Bone marrow impairment during early [177Lu]PSMA-617 radioligand therapy: Haematotoxicity or tumour progression?

EJNMMI Research

Table 4 Results of univariate and multivariate linear regressions of various pre-therapeutic variables with haematological parameters at baseline

Linear regression	Variable	Hb_baseline		PLT_baseline		WBC_baseline
Linear regression	Variable	p	adj. R²	p	adj. R²	p	adj. R²
Univariate	Age	0.371		0.585		0.970
	PSA	< 0.001	0.28	0.009	0.11	0.012	0.10
	TV50	< 0.001	0.32	0.021	0.10	0.037	0.09
	Bone involvement (PROMISE)	< 0.001	0.19	0.001	0.17	0.006	0.15
	Prostatectomy	0.2		0.132		0.661
	Anti-hormonal therapy	0.928		0.764		0.850
	Chemotherapy	0.286		0.376		0.298
	External-beam radiation therapy	0.58		0.252		0.668
	[²²³Ra]Radiumdichloride	0.006	0.10	0.014	0.09	0.041	0.08
Multivariate	PSA	0.004	0.40	0.010	0.23	0.031	0.21
	TV50	0.016		0.034		0.043
	Bone involvement (PROMISE)	0.029		0.002		0.011
	[²²³Ra]Radiumdichloride	0.173		0.261		0.968

All variables with statistically significant results (bold) correlate inversely with haematological parameters (Hb, PLT, WBC) at baseline; Hb = haemoglobin concentration, PLT = platelet count, WBC = white blood cell count, PSA = prostate-specific antigen, TV50 = whole-body tumour volume assessed by semi-automated analysis of PSMA PET/CT acquisitions utilising percentage thresholding (50% of maximal lesion SUV)