Minimally invasive radioguided parathyroidectomy

The utility of the radionuclide probe in parathyroidectomy for primary hyperparathyroidism

INTRODUCTION Parathyroidectomy is the definitive treatment for primary hyperparathyroidism but the intraoperative identification of adenomas is challenging. The aim of this study was to evaluate the utility of a radionuclide probe (RNP) in addition to intraoperative parathyroid hormone ( IOPTH) measurement as an intraoperative diagnostic adjunct in patients undergoing parathyroidectomy for primary hyperparathyroidism. METHODS This was a retrospective cohort study of patients treated between 2004 and 2015 in a university affiliated teaching hospital. Patients were grouped into those with RNP use (RNP+) and those without (RNP-). The primary outcome measure was rate of operative failure, which included false positives. The diagnostic sensitivity and positive predictive value of both RNP and IOPTH were also evaluated. RESULTS A total of 298 patients were included in the study, 127 (42.6%) being in the RNP+ group and 171 (57.4%) in the RNP- group. The false positive rate for the RNP+ patients was 1.6% compared with 9.4% for RNP- patients (p=0.006, hazard ratio [HR]: 6.45). The rates of operative failure were 6.3% and 11.7% respectively (p=0.159, HR: 1.97). RNP use had a sensitivity of 92.0% and a positive predictive value of 98.3% compared with 78.6% and 95.2% respectively for IOPTH monitoring. CONCLUSIONS RNP use is associated with fewer false positives and reduced operative failure than IOPTH measurement. It also has a higher sensitivity and positive predictive value. RNP use is recommended in centres that have the required facilities.

Use of (99m)Tc 2-methoxyisobutyl isonitrile in minimally invasive radioguided surgery in patients with primary hyperparathyroidism: A narrative review of the current literature

The use of technetium-99m 2-methoxyisobutyl isonitrile (^99mTc MIBI) for assistance in minimally invasive radioguided surgery (MIRS) is growing in popularity as a safe, effective, and proficient technique used for parathyroidectomy in primary hyperparathyroidism (PHPT) treatment. Previously, the preferred treatment for PHPT was bilateral neck exploration (BNE), a very invasive, costly, and lengthy procedure. However, as a large majority (80–85% of cases of PHPT) are attributed to a single parathyroid adenoma (PA), a simpler more direct technique such as MIRS is a far better option. The following article is an exploration of the current literature concerning varied protocols utilizing ^99mTc MIBI for assistance in MIRS for patients undergoing treatment of PHPT. This technique boasts many advantageous outcomes for patients suffering from PHPT. These include a reduction in cost, operating time, and patient recovery; less evidence of post-surgical hypocalcaemia, less pain, and complications; superior cosmetic results; same-day discharge; and the possibility of local anaesthesia which is particularly beneficial in elderly patients. Better outcomes for patients with deep or ectopic PAs, reduced intra-operative complications, and improved cosmetic outcomes for patients who have previously undergone thyroid and/or parathyroid surgery are also advantageous. Of the literature reviewed it was also found that no patients suffered any major surgical complications such as laryngeal nerve palsy or permanent hypoparathyroidism using ^99mTc MIBI for assistance in MIRS.

Imaging of parathyroid glands

Preoperative imaging studies have an important role in facilitating successful localization of adenomas for surgeons. Their use has increased and parallels the recent growth of minimally invasive parathyroidectomy. Based on findings that scintigraphy is reported to have the highest accuracy for localization of adenomas when compared with anatomic imaging techniques, this article discusses the current role and limitations of imaging, with a focus on scintigraphy, in the evaluation of patients before surgery for hyperparathyroidism.

A comprehensive overview of radioguided surgery using gamma detection probe technology

The concept of radioguided surgery, which was first developed some 60 years ago, involves the use of a radiation detection probe system for the intraoperative detection of radionuclides. The use of gamma detection probe technology in radioguided surgery has tremendously expanded and has evolved into what is now considered an established discipline within the practice of surgery, revolutionizing the surgical management of many malignancies, including breast cancer, melanoma, and colorectal cancer, as well as the surgical management of parathyroid disease. The impact of radioguided surgery on the surgical management of cancer patients includes providing vital and real-time information to the surgeon regarding the location and extent of disease, as well as regarding the assessment of surgical resection margins. Additionally, it has allowed the surgeon to minimize the surgical invasiveness of many diagnostic and therapeutic procedures, while still maintaining maximum benefit to the cancer patient. In the current review, we have attempted to comprehensively evaluate the history, technical aspects, and clinical applications of radioguided surgery using gamma detection probe technology.

Hyperparathyroidism in patients over 80: clinical characteristics and their ability to undergo outpatient parathyroidectomy

OBJECTIVE

Parathyroid surgery in elderly patients is commonly delayed due to perceived high operative risk. We evaluated the presentation of patients over 80 with primary hyperparathyroidism (PHPT) and their ability to tolerate outpatient, minimally invasive parathyroidectomy.

METHODS

We conducted a prospective cohort study of 150 consecutive patients over the age of 80 for the treatment of sporadic, nonfamilial PHPT. Presenting symptoms were compiled by questionnaire and compared between male and female (32 males, 118 females) and to 2600 patients under the age of 80. All patients underwent minimally invasive parathyroidectomy and were discharged from the recovery room. Operative findings and outcomes were assessed.

RESULTS

97% reported at least one symptom--the majority had five or more. The most common symptoms were fatigue, hypertension, and memory problems (occurring in 62%, 62%, and 57% of patients, respectively). Symptoms were similar between men and women, with the exception of bone pain being twice as common in women and kidney stones being twice as common in men (both p < 0.05). Preoperative calcium and parathyroid hormone (PTH) levels as well as the frequency of each symptom closely paralleled those of patients less than 80 years old with no significant differences. Average operative time was 18 +/- 5 minutes with discharge averaging 1.9 +/- 0.2 hours later. The incidence of single adenoma, double adenoma, or hyperplasia was identical to patients less than 80 (p = NS). Two patients required rehospitalization within 30 days of the procedure (congestive heart failure and pulmonary embolism), neither one for hypocalcemia. There were no deaths, and the cure rate was 99.3%.

CONCLUSION

PHPT is similar symptomatically, biochemically, and histopathologically between patients > 80 years old and younger patients. Modern techniques allow for small incisions, quick operative times, outpatient discharge, and uneventful recovery. Patients over 80 years old tolerate outpatient parathyroidectomy without event.

Sonography of the abnormal parathyroid gland

In 80% to 90% of patients with primary hyperparathyroidism, a single parathyroid adenoma will be identified as the culprit, whereas the remaining 10% to 20% are caused by multiple adenomas, parathyroid hyperplasia, and rarely, parathyroid carcinoma. At the 2002 National Institute of Health consensus meeting, minimally invasive parathyroidectomy was endorsed as a promising and attractive alternative to total parathyroidectomy. Therefore, preoperative localization of the adenoma is critical in the clinical evaluation of the patient before surgical resection. Although adenomas less than 1 cm may be difficult to visualize sonographically, knowledge of typical imaging characteristics of parathyroid adenomas and use of special sonographic techniques will facilitate identification in most patients. Typical imaging characteristics of parathyroid adenomas include homogeneously hypoechoic echotexture on gray scale with an enlarged feeding artery and peripheral arc of vascularity seen on color and power Doppler. Proper neck extension, unilateral graded compression techniques, and patient swallowing will improve visualization of adenomas.