title: 'Reverse discordance' between 68Ga-DOTA-NOC PET/CT and 177Lu-DOTA-TATE posttherapy scan: the plausible explanations and its implications for high-dose therapy with radiolabeled somatostatin receptor analogs.
abstract: In this technical note, an unusual discordance between diagnostic and posttherapeutic scan resulting from the use of different somatostatin receptor ligands in two settings is described. Such observation, we believe, is multifactorial, but most importantly arises due to different receptor affinity profile of the ligands and different somatostatin receptor subtype expression in different tumors. It is important for the treating physician to be aware of this phenomenon that would aid in improving our understanding of complex ligand-receptor interactions in various somatostatin receptor-positive tumors with its possible implications for therapeutic decision making with radiolabeled somatostatin receptor analogues.
authors.affiliation: Radiation Medicine Centre, (BARC), Tata Memorial Hospital Annexe, Jerbai Wadia Road, Parel, Bombay 400 012, Maharashtra, India. drsanb@yahoo.com
authors.forename: Sandip
authors.initials: S
authors.lastname: Basu
authors.forename: Amit
authors.initials: A
authors.lastname: Abhyankar
authors.forename: Purushottam
authors.initials: P
authors.lastname: Kand
authors.forename: Rakesh
authors.initials: R
authors.lastname: Kumar
authors.forename: Ramesh
authors.initials: R
authors.lastname: Asopa
authors.forename: Mysore Govinda Ramakrishna
authors.initials: MG
authors.lastname: Rajan
authors.forename: Uday
authors.initials: U
authors.lastname: Nayak
authors.forename: Hemant
authors.initials: H
authors.lastname: Shimpi
authors.forename: Tapas
authors.initials: T
authors.lastname: Das
authors.forename: Meera
authors.initials: M
authors.lastname: Venkatesh
authors.forename: Sudipta
authors.initials: S
authors.lastname: Chakrabarty
authors.forename: Sharmila
authors.initials: S
authors.lastname: Banerjee
mesh_terms: D016477:Artifacts; D018276:Carcinoma, Medullary / Q000175:diagnosis* / Q000473:pathology / Q000532:radiotherapy; D006801:Humans; D007553:Isotope Labeling; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D015282:Octreotide / Q000031:analogs & derivatives*; D009942:Organometallic Compounds; D049268:Positron-Emission Tomography; D011829:Radiation Dosage; D011879:Radiotherapy Dosage; D017481:Receptors, Somatostatin / Q000378:metabolism*; D013004:Somatostatin / Q000031:analogs & derivatives / Q000627:therapeutic use; D014057:Tomography, X-Ray Computed
chemical_list: C504894:68Ga-DOTANOC; D009942:Organometallic Compounds; D017481:Receptors, Somatostatin; D013004:Somatostatin; C447941:lutetium Lu 177 dotatate; D015282:Octreotide