Original Investigation Testis spectroscopy predicts sperm retrieval rate in men with non-obstructive azoospermia undergoing micro-TESE Çelik et al. Spectroscopy predicts micro-TESE outcomes Önder Çelik 1 , Şafak Hatırnaz 2 , Aynur Erşahin 3 , Alper Başbuğ 4 , Gonca Y. Yıldırım 5 , Vahit Özener 6 , Neslihan Gürpınar 6 , Sudenaz Çelik 7 , Tansu Küçük 8 , Cihat Ünlü 8 1 Clinic of Obstetrics and Gynecology, Private Office, Uşak, Turkey 2 Clinic of Obstetrics and Gynecology, Medicana International Hospital, Samsun, Turkey 3 Clinic of Obstetrics and Gynecology, Medicalpark Göztepe Hospital, İstanbul, Turkey 4 Department of Obstetrics and Gynecology, Düzce University Faculty of Medicine, Düzce, Turkey 5 Clinic of Obstetrics and Gynecology, Kanuni Sultan Süleyman Training and Research Hospital, İstanbul, Turkey 6 Clinic of Radiology, Barış Radiology Center, İzmir, Turkey 7 Kent College High School, İzmir, Turkey 8 Department of Obstetrics and Gynecology, Acıbadem University Faculty of Medicine, İstanbul, Turkey Adress for Correspondence: Önder Çelik - Şafak Hatırnaz e.mail: celiksudenaz@gmail.com - safakhatirnaz@gmail.com DOI: 10.4274/jtgga.galenos.2019.2018.0154 Received: 26 November, 2018 Accepted: 18 October, 2019 Abstract Objective: To investigate whether prior testis magnetic resonance spectroscopy (MRS) predicts the success or failure of micro-dissection testicular sperm extraction (micro-TESE) in patients with non-obstructive azoospermia (NOA). Materials and Method: Nine men with NOA who were scheduled for micro-TESE for the first time, 9 NOA men with a history of previous micro-TESE and 5 fertile men were enrolled. All NOA patients and fertile controls underwent testis spectroscopy. A multi-voxel spectroscopy sequence was used. Testicular signals of choline (Cho), creatine (Cr), myo-inositol (MI), lactate, and lipids were analyzed quantitatively and compared with the results of the micro-TESEs. Results: The most prominent peaks were Cho and Cr in the fertile controls and NOA subjects with positive sperm retrieval in the micro-TESE. A high Cho peak was detected in 87% of the NOA men with positive sperm retrieval. NOA men without sperm at the previous micro-TESE showed a marked decrease in Cho and Cr signals. For positive sperm retrieval in micro-TESE, the cut-off value of Cho was 1.46 ppm, the cut-off value of Cr was 1.43 ppm, and the cut-off value of MI was 0.79 ppm. Conclusions: Testis spectroscopy can be used as a non-invasive screening method to predict the success or failure of micro-TESE. Keywords: Testis, magnetic resonance spectroscopy, sperm retrieval, micro-TESE, non-obstructive azoospermia Introduction The management of patients with non-obstructive azoospermia (NOA) involves micro-TESE combined with intracytoplasmic sperm injection (ICSI) (1). Micro-TESE is not only a diagnostic tool for the presence of spermatozoa, but also a therapeutic procedure for retrieving sperm in ICSI. The sperm retrieval rate in men with NOA is reported to be 50% (2,3). However, micro-TESE is an invasive procedure that requires anesthesia. Moreover, repeated unsuccessful micro-TESE procedures can be devastating for the fertility outcome. Concordantly, excessive and repeated tubule harvesting to find spermatozoa may lead to complications such as testicular atrophy, hemorrhage, and a decline in serum androgen levels (4). In addition to being a surgically invasive procedure, it creates a huge psychological disappointment for infertile couples if sperm cannot be obtained during micro-TESE. The development of non-invasive imaging techniques having the capacity to identify the infertile population of men with NOA where a successful sperm retrieval outcome in micro-TESE is of great clinical significance. An evaluation of serum or seminal fluid biomarkers provides a noninvasive diagnostic approach to predict the presence of spermatozoa in the testes of men with NOA. Allied to this, several predictors such as age, testicular Uncorrected Proof