PET scanning for predicting outcomes for early-stage Hodgkin lymphoma

This study assessed the usefulness of PET scanning in determining outcomes for patients with early-stage Hodgkin lymphoma (HL). This study concluded that PET scanning after chemotherapy was strongly associated with patient outcomes in early-stage HL.

For patients with HL, the goal of treatment is to improve outcomes while reducing side effects. Initial treatment can be highly effective, but side effects can lead to long-term complications. Predicting treatment outcomes and adjusting treatment intensity as therapy progresses is important. A key tool for this is FDG-PET scanning.

Compared to older imaging methods such as CT scanning, FDG-PET scanning more accurately visualizes cancer and can help predict relapse. PET scans are scored. A positive scan result (a higher score) means that cancer cells are still present. A negative scan (a lower score) means that cancer is not present. How helpful PET scans are in predicting outcomes for patients with early-stage HL is under investigation.

This study involved 602 patients with early-stage HL. 562 patients were included in this analysis. All patients received 3 cycles of ABVD (adriamycin, bleomycin, vinblastine, and dacarbazine) chemotherapy. Then, PET and CT scans were given after treatment. Patients who had positive scan results (143 patients) then received 4 cycles of ABVD and radiation therapy. Patients who had negative scan results (211 patients) received either radiation therapy or no further treatment. Patients were followed-up for an average of 61.6 months.

After initial treatment, 74.6% of patients had negative PET scan results. These patients then received radiation therapy or no further treatment. Patients in this group who received radiation therapy had a 60% lower risk of relapse compared to patients who had a positive scan result. 91.4% of these patients were still alive 5 years later without tumor growth or spread.

After initial treatment, 25.4% of patients had positive PET scan results. These patients then received 4 more cycles of ABVD plus radiation therapy. 88.4% of these patients were still alive 5 years later without tumor growth or spread.

Slightly more patients who had negative PET scan results were still alive 5 years later without the cancer returning (relapse) compared to patients who had positive scan results (93.0% vs. 89.7%). Significantly fewer patients with a high PET scan score were still alive 5 years later compared to patients with a low score (85.2% vs. 97.8%).

This study concluded that PET scanning after chemotherapy was strongly associated with patient outcomes in early-stage HL. The authors suggest that a high PET scan score of 5 should guide further treatment rather than a positive result alone.

Patients with bulky disease (tumors bigger than 5 centimeters) were not included in this study. These results may not be applicable for all patients with early-stage HL.