THYROID TREATMENT AND VITAMIN D UPDATEA CPMC Regional CME Event

- An Integrated Approach

Saturday October 27, 2012

THYROID SURGERY

Andrea H. Yeung, MD

San Francisco Otolaryngology Medical Group

OUTLINE OF DISCUSSION

• Indications• Risks• Technical considerations• Postoperative management and follow

up

DISCLOSURES

• No Financial Disclosures

RISING INCIDENCE OF THYROID CANCER OVER TIME

Surveillance, Epidemiology, and End Results (SEER) Program (www.seer.cancer.gov). SEER Stat Database: Incidence - SEER 9 Regs Public-Use, Nov 2005 Sub (1973-2003), National Cancer Institute, DCCPS, Surveillance Research Program, Cancer Statistics Branch, released April 2006.

INCREASED INCIDENCE IN WOMEN

Age at the time of diagnosis of thyroid cancer in men and women from 1975 to 2006. The incidence rate per 100 000 is about 3-fold higher in women compared with men, and peak incidence occurs nearly 20 years earlier in women than men.

Sipos JA, Mazzaferi EL. Thyroid Cancer:Epidemiology and Prognostic Variables. Clinical Oncology. 2010 22(6) 395-404

INCREASED INCIDENCE DUE TO RISE IN SMALL PAPILLARY TUMORS

Davies L, Welch HG. JAMA 2006. 295(18)Cramer JD, Fu P, Harth KC, et al. Analysis of the rising incidence of thyroid cancer using the Surveillance, Epidemiology and End Results national cancer data registry. Surgery. 2010;148:1147-1153

THYROID CANCER INCIDENCE AND MORTALITY 1973-2002

Davies L, Welch HG. JAMA 2006. 295(18)

INCREASING INCIDENCE OF THYROID NODULES

• Predominantly due to increased detection of small papillary cancers- Increased diagnostic scrutiny

• Known existence of a substantial reservoir of subclinical cancer

• Stable overall mortality• Increasing incidence reflects increased

detection of subclinical disease, not an increase in true occurrence of thyroid cancer

INDICATIONS FOR THYROID SURGERY

• Thyroid malignancy• Symptomatic goiter

- Compressive symptoms• Aesthetic concerns due to goiter• Medically refractory hyperthyroidism

• Contraindications- Uncontrolled severe hyperthyroidism- Pregnancy

GOALS FOR SURGICAL THERAPY FOR DIFFERENTIATED THYROID CANCER

• Remove the primary tumor, disease that has extended beyond the thyroid capsule, and involved cervical lymph nodes

• Minimize treatment related morbidity• Permit accurate staging of the disease• Facilitate postop treatment with RAI• Permit accurate long term surveillance for

disease recurrence• Minimize the risk of disease recurrence and

metastatic spread

WHAT IS THE APPROPRIATE OPERATION?

• Nondiagnostic bx or indeterminate biopsy- Initial lobectomy with possible need to return

for completion thyroidectomy• Follicular neoplasm or Hurthle cell neoplasm

- Total thyroidectomy• Large tumors >4cm• Marked atypia is seen on biopsy• Biopsy is suspicious for papillary thyroid carcinoma• Family history of thyroid carcinoma• History of radiation exposure

SURGERY FOR BIOSPY DX OF MALIGNANCY• Total thyroidectomy

- >1cm- Contralateral thyroid nodules present- Regional and distant metastases- Personal history irradiation- First degree family history of thyroid cancer- Older age >45 because of higher recurrence risk

• Thyroid lobectomy- <1cm- Low risk- Unifocal disease- Intrathyroidal PTC in the absence of prior radiation or

involve cervical nodal mets

LYMPH NODE DISSECTION

• Central neck dissection (level VI)- Therapeutic for clinically involved central or

lateral neck LN- Prophylactic with PTC with clinically uninvolved

central neck LN• Advanced primary tumors (T3 and T4)

• Total thyroidectomy without prophylactic CND - Small T1 or T2 noninvasive, clinically node

negative PTCs and most follicular cancers• Lateral neck dissection

- Biopsy proven metastatic lateral cervical LAD

RISKS

• Hypocalcemia related to hypoparathyroidism- transient hypocalcemia vary in the literature from between

5-50%- Permanent hypocalcemia secondary to hypoparathyroidism

(ie, lasting more than 6 months) 0.5-2%• Recurrent laryngeal nerve injury

- Permanent RLN paralysis occurs in 1-2% of thyroidectomies • Superior laryngeal nerve injury

- Often asymmptomatic but may result in vocal fatigue and pitch alteration in professional singers

• Hematoma• Infection • Thyrotoxic storm

INTRAOPERATIVE NERVE MONITORING

• Endotracheal tubes with integrated surface electrodes that contact the vocal cords

• Allows for an intraoperative assessment of nerve function

• May not have a significant difference in reducing nerve injury, but can be used to predict how well the nerve functions postoperatively

TECHNIQUE

• Incision and exposure of thyroid gland• Releasing the superior pole• Identifying the parathyroid glands• Identifying the recurrent laryngeal

nerve• Removing the thyroid gland• Neck dissection• Closure

INCISION AND EXPOSURE OF THE THYROID GLAND

RELEASING THE SUPERIOR POLE

IDENTIFYING PARATHYROID GLANDS

IDENTIFYING RECURRENT LARYNGEAL NERVE

NECK DISSECTION

REMOVAL OF THYROID AND CLOSURE

ALTERNATIVES TECHNIQUES AND METHODS

• Minimally invasive video assisted thyroidectomy- Requires careful patient selection to ensure

feasibility- Decreased postop pain and faster recovery- Increased operative time and cost

• Robotic assisted transaxillary thyroidectomy- Better cosmetic result- More invasive with wider dissection necessary- Technically difficult- Cost prohibitive

OTHER CONSIDERATIONS: SUBSTERNAL GOITER• Most often does not require a sternotomy• These patients are at an increased risk of recurrent

laryngeal nerve injury, with reports as high as 17.5%.

• Sternotomy- Superior vena cava syndrome- Goiter with mediastinal blood supply- Posterior mediastinal goiter- Larger diameter to the intrathoracic component- Recurrent substernal goiters- Malignancy extending into the mediastinum- Presence of significant adhesions to mediastinal vessels

or pleura

POSTOPERATIVE COURSE

• Hemithyroidectomy- 6 week postop TFTs 15% chance need for thyroid

hormone replacement• Total thyroidectomy

- Calcium monitoring for iatrogenic hypoparathyroidism

- Parathyroid hormone as an adjunct or replacement to measuring serum calcium levels in predicting hypoparathyroidism

- 6 month postop ultrasound and Tg for survellience

PEARLS

• As diagnostic techniques have become more sensitive particularly with the advent of ultrasound and FNA increasing incidence of thyroid cancer may reflect an increased diagnostic scrutiny

• The surgical technique of thyroidectomy, as well as adjunct technology, continued to advance

• Most recently, various new instruments and approaches including video-assisted thyroidectomy and robot-assisted thyroidectomy have emerged