Feasibility and Efficacy of Local Radiotherapy With Concurrent Novel Agents in Patients With Multiple Myeloma

Irradiated Bone Marrow Volume is Associated with Hematologic Toxicity in Patients with Multiple Myeloma

PURPOSE/OBJECTIVE(S)

Palliative radiotherapy (RT) is effective for multiple myeloma (MM) but may cause cytopenia. Bone marrow volume receiving 10Gy (BMV10Gy) has been associated with hematologic toxicity (HT) in cervical cancer, but no studies have investigated this in MM. We hypothesized that absolute BMV10Gy is associated with acute HT in MM patients receiving palliative RT.

MATERIALS/METHODS

This single-institution retrospective analysis evaluated 125 MM patients who received palliative RT between 2007-2023 and had ≥ 2 weeks of follow up laboratory data. Lab values were recorded pre-RT, post-RT, and at nadir within 90 days of completing RT. Clinical HT was defined as new transfusion/growth factor, admission for hematologic toxicity, and/or systemic therapy pause/discontinuation. BM was defined as bone volume within RT field. BMV5-40Gy (cc) was recorded for each treatment. Logistic regressions were performed with clinical HT as the primary endpoint.

RESULTS

105 (84%) patients received concurrent systemic therapy. Median BMV10Gy was 266cc (IQR 157-501cc). Median RT EqD2 was 26Gy (IQR 23-33Gy). On univariable analysis, BMV5Gy, BMV10Gy, and BMV15Gy were significantly associated with clinical HT (p=0.014, p=0.018, p=0.050, respectively) while RT EqD2 dose was not (p=0.997). On multivariable analysis, BMV10Gy was significantly associated with clinical HT (p=0.049) after adjusting for dose, number of lesions treated, lesion location (spine, pelvis, limb, soft tissue), and systemic therapy class. Disease course (number of prior systemic therapies) was significantly associated with clinical HT on univariable and multivariable analysis, with late relapsed/refractory patients (≥3 prior systemic therapies) having 9.6 higher odds of clinical HT compared to newly diagnosed patients (p<0.001).

CONCLUSION

To our knowledge, this is the first study to associate volume of irradiated BM with acute HT in MM. In addition to BM V5-15Gy, number of prior relapses and systemic therapy lines were significantly associated with HT. Disease history should be evaluated, and RT field volumes minimized for patients with poor bone marrow reserve (e.g., late relapsed/refractory disease).

Solitary bone plasmacytoma: Long-term clinical outcomes in a single center

BACKGROUND

A solitary plasmacytoma is classified into a solitary plasmacytoma of the bone (SBP) and a solitary extramedullary (soft tissue mass) plasmacytoma, based on the site of the lesion. Despite the high local control rate with radiotherapy, approximately half of patients' conditions progress to multiple myeloma (MM) within 3-5 years after diagnosis, with SBP having a worse prognosis.

PATIENTS AND METHODS

We retrospectively assessed the treatment and outcomes of patients with SBP in a hospital in China from 2008 to 2021. Twenty-four patients treated over 13 years with SBP were enrolled in this retrospective study.

RESULTS

The most common sites for SBP were the axial skeleton and femur. The M protein was detected in 11 patients (46 %), of which 8 (33 %) had light chains, 2 (8 %) had immunoglobulin G kappa and 1 (4 %) had immunoglobulin D kappa. Flow cytometry revealed that 5 patients (21 %) had minimal bone marrow involvement. The treatment included chemotherapy, surgery, and radiotherapy in 18 (75 %), 12 (50 %), and 9 (38 %) patients, respectively, of whom 13 (54 %) received combined treatment. Over a median follow-up period of 67.2 months, 9 patients (38 %) developed MM in a median time of 101.5 months. The 5- and 10-year progression-free survival rates were 67.3 % and 37.4 %, respectively. One patient died due to pneumonia without progression and the other died due to relapse.

CONCLUSION

This study confirmed the high rate of progression of SBP to MM, indicating a need for adjunct chemotherapy for the management of SBP.

Radiotherapy in Combination with Systemic Therapy for Multiple Myeloma-A Critical Toxicity Evaluation in the Modern Treatment Era

Radiotherapy (RT) is an established treatment modality in the management of patients with multiple myeloma (MM), aiming at analgesia and stabilization of osteolytic lesions. As a multifocal disease, the combined use of RT, systemic chemotherapy, and targeted therapy (ST) is pivotal to achieve better disease control. However, adding RT to ST may lead to increased toxicity. The aim of this study was to evaluate the tolerability of ST given concurrently with RT. Overall, 82 patients treated at our hematological center with a median follow-up of 60 months from initial diagnosis and 46.5 months from the start of RT were evaluated retrospectively. Toxicities were recorded from 30 days before RT up to 90 days after RT. 54 patients (65.9%) developed at least one non-hematological toxicity, with 50 patients (61.0%) showing low-grade (grade I or II) and 14 patients (17.1%) revealing high-grade (grade III and IV) toxicities. Hematological toxicities were documented in 50 patients (61.0%) before RT, 60 patients (73.2%) during RT, and 67 patients (81.7%) following RT. After RT, patients who had received ST during RT showed a significant increase in high-grade hematological toxicities (p = 0.018). In summary, RT can be safely implemented into modern treatment regimens for MM, but stringent monitoring of potential toxicities even after completion of RT has to be ensured.

Management of Pathological Thoracolumbar Vertebral Fractures in Patients With Multiple Myeloma: Multidisciplinary Recommendations

STUDY DESIGN

Mutlidisciplinary consensus recommendations for patients suffering from multiple myeloma (MM) involvement of the spinal column by the Spine Section of the German Association of Orthopaedic and Trauma Surgeons.

OBJECTIVE

To provide a comprehensive multidisciplinary diagnostic and therapeutic approach and to summarize the current literature on the management of pathological thoracolumbar vertebral fractures in patients with multiple myeloma.

METHODS

Multidisciplinary recommendations using a classical consensus process provided by radiation oncologists, medical oncologists, orthopaedic- and trauma surgeons. A narrative literature review of the current diagnostic and treatment strategies was conducted.

RESULTS

Treatment decision has to be driven by a multidisciplinary team of oncologists, radiotherapists and spine surgeons. When considering surgery in MM patients, differing factors compared to other secondary spinal lesions have to be included into the decision process: probable neurological deterioration, the stage of the disease and prognosis, patient's general condition, localization and number of the lesions as well as patient's own wishes or expectations. Aiming to improve quality of life, the major goal of surgical treatment is to preserve mobility by reducing pain, secure neurological function and stability.

CONCLUSION

The goal of surgery is primarily to improve quality of life by restoring stability and neurological function. Interventions with an increased risk of complications due to MM-associated immunodeficiency must be avoided whenever feasible to allow early systemic treatment. Hence, treatment decisions should be based on a multidisciplinary team that considers patient's constitution and prognosis.

RR Myelo POINT: A Retrospective Single-Center Study Assessing the Role of Radiotherapy in the Management of Multiple Myeloma and Possible Interactions with Concurrent Systemic Treatment

Background and purpose: Although chemotherapy, biological agents, and radiotherapy (RT) are cornerstones of the treatment of multiple myeloma (MM), the literature regarding the possible interactions of concurrent systemic treatment (CST) and RT is limited, and the optimal RT dose is still unclear. Materials and methods: We retrospectively analyzed the records of patients who underwent RT for MM at our institution from 1 January 2005 to 30 June 2020. The data of 312 patients and 577 lesions (treated in 411 accesses) were retrieved. Results: Most of the treated lesions involved the vertebrae (60%) or extremities (18.9%). Radiotherapy was completed in 96.6% of the accesses and, although biologically effective doses assuming an α/β ratio of 10 (BED 10) > 38 Gy and CST were significantly associated with higher rates of toxicity, the safety profile was excellent, with side effects grade ≥2 reported only for 4.1% of the accesses; CST and BED 10 had no impact on the toxicity at one and three months. Radiotherapy resulted in significant improvements in performance status and in a pain control rate of 87.4% at the end of treatment, which further increased to 96.9% at three months and remained at 94% at six months. The radiological response rate at six months (data available for 181 lesions) was 79%, with only 4.4% of lesions in progression. Progression was significantly more frequent in the lesions treated without CST or BED 10 < 15 Gy, while concurrent biological therapy resulted in significantly lower rates of progression. Conclusion: Radiotherapy resulted in optimal pain control rates and fair toxicity, regardless of BED 10 and CST; the treatments with higher BED 10 and CST (remarkably biological agents) improved the already excellent radiological disease control.

[Benefits of radiotherapy for patients with solitary plasmacytoma or multiple myeloma]

BACKGROUND

Treatment options for patients with solitary plasmacytoma (SP) or multiple myeloma (MM) should be discussed in an interdisciplinary context. This systematic review focuses on the importance of radiotherapy in MM and SP.

OBJECTIVE

Summary of local radio-oncological treatment options for patients with SP and MM.

MATERIALS AND METHODS

Based on a systematic literature search, the current evidence on the topic was analyzed and summarized.

RESULTS

Patients with SP should be primarily treated with radiotherapy with or without surgery. Irradiation concepts may vary depending on risk factors and manifestation (solitary bone plasmacytoma vs. solitary extramedullary plasmacytoma). Although local control rates are high after radiotherapy, progression to multiple myeloma frequently occurs. In patients with MM, radiation is mainly used in palliative settings for pain relief, prevention of fractures or in patients who suffer from neurological symptoms due to spinal cord compression. Irradiation dose and fractionation should be selected based on treatment indication and general condition of the patient.

CONCLUSION

Although most patients receive systemic treatment at initial diagnosis, approximately 40% of patients with MM will require radiation during the course of their disease. While radiation is mainly used for palliation in patients with MM, it represents the primary and curative treatment option in patients with SP.

The Safety and Efficacy of Radiation Therapy with Concurrent Dexamethasone, Cyclophosphamide, Etoposide, and Cisplatin-Based Systemic Therapy for Multiple Myeloma

INTRODUCTION

The concurrent delivery of radiation therapy (RT) with salvage chemotherapies in the management of relapsed and refractory multiple myeloma (MM) is an area of ongoing investigation. This study examined the safety and efficacy of palliative RT given in the setting of concurrent dexamethasone, cyclophosphamide, etoposide, and cisplatin (DCEP).

PATIENTS AND METHODS

Fifty-five patients with MM received RT to 64 different sites within three weeks of receiving DCEP from 2010 to 2020. A median dose of 20 Gray (range 8-32.5 Gy) was delivered in a median of 5 fractions (range 1-15). Patients received a median of 1 cycle (range 1-5) of DCEP. Rates of hematologic and RT toxicity were recorded along with pain, radiographic, and laboratory responses to treatment.

RESULTS

RT was completed in 98% of patients. 21% of patients experienced RTOG grade 3+ hematologic toxicity before RT, which increased to 35% one-month post-RT (P = .13) before decreasing to 12% at 3 to 6 months (P = .02). The most common toxicity experienced was thrombocytopenia. Grade 1 to 2 non-hematologic RT-related toxicity was reported in 15% of patients while on treatment and fell to 6% one-month after completing RT. Pain resolved in 94% of patients with symptomatic lesions at baseline. Stable disease or better was observed in 34/39 (87%) of the targeted lesions on surveillance imaging.

CONCLUSION

RT administered concurrently with DCEP was well-tolerated by most of the patients in this series, with low rates of hematologic and RT-related toxicity. RT was also very effective, with the vast majority of patients demonstrating resolution of their pain and a significant response on follow-up imaging.

Effective Pain Control With Very Low Dose Palliative Radiation Therapy for Patients With Multiple Myeloma With Uncomplicated Osseous Lesions

BACKGROUND

Osteolytic lesions are present in 75% of patients with multiple myeloma (MM) and frequently require palliation with radiation therapy (RT). Prior case series of patients with MM with bone pain undergoing palliative RT suggests doses ≥12 Gy (equivalent dose in 2Gy fractions, EQD2) provide excellent bone pain relief. However, recent advances in care and novel biologic agents have significantly improved overall survival and quality of life for patients with MM. We hypothesized that lower-dose RT (LDRT, EQD2 <12 Gy) offers an effective alternative to higher-dose RT (HDRT, EQD2 ≥12 Gy) for palliation of painful, uncomplicated MM bone lesions.

METHODS

We retrospectively identified patients with MM treated with RT for uncomplicated, painful bone lesions and stratified by EQD2 ≥/< 12 Gy. Clinical pain response (CPR) rates, acute and late toxicity, pain response duration, and retreatment rates between LDRT and HDRT groups were analyzed.

RESULTS

Thirty-five patients with 70 treated lesions were included: 24 patients (48 lesions) treated with HDRT and 11 patients (22 lesions) with LDRT. Median follow-up was 14 and 16.89 months for HDRT and LDRT, respectively. The median dose of HDRT treatment was 20 Gy versus 4 Gy in the LDRT group. The CPR rate was 98% for HDRT and 95% for LDRT. There was no significant difference in any-grade acute toxicity between the HDRT and LDRT cohorts (24.5% vs 9.1%, Χ² P = .20). Pain recurred in 10% of lesions (12% HDRT vs 9.5% LDRT). Median duration of pain response did not significantly differ between cohorts (P = .91). Five lesions were retreated, 2 (9.5%) in the LDRT cohort, and 3 (6.3%) in the HDRT cohort.

CONCLUSION

In this study, LDRT effectively palliated painful, uncomplicated MM bony lesions with acceptable CPR and duration of palliation. These data support prospective comparisons of LDRT versus HDRT for palliation of painful, uncomplicated MM bony lesions.

Utilization of radiation therapy in multiple myeloma: trends and changes in practice

Plasma cell disorders including plasmacytomas and multiple myeloma (MM) are exquisitely radiosensitive, and thus, radiation therapy (XRT) is used effectively in their management. The role of XRT in the setting of novel MM therapeutics has not been explored. The 2016 National Cancer Database (NCDB) for MM with patients diagnosed between 2004 and 2013 was studied. Association between utilization of XRT as part of initial therapy and patient, disease, or treating facility characteristics was studied. A total of 111,281 cases with 91.6% MM, 7% osseous plasmacytoma (PLA-O), and 1.4% extramedullary plasmacytoma (PLA-E) were identified. XRT was utilized as part of initial therapy in 25.4% cases, including 69.3% of PLA-O, 60% of PLA-E, and 21.5% of MM patients. Patients with PLA-E and MM were significantly less likely to receive XRT as compared to PLA-O (p < 0.001). A significantly decreased use of XRT was noted over time (p < 0.001), and for advancing patient age (p < 0.001), women (p < 0.001), and blacks (p < 0.001), and with increasing income (p = 0.015). Patients with Medicare were less likely to receive XRT (OR 0.86, 95% CI 0.78, 0.94) as compared to uninsured as were those with initial treatment at academic or high-volume facilities and facilities performing stem cell transplant. There was overall decreased utilization of XRT in recent years, possibly due to advent of efficacious systemic agents for MM therapy, with a higher XRT utilization for plasmacytomas. Patterns of XRT use need to be explored prospectively, so that uniform standards of healthcare delivery can be maintained and treatment heterogeneity can be minimized.

Multiple Myeloma Associated Bone Disease

The lytic bone disease is a hallmark of multiple myeloma, being present in about 80% of patients with newly diagnosed MM, and in more during the disease course. The myeloma associated bone disease (MBD) severely affects the morbidity and quality of life of the patients. MBD defines treatment demanding MM. In recent years, knowledge of the underlying pathophysiology has increased, and novel imaging technologies, medical and non-pharmaceutical treatments have improved. In this review, we highlight the major achievements in understanding, diagnosing and treating MBD. For diagnosing MBD, low-dose whole-body CT is now recommended over conventional skeletal survey, but also more advanced functional imaging modalities, such as diffusion-weighted MRI and PET/CT are increasingly important in the assessment and monitoring of MBD. Bisphosphonates have, for many years, played a key role in management of MBD, but denosumab is now an alternative to bisphosphonates, especially in patients with renal impairment. Radiotherapy is used for uncontrolled pain, for impeding fractures and in treatment of impeding or symptomatic spinal cord compression. Cement augmentation has been shown to reduce pain from vertebral compression fractures. Cautious exercise programs are safe and feasible and may have the potential to improve the status of patients with MM.

The Safety Profile of Concurrent Therapy for Multiple Myeloma in the Modern Era

Purpose

The management of multiple myeloma has evolved in the modern era, partially owing to the increasing number of biologic therapeutics. Nonetheless, radiation remains an important treatment in the management of painful lytic lesions from multiple myeloma. The goal of this study is to evaluate the side effect profile of radiation therapy (RT) while patients are concurrently treated with biologic agents.

Methods and Materials

We conducted a retrospective study based on data collected from patients receiving RT at our institute from 2007 to 2017. A total of 130 patients (279 treatment sites) were included in this study with a median follow-up time of 14 months. Patients were required to be receiving a biological agent at least within 1 month before starting and up to 1 month after RT. Generalized estimating equations with a log link function and binomial distribution were used to estimate the prevalence ratio (PR) and corresponding 95% confidence interval (CI) and compare the side effects between patients with RT alone and RT + biologic agent.

Results

The median age of all patients in our cohort was 64 years, with 53 men (58.9%) and 37 women (41.1%). The mean Karnofsky performance status score of all cohorts was 80. No significant difference in incidence of acute (PR: 1.33; 95% CI, 0.80-2.22; P = .2660) or subacute (PR: 0.90; 95% CI, 0.49-1.67; P = .7464) toxicities was found between patients with or without biologic agents who were treated concurrently with RT. No significant difference was found in reduction in laboratory values between patients with or without biologic agents treated concurrently with RT for white blood cells (P = .6916), platelets (P = .7779), or hematocrit (P = .0858).

Conclusions

Our study did not detect any significant toxicity rates from palliative radiation while patients were concurrently treated with biologic agents.

Radiation Therapy for Solitary Plasmacytoma and Multiple Myeloma: Guidelines From the International Lymphoma Radiation Oncology Group

PURPOSE

To develop guidelines for the work-up and radiation therapy (RT) management of patients with plasma cell neoplasms.

METHODS AND MATERIALS

A literature review was conducted covering staging, work-up, and RT management of plasma cell neoplasms. Guidelines were developed through consensus by an international panel of radiation oncologists with expertise in these diseases, from the International Lymphoma Radiation Oncology Group. RT volume definitions are based on the International Commission on Radiation Units and Measurements.

RESULTS

Plasma cell neoplasms account for approximately one-fifth of mature B-cell neoplasms in the United States. The majority (∼95%) are diagnosed as multiple myeloma, in which there has been tremendous progress in systemic therapy approaches with novel drugs over the last 2 decades, resulting in improvements in disease control and survival. In contrast, a small proportion of patients with plasma cell neoplasms present with a localized plasmacytoma in the bone, or in extramedullary (extraosseous) soft tissues, and definitive RT is the standard treatment. RT provides long-term local control in the solitary bone plasmacytomas and is potentially curative in the extramedullary cases. This guideline reviews the diagnostic work-up, principles, and indications for RT, target volume definition, treatment planning, and follow-up procedures for solitary plasmacytoma. Specifically, detailed recommendations for RT volumes and dose/fractionation are provided, illustrated with specific case scenarios. The role of palliative RT in multiple myeloma is also discussed.

CONCLUSIONS

The International Lymphoma Radiation Oncology Group presents a standardized approach to the use and implementation of definitive RT in solitary plasmacytomas. The modern principles outlining the supportive role of palliative RT in multiple myeloma in an era of novel systemic therapies are also discussed.