PET Scan Treatment Options & Challenges

Jonathon B. Cohen, MD, MS:Patients with classical Hodgkin’s lymphoma [who] are candidates for our standard curative therapy have historically been treated with the ABVD [doxorubicin (Adriamycin), bleomycin, vinblastine, dacarbazine] regimen. In retrospect, this would typically include 6 cycles of ABVD or 12 treatments for patients with an advanced-stage disease like the one that we discussed in today’s case. Fortunately, over the past several years, there have been 2 large studies that have come out informing our decision, consequently reducing the conventional number of ABVD cycles.

One option, which was selected in the case that we described today, is to use a PET [positron emission tomography]-adapted approach, wherein patients receive 4 treatments of ABVD, after which they are administered a PET scan. Those who receive negative results will be treated with AVD alone, without bleomycin, for the remainder of their treatment, for a total of 6 cycles or, again, 12 treatments. For those patients, however, who are PET-positive, based on the study, they would be escalated to a more intensive therapy such as BEACOPP [bleomycin, etoposide, Adriamycin, cyclophosphamide, Oncovin, procarbazine, prednisone]—a regimen that hasn’t historically been used with frequency in the United States but is commonly used in Germany. It is likely that this intensive therapy has an increased benefit compared [with] ABVD, although with a significant worsening of toxicity.

The other approach is to eschew bleomycin and instead use the novel therapy brentuximab vedotin [BV], which is an antibody drug conjugate targeting CD30 [TNFRSF8/cell membrane protein 30]. For this therapy, patients receive brentuximab vedotin combined with AVD for a total of 6 cycles. During the process, we typically administer routine PET/CT [computed tomography] scans, but there is not a planned PET-adapted therapy, as in the first approach.

Patients [who] are receiving ABVD—although typically young and susceptible to limited comorbidities—require monitoring for toxicities such as a bleomycin-associated lung complication, which may not be easily apparent based on objective findings. Oftentimes, patients [who] are experiencing difficulty going upstairs [or] walking in from the parking lot of the office, or [who have] persistent dry cough, are suffering from said complication. When such symptoms arise, without an alternative explanation, I consider whether we need to abstain from bleomycin administration. Again, it’s critical that anybody receiving bleomycin be monitored closely for comorbidities. Other major toxicities include neuropathy, myelosuppression, infection, and cardiomyopathy, although the latter is less common with our Hodgkin patients.

I typically don’t include radiation therapy for patients with advanced stage Hodgkin’s lymphoma — they either achieve complete remission and enter observation or, if not, proceed to salvage/second-line therapy. The only potential exception would be a patient with initially-bulky disease who has mild FDG [fluorodeoxyglucose] uptake at the conclusion of therapy, which is warranted by data that would suggest there may be benefit in that selected case. Otherwise, most of my patients receive radiation therapy for their Hodgkin lymphoma during the early-stage setting, especially those with incipient bulky disease.

Our patient of interest had an excellent response to their initial chemotherapy. At their interim PET scan, they had a Deauville score of 1, which suggests a complete metabolic response — and so they consequently would meet criteria to de-escalate therapy to the AVD. As we saw in this case, however, obtaining a negative interim PET/CT scan, while a very positive prognostic marker, is not a guarantee of long-term cure. Therefore, to restate, patients still need to be monitored closely for potential relapse.

Transcript edited for clarity.

A 32-Year-Old Man with Stage IV Hodgkin's Lymphoma

• History & Physical:
  • A 32-year-old man presented to his PCP in January 2017 complaining of abdominal pain, pruritus, fevers of over 101⁰ F, and weight loss
• Imaging
  • PET scan showed avid mediastinal mass
• Labs
  • HgB 12.2 g/dL
  • WBC 7,500 mm²
  • ALC 3,200 mm²
  • Albumin 3.9 mg/dL
  • ANC 4,200/mm³
  • Liver and renal function tests WNL
• Biopsy confirmed mixed cellularity classical Hodgkin’s lymphoma (HL)
• Normal lung and cardiac function
• Final Staging: Stage IVB, cHL, IPS score 2
• ECOG PS 2
• He received 2 cycles of ABVD. PET/CT restaging showed Deauville (1-). He received 4 additional cycles of AVD
• He achieved a CR
• 2 years after completion of therapy, the patient complained of a persistent cough and fatigue
• PET/CT showed bilateral mediastinal masses
• Biopsy confirmed cHL