Clinical evaluation and radiotherapeutic management of Hodgkin's disease and the malignant lymphomas

Radiation Therapy in the German Hodgkin Study Group HD 16 and HD 17 Trials: Quality Assurance and Dosimetric Analysis for Hodgkin Lymphoma in the Modern Era

Purpose

Radiation therapy (RT) is an integral part of treatment concepts for early-stage Hodgkin lymphoma. This analysis reports on RT quality in the recent HD16 and 17 trials of the German Hodgkin Study Group (GHSG).

Methods and Materials

All RT plans of involved-node radiation therapy (INRT) in HD 17 were requested for analysis, along with 100 and 50 involved-field radiation therapy (IFRT) plans in HD 16 and 17, respectively. A structured assessment regarding field design and protocol adherence was performed by the reference radiation oncology panel of the GHSG.

Results

Overall, 100 (HD 16) and 176 (HD 17) patients were eligible for analysis. In HD 16, 84% of RT series were evaluated as correct, with significant improvement compared with the predecessor studies (P < .001). In HD 17, 76.1% of INRT cases revealed a correct RT design compared with 69.0% of IFRT-cases, which was superior to previous studies (P < .001). Comparing INRT and IFRT, we found no significant differences in the percentage of any deviation (P = .418) or major deviations (P = .466). Regarding dosimetry, INRT was accompanied by an improvement in thyroid doses. Comparing different RT techniques, we found that intensity-modulated RT showed a reduction of high doses in the lung at the expense of an increased low-dose exposure in HD 17.

Conclusions

The latest study generation of the GHSG demonstrates an improved quality in RT. A modern INRT design could be established without deterioration in quality. On a conceptual level, an individual consideration of the appropriate RT technique has to be performed.

Modern PET-Guided Radiotherapy Planning and Treatment for Malignant Lymphoma

Malignant lymphoma comprises a broad spectrum of diverse entities originating from different types of lymphocytes. In the last century, successive improvements of treatment possibilities have led to an continuous amelioration of patient prognosis from lethal outcome to high rates of disease control and long-term survivors. PET/CT-based imaging plays a key role in stratification of stage and treatment response. Especially for radiotherapy, an essential treatment modality for lymphoma patients, functional imaging and the reevaluation of disease activity after frontline chemotherapy has led to major improvements regarding size of treatment fields and toxicity. International expert groups like the International Lymphoma Radiation Oncology Group (ILROG) develop guidelines for the optimal use of imaging for treatment planning. The shift from uniform large-field treatment volumes to complex individual setups taking into account biological response-assessments based on functional imaging resulted in a further de-escalation of side effects and modernization of lymphoma treatment. This paper aims to summarize the use of FDG-PET-imaging for radiation therapy planning in malignant lymphoma in the context of historic and future developments, as well as associated limitations and challenges ahead. We will discuss the contemporary standard of care as recommended by international expert guidelines like the ILROG, the national comprehensive cancer network (NCCN), as well as the newly updated German S3-guidelines.

Pathfinders in oncology from the time the causal relation between tobacco use and lung cancer was established to publication of the first Cancer Staging Manual by the American Joint Committee on Cancer

During the period from 1962 to 1977, several antigens, notably carcinoembryonic antigen and prostate-specific antigen, were discovered and entered clinical use. Ultrasonography, positron emission tomography scanning, and magnetic resonance imaging were introduced, and adjuvant radiation and chemotherapy after limited surgery became routine procedures. Radioimmunoassay and immunohistochemistry techniques were standardized. The announcement in England and the United States that tobacco is a potent lung carcinogen was long delayed, important news. The US Cancer Act of 1971 made it possible to experiment with newly discovered drugs, transfer promising therapeutic agents from the laboratory to the clinic, and finance randomized clinical trials. Oncologists achieved a series of successes with combination chemotherapy in childhood cancers, adult lymphomas, and testis tumors. Clinical trials demonstrated that breast-conserving therapy is as effective as mastectomy. The discovery of retroviruses, reverse transcriptase, and vascular endothelial growth factor was coupled with learning about oncogenes. The 2-hit theory and the reciprocal translocation of chromosomes helped to solve some of the riddles of oncogenesis. The staging classification of cancers by the American Joint Committee on Cancer unified clinical and pathologic handling and prognostication of malignant tumors. The progress made in oncology between 1962 and 1977 came about through the dedicated work of many individuals. However, there were 9 pathfinders (3 medical oncologists, 2 surgeons, 1 medical nuclear physicist, 1 pediatrician geneticist, 1 hematologist geneticist, and 1 virologist) who, despite their diverse backgrounds, personalities, and interest, made extraordinary contributions to oncology.

The Spread of Malignant Lymphomas in Children

The preferential sites of involvement and the mode of spread of malignant lymphomas have been evaluated in 71 consecutive untreated children up to and including the age of 15 years (33 with Hodgkin's disease, 19 with lymphosarcoma and 19 with reticulum cell sarcoma). In all cases the diagnosis was defined by pathological examination. Lower-extremity lymphography (3–5 ml of Lipiodol Fluid per foot) was carried out only in 17 patients (10 with Hodgkin's disease and 7 with lymphoreticular sarcomas) without untoward reactions or pulmonary complications. Patients were staged according to the international four stage clinical classification proposed at Rye in 1965. Hodgkin's disease was confined to lymph nodes and spleen in practically all patients (97.5%), while in comparison lymphoreticular sarcomas revealed an appreciable involvement of Waldeyer's ring (6.5%) and a considerable extension to extranodal sites (18%) with frequent invasion of adbomen and bone marrow. Mediastinal nodes were definitely more involved in Hodgkin's disease (18.5%) than in lymphoreticular sarcomas (5.5%), while the opposite occurred for extensions below the diaphragm (inguinal, retroperitoneal and mesenteric nodes). The mode of spread has been studied by counting the number of untreated patients (only with primary involvement of lymph nodes and Waldeyer's ring) with contiguous and non contiguous adenopathies, as well as the next sites of involvement after localized radiation therapy. The majority of children with Hodgkin's disease showed adenopathies distributed throughout contiguous areas (15/18 cases). This occurred also in those with lymphoreticular sarcomas (5/8 cases) although in 4/5 patients the disease had its primary onset in Waldeyer's ring where, as in adults, cervical adenopathies are often present. A total of 14 children with Hodgkin's disease developed a recurrence after different lengths of time. This occurred in 10 patients in lymph node-bearing areas clinically uninvolved at the time of initial work up, but adjacent to those treated with local radiation therapy. The lymphoreticular sarcomas, on the contrary, showed a tendency to spread earlier to viscera and bones. The analysis of our pediatric lymphomas shows that the spread of Hodgkin's disease in children is similar to that observed in adults, i.e. with an initially slow and orderly lymphatic progression in the large majority of patients. Lymphoreticular sarcomas on the contrary, with the possible exception of those arising in Waldeyer's ring, were very often a generalized process (Stage IV) at the time of presentation with frequent invasion of bone marrow and abdominal cavity. These observations could be probably explained in part by the fact that lymphoreticular sarcomas arise in the gastrointestinal tract or in lymph nodes below the diaphragm (retroperitoneal, mesenteric) in a much higher percentage than usually seen on routine work up. Therefore through the thoracic duct, and without involvement of mediastinum, malignant cells reach the blood stream earlier. The orderly lymphatic spread in most patients with Hodgkin's disease and the predominant dissemination through the blood stream in lymphoreticular sarcomas could explain the difference in prognosis. On the basis of the mode of spread prophylactic irradiation to adjacent clinically uninvolved lymphoid regions is therefore indicated in patients with Hodgkin's disease and only in lymphoreticular sarcomas with primary involvement of Waldeyer's ring.

The role of radiotherapy in Hodgkin's lymphoma: what has been achieved during the last 50 years?

Currently, Hodgkin's lymphoma (HL) has an excellent clinical outcome, with overall survival of approximately 90% in early stages of the disease. Based on young age of the majority of patients at the time of diagnosis and their long survival time, increased attention has been focused on long-term toxicity of therapy. While novel, directly targeting antitumor agents, with an excellent safety profile, have been developed for HL treatment, the role of radiotherapy is still debated. Radiotherapy may induce cardiovascular disease and impairment of thyroid or pulmonary function and, most importantly, may lead to development of secondary cancers. As a consequence, the current radiation therapy planning paradigm is mainly focused on a reduction of field size. As it was investigated in clinical trials regional therapy is as effective as extended field radiotherapy, but less toxic. Although chemotherapy is the mainstay of HL treatment, consolidative involved field radiation therapy is still considered to be the standard of care in both early and advanced stages. Recently, further field reduction has been investigated to further decrease the late radiation-induced toxicity. In this paper we describe the role and safety profile of radiotherapy in the past and present and hope for the novel techniques in the future.

The Evolving Role of Radiotherapy in Early Stage Hodgkin's Lymphoma

Radiation therapy has a key role in the combined modality treatment of early-stage Hodgkin’s Lymphoma (HL). Nevertheless, late toxicity still remains an issue. A modern approach in HL radiotherapy includes lower doses and smaller fields, together with the implementation of sophisticated and dedicated delivery techniques. Aim of the present review is to discuss the current role of radiotherapy and its potential future developments, with a focus on major clinical trials, technological advances and their repercussion in the clinical management of HL patients.

Management of early-stage Hodgkin lymphoma: is there still a role for radiation?

Although radiotherapy is highly effective for the treatment of Hodgkin lymphoma, the realization of its potential long-term toxicity and the demonstration of excellent results from combination chemotherapy have led to a retreat from its use in early-stage disease. Recent trials using functional imaging may allow better identification of those patients for whom radiotherapy may be safely omitted without compromising cure rates and this review examines the evidence for this.

The case for combined-modality therapy for limited-stage Hodgkin's disease

Results of the Hodgkin's Disease.6 trial are critically examined in light of the advances in radiation therapy techniques that have occurred since it was initiated. The ultimate findings of the HD.6 trial do not close the case for combined-modality treatment of limited-stage Hodgkin's disease.

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.

Evolution of treatment for Hodgkin's disease: a population-based study of radiation therapy use and outcome

AIM

To examine changes in radiotherapy (RT) use, cause-specific survival (CSS), and overall survival (OS) in a population-based cohort of Hodgkin's disease (HD) patients diagnosed from 1982 to 1996.

MATERIALS AND METHODS

Adult patients with HD diagnosed from 1 January 1982 to 31 December 1996 (n = 3957) were identified from the Ontario Cancer Registry. The cohort was divided into three consecutive 5-year periods: 1982-1986, 1987-1991, and 1992-1996. RT use, CSS and OS in each of these three periods were compared. For the entire cohort, the cumulative incidence of different causes of death was calculated.

RESULTS

The proportion of patients receiving RT within 11 weeks of diagnosis declined over the three consecutive periods (25.1%, 15.6%, 11.7%, P < 0.001), as did the proportion receiving RT within 45 weeks (57.0%, 51.0%, 48.1%; P < 0.001). There was a significant increase in 5-year CSS over time (81%, 87%, 89%; P < 0.001), and OS (72%, 77%, 82%; P < 0.001), which remained significant in multivariable analyses. The cumulative incidence of death from causes other than HD was equal to the incidence of HD-related death within 12 years of diagnosis.

CONCLUSIONS

There was a significant decline in the use of RT as the primary treatment modality and as part of the initial management of HD from 1982-1996 in Ontario. A greater proportion of patients received their RT after a delay consistent with the receipt of prior chemotherapy. There was also a significant increase in the CSS and OS over this period. These findings are in keeping with the adoption of effective chemotherapy in the treatment of HD.

Changing role and decreasing size: current trends in radiotherapy for Hodgkin's disease

Radiotherapy, the first cancer treatment modality that offered cure, is still considered to be the most effective "single agent" in treating Hodgkin's disease (HD). Yet, the role of radiotherapy in HD has changed dramatically with the advent of effective combination chemotherapy and the rising concern of long-term complications associated with successful treatment of HD. The new principles of integrating radiotherapy into a combined-modality regimen for HD at different prognostic stages are reviewed here, along with the effect of this new role on radiation field size and design.

Influence of dose intensity and density on therapeutic and toxic effects in Hodgkin's disease

From 1972 to 1976, 95 patients with clinical stages I-IIIA Hodgkin's disease were treated by chemotherapy with cyclophosphamide, vinblastine, procarbazine and prednisone (CVPP) before and after extended field radiotherapy. The CVPP schedule gave: (1) a constant drug dosage for each patient independent of body surface or weight; and (2) a total drug dosage dependent on haematological tolerance, since the treatment was given for 21 days or until the leukocyte count dropped to 2 x 10(9) l-1. The drug dosage per unit body surface (or 'dose density') significantly correlates with the drop in leukocyte count (P less than 0.001) and the tumour regression at the end of the induction course (P = 0.020). Disease-free survival is significantly related to dose density (P = 0.050) but not to dose intensity calculated on the duration of treatment (P = 0.240). However, after exclusion of three marginal recurrences due to border-line radiotherapy, the dose intensity significantly correlates with the disease-free survival (P = 0.031) and with the duration of complete remission (r = 0.870).

Brief chemotherapy associated with extended field radiotherapy in Hodgkin's disease. Long-term results in a series of 102 patients with clinical stages I-IIIA

From 1972 to 1976, 102 patients with stages I-IIIA Hodgkin's disease (HD) were treated by chemotherapy with cyclophosphamide, vinblastine, procarbazine and prednisone (CVPP: two courses) associated with extended field radiotherapy. Staging included neither laparotomy nor splenectomy (clinical staging). Treatment included neither splenic irradiation nor maintenance therapy. Complete remission was achieved for 98 patients and 11 of them recurred up to 94 months after treatment. Median follow-up of this controlled study is 13 years. Disease free survival (DFS) is 87% at 6 years and 84% at 10 and 15 years. Overall survival is 77% at 10 and 74% at 15 years. Disease specific survival is better (91% at 10 and 87% at 15 years) since only 38% (10/26) deaths were due to HD. The other deaths (16/26) with no evidence of HD were due to second cancer and intercurrent disease. Prognostic analysis of DFS by log-rank test gives significance to the following factors: contiguous extra-nodal involvement (P = 0.008), more than 3 involved sites (P = 0.01), signs of compression (P = 0.02), clinical stage IIIA (P = 0.03), infradiaphragmatic stages I-II (P = 0.04). The potential risk of secondary cancer is difficult to assess.

New aspects of Hodgkin's disease: staging for conservative management

A variety of curative primary and salvage therapies exist for the management of Hodgkin's disease (HD). Consideration of the toxicity of initial therapy is becoming critical for long-term patient management. The recommendation for the routine use of combined modality therapy or whole lung irradiation has been made for the treatment of Stage IA and IIA bulky mediastinal HD based on the correlation between chest X-ray data and increased failure rates in patients managed initially with radiation alone. Thoracic CT scan data has yielded important information as to the possible cause of failure in those patients managed with radiation alone and recommendations are made to substage mediastinal HD for conservative management and to reevaluate the routine use of combined modality therapy. The management of Stage IIIA disease with radiation and/or chemotherapy, the role of splenic involvement for therapy, and the proposed value of substaging disease into IIIA1 and IIIA2 anatomic subsets is discussed. Finally, biochemical and immunological testing may play a future role for initial management.

A randomized study of radiotherapy versus radiotherapy plus chemotherapy in stage I-II non-Hodgkin's lymphomas

In a randomized, prospective trial from 1974-1978, 73 patients with non-Hodgkin's lymphomas in clinical Stage I or II were treated with extended field radiotherapy alone (RT) or RT plus adjuvant chemotherapy with vincristine, streptonigrin, cyclophosphamide and prednisone (RT + CT). With a median follow-up time of five years, 54% have relapsed in the RT group versus only 10% in the RT + CT group (P less than 0.01). There is no statistical difference in the overall survival yet, but 13/14 deaths in the RT group versus only 3/12 in the RT + CT group were due to progressive disease. Among patients with unfavorable histology, 13/22 in the RT group have died from disease progression against 3/34 in the RT + CT group (P less than 0.01). The results are in agreement with those from two other series published in detail. Based on these results we therefore recommend to use adjuvant CT with RT in all Stage I-II patients with unfavorable histology. Further observation is necessary before a conclusion can be drawn for the lymphoma patients with more favorable histology.

Chronic pericardial effusion after mediastinal radiotherapy

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The Value and Present Indications of Staging Laparotomy in Hodgkin's Disease

From December 1971 to December 1976 224 patients with Hodgkin's disease underwent diagnostic laparotomy and splenectomy under a multidisciplinary protocol of treatment. In 149/224 (66.5%) the clinical stage of the disease was confirmed, whereas in 75/224 (33.5%) it was modified after surgery. In 7.6% of the patients (17/224) there were postoperative complications. One patient died of myocardial infarction. The rate of complications in the last 100 cases was 5%. Preoperative patient selection, excluding those definitely in stage IV, is of relevance, and it can be done by iliac crest biopsy and laparoscopy. Although a better exploitation of some diagnostic procedures (lymphangiography, laparoscopy) and the expanding use of chemotherapy may reduce in the future the need for staging laparotomy and splenectomy, diagnostic laparotomy is still indicated for the selection and preparation of patients for radiation therapy in stages I, II and III.

Survival and complications of radiotherapy following involved and extended field therapy of Hodgkin's disease, stages I and II. A collaborative study

A collaborative trial with random assignment to involved field or extended field radiotherapy for localized Hodgkin's disease was begun in 1967. Case accession was completed in 1973, with 224 eligible patients assigned to involved field and 243 to extended field. With a median follow-up time of 27 months no significant survival difference is found between involved and extended field regimens for the total patient group or for most subgroups defined by age, sex, histology, stage, class, and use of laparotomy for staging. A single exception is an improved survival in the involved field group for female patients. Survival free of distant extension shows a similar lack of treatment effect, but survival free of any extension, local or distant, shows a significant benefit from extended field treatment. Complications of radiotherapy are significantly increased following extended field treatment. Survival following local extension is similar to survival following periods free of any extension.

A combined modality approach to the treatment of Hodgkin's disease. Preliminary results of a prospectively randomized clinical trial

Eighty-seven previously untreated patients with pathologic Stage IA, II (A or B), or IIIA Hodgkin's disease were randomized over a 48-month period to receive either megavoltage extended field radiotherapy alone or megavoltage radiotherapy limited to involved lymph node sites (including at least an upper mantle field) followed by combination chemotherapy with nitrogen mustard, vincristine, prednisone, and procarbazine (MOPP). Four patients (4.6%) failed to achieve remission with initial radiotherapy. Seventy-two evaluable patients have currently completed therapy. Ten of 41 patients achieving remission with radiation alone have relapsed, compared to only 1 of 31 receiving radiation plus chemotherapy. Seven patients have died, 3 of whom failed to achieve remission with initial radiotherapy. The other 4 had Stage IIIA disease treated with radiation alone. Severe myelosuppression occurred infrequently during chemotherapy, and neither serious infections nor second neoplasms have observed. Although these preliminary results are encouraging, longer followup is required to determine the ultimate effects of combined modality therapy on survival and long-term complications.

The staging of Hodgkin's disease in children reviewed

The accurate staging of Hodgkin's disease is of greater importance in children than in adults, because the deleterious effects of extensive radiation therapy and of prolonged multiple-agent chemotherapy are of greater significance in this age group. The physician concerned with Hodgkin's disease in children must separate those aspects of developments in this field which are applicable to the pediatric age group from the relatively large adult experience. Isotope scanning is effective in demonstrating disseminated disease in pediatric patients. Lymphangiograms are useful, but are more difficult to perform and to interpret in children. When laparotomy is performed in children with clinical Stage I, II, or III Hodgkin's disease, stage will be altered (upward or downward) in approximately 40% of children subjected to the procedure. As growth retardation, skeletal deformity, and secondary neoplasia follow radiotherapy in children, the major function of the laparotomy is to delineate the extent of the disease and thus define appropriate limitations of therapy.

Management of Hodgkin's and non-Hodgkin's lymphomas

These diseases of the lymphoreticular system with neoplastic alteration of the involved tissues represent different entities and show marked variability in their clinical manifestations, pathologic behavior, prognosis, and response to treatment. New diagnostic, histopathologic, and therapeutic concepts in the past decade have led to significant advances in the care and management of these patients, particularly those with Hodgkin's disease.

Curative radiotherapy in Hodgkin's disease: significance of haematogenous dissemination established by examination of peripheral blood and spleen

Studies of peripheral blood leucocyte concentrates in patients with Hodgkin's disease showed two types of cells believed to be typical for the disease in a number of patients. Involvement of the spleen as diagnosed after splenectomy and histological examination showed a close correlation with the presence of these characteristic cells in the peripheral blood. This is believed to be an argument for haematogenous spread or a multicentric origin of the disease in these cases. The results of attempted curative high-voltage radiotherapy with total node irradiation in 24 patients seem to support this concept. On the basis of the Rye classification of clinical stages the results of radiotherapy are not predictable. Six patients in stage II and seven in stage III were in remission, one in each of stages II and IV, and six in stage III had recurrences of the disease within one year. A division into localized or disseminated forms of the disease based on the investigations of blood and spleen showed all localized cases in remission; of the disseminated cases one reached a remission and all others had recurrences. In three patients the therapy could not be completed. These preliminary treatment results are believed to support the idea of a special role of the spleen in the dissemination of the disease. A new classification of clinical stages in Hodgkin's disease is proposed.

Subacute effusive-constrictive pericarditis

Clinical and hemodynamic observations are reported in 13 patients who demonstrated a distinct pathophysiologic form of compressive pericardial disease characterized by effusion into a free pericardial space associated with constriction of the heart by the visceral pericardium. The pericardial disease was idiopathic (nine patients) or subsequent to radiotherapy (four patients), with a maximal duration of symptoms of 16 months. Enlarged heart shadow, prominent paradoxical pulse, predominant systolic dip in the venous pressure pulse, and absence of atrial fibrillation were features that tended to distinguish the effusive-constrictive cases from those with noneffusive chronic constrictive pericarditis. The value of pressure measurements during combined cardiac catheterization and pericardiocentesis is emphasized in the differentiation of effusive-constrictive pericarditis from cardiac tamponade without constriction. Four patients were observed to progress through an effusive-constrictive phase to noneffusive constrictive pericarditis. Corticosteroids, pericardiocentesis, and other medical therapy produced some benefit but did not relieve constriction. The results of surgery were generally satisfactory.

Nodular sclerotic lymphosarcoma. A further review

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