FDG-PET/CT for Response Monitoring in Metastatic Breast Cancer: The Feasibility and Benefits of Applying PERCIST

Abstract

Background: We aimed to examine the feasibility and potential benefit of applying PET Response Criteria in Solid Tumors (PERCIST) for response monitoring in metastatic breast cancer (MBC). Further, we introduced the nadir scan as a reference. Methods: Response monitoring FDG-PET/CT scans in 37 women with MBC were retrospectively screened for PERCIST standardization and measurability criteria. One-lesion PERCIST based on changes in SULpeak measurements of the hottest metastatic lesion was used for response categorization. The baseline (PERCISTbaseline) and the nadir scan (PERCISTnadir) were used as references for PERCIST analyses. Results: Metastatic lesions were measurable according to PERCIST in 35 of 37 (94.7%) patients. PERCIST was applied in 150 follow-up scans, with progression more frequently reported by PERCISTnadir (36%) than PERCISTbaseline (29.3%; p = 0.020). Reasons for progression were (a) more than 30% increase in SULpeak of the hottest lesion (n = 7, 15.9%), (b) detection of new metastatic lesions (n = 28, 63.6%), or both (a) and (b) (n = 9, 20.5%). Conclusions: PERCIST, with the introduction of PERCISTnadir, allows a graphical interpretation of disease fluctuation that may be beneficial in clinical decision-making regarding potential earlier termination of non-effective toxic treatment. PERCIST seems feasible for response monitoring in MBC but prospective studies are needed to come this closer.

Clinical Impact of FDG-PET/CT Compared with CE-CT in Response Monitoring of Metastatic Breast Cancer

“…Since our results were part of the clinical routine, a standardized set of response criteria such as PERCIST was not applied for FDG-PET/CT. However, we showed in previous studies that the clinical application of PERCIST is feasible [29] and has the potential to increase the level of inter-observer agreement and reliability when compared with qualitative visual assessment [30].…”

Comparison of Image Quality and Quantification Parameters between Q.Clear and OSEM Reconstruction Methods on FDG-PET/CT Images in Patients with Metastatic Breast Cancer

“…It has also been reported that PERCIST has high applicability [ 16 ], has a higher level of overall interrater agreement and reliability compared with a qualitative assessment [ 35 , 36 ], and is superior in the detection of new lesions or unequivocal progression in nontarget lesions [ 37 ]. Therefore, clinical implementation of the PERCIST assessment may improve the prognostic stratification [ 15 , 37 , 38 ] and provide a standardized approach independent of interpreters and reconstruction methods.…”

“…Response evaluation using 2-[ 18 F]FDG-PET/CT may improve clinical management and survival [ 12 , 13 , 14 ]. Quantitative PET/CT is becoming increasingly important for more objective evaluations of tumor response [ 7 ], with the PET Response Criteria in Solid Tumors (PERCIST) being suggested as feasible and valuable criteria in breast cancer [ 15 , 16 , 17 ].…”

Breast PET/MRI Hybrid Imaging and Targeted Tracers

“…According to such criteria, an uptake decrease by 30% is considered an index of tumor response, with a minimum SUL absolute difference of 0.8 59 . Recent evidence also suggests the feasibility of PERCIST for treatment monitoring of metastatic breast cancer with a possible clinical decision‐making role as to whether or not to stop unresponsive chemotherapy schedules early 60 . Functional assessment is also promising to predict response to treatment at baseline evaluation, thereby aiding in the selection of patients for neoadjuvant chemotherapy; for those patients predicted to have a low probability of achieving pathological complete response following neoadjuvant chemotherapy, they can be selected for surgical excision instead, avoiding unnecessary toxicity and psychologic distress.…”