How useful is PET scanning during treatment for patients with newly diagnosed Hodgkin lymphoma?

This article reviewed the importance of PET scanning during treatment for patients with Hodgkin lymphoma (HL).

PET scanning during treatment (interim PET) is used to guide therapy for patients with newly diagnosed HL. Depending on the scan results, treatment can be decreased, increased, or changed to a different treatment. A negative scan result (minimal to no signs of cancer) can mean that treatment needs to be decreased.

PET scanning makes it easier to identify patients who can achieve better outcomes with less therapy or who need their therapies changed. PET scanning can also be combined with CT scanning. CT scanning combined with PET scanning is more accurate than a PET scan alone. Whether PET scanning can help predict outcomes for patients with HL who are receiving first-line therapy is unclear.

This study reviewed the results of 23 studies with a total of 7335 patients with HL. Patients were treated with chemotherapy, with or without radiation therapy. Patients had PET scanning after at least 2 cycles of chemotherapy (PET2). Some patients also received CT scanning. Patients were followed up from 2 to 195 months.

In an analysis of 9 studies, 475 patients had positive interim PET scan results. 1327 patients had negative interim PET scan results. Having a negative PET scan resulted in 5.09 times higher odds of survival compared to those with positive interim PET.

In an analysis of 14 studies, 529 patients had positive interim PET scan results. 1550 patients had negative interim PET scan results. Having a negative PET scan result may be associated with a 4.90-fold lower risk of cancer growing or spreading after treatment.

The authors suggested that interim PET scanning can help distinguish between patients with a poor prognosis versus a good prognosis. This can help guide decision-making during treatment.

The studies analyzed here had some differences, such as treatment regimens and the number of patients. The smallest study had 23 patients, while the largest study had 1945 patients. The studies also had different follow-up periods. These differences may limit these results.