Involved-nodal radiation therapy as a component of combination therapy for limited-stage Hodgkin's lymphoma: a question of field size

Pediatric Hodgkin's lymphoma: changing concepts and moving points in radiation therapy

The classic treatment of Hodgkin's lymphoma (HL) in children resulted in significant late toxicity in long-term survivors. Late treatment effects included skeletal, cardio- pulmonary, gonadal toxicities, and second malignant tumor (SMN). This has driven pediatric HL groups to adopt treatment strategies using less intense chemotherapy, less alkylating agents, reduced radiation dose and volume, and omission of radiation therapy in selected group of patients. In limited disease, the aim is to maintain a high cure rate with minimal side effects. Patients with advanced-stage HL have a lower outcome, and need treatment intensification. Dose-dense, risk and response-adapted treatment strategies are evolving aiming at improving outcome and reducing toxicity.

Cardiac complications of thoracic irradiation

Adjuvant radiation therapy in the management of early stage breast cancer, Hodgkin's disease, and to a lesser extent other thoracic malignancies has led to a significant improvement in disease-specific survival. Cardiovascular disease is now the most common nonmalignancy cause of death in radiation-treated cancer survivors, most often occurring decades after treatment. The spectrum of radiation-induced cardiac disease is broad, potentially involving any component of the heart. The relative risk of coronary artery disease, congestive heart failure, valvular heart disease, pericardial disease, conduction abnormalities, and sudden cardiac death is particularly increased. Over the years contemporary techniques have been introduced to reduce cardiac morbidity and mortality in radiation-treated cancer survivors; however, the long-term effects on the heart still remain unclear, mandating longer follow-up. Awareness and early identification of potential cardiac complications is crucial in cancer survivors, with the management often being quite complex. This review examines the epidemiology of radiation-induced cardiac disease together with its pathophysiology and explores the available treatment strategies and the potential utility of various screening strategies for affected cancer survivors.

Is there a role for consolidation radiotherapy in Hodgkin’s lymphoma in the era of the PET scan?

SUMMARY Treatment results of Hodgkin’s lymphoma have dramatically improved with the introduction of combined modality treatment with multiagent chemotherapy regimens and radiotherapy in the last half century. However, in the last decade, with the increasing efficacy of chemotherapy, the enthusiasm for radiotherapy has waned as a result of the late effects among survivors. Furthermore, risk-adapted treatment approaches using functional imaging as a prognostic tool have become the focus of recent trials. Here we discuss current evidence for the use of radiotherapy to improve local control, and how patients may be selected who will benefit.

Point/counterpoint: early-stage Hodgkin lymphoma and the role of radiation therapy

The results of recent clinical trials for the management of limited-stage Hodgkin lymphoma have led to considerable debate, especially regarding the role of radiation therapy. This review highlights those recent trials and provides perspectives regarding their interpretation from a radiation oncologist and a hematologist. The trial protocol is available at http://www.nejm.org/doi/suppl/10.1056/NEJMoa1111961/suppl_file/nejmoa1111961_protocol.pdf.

Involved node radiation therapy: an effective alternative in early-stage hodgkin lymphoma

PURPOSE

The involved node radiation therapy (INRT) strategy was introduced for patients with Hodgkin lymphoma (HL) to reduce the risk of late effects. With INRT, only the originally involved lymph nodes are irradiated. We present treatment outcome in a retrospective analysis using this strategy in a cohort of 97 clinical stage I-II HL patients.

METHODS AND MATERIALS

Patients were staged with positron emission tomography/computed tomography scans, treated with adriamycin, bleomycin, vinblastine, and dacarbazine chemotherapy, and given INRT (prechemotherapy involved nodes to 30 Gy, residual masses to 36 Gy). Patients attended regular follow-up visits until 5 years after therapy.

RESULTS

The 4-year freedom from disease progression was 96.4% (95% confidence interval: 92.4%-100.4%), median follow-up of 50 months (range: 4-71 months). Three relapses occurred: 2 within the previous radiation field, and 1 in a previously uninvolved region. The 4-year overall survival was 94% (95% confidence interval: 88.8%-99.1%), median follow-up of 58 months (range: 4-91 months). Early radiation therapy toxicity was limited to grade 1 (23.4%) and grade 2 (13.8%). During follow-up, 8 patients died, none from HL, 7 malignancies were diagnosed, and 5 patients developed heart disease.

CONCLUSIONS

INRT offers excellent tumor control and represents an effective alternative to more extended radiation therapy in the combined modality treatment for early-stage HL.

Point/counterpoint: early-stage Hodgkin lymphoma and the role of radiation therapy

The results of recent clinical trials for the management of limited-stage Hodgkin lymphoma have led to considerable debate, especially regarding the role of radiation therapy. This review highlights those recent trials and provides perspectives regarding their interpretation from a radiation oncologist and a hematologist. The trial protocol is available at http://www.nejm.org/doi/suppl/10.1056/NEJMoa1111961/suppl_file/nejmoa1111961_protocol.pdf.

Multicenter evaluation of different target volume delineation concepts in pediatric Hodgkin's lymphoma. A case study

BACKGROUND AND PURPOSE

In pediatric Hodgkin's lymphoma (PHL) improvements in imaging and multiagent chemotherapy have allowed for a reduction in target volume. The involved-node (IN) concept is being tested in several treatment regimens for adult Hodgkin's lymphoma. So far there is no consensus on the definition of the IN. To improve the reproducibility of the IN, we tested a new involved-node-level (INL) concept, using defined anatomical boundaries as basis for target delineation. The aim was to evaluate the feasibility of IN and INL concepts for PHL in terms of interobserver variability.

PATIENTS AND METHODS

The INL concept was defined for the neck and mediastinum by the PHL Radiotherapy Group based on accepted concepts for solid tumors. Seven radiation oncologists from six European centers contoured neck and mediastinal clinical target volumes (CTVs) of 2 patients according to the IN and the new INL concepts. The median CTVs, coefficient of variation (COV), and general conformity index (CI) were assessed. The intraclass correlation coefficient (ICC) for reliability of delineations was calculated.

RESULTS

All observers agreed that INL is a feasible and practicable delineation concept resulting in stronger interobserver concordance than the IN (mediastinum CI(INL) = 0.39 vs. CI(IN) = 0.28, neck left CI(INL) = 0.33; CI(IN) = 0.18; neck right CI(INL) = 0.24, CI(IN) = 0.14). The COV showed less dispersion and the ICC indicated higher reliability of contouring for INL (ICC(INL) = 0.62, p < 0.05) as for IN (ICC(IN) = 0.40, p < 0.05).

CONCLUSION

INL is a practical and feasible alternative to IN resulting in more homogeneous target delineation, and it should be therefore considered as a future target volume concept in PHL.

Tailored strategies for radiation therapy in classical Hodgkin's lymphoma

Radiotherapeutic advances have contributed to the evolution of Hodgkin's lymphoma (HL) treatment paradigms. A reduction in radiation therapy (RT) field size and dose has the potential to significantly impact the therapeutic ratio by diminishing late toxicities while maintaining curability. Substantial progress in risk stratification has contributed to the development of tailored RT strategies which address both field design as well as dose. Technologic improvements have also enhanced the ability to adapt the RT technique to the individual patient. The refinement of the RT approach and its incorporation into current combined modality strategies in adult classical HL is the subject of ongoing investigation and is critically reviewed.

Impact of PET-CT on involved field radiotherapy design for pediatric Hodgkin lymphoma

PURPOSE

To determine how the incorporation of PET-CT changes radiotherapy treatment in pediatric Hodgkin lymphoma.

PROCEDURE

Fifty-three Hodgkin lymphoma patients with a median age of 14 years (6-21 years) underwent multiagent chemotherapy followed by involved field radiotherapy (IFRT) to initial sites of disease. All patients had conventional staging which included CT scan of the neck, chest, abdomen and pelvis, bone marrow biopsy ± MRI, Gallium scan and bone scan. All had an initial 18-F-fluoro-deoxy-D-glucose (FDG) PET-CT. When there was discordance between conventional staging and PET-CT staging, true sites of disease were determined either by biopsy or response to multiagent chemotherapy.

RESULTS

In 19 of 53 (35.8%) patients, there was discordance between conventional staging and PET-CT findings. The most common location for the 23 sites of discordance were the spleen in 6 (26.1%), neck in 3 (13%), inguinal nodes in 3 (13%) and mediastinum in 3 (13%). A change in stage occurred in 5 (9.4%) as a result of PET-CT imaging. A change in IFRT fields occurred in 9 (17%); eight were more extensive while one was less extensive. For PET-CT, the specificity, sensitivity, positive predictive value and accuracy were 99.5%, 96.3%, 97.9%, and 98.9%.

CONCLUSION

Incorporation of PET-CT information was found to influence IFRT design in 17% of patients, with most having more extensive radiotherapy fields.

Minimising critical organ irradiation in limited stage Hodgkin lymphoma: a dosimetric study of the benefit of involved node radiotherapy

BACKGROUND

Chemotherapy plus radiotherapy is the standard of care for patients with limited stage Hodgkin lymphoma (HL). Radiotherapy is evolving from involved field radiotherapy (IFRT) to involved node radiotherapy (INRT) to decrease radiotherapy-related morbidity. In the absence of long-term toxicity data, dose-volume metrics of organs at risk (OAR) provide a surrogate measure of toxicity risk.

PATIENTS AND METHODS

Ten female patients with stage I-IIA supradiaphragmatic HL were randomly selected. All patients had pre-chemotherapy computerised tomography (CT) and CT-positron emission tomography staging. Using CT planning, three radiotherapy plans were produced per patient: (i) IFRT, (ii) INRT using parallel-opposed beams and (iii) INRT using volumetric modulated arc therapy (VMAT). Radiotherapy dose was 30.6 Gy in 1.8 Gy fractions. OAR evaluated were lungs, breasts, thyroid, heart and coronary arteries.

RESULTS

Compared with IFRT, INRT significantly reduced mean doses to lungs (P < 0.01), breasts (P < 0.01), thyroid (P < 0.01) and heart (P < 0.01), on Wilcoxon testing. Compared with conventional INRT, VMAT improved dose conformality but increased low-dose radiation exposure to lungs and breasts. VMAT reduced the heart volume receiving 30 Gy (V30) by 85%.

CONCLUSIONS

Reduction from IFRT to INRT decreased the volumes of lungs, breasts and thyroid receiving high-dose radiation, suggesting the potential to reduce long-term second malignancy risks. VMAT may be useful for patients with pre-existing heart disease by minimising further cardiac toxicity risks.

Dosimetric and clinical outcomes of involved-field intensity-modulated radiotherapy after chemotherapy for early-stage Hodgkin's lymphoma with mediastinal involvement

PURPOSE

To evaluate the dosimetric and clinical outcomes of involved-field intensity-modulated radiotherapy (IF-IMRT) for patients with early-stage Hodgkin's lymphoma (HL) with mediastinal involvement.

METHODS AND MATERIALS

Fifty-two patients with early-stage HL that involved the mediastinum were reviewed. Eight patients had Stage I disease, and 44 patients had Stage II disease. Twenty-three patients (44%) presented with a bulky mediastinum, whereas 42 patients (81%) had involvement of both the mediastinum and either cervical or axillary nodes. All patients received combination chemotherapy followed by IF-IMRT. The prescribed radiation dose was 30-40 Gy. The dose-volume histograms of the target volume and critical normal structures were evaluated.

RESULTS

The median mean dose to the primary involved regions (planning target volume, PTV1) and boost area (PTV2) was 37.5 Gy and 42.1 Gy, respectively. Only 0.4% and 1.3% of the PTV1 and 0.1% and 0.5% of the PTV2 received less than 90% and 95% of the prescribed dose, indicating excellent PTV coverage. The median mean lung dose and V20 to the lungs were 13.8 Gy and 25.9%, respectively. The 3-year overall survival, local control, and progression-free survival rates were 100%, 97.9%, and 96%, respectively. No Grade 4 or 5 acute or late toxicities were reported.

CONCLUSIONS

Despite the large target volume, IF-IMRT gave excellent dose coverage and a favorable prognosis, with mild toxicity in patients with early-stage mediastinal HL.

Risk of developing cardiovascular disease after involved node radiotherapy versus mantle field for Hodgkin lymphoma

PURPOSE

Hodgkin lymphoma (HL) survivors are known to have increased cardiac mortality and morbidity. The risk of developing cardiovascular disease after involved node radiotherapy (INRT) is currently unresolved, inasmuch as present clinical data are derived from patients treated with the outdated mantle field (MF) technique.

METHODS AND MATERIALS

We included all adolescents and young adults with supradiaphragmatic, clinical Stage I-II HL treated at our institution from 2006 to 2010 (29 patients). All patients were treated with chemotherapy and INRT to 30 to 36 Gy. We then simulated a MF plan for each patient with a prescribed dose of 36 Gy. A logistic dose-response curve for the 25-year absolute excess risk of cardiovascular disease was derived and applied to each patient using the individual dose-volume histograms.

RESULTS

The mean doses to the heart, four heart valves, and coronary arteries were significantly lower for INRT than for MF treatment. However, the range in doses with INRT treatment was substantial, and for a subgroup of patients, with lymphoma below the fourth thoracic vertebrae, we estimated a 25-year absolute excess risk of any cardiac event of as much as 5.1%.

CONCLUSIONS

Our study demonstrates a potential for individualizing treatment by selecting the patients for whom INRT provides sufficient cardiac protection for current technology; and a subgroup of patients, who still receive high cardiac doses, who would benefit from more advanced radiation technique.

Treating limited-stage nodular lymphocyte predominant Hodgkin lymphoma similarly to classical Hodgkin lymphoma with ABVD may improve outcome

The appropriate therapy for limited-stage nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is unclear. In contrast to classical Hodgkin lymphoma (CHL), chemotherapy is often omitted; however, it is unknown whether this impacts the risk of relapse. Herein, we compared the outcome of patients with limited-stage NLPHL treated in an era in which ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) chemotherapy was routinely incorporated into the primary therapy to an earlier era in which radiotherapy (RT) was used as a single modality. Using the British Columbia Cancer Agency Lymphoid Cancer Database, 88 patients with limited-stage NLPHL (stage 1A/1B or 2A, nonbulky disease < 10 cm) were identified. Treatment followed era-specific guidelines: before 1993, (n = 32) RT alone; and 1993 to present (n = 56), ABVD-like chemotherapy for 2 cycles followed by RT with the exception of 14 patients who received ABVD chemotherapy alone. Most patients were male (75%) with stage I disease (61%). In an era-to-era comparison, the 10-year time to progression (98% vs 76% P = .0074), progression-free survival (91% vs 65% P = .0024), and OS (93% vs 84%, P = .074) favored the ABVD treatment era compared with the RT alone era. Treating limited-stage NLPHL similarly to CHL may improve outcome compared with the use of radiation alone.

Hodgkin lymphoma: answers take time!

In this issue of Blood, Straus and colleagues on behalf of the Cancer and Leukemia Group B (CALGB) present the outcome of a phase 2 trial of doxorubicin, vinblastine,and gemcitabine for patients with early-stage, non-bulky, Hodgkin lymphoma.The complete response rate and progression-free survival were inferior to comparable series, emphasizing the challenges of improving outcome in this highly curable population.

Current concepts and controversies in the management of early stage Hodgkin lymphoma

Over the past three decades, due to the recognition of late effects related to high-dose extended field radiotherapy and heavy alkylator chemotherapy, combined modality therapy with abbreviated chemotherapy and limited field radiotherapy has emerged as the standard of care for early stage Hodgkin lymphoma, with cure rates in excess of 80%. Currently, however, controversy remains over identifying the most appropriate criteria to risk-stratify patients with early stage disease, so that those with a favorable prognosis receive limited treatment without compromising cure rates and those with unfavorable risk receive more intensified therapy. The optimal risk stratification system remains unclear, with variable definitions of favorable and unfavorable disease used by research groups in North America and Europe. Thus, comparison of clinical trial results has been challenging, and additional controversies persist regarding optimal chemotherapy regimens, duration of therapy, and the role of radiotherapy. Investigations are ongoing to assess the potential of functional imaging and biomarkers as tools for risk stratification. The collective goal is to further refine current stratification strategies to allow for an individualized, risk-adapted treatment approach that minimizes long-term late effects without compromising high cure rates.

Interobserver variability of clinical target volume delineation in supra-diaphragmatic Hodgkin's disease: a multi-institutional experience

BACKGROUND

To determine interobserver variability in clinical target volume (CTV) of supra-diaphragmatic Hodgkin's lymphoma.

MATERIALS AND METHODS

At the 2008 AIRO (Italian Society of Radiation Oncology) Meeting, the Radiation Oncology Department of Chieti proposed a multi-institutional contouring dummy-run of two cases of early stage supra-diaphragmatic Hodgkin's lymphoma after chemotherapy. Clinical history, diagnostics, and planning CT imaging were available on Chieti's radiotherapy website (www.radioterapia.unich.it). Participating centers were requested to delineate the CTV and submit it to the coordinating center. To quantify interobserver variability of CTV delineations, the total volume, craniocaudal, laterolateral, and anteroposterior diameters were calculated.

RESULTS

A total of 18 institutions for case A and 15 institutions for case B submitted the targets. Case A presented significant variability in total volume (range: 74.1-1,157.1 cc), craniocaudal (range: 6.5-22.5 cm; median: 16.25 cm), anteroposterior (range: 5.04-14.82 cm; median: 10.28 cm), and laterolateral diameters (range: 8.23-22.88 cm; median: 15.5 cm). Mean CTV was 464.8 cc (standard deviation: 280.5 cc). Case B presented significant variability in total volume (range: 341.8-1,662 cc), cranio-caudal (range: 8.0-28.5 cm; median: 23 cm), anteroposterior (range: 7.9-1.8 cm; median: 11.1 cm), and laterolateral diameters (range: 12.9-24.0 cm; median: 18.8 cm). Mean CTV was 926.0 cc (standard deviation: 445.7 cc).

CONCLUSION

This significant variability confirms the need to apply specific guidelines to improve contouring uniformity in Hodgkin's lymphoma.

The staging and treatment of multicentric high-grade lymphoma in dogs: a review of recent developments and future prospects

In recent years, considerable progress has been made in understanding the biology of canine lymphoma with resultant enhanced classification schemes and the possibility of individualised, tailored therapies. However, although complete remission may be achieved using multi-agent chemotherapy, the mortality rate from this neoplasm remains high. This review focuses on the staging of high-grade multicentric lymphoma in the dog, on conventional and novel treatment strategies (including chemotherapy, bone marrow transplantation, radiation therapy and molecular-targeted agents), and on the management of relapsed or refractory cases.

Use of prechemotherapy positron emission tomography-CT imaging, acquired in the treatment position, to help plan involved nodal radiotherapy for a patient with diffuse large B-cell lymphoma

Fused positron emission tomography/computed tomography (PET-CT) images are increasingly being used to assist radiation oncologists in the definition of treatment volumes for patients with metabolically active tumours. This is the first report in which baseline fluorodeoxyglucose-PET-CT images were acquired in the treatment position in a case of diffuse large B-cell lymphoma and incorporated directly into the radiotherapy treatment planning process. It highlights the potential benefits of using combined 3-D functional and structural imaging for the design of radiation target volumes in patients with aggressive lymphomas that are managed with combined chemo and radiotherapy.

Doxorubicin, vinblastine, and gemcitabine (CALGB 50203) for stage I/II nonbulky Hodgkin lymphoma: pretreatment prognostic factors and interim PET

To reduce doxorubicin, bleomycin, vinblastine and dacarbazine toxicity, the Cancer and Leukemia Group B conducted a phase 2 trial of doxorubicin, vinblastine, and gemcitabine for newly diagnosed, nonbulky stages I and II Hodgkin lymphoma. Ninety-nine assessable patients received 6 cycles of doxorubicin 25 mg/m(2), vinblastine 6 mg/m(2), and gemcitabine 800 mg/m(2) (1000 mg/m(2) in first 6) on days 1 and 15 every 28 days. Computed tomography (CT) and positron emission tomography (PET) were performed before and after 2 and 6 cycles. Complete remission (CR)/CR unconfirmed was achieved in 72 of 99 patients (72.7%) and partial remission in 24 of 99 patients (24.2%). The CR rate was 81% when using PET criteria. Two patients have died of Hodgkin lymphoma progression. Median follow-up for nonprogressing patients is 3.3 years. The progression-free survival (PFS) at 3 years was 77% (95% confidence interval, 68%-84%). The relapse rate was less than 10% for patients with favorable prognostic factors. The 2-year PFS for cycle 2 PET-negative and -positive patients was 88% and 54%, respectively (P = .0009), compared with 89% and 27% for cycle 6 PET-negative and -positive patients (P = .0001). Although the CR rate and PFS were lower than anticipated, patients with favorable prognostic features had a low rate of relapse. Cycle 2 PET and cycle 6 PET were predictive of PFS.

State-of-the-art issues in Hodgkin's lymphoma survivorship

The prognosis of Hodgkin's lymphoma (HL) has markedly improved as management strategies evolved. In the modern era, less than 15% of patients with early-stage, non-bulky HL will relapse, and less than one third of those with advanced disease will relapse. As therapy for HL intensified, and as disease-related outcomes improved, the impact of the late effects of therapy has become increasingly important. There is a growing body of literature describing the late morbidity experienced by survivors of HL, including risks of second primary malignancy, cardiac disease, pulmonary disease, and endocrine dysfunction. Additionally, the impact of disease and treatment on psychosocial function and quality of life has been a subject of investigation, with survivors often suffering from impairment. An understanding of these risks and the management implications inherent to them is central to the care of survivors of HL.

Late effects in the era of modern therapy for Hodgkin lymphoma

Extended-field and subtotal nodal radiation therapy (RT), developed in the 1960s, was the first reliably curative treatment for early-stage Hodgkin lymphoma (HL). However, the large volume of normal tissue irradiated resulted in significant delayed toxicity, including cardiac disease and second cancers (SCs). The 30-year cumulative incidence of heart disease among adult survivors receiving 40-45 Gy of extended-field or mantle RT is approximately 30%; the incidence of SCs is similar. Improving disease control while reducing the toxicity of treatment has been a major objective of HL trials for more than 2 decades. Contemporary involved-field RT (IFRT) reduces irradiated volumes and produces significant reductions in normal tissue dose compared with historic treatments. Recent data indicate that, compared with mantle RT, IFRT reduces the relative risk of breast cancer among young females receiving mediastinal RT by approximately 60% and also reduces cardiac dose. The recent transition to involved-node RT allows further reductions in normal tissue dose. Response-adapted therapy is being evaluated in clinical trials as a means of identifying those patients most likely to benefit from treatment reduction or intensification, enhanced screening will facilitate early intervention to reduce the clinical burden of late effects, and there is increasing interest in elucidating the genetic correlates of treatment toxicity.

Role of Radiotherapy in Modern Treatment of Hodgkin's Lymphoma

Hodgkin's Lymphoma was incurable until the advent of effective therapeutic radiation around the first half of the 20th century. As survival rates improved, the long-term toxicities from radiotherapy began to emerge. This together with the availability of effective chemotherapy has encouraged a combined modality approach for early-staged disease and the omission of radiotherapy in advanced-staged disease. The differing toxicities of radiotherapy and chemotherapy has promoted ongoing research to identify the utility of each of these modalities in the modern management of Hodgkin's Lymphoma. This article will provide a critical review of the developments and indications for modern radiotherapy, in context with advances in chemotherapy, for the treatment of Hodgkin's Lymphoma.

Long-term outcomes for patients with limited stage follicular lymphoma: involved regional radiotherapy versus involved node radiotherapy

BACKGROUND

Given the indolent behavior of follicular lymphoma (FL), it is controversial whether limited stage FL can be cured using radiotherapy (RT). Furthermore, the optimal RT field size is unclear. The authors of this report investigated the long-term outcomes of patients with limited stage FL who received RT alone and studied the impact of reducing the RT field size from involved regional RT (IRRT) to involved node RT with margins up to 5 cm (INRT<or=5 cm).

METHODS

Eligible patients had limited stage, grade 1 through 3A FL diagnosed between 1986 and 2006 and treated were with curative-intent RT alone. IRRT encompassed the involved lymph node group plus>or=1 adjacent, uninvolved lymph node group(s). INRT<or=5 cm covered the involved lymph node(s) with margins<or=5 cm.

RESULTS

In total, 237 patients were identified (median follow-up, 7.3 years) and included 48% men, 54% aged>60 years, stage IA disease in 76% of patients, elevated lactate dehydrogenase (LDH) in 7% of patients, grade 3A tumors in 12% of patients, and lymph node size>or=5 cm in 19% of patients. The 2 RT groups were IRRT (142 patients; 60%) and INRT<or=5 cm (95 patients; 40%). At 10 years, the progression-free survival (PFS) rate was 49%, and the overall survival (OS) rate was 66%. Only 2 patients developed recurrent disease beyond 10 years. The most common pattern of first failure was a distant recurrence only, which developed in 38% of patients who received IRRT and in 32% of patients who received INRT<or=5 cm. After INRT<or=5 cm, 1% of patients had a regional-only recurrence. Significant risk factors for PFS were lymph nodes>or=5 cm (P=.008) and male gender (P=.042). Risk factors for OS were age>60 years (P<.001), elevated LDH (P=.007), lymph nodes>or=5 cm (P=.016), and grade 3A tumors (P=.036). RT field size did not have an impact on PFS or OS.

CONCLUSIONS

Disease recurrence after 10 years was uncommon in patients who had limited stage FL, suggesting that a cure is possible. Reducing RT fields to INRT<or=5 cm did not compromise long-term outcomes.

Predicted risk of radiation-induced cancers after involved field and involved node radiotherapy with or without intensity modulation for early-stage hodgkin lymphoma in female patients

PURPOSE

To assess the excess relative risk (ERR) of radiation-induced cancers (RIC) in female patients with Hodgkin lymphoma (HL) female patients treated with conformal (3DCRT), intensity modulated (IMRT), or volumetric modulated arc (RA) radiation therapy.

METHODS AND MATERIALS

Plans for 10 early-stage HL female patients were computed for 3DCRT, IMRT, and RA with involved field RT (IFRT) and involvednode RT (INRT) radiation fields. Organs at risk dose--volume histograms were computed and inter-compared for IFRT vs. INRT and 3DCRT vs. IMRT/RA, respectively. The ERR for cancer induction in breasts, lungs, and thyroid was estimated using both linear and nonlinear models.

RESULTS

The mean estimated ERR for breast, lung, and thyroid were significantly lower (p < 0.01) with INRT than with IFRT planning, regardless of the radiation delivery technique used, assuming a linear dose-risk relationship. We found that using the nonlinear model, the mean ERR values were significantly (p < 0.01) increased with IMRT or RA compared to those with 3DCRT planning for the breast, lung, and thyroid, using an IFRT paradigm. After INRT planning, IMRT or RA increased the risk of RIC for lung and thyroid only.

CONCLUSIONS

In this comparative planning study, using a nonlinear dose--risk model, IMRT or RA increased the estimated risk of RIC for breast, lung, and thyroid for HL female patients. This study also suggests that INRT planning, compared to IFRT planning, may reduce the ERR of RIC when risk is predicted using a linear model. Observing the opposite effect, with a nonlinear model, however, questions the validity of these biologically parameterized models.

Does radiotherapy still have a place in Hodgkin lymphoma?

Over half a century, radiation therapy (RT) for Hodgkin lymphoma has been transformed from a radical, extensive, high-dose therapy (which alone cured most patients) into an essential component of a comprehensive combined-modality program. RT is now used in a "mini" version that encompasses only the clinically involved sites following chemotherapy and is administered in a markedly reduced dose. This change has considerably reduced the long-term complications that were associated with the now-outdated radical RT approach. The use of RT also allows a shorter and safer course of chemotherapy. The combination of reduced chemotherapy followed by mini-RT has produced disease control and even overall results that are significantly superior to those achieved with chemotherapy alone. This review discusses controversial issues regarding RT, the studies that have addressed them, the new indications for integrating RT, and the safety of minimizing the radiation field and dose.

Involved-node and involved-field volumetric modulated arc vs. fixed beam intensity-modulated radiotherapy for female patients with early-stage supra-diaphragmatic Hodgkin lymphoma: a comparative planning study

PURPOSE

A comparative treatment planning study was performed to compare volumetric-modulated arc (RA) to conventional intensity modulated (IMRT) for involved-field (IFRT) and involved-node (INRT) radiotherapy for Hodgkin lymphoma (HL).

METHODS AND MATERIALS

Plans for 10 early-stage HL female patients were computed for RA and IMRT. First, the planning target volume (PTV) coverage and organs at risk (OAR) dose deposition was assessed between the two modalities. Second, the OAR (lung, breast, heart, thyroid, and submandibular gland) dose-volume histograms were computed and compared for IFRT and INRT, respectively.

RESULTS

For IFRT and INRT, PTV coverage was equally homogeneous with both RA and IMRT. By and large, the OAR irradiation with IFRT planning was not significantly different between RA and IMRT. For INRT, doses computed for RA were, however, usually lower than those with IMRT, particularly so for the lung, breast, and thyroid. Regardless of RA and IMRT modalities, a significant 20-50% decrease of the OAR computed mean doses was observed with INRT when compared with IFRT (Breast D(Mean) 1.5 +/- 1.1 vs. 2.6 +/- 1.7 Gy, p < 0.01 and 1.6 +/- 1.1 vs. 2.9 +/- 1.9 Gy, p < 0.01 for RA and IMRT, respectively).

CONCLUSIONS

RA and IMRT results in similar level of dose homogeneity. With INRT but not IFRT planning, the computed doses to the PTV and OAR were usually higher and lower with RA when compared to IMRT. Regardless of the treatment modality, INRT when compared with IFRT planning led to a significant decrease in OAR doses, particularly so for the breast and heart.