Artificial Intelligence in Breast Cancer: A Systematic Review on PET Imaging Clinical Applications.

BACKGROUND: 18F-FDG PET/CT imaging represents the most important functional imaging method in oncology. European Society of Medical Oncology and the National Comprehensive Cancer Network guidelines defined a crucial role of 18F-FDG PET/CT imaging for local/locally advanced breast cancer. The application of artificial intelligence on PET images might potentially contributes in the field of precision medicine. OBJECTIVE: This review aims to summarize the clinical indications and limitations of PET imaging for comprehensive artificial intelligence in relation to breast cancer subtype, hormone receptor status, proliferation rate, and lymphonodal (LN)/distant metastatic spread, based on recent literature. METHODS: A literature search of the Pubmed/Scopus/Google Scholar/Cochrane/EMBASE databases was carried out, searching for articles on the use of artificial intelligence and PET in breast tumors. The search was updated from January 2010 to October 2021 and was limited to original articles published in English and about humans. A combination of the search terms "artificial intelligence", "breast cancer", "breast tumor", "PET", "Positron emission tomography", "PET/CT", "PET/MRI", "radiomic"," texture analysis", "machine learning", "deep learning" was used. RESULTS: Twenty-three articles were selected following the PRISMA criteria from 139 records obtained from the Pubmed/Scopus/Google Scholar/Cochrane/EMBASE databases according to our research strategy. The QUADAS of 30 full-text articles assessed reported seven articles that were excluded for not being relevant to population and outcomes and/or for lower level of evidence. The majority of papers were at low risk of bias and applicability. The articles were divided per topic, such as the value of PET in the staging and re-staging of breast cancer patients, including new radiopharmaceuticals and simultaneous PET/MRI. CONCLUSION: Despite the current role of AI in this field remains still undefined, several applications for PET/CT imaging are under development, with some preliminary interesting results particularly focused on the staging phase that might be clinically translated after further validation studies.

Choline-PET/CT in the Differential Diagnosis Between Cystic Glioblastoma and Intraparenchymal Hemorrhage.

OBJECTIVE: Glioblastoma multiforme (GBM) represents the most common and malignant glioma, accounting for 45%-50% of all gliomas. The median survival time for patients with glioblastoma is only 12-15 months after surgical, chemioterapic and radiotherapic treatment; a correct diagnosis is naturally fundamental to establish a rapid and correct therapy. Non-invasive imaging plays a pivotal role in each phase of the diagnostic workup of patients with suspected for diagnosis. The aim of this case report was to describe the potential clinical impact of 18F-fluorocholine (FCH) PET/CT in the assessment of a cystic GBM mimicking a spontaneous hemorrhage. METHODS: a 57 years-old male with intraparenchymal hemorrhage at CT imaging initially in reduction ad serial imaging and suspected right fronto-temporo-parietal lesion at MRI underwent dynamic and static (60' after tracer injection) FCH PET/CT of the brain. RESULTS: FCH PET/CT showed rapid tracer uptake after few second from injection at dynamic acquisition and consequent incremental mild uptake at static imaging after 60 minutes at the level of oval formation in the right cerebral hemisphere characterized by annular and peripheral high metabolic activity. The central region of the lesion was characterized by the absence 18F-FCH uptake most likely due to blood component. The patient underwent surgery for tumor removal; the histopathological examination confirmed the suspect of GBM. Chemo-radiotherapic adjuvant protocol according to Stupp protocol was therefore administrated; to date the patient is alive without any progression disease at 5 months from treatment. CONCLUSION: In this case report FCH PET/CT represented the final diagnostic technique to confirm the suspicious of a cystic GBM. Our case demonstrated the potential role of 18F-FCH PET/CT for discrimination of higher proliferation area over intraparenchymal hemorrhage, supporting the potential use of this imaging biomarker in surgical or radiosurgical approach. Obviously, further prospective studies are needed to confirm this role and to exactly define possible routinely applications.

Could 68-Ga PSMA PET/CT become a new tool in the decision-making strategy of prostate cancer patients with biochemical recurrence of PSA after radical prostatectomy? A preliminary, monocentric series.

AIM: To evaluate the impact of gallium68 PSMA-11 (HBED-CC)-PET/CT on decision-making strategy of patients with relapsing prostate cancer (PC) presenting a second biochemical relapse after radical prostatectomy (RP) and salvage RT or salvage androgen deprivation therapy (ADT). MATERIALS AND METHODS: 40 patients were retrospectively analyzed. All of them had received prostatectomy. Thirteen out of 40 were addressed to gallium68 PSMA-11 (HBED-CC)-PET/CT for a biochemical relapse after RP, 14/40 after a salvage RT and 13/40 after salvage or adjuvant ADT. The PSA level ranged between 0.1 and 1.62 ng/ml (median value: 0.51 ng/ml). We studied the impact on the decision-making process of a multidisciplinary tumor board of additional data obtained from gallium68 PSMA-11 (HBED-CC)-PET/CT. RESULTS: Thirty-one out of 40 evaluated patients showed positive findings at gallium68 PSMA-11 (HBED-CC)-PET/CT (77.5%). Of them, five were positive in the prostatic bed, nine in the pelvic nodes, twelve in nodes outside the pelvis and eight at bone level. Nine patients presented two different sites of relapse (22.5%). Gallium68 PSMA-11 (HBED-CC)-PET/CT data changed the therapeutic approach in 28 patients (70%). CONCLUSIONS: Gallium68 PSMA-11 (HBED-CC)-PET/CT can be a useful tool in the restaging of post-RP, RT or ADT patients presenting biochemical relapse of PC and it could change the decision-making process in up of 70% of these patients. Prospective, larger series are needed to establish the correct role of this very promising tool in the staging and therapeutic approach of PC patients.

[11C]choline-PET-guided helical tomotherapy and estramustine in a patient with pelvic-recurrent prostate cancer: local control and toxicity profile after 24 months.

[11C]choline positron emission tomograhy can be useful to detect metastatic disease and to localize isolated lymph node relapse after primary treatment in case of prostate-specific antigen failure. In case of lymph node failure in prostate cancer patients, surgery or radiotherapy can be proposed with a curative intent. Some reports have suggested that radiotherapy could have a role in local control of oligometastatic lymph node disease. This is the first reported case of [11C]choline positron emission tomography-guided helical tomotherapy concomitant with estramustine for the treatment of pelvic-recurrent prostate cancer. At 24 months after the end of helical tomotherapy, prostate-specific antigen was undetectable and no late toxicities were recorded. A disease-free survival of 24 months, in the absence of any type of systemic therapy, is uncommon in metastatic prostate cancer. The therapeutic approach of the case report is discussed and a literature review on the issue is presented.