Source: Medscape News Today

When head and neck cancer recurs and surgery is not an option, reirradiation provides the only potentially curative option. However, because the tumor often recurs in the same place or very close to tissue that has already been irradiated, this treatment approach represents a “significant challenge.”

For this reason, it should be handled at a tertiary-care center, according to a new guideline issued by the American College of Radiology. Specifically, it stipulates that the tertiary center should have a head and neck oncology team that is equipped with the resources and the experience to manage the complexities and toxicities of retreatment.

In the guideline, published in the International Journal of Radiation Oncology, Biology and Physics, a panel of experts outline appropriateness criteria for various clinical scenarios that arise with such patients.

It provides a consensus on how patients should be managed.

“This is an important document because it is the first set of guidelines for the potentially curative treatment of patients who have regrowth of head and neck tumors. It provides a consensus on how patients should be managed,” coauthor Madhur Kumar Garg, MD, said in a statement. Dr. Garg is from the Department of Radiation Oncology at Montefiore Medical Center, in the Bronx, New York, where about a dozen reirradiation procedures are performed annually.

Commitment to Retreatment

Retreatment is justified because clinical trial results have shown that local treatment improves overall survival, the panel of experts notes.

However, they emphasize that, before a commitment to retreatment is made, patients presenting with recurrent or second primary tumors need to undergo careful restaging evaluation. In addition to computed tomography (CT) or magnetic resonance imaging to evaluate the extent of the recurrent tumor, the panel urges that strong consideration be given to positron emission tomography with CT to evaluate for metastatic disease, or “at a minimum, a CT scan of the chest should be performed.”

In addition, a detailed history and assessment is needed, which includes documentation of the sequelae of previous treatment, such as fibrosis, carotid stenosis, dysphagia, xerostomia, and osteoradionecrosis.

Retreatment options include surgical resection and palliative chemotherapy — both are regarded as standard of care, the panel writes. But for patients with unresectable disease, reirradiation is the “only potentially curative treatment,” they add.

Two phase 2 clinical trials conducted by the Radiation Therapy Oncology Group (RTOG) have shown survival outcomes with reirradiation plus chemotherapy that appear to be superior to those seen with chemotherapy alone in other studies. However, “whether this apparent improvement is the result of selection bias is uncertain,” the panel explains. A larger phase 3 comparing reirradiation plus chemotherapy with chemotherapy alone was closed because of poor accrual.

In terms of the dose of radiation delivered in the second treatment course, it appears that at least 50 to 60 Gy is needed, the experts report. Both of the phase 2 studies conducted by the RTOG delivered a total dose of 60 Gy, using an accelerated hyperfractionated regimen delivering 1.4 Gy twice daily in 4 week-on/week-off cycles. Multiple single-institution reports of reirradiation have used once-daily standard fractionation in a planned continuous treatment course with less toxicity, they note. However, differences in study designs and in the chemotherapy regimens make it difficult to discern what independent effect, if any, differences in radiation fractionation had on the toxicity that was seen.

This news story was resourced by the Oral Cancer Foundation, and vetted for appropriateness and accuracy.