Our objective was to develop version 1.0 of a novel framework for response evaluation criteria in prostate-specific membrane antigen (PSMA) PET/CT (RECIP) and a composite response classification that ...combines responses by prostate-specific antigen (PSA) measurements and by RECIP 1.0 (PSA + RECIP).
This was an international multicenter, retrospective study. One hundred twenty-four men with metastatic castration-specific prostate cancer (mCRPC) who underwent
Lu-PSMA therapy and received PSMA PET/CT at baseline and at an interim time point of 12 wk were included. Pairs of baseline interim PET/CT scans were interpreted by consensus among 3 masked readers for appearance of new lesions. Tumor lesions were segmented, and total PSMA-positive tumor volume (PSMA-VOL) was obtained. Appearance of new lesions and changes in PSMA-VOL were combined to develop RECIP 1.0, which included classifications of complete response (RECIP-CR: absence of any PSMA-ligand uptake on interim PET/CT), partial response (RECIP-PR: decline ≥ 30% in PSMA-VOL and no appearance of new lesions), progressive disease (RECIP-PD: increase ≥ 20% in PSMA-VOL and appearance of new lesions), and stable disease (RECIP-SD: any condition but RECIP-PR or RECIP-PD). Changes in PSA levels at 12 wk by Prostate Cancer Working Group Criteria 3 were recorded. PSA + RECIP results were defined as response (PSA decline ≥ 50% or RECIP-PR/CR) or progression (PSA increase ≥ 25% or RECIP-PD). The study's primary outcome measure was the prognostic value of RECIP 1.0 for overall survival (OS). The secondary outcome measure was the prognostic accuracy (C-index) of PSA + RECIP versus PSA responses.
Patients with RECIP-PD (
= 39; 8.3 mo) had a shorter OS than patients with stable disease (RECIP-SD) (
= 47; 13.1 mo;
< 0.001) or RECIP-PR (
= 38; 21.7 mo;
< 0.001). In identifying responders and progressors, PSA + RECIP had C-indices superior to those of PSA only: 0.65 versus 0.62 (
= 0.028) and 0.66 versus 0.63 (
= 0.044), respectively.
PSMA PET/CT by RECIP 1.0 is prognostic for OS and can be used as a response biomarker to monitor early efficacy of
Lu-PSMA in men with mCRPC. PSA + RECIP may be used as a novel composite endpoint in mCRPC clinical trial design.
Purpose
To compare the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1, the adapted Prostate Cancer Working Group Criteria 3 (aPCWG3), the adapted Positron Emission Tomography Response ...Criteria in Solid Tumors (aPERCIST), the PSMA PET Progression (PPP), and the Response Evaluation Criteria In PSMA-Imaging (RECIP) 1.0 for response evaluation using prostate-specific membrane antigen (PSMA)-PET/CT in men with metastatic castration-resistant prostate cancer (mCRPC) treated with
177
Lu-PSMA radioligand therapy.
Methods
A total of 124 patients were included in this multicenter retrospective study. All patients received
177
Lu-PSMA and underwent PSMA-PET/CT scans at baseline (bPET) and at 12 weeks (iPET). Imaging responses according to RECIST 1.1, aPCWG3, aPERCIST, PPP, and RECIP 1.0 were interpreted by consensus among three blinded readers. Changes in total tumor burden were obtained using the semi-automatic qPSMA software. The response according to each criterion was classified to progressive disease (PD) vs no-PD. Primary outcome measure was the prognostic value (by Cox regression analysis) for overall survival (OS). Secondary outcome measure was the inter-reader reliability (by Cohen’s
κ
coefficient).
Results
A total of 43 (35%) of patients had non-measurable disease according to RECIST 1.1. Sixteen (13%), 66 (52%), 72 (58%), 69 (56%), and 39 (32%) of 124 patients had PD according to RECIST 1.1, aPCWG3, aPERCIST, PPP, and RECIP, respectively. PD vs no-PD had significantly higher risk of death according to aPCWG3 (HR = 2.37; 95%CI, 1.62–3.48;
p
< 0.001), aPERCIST (HR = 2.48; 95%CI, 1.68–3.66;
p
< 0.001), PPP (HR = 2.72; 95%CI, 1.85–4.01;
p
< 0.001), RECIP 1.0 (HR = 4.33; 95%CI, 2.80–6.70;
p
< 0.001), but not according to RECIST 1.1 (HR = 1.29; 95%CI, 0.73–2.27;
p
= 0.38). The
κ
index of RECIST 1.1, aPCWG3, aPERCIST 1.0, PPP, and RECIP 1.0 for identifying PD vs no-PD were 0.50 (95%CI, 0.32–0.76), 0.72 (95%CI, 0.63–0.82), 0.68 (95%CI, 0.63–0.73), 0.73 (95%CI, 0.63–0.83), and 0.83 (95%CI, 0.77–0.88), respectively.
Conclusion
PSMA-PET-specific criteria for early response evaluation in men with mCRPC treated with
177
Lu-PSMA achieved higher prognostic values and inter-reader reliabilities in comparison to conventional CT assessment or to criteria adapted to PSMA-PET from other imaging modalities. RECIP 1.0 identified the fewest patients with PD and achieved the highest risk of death for PD vs. no-PD, suggesting that other classification methods tend to overcall progression. Prospective validation of our findings on an independent patient cohort is warranted.
Fibroblast-activation protein (FAP) is a serine protease classified in the dipeptidyl peptidase 4 (DPP4) family. FAP is predominantly expressed in activated fibroblasts such as the cancer-associated ...fibroblasts (CAFs). FAP expression in CAFs is associated with tumor progression and poor prognosis in solid cancers. Recently, radiolabeled FAP inhibitors (FAPI) has been developed, which enables positron emission tomography (PET) imaging of FAP. FAPI PET/CT can provide a higher tumor-to-background ratio (TBR) than
F-fludeoxyglucose PET/CT in various cancers, and thus has attracted substantial attention. As studies on FAPI PET grow in number and size, incidental findings related to non-oncologic conditions have been increasingly reported. FAPI PET uptake has been reported in various conditions such as benign tumors, fibrotic, granulomatosis, scarring/wound, degenerative diseases, and inflammatory diseases.The knowledge of physiological and non-oncologic causes of FAPI uptake is indispensable for accurate FAPI PET/CT interpretation and can help appropriate management of incidental findings on FAPI PET/CT in patients referred for cancer staging indications. In this review article, we describe for each organ system (Brain, Oral mucosa, Salivary Glands, Thyroid, Lung, Myocardium, Breast, Esophagus, Stomach, Intestine, Liver, Gallbladder, Pancreas, Spleen, Kidney, , Uterus, Bone marrow, Joints, Muscle, Vessels, Lymph nodes), the patterns of physiological FAPI uptake and the main causes of non-oncological uptake reported from the literature with FAPI-02, FAPI-04 and FAPI-46. We also illustrate some examples from our institutional database at UCLA.
Sarcomas are rare tumors of mesenchymal origin and comprise only around 1% of adult cancers. The abundance of sarcoma histiotypes, with distinct imaging characteristics, biology, clinical behavior ...and treatment strategy, result in a complex disease presentation, requiring management by multidisciplinary specialized sarcoma centers. Oncologic and musculoskeletal radiology guidelines provide minimal guidance and only fragmentary information on the indications of 18F-FDG PET/CT in sarcoma. Therefore, knowledge of various phenotypes with preference for bone and lymph node metastases or higher incidence of local and distant recurrence is essential to select the appropriate diagnostic imaging tests and its interpretation. Benign and malignant soft tissue and bone tumors often share common radiographic and metabolic imaging characteristics. In addition, metastases of various histiotypes might exhibit a spectrum of atypical imaging appearances. Therefore, imaging specialists need to be aware of these variants and associated pitfalls of sarcoma imaging.
Prostate-specific membrane antigen (PSMA)-targeted radioligand therapy can improve the outcome of patients with advanced metastatic castration-resistant prostate cancer, but patients do not respond ...uniformly. We hypothesized that using the salivary glands as a reference organ can enable selective patient stratification. We aimed to establish a PSMA PET tumor-to-salivary gland ratio (PSG score) to predict outcomes after
LuPSMA.
In total, 237 men with metastatic castration-resistant prostate cancer treated with
LuPSMA were included. A quantitative PSG (qPSG) score (SUV
ratio of whole-body tumor to parotid glands) was semiautomatically calculated on baseline
GaPSMA-11 PET images. Patients were divided into 3 groups: high (qPSG > 1.5), intermediate (qPSG = 0.5-1.5), and low (qPSG < 0.5) scores. Ten readers interpreted the 3-dimensional maximum-intensity-projection baseline
GaPSMA-11 PET images and classified patients into 3 groups based on visual PSG (vPSG) score: high (most of the lesions showed higher uptake than the parotid glands) intermediate (neither low nor high), and low (most of the lesions showed lower uptake than the parotid glands). Outcome data included a more than 50% prostate-specific antigen decline, prostate-specific antigen (PSA) progression-free survival, and overall survival (OS).
Of the 237 patients, the numbers in the high, intermediate, and low groups were 56 (23.6%), 163 (68.8%), and 18 (7.6%), respectively, for qPSG score and 106 (44.7%), 96 (40.5%), and 35 (14.8%), respectively, for vPSG score. The interreader reproducibility of the vPSG score was substantial (Fleiss weighted κ, 0.68). The more than 50% prostate-specific antigen decline was better in patients with a higher PSG score (high vs. intermediate vs. low, 69.6% vs. 38.7% vs. 16.7%, respectively, for qPSG
< 0.001 and 63.2% vs 33.3% vs 16.1%, respectively, for vPSG
< 0.001). The median PSA progression-free survival of the high, intermediate, and low groups by qPSG score was 7.2, 4.0, and 1.9 mo (
< 0.001), respectively, by qPSG score and 6.7, 3.8, and 1.9 mo (
< 0.001), respectively, by vPSG score. The median OS of the high, intermediate, and low groups was 15.0, 11.2, and 13.9 mo (
= 0.017), respectively, by qPSG score and 14.3, 9.6, and 12.9 mo (
= 0.018), respectively, by vPSG score.
The PSG score was prognostic for PSA response and OS after
LuPSMA. The visual PSG score assessed on 3-dimensional maximum-intensity-projection PET images yielded substantial reproducibility and comparable prognostic value to the quantitative score.
Few publications have investigated the diagnostic value of dual-time-point prostate-specific membrane antigen (PSMA) PET/CT imaging with a standard whole-body (WB) acquisition at 60 min after ...injection and an additional late acquisition at 160–180 min (1-3). Implementing a late PET/CT acquisition such as at 180 min after injection faces clinical challenges, including patient compliance, scheduling, and PET/CT workflows. Therefore, since 2019, the standard protocol for staging, assessment of biochemical recurrence, and treatment response monitoring at our institution has been a dual-time-point acquisition with postvoid WB 68GaGa-PSMA-11 PET/CT 60 min after injection and additional late postvoid pelvic PET/CT 90 min after injection without forced diuresis using furosemide (Fig. 1). In our experience, postvoid pelvic imaging at 90 min after injection is feasible and improves lesion detection and characterization for several reasons: increased tumor 68GaGa-PSMA-11 uptake on late PET/CT acquisitions, with an improved target-to-background ratio; decreased radiotracer uptake on late PET images in nontumoral lesions in the setting of nonspecific uptake on standard WB 68GaGa-PSMA-11 PET/CT; and a CT urographic phase with optimal contrast medium enhancement of the collecting system, ureter, and urinary bladder. Typical clinical scenarios include the detection of local recurrence after radical prostatectomy, differentiation between a postinterventional defect and residual or recurrent tumor after high-intensity focused ultrasound or radiofrequency ablation, confirmation of pelvic lymph node metastases with low PSMA uptake on standard WB 68GaGa-PSMA-11 PET/CT, and specification of nonspecific PSMA uptake on standard WB 68GaGa-PSMA-11 PET/CT as false-positive.
[ 68 Ga]Ga-FAPI-46 PET in a Borderline Ovarian Tumor Unterrainer, Lena M; Memarzadeh, Sanaz; Moatamed, Neda A ...
Journal of Nuclear Medicine,
2024-May-01, 2024-05-00, 20240501, Letnik:
65, Številka:
5
Journal Article
177LuLu-labeled prostate-specific membrane antigen (PSMA) radioligand therapy effectively treats metastatic castration-resistant prostate cancer. Patients requiring treatment, and consequently the ...number of theranostic centers, are expected to increase significantly after Food and Drug Administration and European Medicines Agency approval. This requires standardization or harmonization among theranostic centers. The aim of this study was to assess operational differences and similarities among 177LuLu-PSMA treatment centers. Methods: A questionnaire comprising 62 items, designed by a core team of 5 physicians and externally reviewed by international experts, was developed. Study participants were asked to provide answers about their center, patient selection, radiopharmaceuticals, clinical assessment before and after 177LuLu-PSMA treatments, laboratory values, treatment discontinuation, posttreatment imaging, and general information. An invitation e-mail to participate in the study was sent in June 2022. Duplicates were removed to allow for only one valid response per center. Results: Ninety-five of 211 (45%) contacted centers completed the questionnaire. Most participating centers were in Europe (51%), followed by America (22%) and Asia (22%). During the 12 mo before this study, a total of 5,906 patients received 177LuLu-PSMA therapy at the 95 participating centers. Most of these patients were treated in Europe (2,840/5,906; 48%), followed by Asia (1,313/5,906; 22%) and Oceania (1,225/5,906; 21%). PSMA PET eligibility for 177LuLu-PSMA was determined most frequently using 68Ga-PSMA-11 (77%). Additional pretherapy imaging included 18F-FDG PET/CT, CT, renal scintigraphy, and bone scintigraphy at 41 (49%), 27 (32%), 25 (30%), and 13 (15%), respectively, of the 84 centers for clinical standard of care, compassionate care, or local research protocols and 11 (26%), 25 (60%), 9 (21%), and 28 (67%), respectively, of the 42 centers for industry-sponsored trials. PSMA PET eligibility criteria included subjective qualitative assessment of PSMA positivity at 33% of centers, VISION criteria at 23%, and TheraP criteria at 13%. The mean standard injected activity per cycle was 7.3 GBq (range, 5.5–11.1 GBq). Sixty-two (65%) centers applied standardized response assessment criteria, and PSMA PET Progression Criteria were the most applied (37%). Conclusion: Results from this international survey revealed interinstitutional differences in several aspects of 177LuLu-PSMA radionuclide therapy, including patient selection, administered activity, and the response assessment strategy. Standardization or harmonization of protocols and dedicated training are desirable in anticipation of increasing numbers of patients and theranostic centers.
