Clinical significance of prostate 18F-labelled fluorodeoxyglucose uptake on positron emission tomography/computed tomography: A five-year review

Table 1 Characteristics of patients who had both ¹⁸F-labelled fluorodeoxyglucose positron emission tomography/computed tomography and prostate magnetic resonance imaging studies

Age(yr)	MRI before or after PET/CT?	18F-FDG PET/CTindication	Prostate SUVmax	Prostate MRI indication	MRI result	PSA (ng/mL)	Biopsy result
73	2 mo before	Bone metastases (prostate primary)	3.4	Negative TRUS biopsy	T2aNxMx	20.8	Gleason 4 + 5 = 9
72	11 mo after	Non-Hodgkin lymphoma	2.7	Elevated PSA, negative TRUS biopsy	T2aNxMx	8.8	Gleason 5 + 3 = 8
62	3 mo after	Cancer of unknown primary	3.9	Prostate cancer staging	T3bNxMx	37	Gleason 4 + 3 = 7
75	46 mo after	Head and neck cancer	3.4	Active surveillance	T1NxMx	2.28	Gleason 4 + 3 = 7
76	6 mo before	Gastrointestinal stromal tumour	3	Elevated PSA, negative TRUS biopsy	T2bNxMx	150	Gleason 3 + 4 = 7
79	22 mo after	Non-Hodgkin lymphoma	2.9	Elevated PSA	T2aNxMx	5.4	Gleason 3 + 4 = 7
66	30 mo after	Non-Hodgkin lymphoma	3.1	Active surveillance	T2cNxMx	4.8	Gleason 3 + 4 = 7
73	26 mo after	Oesophageal cancer	2.4	Active surveillance	T2cNxMx	7.8	Gleason 3 + 3 = 6
68	18 mo after	Cancer of unknown primary	3.9	Elevated PSA	T2aNxMx	6.1	Gleason 3 + 3 = 6
74	5 mo before	Oesophageal cancer	3.9	Elevated PSA	T1NxMx	7.3	Gleason 3 + 3 = 6
68	5 mo before	Hodgkin lymphoma	9.9	Elevated PSA, negative biopsy	No focus of tumour	4.7	High-grade PIN
65	39 mo before	Colorectal cancer	5.2	Elevated PSA, negative TRUS biopsy	No focus of tumour	8.6	High-grade PIN
76	34 mo before	Non-Hodgkin lymphoma	4.2	Elevated PSA	Suspicious foci bilaterally	15	Benign
67	4 mo before	Non-Hodgkin lymphoma	4.1	Incidental prostatic 18F-FDG uptake	Suspicious foci bilaterally	5.5	Benign
72	16 mo after	Pyrexia of unknown origin	2.7	Chronic urinary infection	Likely prostatitis	Not done	Biopsy not performed
78	1 mo after	Non-Hodgkin lymphoma	3.1	Elevated PSA	No focus of tumour	11.4	Biopsy not performed
61	12 mo after	Lung nodule	5.2	Elevated PSA, positive family history	No focus of tumour	4.5	Biopsy not performed
68	7 mo after	Colorectal cancer	8.8	Incidental prostatic 18F-FDG uptake	No focus of tumour	3	Biopsy not performed

SUV: Standardised uptake value, PSA: Prostate specific antigen, TRUS: Transrectal ultrasound.

Table 2 Sectorial analysis, case-control analysis and subgroup analysis showed no significant difference in ¹⁸F-labelled fluorodeoxyglucose uptake

	Mean SUVmax	MeanSUVmean
Sectorial analysis
MRI - normal prostatic sectors	3.02	1.74
MRI - suspicious prostatic sectors	3.1	1.89
Histopathology - benign prostatic lobe	2.86	1.79
Histopathology - malignant prostatic lobe	3.13	1.82
Case-control analysis
Age-matched controls	3.09	1.83
Cases with prostate cancer	3.26	1.81
Subgroup analysis
Biopsy not performed	4.95	1.91
Benign disease and high-grade PIN	5.85	2.86
Low-grade prostate cancer (Gleason ≤ 3 + 4)	3.2	1.83
High-grade prostate cancer (Gleason score ≥ 4 + 3)	3.35	1.78

SUV: Standardised uptake value, PIN: Prostatic intraepithelial neoplasia.

Table 3 Characteristics of patients in whom elevated prostatic ¹⁸F-labelled fluorodeoxyglucose uptake was investigated

Age (yr)	18F-FDG PET/CT indication	Prostate SUVmax	PSA (ng/mL)	Urology referral made	Urology outcome
68	Adrenal nodule	10.4	3	Yes	MRI - no suspicious foci
77	Lung nodule	4.5	2.78	Yes	Biopsy - high-grade PIN
67	Non-Hodgkin lymphoma	4.5	5.5	Yes	MRI - suspicious foci
					Biopsy - benign
68	Colorectal cancer	5.9	3.04	Yes	PSA monitoring
58	Colorectal cancer	7.6	1.38	Yes	PSA monitoring
64	Non-Hodgkin lymphoma	5.4	1.84	Yes	PSA monitoring
58	Non-Hodgkin lymphoma	19.9	7.44	Yes	PSA monitoring
81	Cholangiocarcinoma	10.3	18	Yes	Lost to follow up
75	Hepatic metastases (colorectal primary)	8	-	Yes	Lost to follow up
61	Colorectal cancer	14	1.47	No - PSA normal
55	Paraneoplastic syndrome	4.8	0.62	No - PSA normal
61	Non-Hodgkin lymphoma	5.8	2.85	No - PSA normal
68	Gastrointestinal stromal tumour	13.2	1.48	No - PSA normal
71	Hepatic metastases (colorectal primary)	9.2	4.9	No - palliative care
87	Oesophageal cancer	5.3	11.86	No - palliative care
82	Colorectal cancer	15.4	3.85	No - palliative care
35	Hodgkin lymphoma	11.8	3.04	No - suspected prostatitis
71	Oesophageal cancer	7.3	4.58	No - likely urethral uptake

SUV: Standardised uptake value; PSA: Prostate specific antigen; PIN: Prostatic intraepithelial neoplasia.