A 79-year-old man treated for prostate cancer (PCa) in 2018 with concurrent hormone therapy and radical radiotherapy (RT) was given metastasis-directed RT because of skeletal progression of PCa in 2021. On [18F]-choline positron emission tomography/computed tomography (CT) for biochemical recurrence (prostate-specific antigen level: 4.96 ng/mL), he showed significant uptake in multiple skeletal lesions and focal uptake in a left lung nodule. CT-guided biopsy revealed a sarcomatoid lung carcinoma. This case confirms that histopathological evaluation is mandatory in the event of significant radiolabeled choline uptake in a single lung nodule.

ABSTRACT:We present a case of neuroendocrine tumor localized in the gastric mucosa, incidentally detected by 18F-choline PET/CT in a 69-year-old man with prostate cancer. 18F-choline PET/CT scan showed an increased activity in the stomach, later diagnosed as a well-differentiated neuroendocrine tumor, at biopsy. A careful attention of reading 18F-choline PET/CT images should be made, in order to avoid the missing of potential concomitant neoplasia in patients with prostate cancer.

Purpose The primary aim of this multicenter retrospective analysis is to examine the role of(18)F-choline PET/CT as a diagnostic tool for staging and restaging prostate cancer (PCa) in a large population in the light of 10 years of clinical experience. A secondary aim of the study is to produce data on the predictors of a positive(18)F-choline PET/CT result in the setting of PCa primaries and biochemical recurrences. Materials and Methods This multicenter retrospective cohort study is based on data collected by 9 Italian nuclear medicine departments. Between October 2008 and September 2019, 3343 men underwent(18)F-choline PET/CT scans before receiving definitive treatments for a primary PCa or biochemical recurrence. Inclusion criteria were (1) histologically proven PCa (on surgical specimens or prostate biopsies from patients not treated surgically) and (2) availability of clinical and pathological data, including serum prostate specific antigen (PSA) level at the time of PET/CT scanning. Results F-18-choline PET/CT was performed in 545 cases (16.4%) for cancer staging and in 2798 (83.6%) for restaging purposes, and the result was positive in 540 (99.1%) for the former and 1993 (71.2%) for the latter. A positive PET/CT result was always associated with a high Gleason score (>7) and high PSA levels (P< 0.01). The percentage of patients with a PSA threshold less than 1.0 ng/mL for performing PET/CT was higher in the years 2014 to 2019 (n = 341, 25% of cases) than during the previous period (n = 148, 16%; in 2008-2013). When used for staging purposes, receiver operating characteristic analysis showed that PSA levels of 9.2, 16.4, and 16.6 ng/mL were the optimal cutoffs for distinguishing between positive and negative PET/CT findings for local disease, lymph node involvement, and metastasis, respectively. In the restaging setting, a PSA level of 1.27 ng/mL was the optimal cutoff for distinguishing between a positive and negative PET/CT scan. Conclusions F-18-choline PET/CT can help identify early recurrences, even in the case of low PSA levels (<1 ng/mL). Our data suggest that important improvements have been made in the interpretation of(18)F-choline images and in patient selection in the last 5 years.

With the introduction of an organized mammographic screening, the incidence of ductal carcinoma in situ (DCIS) has experienced an important increase. Our experience with sentinel lymph node biopsy (SLNB) among patients with DCIS is reviewed. We collected retrospective data on patients operated on their breasts for DCIS (pTis), DCIS with microinvasion (DCISM) (pT1mi) and invasive ductal carcinoma (IDC) sized <= 2cm (pT1) between January 2002 and June 2016, focusing on the result of SLNB. 543 DCIS, 84 DCISM, and 2111 IDC were included. In cases of DCIS and DCISM, SLNB resulted micrometastatic respectively in 1.7% and 6.0% of cases and macrometastatic respectively in 0.9% and 3.6% of cases. 5-year disease-free survival and overall survival in DCISM and IDC were similar, while significantly longer in DCIS. 5-year local recurrence rate of DCIS and DCISM were respectively 2.5% and 7.9%, and their 5-year distant recurrence rate respectively 0% and 4%. IDC, tumor grading >= 2 invasive component in DCIS were tumor multifocality/multicentricity, grading >= 2, ITCs and micrometastases. Our study suggests that despite its rarity, sentinel node metastasis may also occur in case of DCIS, which in most cases are micrometastases. Even in the absence of an evident invasive component, microinvasion should always be suspected in these cases, and their management should be the same as for IDC.

118 Objectives The aim of this study was to evaluate the role of PET in detecting and localizing recurrences in a series of pts with biochemical relapse from prostate cancer. Methods 221 consecutive pts (ma 70.7±7.8 y) with increased PSA after radical prostatectomy (164) or radiotherapy (57) were investigated. All pts underwent whole-body PET; at the time of PET examination mean PSA was 12.2±41.4 ng/ml; 132/221 of them were receiving hormone therapy. Pathological findings were confirmed by further exams, biopsies and follow-up. The relationships between PET results and both the primary prostate tumor differentiation/growth pattern, expressed by Gleason Score (GS) and PSA at the time of PET were investigated. We divided our pts into 6 subgroups, 4 on the basis of PSA (PSA≤1, 1 5 ng/ml) and 2 as respect to GS (GS≤7 and GS>7). Results PET correctly detected malignancies in 132 pts (60%): 53 had local recurrences,79 metastatic lymph nodes, 52 bone metastases, 10 different distant mets (especially in lungs and liver) and many had both local and distant disease. We found a clear positive correlation of pathological PET and both PSA levels and GS. In fact PET was positive in: 27.8% (10/36) of pts with PSA≤1 (80% were receiving hormone treatment), 40.4% (19/47) of pts with 1 5 ng/ml. Pet was positive in 53.7% of pts with GS ≤7 and in 76.5% of those with a GS >7. Mean PSA was 18±52 ng/ml in pts with positive PET vs 2.6±3.9 ng/ml in pts with negative scans. Recurrences were found in 47/57 (82.5%) of pts treated with radiotherapy and in 77/164 (47.0%) after radical prostatectomy Conclusions PET is a reliable whole-body tool that allows disease detection and localization in pts with biochemical relapse from prostate cancer. Its detection rate positively correlates to PSA levels and tumor GS and may be also useful in pts with PSA≤1ng/ml as wel

424 Objectives To examine if Tc is adeguate for post TRD scan and verify if the lower radiation dose delivered to remnant thyroid tissue, reducing stunning can improve outcome after ablative I therapy. Methods 508 consecutive pts after TRD for non metastatic papillary or follicular cancer of the thyroid (TSH>30mIU/mL) entered the study and were divided into 2 groups (G): G1 (176 pts, from 2002 to 2004) had a scan with 185 MBq of I; G2 (318 pts, from 2005 to 2009) had a scan with 370 MBq of Tc. 14/508 pts had a Tc not detecting tissue remnant and were excluded. In case of scan evidence of residual thyroid tissue, after 72h from diagnostic dose of Tc or I, pts of both groups were treated with a standard dose of 3.7 GBq of I to ablate the remnant thyroid tissue. We considered the ablation was successfully if at 1 year a negative thyroid scan and an undetectable serum thyroglobulin (Tg) level ( 0.05 were considered of statistical consistency. Results The 2 G were comparable (Tab) as for age, sex ratio, tumour type, stage, Tg and AbTg (p > 0.05). Only 14/318 Tc scans did not detect remnant tissue, while among them in 7/14 pts a subsequent I scan did detect it. Based on 1y negative scan-Tg-AbTg successful ablation were obtained in 111/176 (63%) in G1 and in 270/318 (85%) in G2 and in 116/176 (66%) in G1 and 290/318 (91%) in G2, if just a negative scan was considered as successful ablation (Tab) (p Conclusions Tc could be the first choice for post TRD scan, reserving I only in case of a negative scan. The better post ablation outcome which follows Tc scintigraphy is suggestive of some thyroid radiation stunning after I scintigraphy and this should further push to replace I with Tc for post TRD scan