PET/CT FAPI: Procedure and evidence review in oncology.

Neoplasms are composed of malignant tumor cells, which are surrounded by other non-tumor cellular elements, in what has been defined as the microenvironment or tumor stroma. Evidence on the importance of the tumor microenvironment has not stopped growing in recent years. It plays a central role in cell proliferation, tissue invasion, angiogenesis and cell migration. The paradigm is the family of new FAPI radiopharmaceuticals that show the density of the fibroblast activation protein (FAP) which is overexpressed in the cell membrane of activated cancer-associated fibroblasts (CAF), and its presence is related to poor prognosis. This educational document includes the procedure for performing PET/CT FAPI, biodistribution and the main potentially clinical applications in oncology to date.

[Comparison of administration of rhTSH with withdrawal of thyroid hormone. Follow-up of patients with differentiated thyroid carcinoma]. / Estudio comparativo entre la utilización de TSH recombinante y la estimulación endógena con TSH. Valoración en el seguimiento de los pacientes con carcinoma diferenciado de tiroides.

UNLABELLED: Recombinant human thyrotropin (rhTSH) has been introduced recently in follow up of differentiated thyroid cancer (DTC) patients, as an alternative of thyroid hormone withdrawal. The aim of this retrospective study is to compare recombinant human thyrotropin versus endogenous stimulation. MATERIAL AND METHODS: Thirty-three patients with DTC with previous thyroidectomy and thyroid ablation were selected. All patients underwent whole-body radioiodine scanning and third day serum thyroglobulin (TG) measurement by two techniques, the first one after conventional thyroid hormone withdrawal (TSHe, TGe), and the second one after rhTSH stimulation (TSHr, TGr). Measurement of TG was performed on the third day due to the infrastructure. We only included patients with stable disease, without therapeutic interventions between two consecutive controls in an interval inferior to one year. Two qualitative categories were defined for TG (positive TG > 2 ng/ml or negative TG<2 ng/ml) and whole-body radioiodine scan (positive or negative). RESULTS: TSHe: 62.9 +/- 55.48; TSHr: 113.16 +/- 50.6; (p: ns); TGe: 62.5 +/- 115.7; TGr: 54.6 +/- 111.1; (p: 0.044). Quantitative data analysis showed significant differences between two techniques. Qualitative data analysis showed no significant differences in clinical setting based in TG and radioiodine scan. CONCLUSIONS: Administration of rhTSH produces a significantly higher increase of TSH than thyroid hormone withdrawal and lower increase in TG levels. There were no significant differences in the stage of disease (TG and whole-body radioiodine scan).

Usefulness of sentinel lymph node detection in early stages of cervical cancer.

PURPOSE: Sentinel lymph node (SLN) mapping in combination with surgical biopsy is an emerging technique for use in the early stages of cervical cancer. The purpose of this study was to evaluate the technique in a series of 40 consecutive women with early stage cervical cancer. METHODS: Forty patients with early stage cervical cancer [FIGO stage IA2 (2), IB1 (34), IB2 (1) or IIA (3)] were referred for radical hysterectomy with pelvic lymphadenectomy. Patients were submitted to preoperative lymphoscintigraphy (four 99mTc-nanocolloid injections around the tumour) and intraoperative SLN detection. Hand-held or laparoscopic gamma probes were used to locate SLNs during surgery. RESULTS: The mean number of SLNs was 2.5 per patient (interiliac 49%, external iliac 19%). Of the total of 99 SLNs, six, in four women, showed metastases (all 68 non-SLNs removed were negative). In the other 36 patients, all the removed lymph nodes (sentinel and non-sentinel) were negative (0% false negative rate). During the follow-up (median 25 months), only two patients presented distant metastases: one died 6 months after surgery (two of three SLNs positive, both hot and blue), while the second patient is alive 4 years after surgery (lung metastasis, no isotope drainage, negative blue SLN). The survival rate was 95% and disease-free survival, 97%. CONCLUSION: SLN surgical biopsy based on lymphoscintigraphy and blue dye is a feasible and useful technique to avoid lymph node dissection in the early stages of cervical cancer. It has a high negative predictive value, can be incorporated into clinical routine (laparoscopy or open surgery) and is close to achieving validation in this setting.