This review paper will discuss the use of positron emission tomography/computed tomography (PET/CT) in paediatric oncology. Functional imaging with PET/CT has proven useful to guide treatment by accurately staging disease and limiting unnecessary treatments by determining the metabolic response to treatment. ¹⁸F-Fluorodeoxyglucose (2-[¹⁸F]FDG) PET/CT is routinely used in patients with lymphoma. We highlight specific considerations in the paediatric population with lymphoma. The strengths and weaknesses for PET/CT tracers that compliment Meta-[¹²³I]iodobenzylguanidine ([¹²³I]mIBG) for the imaging of neuroblastoma are summarized. 2-[¹⁸F]FDG PET/CT has increasingly been used in the staging and evaluation of disease response in sarcomas. The current recommendations for the use of PET/CT in sarcomas are given and potential future developments and highlighted. 2-[¹⁸F]FDG PET/CT in combination with conventional imaging is currently the standard for disease evaluation in children with Langerhans-cell Histiocytosis (LCH) and the non-LCH disease spectrum. The common pitfalls of 2-[¹⁸F]FDG PET/CT in this setting are discussed.

Hypoxia in cervical cancer has been associated with a poor prognosis. Over the years ⁶⁸Ga labelled nitroimidazoles have been studied and have shown improved kinetics. We present our initial experience of hypoxia Positron Emission Tomography (PET) imaging in cervical cancer with ⁶⁸Ga-Nitroimidazole derivative and the correlation with ¹⁸F-FDG PET/CT and immunohistochemistry. Twenty women with cervical cancer underwent both ¹⁸F-FDG and ⁶⁸Ga-Nitroimidazole PET/CT imaging. Dual-point imaging was performed for ⁶⁸Ga-Nitroimidazole PET. Immunohistochemical analysis was performed with hypoxia inducible factor-1α (HIF-1α). We documented SUVmax, SUVmean of the primary lesions as well as tumor to muscle ratio (TMR), tumor to blood (TBR), metabolic tumor volume (MTV) and hypoxic tumor volume (HTV). There was no significant difference in the uptake of ⁶⁸Ga-Nitroimidazole between early and delayed imaging. Twelve patients had uptake on ⁶⁸Ga-Nitroimidazole PET. Ten patients demonstrated varying intensities of HIF-1α expression and six of these also had uptake on ⁶⁸Ga-Nitroimidazole PET. We found a strong negative correlation between HTV and immunohistochemical staining (r = −0.660; p = 0.019). There was no correlation between uptake on PET imaging and immunohistochemical analysis with HIF-1α. Two-thirds of the patients demonstrated hypoxia on ⁶⁸Ga-Nitroimidazole PET imaging.

Malignant melanoma is one of the more aggressive cancers in the skin, with an increasing incidence every year. Melanoma has a better prognosis if diagnosed early and survival tends to decrease once the disease has metastasized. Positron emission tomography (PET) with 2-[¹⁸F]fluoro-2-deoxy-D-glucose (¹⁸F-FDG) has been used extensively over the past two decades in staging and assessing responses to therapy in patients with melanoma. Metabolic PET parameters have been demonstrated to be independent prognostic factors for progression-free survival (PFS) and overall survival (OS) in different malignancies, melanoma included. In our study, we evaluated the metabolic parameters of ¹⁸F-FDG PET/CT (flourodeoxyglucose positron emission tomography/computed tomography) in predicting the overall survival in patients with malignant melanoma who presented for restaging. Metabolic PET parameters (maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG)) of the primary tumor, as well as whole-body MTV and TLG of the metastatic disease, were measured. Survival curves for OS were constructed and mortality rates were determined using the different PET variables. Forty-nine patients who presented for a PET/CT restaging in melanoma were included in this study. We found that non-survivors had significantly higher median MTV (11.86 cm³ vs. 5.68 cm³; p-value = 0.022), TLG (3125 vs. 14; p-value = 0.0357), whole-body MTV (53.9 cm³ vs. 14.4 cm³; p-value = 0.0076) and whole-body TLG (963.4 vs. 114.6; p-value = 0.0056). This demonstrated that high MTV and TLG values of the primary tumor and whole-body TLG as quantified by ¹⁸F-FDG PET/CT were prognostic factors for overall survival. The findings may potentially guide clinicians in decision making and identifying patients with a poorer prognosis.

Prostate adenocarcinoma (PCa) is a leading cause of mortality. Black males with high-risk PCa have a poorer prognosis compared to white males. Patients with International Society of Urological Pathology (ISUP) Grade Group (GG) 1 and 2 PCa have little potential for metastases post radical prostatectomy. ⁶⁸Gallium prostate specific membrane antigen (⁶⁸Ga-PSMA) PET/CT imaging for metastatic PCa is superior to conventional imaging in staging high-risk PCa. No strong evidence is available to support imaging low-risk patients. We aimed to evaluate the value of ⁶⁸Ga-PSMA PET/CT in black and white South African (BSA and WSA) males with GG1 and 2 PCa at initial staging. We evaluated 25 WSA and 123 BSA males. The image findings were correlated with prostate specific antigen (PSA). PSA levels significantly correlated with both primary tumor and whole-body PSMA-tumor volume (PSMA-TV) and were higher in BSA males. No differences were noted in the occurrence of metastases; however, PSA, seminal vesicle invasion and black race predicted metastases. Our findings suggest higher PSMA expression and tumor burden in BSA with histologically low-risk PCa, and future research with immunohistochemistry evaluation will be essential to confirm these findings.

Introduction: Multicystic dysplastic kidney disease (MCDK) is a notable congenital anomaly of the kidney and urinary tract, with potential risk for chronic kidney disease, yet data from sub-Saharan Africa remain scarce. This study examined the pattern of MCDK, associated contralateral kidney abnormalities, determined the predictors of MCDK involution and assessed short-term outcomes in children followed beyond one year in South Africa. Method: This retrospective study involved children under 13 years of age with suspected unilateral MCDK, confirmed on kidney ultrasound and [ ^99m Tc]Tc-MAG3 scans at the Red Cross War Memorial Children’s Hospital between January 1, 2014, and December 31, 2023. Demographic, clinical, and radiologic data were obtained. The Log-rank test and Cox Proportional Hazards regression analyses were used to identify predictors of MCDK involution. Results: Among 1,581 new cases, 98 (6.2%) had unilateral MCDK. 50% were male, and 57.1% had left-sided involvement. Median follow-up was 60 months (IQR: 12–72). Contralateral kidney abnormalities occurred in 17 (17.3%), most commonly duplex kidney (35.3%) and ureteropelvic junction obstruction (29.4%), but no vesicoureteric reflux was noted. Of 81 children followed beyond a year, 80.2% demonstrated contralateral hypertrophy, and 69.1% exhibited involution of the affected kidney. Initial kidney size ≤ 5.0 cm was the sole predictor of involution (Hazard Ratio: 2.42, 95% CI: 1.31–4.48). Urinary tract infections occurred in 18.5%, proteinuria in 2.5%, hypertension in 1.2%, and 2.5% developed chronic kidney disease related to contralateral dysplasia. One nephrectomy was performed, and no malignancies or deaths. At last follow-up, 28.4% were lost to follow-up, and 12.3% had transitioned to adolescent clinics. Conclusion: All MCDK cases were unilateral, with duplex kidney being the most common contralateral abnormality, a distinctive finding previously unreported. Follow-up into adolescence may be beneficial, as progression of chronic kidney disease is rare in those without contralateral anomalies. Multicentre long-term studies are needed to provide standardised follow-up guidelines.