher, but without permission to change them in any way or use them commercially.

We present a case of a 79-year-old asymptomatic patient with prostate adenocarcinoma, Gleason score 9 (4 + 5), with the initial prostate-specific antigen (PSA) level of 17 ng/mL, treated with radiotherapy and hormonotherapy, who was diagnosed with the rapid growth of PSA levels up to 78.8 ng/mL. Due to suspected bone metastases, first, bone scintigraphy was performed. However, it showed only one intense “hot” lesion in the Th7 projection. This image was not consistent with a high level of PSA, for which reason a computed tomography (CT) scan was performed. It revealed lytic metastasis in Th7 and one more suspicious change in L2, which still was inconsistent with the patient’s clinical picture. The patient was referred for [68Ga]Ga-PSMA-11 PET/CT. It showed an uncountable number of foci of increased marker accumulation in bones, mostly without visible change in CT examination. This case showed that the clinical results and suspicions of the advancement of a patient’s disease are still the most important data in care and therapy planning.
KEY words: PSMA; recurrent prostate cancer; bone metastases; [68Ga]Ga-PSMA-11
Nucl Med Rev 2023; 26, 7476

Bone metastases are a significant clinical problem, indicating a disseminated, advanced neoplastic disease. Among the cancers: prostate and breast cancers are responsible for the highest incidence of bone metastases. Prostate cancer is the most common cancer among men in Poland and the second most lethal. The positron emission tomography/computed tomography (PET/CT) targeted at the prostate-specific membrane antigen (PSMA) expressed on prostate cancer cells is currently the best solution for prostate cancer imaging with the highest sensitivity.

A 79-year-old man with prostate adenocarcinoma, Gleason score 9 (4 + 5), with an initial PSA level of 17 ng/mL, treated with radiotherapy and hormonotherapy was diagnosed with the rapid growth of PSA levels up to 78.8 ng/mL. Apart from the elevated level of the neoplastic marker, the patient was asymptomatic. The PSA level was higher than 2 ng/mL more than the patient’s minimal level, so the biochemical recurrence has been recognized. Due to the high level of the marker, distant metastases were suspected, and the patient underwent bone scintigraphy. It showed one intense “hot” lesion in the Th7 projection, which was inconsistent with such a rapid growth of the PSA level (Fig. 1). The next stage of diagnosis was the computed tomography (CT) examination, which revealed lytic metastasis in Th7 and one more suspicious change in L2. The results still did not agree with the biochemical advancement; therefore, steps were taken on further diagnostics. The patient was referred for [68Ga]Ga-PSMA-11 PET/CT. Which was performed one month after, with a PSA level of 151.5 ng/mL, with the last dose of hormonotherapy 2 months before. It showed an uncountable number of foci of increased marker accumulation in bones, mostly without visible lesions in CT examination (Fig. 2, 3). The result of this, final study was consistent with the clinical suspicion concerning the advancement of the disease.

Figure 1. Whole body scintigraphy: A — anterior-posterior view; B — posterior-anterior view; The arrow shows the only visible hot lesion in the Th7 vertebra
Figure 2. Maximum intensity projection (MIP) of [68Ga]Ga-PSMA-11 PET/CT — arrow indicates the only focus of bone metastases which was visible in the bone scintigraphy, the arrowheads indicate some of many other foci of bone metastases
Figure 3. [68Ga]Ga-PSMA-11 PET/CT images which show foci of increased marker accumulation in bones, mostly without visible change in CT examination; A — CT; B — fusion; C — PET — the arrow points to the lesion in Th7 vertebra, visible on the PET as well as on the CT as mixed bone metastasis, the arrowhead points at the foci in left scapula — bone metastases visible only in the PET/CT; D — CT; E — fusion; F — PET — the axial cross-section through L1 vertebra — the arrowhead points into the focus of increased tracer accumulation in PET with a hardly visible lesion in CT; G — CT; H — fusion; I — PET — the axial cross-section through left rib — the arrowhead points into the focus of increased tracer accumulation visible only in PET without visible lesion in CT

This case showed that the clinical results and suspicions of the advancement of a patient’s disease are still the most important data in care and therapy planning. Despite the wide access to imaging tests, their results, contradicting the clinic, should raise concern and lead to a further diagnosis. It is worth considering choosing more and more advanced methods — in this case, bone scintigraphy, despite its high sensitivity at this PSA level, turned out to be insufficient. The [68Ga]Ga-PSMA-11 PET/CT allowed us to know the real scale of the disease in this patient’s case, which helped in planning an appropriate treatment path. The results of the imaging tests initially performed could lead to a treatment, that would not help the patient’ but only extend the time to the final diagnosis. This shows that in the case of difficult patients, we should always strive for a full diagnosis, using more and more complicated methods.

In clinical suspicions of bone metastases, with inadequate classical imaging methods, it is worth to consider a [68Ga]Ga-PSMA-11 PET/CT study it is currently the best method for prostate cancer imaging.

Conflicts of interest

The authors declare no conflicts of interest.

References

  1. Manohar PR, Rather TA, Khan SH. Determination of the optimal cut-off value of serum prostate-specific antigen in the prediction of skeletal metastases on technetium-99m whole-body bone scan by receiver operating characteristic curve analysis. World J Nucl Med. 2020; 19(3): 255259, doi: 10.4103/wjnm.WJNM_77_19, indexed in Pubmed: 33354181.
  2. Macedo F, Ladeira K, Pinho F, et al. Bone metastases: an overview. Oncol Rev. 2017; 11(1): 321, doi: 10.4081/oncol.2017.321, indexed in Pubmed: 28584570.
  3. Anttinen M, Ettala O, Malaspina S, et al. A prospective comparison of 18F-prostate-specific membrane antigen-1007 positron emission tomo­graphy computed tomography, whole-body 1.5 t magnetic resonance imaging with diffusion-weighted imaging, and single-photon emission computed tomography/computed tomography with traditional imaging in primary distant metastasis staging of prostate cancer (PROSTAGE). Eur Urol Oncol. 2021; 4(4): 635644, doi: 10.1016/j.euo.2020.06.012, indexed in Pubmed: 32675047.
  4. Pyka T, Okamoto S, Dahlbender M, et al. Comparison of bone scintigraphy and Ga-PSMA PET for skeletal staging in prostate cancer. Eur J Nucl Med Mol Imaging. 2016; 43(12): 21142121, doi: 10.1007/s00259-016-3435-0, indexed in Pubmed: 27290607.