Radiotherapy of extranodal low-grade follicular and marginal zone lymphomas: long-term follow-up of 159 patients

Orbital follicular lymphoma with large cell component treated with low-dose radiotherapy: A case report and review of literature

A 77-year-old woman was referred for a one-eyed palpebral edema associated with diplopia. An orbit magnetic resonance imaging showed an orbital mass in the superior medial portion of the internal right orbit without any intraorbital involvement. Biopsies demonstrated a nodular lymphoma with mixed follicular grade 1-2 (60%) and large cell components. The tumor mass was treated with a low-dose radiation therapy (4Gy in 2 fractions) with a complete disappearance of diplopia within one week. At 2-year follow-up, patient was in complete remission. To the best of our knowledge, this is the first case of mixed component follicular and large components orbital lymphoma managed by first-intent low-dose radiation therapy.

Impact of radiation techniques on lung toxicity in patients with mediastinal Hodgkin's lymphoma

PURPOSE

Mediastinal radiotherapy (RT), especially when combined with bleomycin, may result in substantial pulmonary morbidity and mortality. The use of modern RT techniques like intensity-modulated radiotherapy (IMRT) is gaining interest to spare organs at risk.

METHODS

We evaluated 27 patients who underwent RT for Hodgkin's lymphoma between 2009 and 2013 at our institution. For each patient, three different treatment plans for a 30-Gy involved-field RT (IFRT) were created (anterior-posterior-posterior-anterior setup [APPA], 5‑field IMRT, and 7‑field IMRT) and analyzed concerning their inherent "normal tissue complication probability" (NTCP) for pneumonitis and secondary pulmonary malignancy.

RESULTS

The comparison of different radiation techniques showed a significant difference in favor of standard APPA (p < 0.01). The risk of lung toxicity was significantly higher in plans using 7‑field IMRT than in plans using 5‑field IMRT. The absolute juxtaposition showed an increase in risk for radiation pneumonitis of 1% for plans using 5‑field IMRT over APPA according to QUANTEC (Quantitative Analyses of Normal Tissue Effects in the Clinic) parameters (Burman: 0.15%) and 2.6% when using 7‑field IMRT over APPA (Burman: 0.7%) as well as 1.6% when using 7‑field IMRT over 5‑field IMRT (Burman: 0.6%). Further analysis showed an increase in risk for secondary pulmonary malignancies to be statistically significant (p < 0.01); mean induction probability for pulmonary malignoma was 0.1% higher in plans using 5‑field IMRT than APPA and 0.19% higher in plans using 7‑field IMRT than APPA as well as 0.09% higher in plans using 7‑field IMRT than 5‑field IMRT. During a median follow-up period of 65 months (95% confidence interval: 53.8-76.2 months), only one patient developed radiation-induced pneumonitis. No secondary pulmonary malignancies have been detected to date.

CONCLUSION

Radiation-induced lung toxicity is rare after treatment for Hodgkin lymphoma but may be influenced significantly by the RT technique used. In this study, APPA RT plans demonstrated a decrease in potential radiation pneumonitis and pulmonary malignancies. Biological planning using NTCP may have the potential to define personalized RT strategies.

How to manage early-stage follicular lymphoma

INTRODUCTION

Early-stage follicular lymphoma (FL) is characterized by good prognosis and can be cured with involved-field radiotherapy (IF-RT) in most cases. PET scan is a milestone of diagnostic work-up, with the aim of identifying a truly localized disease; however, staging in most of the studies was without PET.

AREAS COVERED

We have searched in MEDLINE (inclusive dates 1994-2020) data about localized FL management. While high-quality evidence is lacking, current guidelines recommend IFRT or involved-site RT as first-line treatment in limited stages FL. Since a significant proportion of disease relapse occurred in non-irradiated areas, it has been hypothesized that occult disease could be present at diagnosis and could persist after RT, contributing to relapse. Available treatment options include watch-and-wait, chemotherapy, RT plus chemo- or chemo-immunotherapy, and RT combined with rituximab (R).

EXPERT OPINION

RT combined with chemotherapy could increase PFS, but a clear OS benefit is lacking and toxic effects could be unacceptable. A promising strategy is represented by R combined with IF-RT, with low relapse rate outside the radiation fields and without the toxicity reported with chemotherapy. The study of prognostic factors in PET-staged patients, the reduction of RT fields and doses, and a response-adapted strategy represent new perspectives to investigate.

Analysis of the response time to involved-field radiotherapy in primary gastrointestinal low-grade B-cell lymphoma

BACKGROUND

Early-stage primary gastrointestinal (GI) low-grade B-cell lymphoma shows good therapeutic response to primary radiotherapy. However, there is no clear guideline for the evaluation of response to radiation therapy currently. The aim of this study was to analyze the relationship between the best response time and the clinical course after radiotherapy.

METHODS

Patients who underwent radiotherapy for treatment of primary GI low-grade B-cell lymphoma from September 2007 to December 2018 at Seoul St. Mary's Hospital were included. Early responders were defined by best response within 6 months after radiotherapy, and delayed responders after 6 months. Clinical and pathological factors associated with delayed response and survival analyses were performed to investigate the recurrence and survival during follow-up.

RESULTS

A total of 43 patients were evaluated and the number of gastric mucosa-associated lymphoid tissue and duodenal follicular lymphoma was 36 and 7, respectively. All of 43 patients showed complete remission to radiotherapy and the best response time after radiotherapy was a median of 3 months. There were 8 delayed responders with a median duration of 8.9 months. Early and delayed responders were characterized by a significant difference in depth of invasion beyond the mucosal layer.

CONCLUSIONS

Delayed responders did not show differences in oncological outcomes compared with early responders. They were allowed to watch and wait for an additional 6 to 12 months without further treatment.

Maximizing the Clinical Benefit of Radiotherapy in Solitary Plasmacytoma: An International Multicenter Analysis

Objective: Although local definitive radiotherapy (RT) is considered the standard of care for solitary plasmacytoma (SP), the optimal RT parameters for SP patients have not been defined. The aim of this retrospective study is to analyze the effectiveness of various RT doses, volumes, and techniques, as well as to define the relevant prognostic factors in SP. Methods: Between 2000 and 2019, 84 patients, including 54 with solitary bone plasmacytoma (SBP) and 30 with extramedullary plasmacytoma (EMP), underwent RT at six institutions. Results: The overall RT median dose was 42 Gy (range, 36.0–59.4). The median follow-up period was 46 months. Overall, the local control (LC) rate was 96%, while the complete remission (CR) rate was 46%. The 5-year local relapse-free survival (LRFS), multiple myeloma-free survival (MMFS), progression-free survival (PFS), and overall survival (OS) rates were 89%, 71%, 55%, and 93%, respectively. Using an RT dose above 40 Gy was associated with a higher complete remission (CR) rate and a lower rate of local relapse. Modern irradiation techniques were associated with a trend toward a higher LC rate (98% vs. 87% for conventional, p = 0.09) and a significantly lower local relapse rate (6% vs. 25% for conventional, p = 0.04). However, RT dose escalation and technique did not lead to a significant effect on MMFS, PFS, and OS. Univariate analyses identified several patient characteristics as potentially relevant prognostic factors. In SBP patients, systemic therapy administration was associated significantly with MMFS and PFS rates. Conclusion: Using an RT dose >40 Gy and modern RT techniques may improve the local control and reduce the rate of relapse, without a significant impact on survival rates. The addition of systemic therapies may improve the MMFS and PFS rates of SBP patients.

De-escalated radiotherapy for indolent primary cutaneous B-cell lymphoma

OBJECTIVE

Radiotherapy (RT) has an established role in the curative treatment of indolent primary cutaneous B‑cell lymphoma (PCBCL). With the role of low-dose regimens such as 2 × 2 Gy being uncertain, we compared conventional-dose RT to a low-dose approach and investigated outcome and toxicities.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 26 patients with 44 cutaneous lesions treated at our institution between 2007 and 2017, comprising 22 marginal zone lymphoma (PCMZL) lesions and 22 follicle center lymphoma (PCFCL) lesions. Seven lesions (16%) were treated with low-dose RT (LDRT) (4 Gy) and 37 (84%) with conventional-dose RT (≥24 Gy, median 40 Gy). Median follow-up duration was 76 months.

RESULTS

The overall response rate (ORR) was 91% (complete response rate [CRR]: 75%). The 5‑year local control rate (LCR) was 88% and the 10-year LCR was 84%. The response rates were significantly higher following conventional-dose RT (ORR: 92% vs. 86%; CRR: 84% vs. 29%; P = 0.007). In terms of radiation dose, the rate of infield relapses (14% vs. 11%, P = 0.4) and the 5‑year LCR (86% vs. 90%, P = 0.4) were comparable in the LDRT and conventional-dose RT groups. During RT courses, about two-thirds of patients experienced mild toxicities, with grade I and II acute toxicity rates of 61% and 9%, respectively, with lower incidences of grade I (14% vs. 70%) and grade II (0% vs. 8%, P = 0.004) toxicities following LDRT.

CONCLUSION

This long-term analysis confirms the excellent outcome of RT in the management of PCBCL. The LDRT concept with 4 Gy was associated with a comparable LCR and reduced rates of acute toxicity. However, the response rates were significantly lower for this group and LDRT may therefore not be recommended as standard treatment.