Faculty Bibliography

As part of a randomized, prospective clinical trial in large cell lymphoma, we conducted serial fluorodeoxyglucose positron emission tomography (FDG-PET) at baseline, after 2 cycles of chemotherapy (interim PET [i-PET]), and at end of treatment (EoT) to identify biomarkers of response that are predictive of remission and survival. Scans were interpreted in a core laboratory by 2 imaging experts, using the visual Deauville 5-point scale (5-PS), and by calculating percent change in FDG uptake (change in standardized uptake value [ΔSUV]). Visual scores of 1 through 3 and ΔSUV ≥66% were prospectively defined as negative. Of 524 patients enrolled in the parent trial, 169 agreed to enroll in the PET substudy and 158 were eligible for final analysis. In this selected population, all had FDG-avid disease at baseline; by 5-PS, 55 (35%) remained positive on i-PET and 28 (18%) on EoT PET. Median ΔSUV on i-PET was 86.2%. With a median follow-up of 5 years, ΔSUV, as continuous variable, was associated with progression-free survival (PFS) (hazard ratio [HR] = 0.99; 95% confidence interval [CI], 0.97-1.00; P = .02) and overall survival (OS) (HR, 0.98; 95% CI, 0.97-0.99; P = .03). ΔSUV ≥66% was predictive of OS (HR, 0.31; 95% CI, 0.11-0.85; P = .02) but not PFS (HR, 0.47; 95% CI, 0.19-1.13; P = .09). Visual 5-PS on i-PET did not predict outcome. ΔSUV, but not visual analysis, on i-PET predicted OS in DLBCL, although the low number of events limited the statistical analysis. These data may help guide future clinical trials using PET response-adapted therapy. This trial was registered at www.clinicaltrials.gov as #NCT00118209.

The utility of posttreatment bone marrow biopsy (BMB) histology to confirm complete response (CR) in lymphoma clinical trials is in question. We retrospectively evaluated the impact of BMB on response assessment in immunochemotherapy-treated patients with previously untreated follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL) in the phase 3 Study of Obinutuzumab (RO5072759) Plus Chemotherapy in Comparison With Rituximab Plus Chemotherapy Followed by Obinutuzumab or Rituximab Maintenance in Patients With Untreated Advanced Indolent Non-Hodgkin's Lymphoma (GALLIUM; NCT01332968) and A Study of Obinutuzumab in Combination With CHOP Chemotherapy Versus Rituximab With CHOP in Participants With CD20-Positive Diffuse Large B-Cell Lymphoma (GOYA; NCT01287741) trials, respectively. Baseline BMB was performed in all patients, with repeat BMBs in patients with a CR by computed tomography (CT) at end of induction (EOI) and a positive BMB at baseline, to confirm response. Positron emission tomography imaging was also used in some patients to assess EOI response (Lugano 2014 criteria). Among patients with an EOI CR by CT in GALLIUM and GOYA, 2.8% and 4.1%, respectively, had a BMB-altered response. These results suggest that postinduction BMB histology has minimal impact on radiographically (CT)-defined responses in both FL and DLBCL patients. In GALLIUM and GOYA, respectively, 4.7% of FL patients and 7.1% of DLBCL patients had a repeat BMB result that altered response assessment when applying Lugano 2014 criteria, indicating that bone marrow evaluation appears to add little value to response assessment in FL; however, its evaluation may still have merit in DLBCL.

Lymphoma is a potentially curable disease; however, the clinical challenge lies in further improvement of outcomes. PET with fludeoxyglucose is an effective imaging tool. PET-derived quantitative metrics have raised significant interest to be used as a prognostic factor to complement clinical parameters for treatment decisions. The most optimized use of these quantitative PET metrics, however, will be possible with the standardization of imaging procedures. In this article, we review the technical and methodological considerations related to PET-derived quantitative metrics, and the relevant published data to emphasize the potential value of these metrics in patient prognosis and treatment response in lymphoma.

"PET imaging with fluorodeoxyglucose (FDG), integrated with PET/computed tomography (FDG-PET/CT), is an effective management tool of diffuse large B-cell lymphoma (DLBCL). The results of end-of-treatment (EOT) FDG-PET/CT are more accurate for detection of active disease with residual masses on CT. Complete response defined by EOT FDG-PET/CT (PET-CR) correlates with long-term outcome of patients. Treatment efficacy is determined using EOT PET/CT rather than progression-free survival (PFS) for clinical trials assessing novel drugs. If the correlation of EOT PET/CT with PFS is further proven in large studies and meta-analyses, EOT PET-CR could serve as an expedited novel endpoint replacing PFS."

Patients with metastatic or unresectable (advanced) pheochromocytoma and paraganglioma (PPGL) have poor prognoses and few treatment options. This multicenter, phase 2 trial evaluated the efficacy and safety of high-specific-activity ¹³¹I-meta-iodobenzylguanidine (HSA ¹³¹I-MIBG) in patients with advanced PPGL. Methods: In this open-label, single-arm study, 81 PPGL patients were screened for enrollment, and 74 received a treatment-planning dose of HSA ¹³¹I-MIBG. Of these patients, 68 received at least 1 therapeutic dose (∼18.5 GBq) of HSA ¹³¹I-MIBG intravenously. The primary endpoint was the proportion of patients with at least a 50% reduction in baseline antihypertensive medication use lasting at least 6 mo. Secondary endpoints included objective tumor response as assessed by Response Evaluation Criteria in Solid Tumors version 1.0, biochemical tumor marker response, overall survival, and safety. Results: Of the 68 patients who received at least 1 therapeutic dose of HSA ¹³¹I-MIBG, 17 (25%; 95% confidence interval, 16%-37%) had a durable reduction in baseline antihypertensive medication use. Among 64 patients with evaluable disease, 59 (92%) had a partial response or stable disease as the best objective response within 12 mo. Decreases in elevated (≥1.5 times the upper limit of normal at baseline) serum chromogranin levels were observed, with confirmed complete and partial responses 12 mo after treatment in 19 of 28 patients (68%). The median overall survival was 36.7 mo (95% confidence interval, 29.9-49.1 mo). The most common treatment-emergent adverse events were nausea, myelosuppression, and fatigue. No patients had drug-related acute hypertensive events during or after the administration of HSA ¹³¹I-MIBG. Conclusion: HSA ¹³¹I-MIBG offers multiple benefits, including sustained blood pressure control and tumor response in PPGL patients.

PURPOSE:The prospective, multicenter LOCATE (F Fluciclovine [FACBC] PET/CT in Patients with Rising PSA after Initial Prostate Cancer Treatment) trial assessed the impact of positron emission tomography/computerized tomography with F-fluciclovine on treatment plans in patients with biochemical recurrence of prostate cancer after primary therapy with curative intent. MATERIALS AND METHODS:Men who had undergone curative intent treatment of histologically confirmed prostate cancer but who were suspected to have recurrence based on rising prostate specific antigen levels were enrolled prospectively. Each man had negative or equivocal findings on standard of care imaging. F-fluciclovine positron emission tomography/computerized tomography was performed according to standardized protocols. Treating physicians completed a questionnaire regarding the patient treatment plan before and after scanning, recording changes to the treatment modality (eg salvage radiotherapy to systemic androgen deprivation therapy) as major and changes in a modality (eg modified radiotherapy fields) as other. RESULTS:Between June 2016 and May 2017, 213 evaluable patients with a median age of 67 years and median prostate specific antigen 1.00 ng/ml were enrolled in study. F-fluciclovine avid lesions were detected in 122 of the 213 patients (57%). Overall 126 of the 213 patients (59%) had a change in management after the scan, which were major in 98 of 126 (78%) and in 88 (70%) were informed by positive positron emission tomography/computerized tomography findings. The most frequent major changes were from salvage or noncurative systemic therapy to watchful waiting (32 of 126 cases or 25%), from noncurative systemic therapy to salvage therapy (30 of 126 or 24%) and from salvage therapy to noncurative systemic therapy (11 of 126 or 9%). CONCLUSIONS:F-fluciclovine positron emission tomography/computerized tomography detected 1 or more recurrence sites in the majority of men with biochemical recurrence, frequently resulting in major changes to management plans. Future studies will be planned to determine whether a management change leads to improved outcomes.

OBJECTIVE:Tc-macroaggregated albumin (MAA) SPECT/CT versus post-therapy PET/MRI imaging among patients with primary or metastatic hepatic tumors. MATERIALS AND METHODS/METHODS:Y dosimetry. The Passing-Bablok regression scatter diagram and the Bland and Altman method were used to analyze the difference between dosimetry values. RESULTS:For MAA and PET/MRI modalities, the mean liver doses for all 32 subjects were 43.0 ± 20.9 Gy and 46.5 ± 22.7 Gy, respectively, with a mean difference of 3.4 ± 6.2 Gy. The repeatibility coefficient was 12.1 (27.0% of the mean). The Spearman rank correlation coefficient was high (ρ = 0.92). Although, there was a substantial difference in the maximum doses to the liver between the modalities, the mean liver doses were relatively close, with a difference of 24.0% or less. CONCLUSIONS:Y studies were not significantly different.

A negative interim positron emission tomography/computerized tomography (PET/CT) after 1 to 3 cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) in patients with newly diagnosed, nonbulky stage I or II Hodgkin lymphoma (HL) predicts a low relapse rate. This phase 2 trial was designed to determine if a population of patients with early-stage disease can be treated with short-course ABVD without radiation therapy (RT) on the basis of a negative interim PET/CT, thereby limiting the risks of treatment. Between 15 May 2010 and 21 February 2013, 164 previously untreated patients with nonbulky stage I/II HL were enrolled, and 149 were included in the final analysis. Patients received 2 cycles of ABVD followed by PET. Deauville scores 1 to 3 were negative (≤ liver uptake) based on central review. PET^- patients received 2 more cycles of ABVD, and PET⁺ patients received 2 cycles of dose-intense bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (escalated BEACOPP) plus 3060-cGy involved-field RT. The primary objective was to determine 3-year progression-free survival (PFS) for the PET^- group. One hundred thirty-five patients (91%) were interim PET^-, and 14 patients (9%) were PET⁺ With median follow-up time of 3.8 years, the estimated 3-year PFS was 91% for the PET^- group and 66% for the PET⁺ group (hazard ratio, 3.84; 95% confidence interval, 1.50-9.84; P = .011). There was 1 death as a result of suicide. Four cycles of ABVD resulted in durable remissions for a majority of patients with early-stage nonbulky HL and a negative interim PET. This trial was registered at www.clinicaltrials.gov as #NCT01132807.

BACKGROUND:Y dosimetry. A Passing-Bablok regression scatter diagram and the Bland and Altman method were used to analyze the difference between the dosimetry values. RESULTS:The phantom study showed that both modalities were calibrated with less than 1% error. The mean liver doses for the 32 subjects calculated from PET/CT and PET/MRI were 51.6 ± 24.7 Gy and 46.5 ± 22.7 Gy, respectively, with a mean difference of 5.1 ± 5.0 Gy. The repeatability coefficient was 9.0 (18.5% of the mean). The Spearman rank correlation coefficient was very high, ρ = 0.97. Although the maximum dose to the liver can be significantly different (up to 40%), mean liver doses from each modalities were relatively close, with a difference of 18.5% or less. CONCLUSIONS:Y studies were similar.

BACKGROUND/AIM:Current guidelines derived from a pre-human papilloma virus (HPV) era in oropharyngeal cancer do not recommend routine surveillance imaging. We aimed to analyze the method of recurrence detection in HPV+ disease to determine a role for follow-up imaging. PATIENTS AND METHODS:All HPV+ and HPV- oropharyngeal cancer patients treated at our institution from 2005-2016 with biopsy-proven recurrence were identified and their method of recurrence detection was analyzed. RESULTS:A total of 16 HPV+ oropharyngeal cancer patients were identified to have recurrence, 12 (75%) of which experienced distant recurrence and 13 (81.3%) were detected asymptomatically with imaging at a median time of 19.7 months after initial treatment and verifying no residual disease. Twelve (75%) detections were with PET-CT. While HPV- patients (17 patients) also have a high rate of asymptomatic detection (16 patients, 94.1%), their 3-year post-recurrence survival was significantly lower at 6.5% compared to 83.6% for the HPV+ group (p<0.01). CONCLUSION:In HPV+ patients, a large proportion of failures are asymptomatic distant metastases, which occur beyond 6 months following treatment completion, and are detected with whole body imaging alone. In light of long term post-recurrence survival observed, this preliminary data suggests that routine surveillance imaging should be further studied for HPV+ disease.