Iodine-131

Evidence supports optional use of RAI for papillary thyroid cancer.

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The use of radioactive iodine for the management of papillary thyroid cancer has been recommended for years, but researchers said it should not be a “blanket treatment” for all patients.

Guidelines for the management of well-differentiated thyroid cancer (WDTC) recommend routine usage of radioactive iodine (RAI) in patients with T3 disease or distant metatases, and selected use in patients with more limited disease.

However, lain J. Nixon, MBCHB, clinical fellow in the head and neck surgery department of Memorial Sloan-Kettering Cancer Center, told Endocrine Today that, due to a lack of evidence, the American Thyroid Association’s guidelines are not definitive for most patients when it comes to treatment.

“Over the years, different groups have looked at outcomes of patients who were treated with RAI. And initially, it dramatically improved patient outcomes. But, as treatment has progressed over the years and surgery is better now than it was in the 1940s, groups have discovered the  benefit is probably limited to high-risk patients,” Nixon said. “We now know that high-risk patients benefit, but low-risk patients don’t. The difficulty for clinicians is that most patients are somewhere between those two extremes, and there isn’t very good guidance about who should and should not receive RAI in that middle group.”

Nixon and colleagues conducted a review of 1,129 patients (median age of 46 years) who underwent total thyroidectomy at Memorial Sloan-Kettering Cancer Center between 1986 and 2005. After an average follow-up of 63 months, the researchers found that some patients with early primary disease (pTl/T2) and low-volume metastatic disease in the neck (pTl/T2 N1) who were managed without RAI displayed positive outcomes.

“It’s not a study that proves whether RAI works or it doesn’t,” Nixon said. “The idea of it is to give clinicians who are interested in the concept of managing patients without RAI some evidence to back up that position.”

For patients with advanced local disease (pT3/T4), some patients with pT3NO disease were safely managed without RAI. The 5-year disease-specific survival (DSS) and recurrence-free survival (RFS) rates for the pTl/T2NO group were 100% and 92%; for the pT1/T2N1, rates were 100% and 92%; and for the pT3/T4 group, rates were 98% and 87%, according to data.

Despite the traditional recommendations, the researchers suggest that RAI should be administered on a case­by-case basis through a multidisciplinary team with extensive experience in managing thyroid cancer.

“Our experience is that in properly selected patients, it’s very safe to manage them without RAI,” Nixon said. – by Samantha Costa

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Disclosure: The researchers report no relevant financial disclosures.

Perspective

 

Megan R. Haymart

  • Nixon and colleagues performed a retrospective review of 1,129 patients who underwent total thyroidectomy for thyroid cancer at a tertiary referral center between 1986 and 2005. They evaluated mortality and cancer recurrence in those patients that received radioactive iodine post thyroid surgery versus those that did not. They found that select patients do well without radioactive iodine treatment. This study suggests that it is time for the pendulum to swing. Although radioactive iodine treatment has clear benefit in high risk iodine avid patients, for many patients management with surgery alone may be adequate.
  • Source: Endocrine Today.