Purpose: Patients with abscopal regressions of lymphoma after palliative involved-site radiation therapy (ISRT), detected on sequential F-fluorodeoxyglucose positron emission tomography (FDG-PET), were identified by audit. A retrospective analysis was subsequently conducted to estimate the frequency of abscopal regression in follicular lymphoma (FL).
Methods And Materials: Potential cases were identified at multidisciplinary lymphoma meetings and fulfilled these criteria: (1) palliative ISRT given for histologically confirmed lymphoma, (2) >2 lesions visualized on FDG-PET, (3) >1 unirradiated lesion(s) outside ISRT volume, (4) no systemic therapy delivered <2 months before radiation therapy or between radiation therapy and response assessment, (5) complete metabolic response (CMR) in ≥1 unirradiated lesions detected on serial FDG-PET/CT. All ISRT patients with FL treated in 2016 to 2018 were systematically reviewed.
Results: Seven cases of abscopal regression were identified, including 4 patients with FL. In all cases, a CMR was apparent both within the ISRT volume and in ≥1 unirradiated lesions. One patient each was identified with mantle cell lymphoma (4 Gy in 2 fractions), Hodgkin lymphoma (20 Gy in 3 fractions, then 30 Gy in 15 fractions to the same volume), and Richter transformation of chronic lymphatic leukemia (30 Gy in 10 fractions). The 4 patients with FL received either 4 Gy in 2 fractions (n = 3) or 4 Gy followed 8 months later by 30 Gy in 15 fractions (n = 1). From 2016 to 2018, 29 courses of ISRT were prescribed for multifocal FL, after which 4 of 29 (13.8%) abscopal responses were detected, including in 4 of 9 (44.4%) patients with serial PET scans. Two patients, with relapsed disease after initial abscopal responses, experienced durable CMRs with immunotherapies.
Conclusions: In 4 of 7 cases, PET-detected abscopal regression of lymphoma occurred after 4 Gy, in 2 of 7 cases after repeated ISRT to the same volume, and in 2 of 7 was associated with subsequent complete response to immunotherapy, consistent with an immune basis for the abscopal effect. Abscopal regressions in FL appear to be more common than previously suspected.
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http://dx.doi.org/10.1016/j.ijrobp.2020.02.636 | DOI Listing |
Hematol Oncol Clin North Am
January 2025
Department of Radiation Oncology, Mayo Clinic Florida, 4500 San Pablo Road S, Jacksonville, FL 32224, USA. Electronic address:
The abscopal effect in radiotherapy (RT) refers to the phenomenon where localized radiation treatment causes regression of distant, nonirradiated tumors. Although rare, recent research shows that combining radiation with immunotherapies, such as immune checkpoint inhibitors, can enhance this effect. The interaction between radiation-induced cell death, immune responses, and the tumor microenvironment manifests in competing biologic mechanisms resulting in complex immunologic outcomes.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
Department of Pharmaceutics, The affiliated Suqian First People's Hospital of Nanjing Medical University, Suqian, Jiangsu, 223800, China.
Elesclomol (ES) as an efficient Cu ionophore can specifically transport Cu into mitochondria and disrupt intracellular Cu homeostasis. Extra intracellular Cu induces cuproptosis and chemodynamic therapy (CDT), which further cascades immunogenic cell death (ICD) and activates antitumor immune responses. However, the tumor immunosuppressive microenvironment (TIM) attenuates the efficiency of the immune response.
View Article and Find Full Text PDFFront Oncol
November 2024
Department of Radiation Oncology, Health Sciences University Bakirkoy Dr. Sadi Konuk Training and Research Hospital, Istanbul, Türkiye.
The abscopal effect refers to an anti-tumor response that occurs in areas where radiotherapy (RT) has not been directly administered but is triggered by the immune system. We presented a case of an undifferentiated pleomorphic sarcoma with three relapses that showed a complete response after distant metastatic disease. The tumor was initially detected in the left pectoral muscle.
View Article and Find Full Text PDFCureus
November 2024
Oncology, Stanford University Medical Center, Stanford, USA.
Despite modern advancements in systemic therapies, melanoma remains a highly malignant cancer, with persistent resistance to therapies such as checkpoint inhibitors and inhibitors of mutated BRAF V600E. Current therapy for targeting metastatic melanoma remains palliative radiation therapy, particularly directly at symptomatic sites. Extraordinarily, few case studies have reported locally targeted radiation resulting in regression of distal non-targeted lesions.
View Article and Find Full Text PDFImmunol Lett
February 2025
Department of Vaccine Immunology, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan; Division of Vaccine Immunology, Hokkaido University International Institute for Zoonosis Control, Sapporo 001-0020, Japan; Nebuta Research Institute for Life Sciences, Aomori University, Aomori 030-0943, Japan. Electronic address:
Radiation therapy (RT) rarely induces tumor regression at untreated metastatic sites, the so-called abscopal effect. A syngeneic tumor (EG7) transplanted into a Th1-dominant mouse strain (C57BL/6) regressed significantly on the treated side and less on the contralateral side after RT. Additional subcutaneous administration of ARNAX, a non-inflammatory adjuvant, further accelerated tumor regression on the untreated side.
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