Consolidative Radiotherapy After Autologous Stem Cell Transplantation for Relapsed or Refractory Diffuse Large B-cell Lymphoma

INTRODUCTION

We evaluated the role of consolidative radiotherapy (RT) for patients undergoing high-dose chemotherapy (HDC) and autologous stem cell transplantation (ASCT) for relapsed or refractory diffuse large B-cell lymphoma (DLBCL).

MATERIALS AND METHODS

We reviewed the medical records of 72 consecutive patients who had undergone ASCT for relapsed or refractory DLBCL at our institution from 2006 to 2014. Pretransplant conditioning consisted of HDC and total body irradiation. Of the 72 patients, 13 received post-transplant consolidative RT at the discretion of the consulted radiation oncologist.

RESULTS

Consolidative RT was associated with significantly improved 2-year locoregional control (LRC) (92% vs. 68%; P = .04). However, no difference was seen in either the 2-year progression-free survival (PFS) (69% vs. 54%; P = .25) or overall survival (OS) (85% vs. 59%; P = .44). Analysis of the subgroup of 19 patients with persistent residual masses ≥ 2 cm on post-transplant imaging demonstrated a significant improvement in LRC (100% vs. 36%; P < .01), PFS (88% vs. 27%; P = .01), and OS (100% vs. 45%; P = .02) with consolidative RT.

CONCLUSION

The use of consolidative RT after HDC and ASCT for relapsed or refractory DLBCL appears to significantly improve LRC. For patients with masses ≥ 2 cm after ASCT, improved 2-year PFS and OS were seen. Prospective trials are needed to further identify the patients who would derive the most benefit from consolidative RT in the ASCT setting.

Lung reirradiation with stereotactic body radiotherapy (SBRT)

INTRODUCTION

There is limited data on the use of SBRT in reirradiation of lung tumors. We reviewed outcomes following SBRT after previous thoracic radiotherapy at the University of Minnesota Medical Center.

METHODS

From August 2006 through October 2012, fourteen lung tumors in thirteen patients with either biopsy confirmed or presumed non-small cell lung cancer in patients who were medically unable to undergo biopsy, were retreated with SBRT. Eligible patient charts were reviewed to evaluate survival, recurrence patterns and toxicity following reirradiation.

RESULTS

The median age of patients at the time of SBRT was 67.9 years. The median duration of follow-up was 11.4 months. Ten patients received prior conventional thoracic irradiation (median dose 6120 cGy). Two patients received prior SBRT with curative intent. The median time to reirradiation with SBRT was 19.7 months. Following reirradiation with SBRT, four patients (33%) are alive and disease free. Eight patients (67%) experienced progressive disease. There were five distant and two regional recurrences. There was one isolated local recurrence. Local control was 92% with a median survival of 24 months (95% CI: 8-38 months). 1- and 2-year overall survival were 80% (95% CI: 41%-95%) and 36% (95% CI: 6%-68%) respectively. There was one grade 2 and one grade 3 toxicity. No grade 4 or 5 toxicities were seen.

CONCLUSIONS

SBRT is a reasonable salvage therapy for lung tumor recurrence or second primary lung malignancy in patients previously treated with thoracic radiotherapy, offering good local control and resulting in acceptable toxicity. Further evaluation of this treatment option is warranted.

Clinical outcomes of patients receiving integrated PET/CT-guided radiotherapy for head and neck carcinoma

PURPOSE

We previously reported the advantages of (18)F-fluorodeoxyglucose-positron emission tomography (PET) fused with CT for radiotherapy planning over CT alone in head and neck carcinoma (HNC). The purpose of this study was to evaluate clinical outcomes and the predictive value of PET for patients receiving PET/CT-guided definitive radiotherapy with or without chemotherapy.

METHODS AND MATERIALS

From December 2002 to August 2006, 42 patients received PET/CT imaging as part of staging and radiotherapy planning. Clinical outcomes including locoregional recurrence, distant metastasis, death, and treatment-related toxicities were collected retrospectively and analyzed for disease-free and overall survival and cumulative incidence of recurrence.

RESULTS

Median follow-up from initiation of treatment was 32 months. Overall survival and disease-free survival were 82.8% and 71.0%, respectively, at 2 years, and 74.1% and 66.9% at 3 years. Of the 42 patients, seven recurrences were identified (three LR, one DM, three both LR and DM). Mean time to recurrence was 9.4 months. Cumulative risk of recurrence was 18.7%. The maximum standard uptake volume (SUV) of primary tumor, adenopathy, or both on PET did not correlate with recurrence, with mean values of 12.0 for treatment failures vs. 11.7 for all patients. Toxicities identified in those patients receiving intensity modulated radiation therapy were also evaluated.

CONCLUSIONS

A high level of disease control combined with favorable toxicity profiles was achieved in a cohort of HNC patients receiving PET/CT fusion guided radiotherapy plus/minus chemotherapy. Maximum SUV of primary tumor and/or adenopathy was not predictive of risk of disease recurrence.