1290 A Move to Magseed For Breast Conserving Surgery

Aim Wire guided localisation(WGL) to localise non-palpable breast tumours has been the standard for years. WGL has limitations; patient discomfort, fixed scheduling to facilitate insertion on the day of surgery and wire migration. A 2015 audit in our department found that 51% of patients undergoing wide local excision (WLE) used preoperative localisation techniques; of which 84% was WGL. The overall re-excision rate for WLE was 27%. We altered our practice to Magseed localisation from July 2019 to improve patient experience, and surgical efficiency, as there are similar outcomes between WGL and Magseed in the literature. This audit aims to examine if there are improvements in our re-excision rate. We aim to evaluate which is the best method for localisation in our department. Method A retrospective audit was conducted following registration with the local audit office. Patients who underwent breast conserving surgery between September 2019 and September 2020 were identified. The surgical approach, re-excision and complications were recorded and compared to the 2015 results. Results 100 patients underwent WLE in the study period. The percentage of patients undergoing therapeutic mammaplasty was 26% (14% in 2015). 63% underwent preoperative localisation; of which 71% used Magseed and 5% used wire. The overall re-excision rate was 20%. Conclusions Our re-audit has demonstrated an increase in patients requiring pre-operative localisation, probably due to the use of primary endocrine treatment during COVID-19. We gladly observed 26% improvement in re-excision rates suggesting success with Magseed.

1108 Comparing the Accuracy of Ultrasonography and Nuclear Imaging Scan in Preoperative Localisation of Parathyroid Lesions in Patients with Primary Hyperparathyroidism

Aim Parathyroidectomy remains the only method to cure Primary Hyperparathyroidism. Preoperative localisation of the lesion is vital for successful surgical management. The preferred initial preoperative imaging is an ultrasound scan (USS) of the neck. NICE recommends a second preoperative imaging modality to guide the surgical management. This study was conducted to compare the effectiveness of USS of the neck and SPECT scan in the preoperative localisation of parathyroid lesions in a single Teaching Hospital. Method A retrospective study performed included a cohort of patients between 2018 and 2020. 31 patients that underwent elective focussed parathyroidectomy were followed up. Data on preoperative investigations including USS of the neck and SPECT and final histological diagnosis of the specimen was captured using the hospital’s electronic medical records Quadramed. Results Both USS and SPECT scan correctly identified the nature and location of the lesion in only 35.4% patients. USS alone correctly identified the nature and location of the lesion in 50.0% patients whereas SPECT was 46.7%. USS incorrectly identified the nature or the location of the lesion in 33.3% patients whereas SPECT was 40.0%. Interestingly, the USS did not identify any abnormal pathology in 5 patients and SPECT in 4 patients, although all 9 showed pathological histology findings. Conclusions Data collected shows that either scan alone would not be sufficient to confirm the absence of parathyroid pathology. A second scan decreases the likelihood of missing any abnormal pathology. However, in patients with a high clinical suspicion abnormality cannot be ruled out despite having two negative scan results.

Iodine seed localisation of non-palpable lesions in breast surgery − first experience

Surgical therapy of non-palpable malignant breast lesions requires precise preoperative localisation. Recently, radioactive iodine seed localisation has excelled among the number of localisation methods. We present our first experience with this method at our department. We describe the structure of the radioactive iodine seed, the principles of preoperative localisation and peroperative detection of the seed, the specimen transport process, histopathological examination, storage and disposal of the seed, as well as aspects of radiation protection.

The preoperative localisation of small parathyroid adenomas improves when adding Tc-99m-Sestamibi SPECT to multiphase contrast-enhanced CT

Objectives To investigate the incremental value of Sestamibi SPECT combined with a non-enhanced and contrast-enhanced CT, using SPECT/CT, for the preoperative localisation of small parathyroid adenomas (PTA). Methods Retrospectively, 147 patients surgically cured from primary hyperparathyroidism, as verified by biochemistry 6 months postoperatively, were included. All patients had preoperatively undergone a dual time 99mTechnetium-Sestamibi SPECT (S) with multiphase CT including native (N), arterial (A) and venous (V) phases. Independently, two radiologists blinded from both the surgical and the preoperative imaging reports, sequentially performed PTA localisation starting with either [A] or [V], thereafter [A + N] or [V + N] and finally with the complete [A + N + S] or [V + N + S]. PTA localisation was reported for each image-set. The readers results were combined and the diagnostic performance for each image set was determined. Sensitivity was also calculated for the different quartiles of PTA weight distribution. Results The median adenoma weight was 315 mg. No statistically significant differences in diagnostic performance between arterial and venous based image sets were found. The net effect of adding [N] was to increase specificity. Sestamibi SPECT significantly increased the overall diagnostic accuracy for arterial- and venous-based image sets, p = 0.0008 and p = 0.001, respectively. [A + N + S] was found to have the highest diagnostic performance with 86.5% sensitivity and 94.9% overall accuracy. [A + N + S] was particularly advantageous for locating PTA in the lower weight quartiles. Conclusions Native CT-phase and dual time point Sestamibi SPECT increase specificity and sensitivity, respectively. These, in combination with a single contrast-enhanced CT-phase is the most optimal examination protocol for preoperative localisation of PTA using SPECT/CT.

Combined ultrasound and Sestamibi scintigraphy provides accurate preoperative localisation for patients with primary hyperparathyroidism

Introduction Minimally invasive parathyroidectomy has advantages over the traditional bilateral neck exploration for the surgical treatment of primary hyperparathyroidism. It requires accurate localisation of the parathyroid pathology prior to surgery. The best method of preoperative localisation in a district general hospital setting is not well understood. Methods All patients who underwent parathyroidectomy for primary hyperparathyroidism from 2008 to 2016 were identified from a prospectively maintained database. Operative findings were correlated with radiological and histological results. Sensitivity and specificity of ultrasound, sestamibi scintigraphy and the two together were calculated for diagnostic precision and compared. Results One hundred and eighty-four patients met the inclusion criteria, of whom 81.5% had a histological diagnosis of a parathyroid adenoma. Ultrasound had higher sensitivity than sestamibi scintigraphy. Used together, ultrasound and sestamibi scintigraphy performed better than either ultrasound or sestamibi scintigraphy alone (P< 0.001). Twenty-two of 184 cases had no lesion located by either ultrasound or sestamibi scintigraphy preoperatively. Where neither ultrasound nor sestamibi scintigraphy located the lesion, additional computed tomography led to the excision of parathyroid pathology in one in ten patients. Conclusion The combination of ultrasound and sestamibi scintigraphy provides the highest sensitivity of preoperative localisation. This approach led to a high success rate of minimally invasive parathyroidectomy. Where preoperative localisation is not achieved with ultrasound or sestamibi scintigraphy, computed tomography adds little additional benefit. In this setting other modalities of localisation such a selective venous sampling, intraoperative methylene blue or intraoperative parathyroid hormone levels could be considered.