Radiation dose selection in Hodgkin's disease patients with large mediastinal adenopathy treated with combined modality therapy

Analyses of patterns-of-failure and prognostic factors according to radiation fields in early-stage Hodgkin lymphoma

PURPOSE

Doses and volumes of radiation therapy (RT) for early stages of Hodgkin lymphoma (HL) have been reduced over the last 30 years. Combined modality therapy (CMT) is currently the standard treatment for most patients with early-stage HL. The aim of this study was to analyze the site of relapse after RT according to the extent of radiation fields.

PATIENTS AND METHODS

Between 1987 and 2011, 427 patients were treated at our institution with RT ± chemotherapy for stage-I/II HL. Among these, 65 patients who experienced a relapse were retrospectively analyzed. Most patients had nodular sclerosis histology (86 %) and stage-II disease (75.9 %). Bulky disease was present in 21 % and 56 % of patients belonged to the unfavorable risk group according to European Organization for Research and Treatment of Cancer (EORTC)/The Lymphoma Study Association (LYSA) definitions. CMT was delivered to 91 % of patients. All patients received RT with doses ranging from 20 to 45 Gy (mean = 34 ± 5.3 Gy). The involved-field RT technique was used in 59 % of patients.

RESULTS

The mean time between diagnosis and relapse was 4.2 years (range 0.3-24.5). Out-of-field relapses were suffered by 53 % of patients. Relapses occurred more frequently at out-of-field sites in patients with a favorable disease status, whereas in-field relapses were associated with bulky mediastinal disease. Relapses occurred later for favorable compared with the unfavorable risk group (3.5 vs. 2.9 years, p = 0.5). From multivariate analyses, neither RT dose nor RT field size were predictive for an in-field relapse (p = 0.25 and p = 0.8, respectively), only bulky disease was predictive (p = 0.018).

CONCLUSION

In patients with bulky disease, RT dose and RT field size were not predictive for an in-field relapse. In this subgroup of patients, chemotherapy should be intensified. We confirmed the bad prognosis of early relapses.

Low-dose consolidation radiation therapy for early stage unfavorable Hodgkin lymphoma

PURPOSE

The German Hodgkin Study Group (GHSG) trial HD11 established 4 cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) and 30 Gy of radiation therapy (RT) as a standard for early stage (I, II), unfavorable Hodgkin lymphoma (HL). Additional cycles of ABVD may allow for a reduction in RT dose and improved toxicity profile.

METHODS AND MATERIALS

Patients treated with combined modality therapy at the Duke Cancer Institute for early stage, unfavorable HL by GHSG criteria from 1994 to 2012 were included. Patients who did not undergo post-chemotherapy functional imaging (positron emission tomography or gallium imaging) or who failed to achieve a complete response were excluded. Clinical outcomes were estimated using the Kaplan-Meier method. Late effects were also evaluated.

RESULTS

A total of 90 patients met inclusion criteria for analysis. Median follow-up was 5 years. Chemotherapy consisted primarily of ABVD (88%) with a median number of 6 cycles. The median dose of consolidation RT was 23.4 Gy. Four patients had relapses, 2 of which were in-field. Ten-year progression-free survival (PFS) and overall survival (OS) were 93% (95% confidence interval [CI]: 0.82-0.97) and 98% (95% CI: 0.92-0.99), respectively. For the subset of patients (n=46) who received 5 to 6 cycles of chemotherapy and ≤ 24 Gy, the 10-year PFS and OS values were 88% (95% CI: 70%-96%) and 98% (95% CI: 85% - 99%), respectively. The most common late effect was hypothyroidism (20%) with no cardiac complications. Seven secondary malignancies were diagnosed, with only 1 arising within the RT field.

CONCLUSIONS

Lower doses of RT may be sufficient when combined with more than 4 cycles of ABVD for early stage, unfavorable HL and may result in a more favorable toxicity profile than 4 cycles of ABVD and 30 Gy of RT.

Mediastinal bulky tumour in Hodgkin's disease and prognostic value of positron emission tomography in the evaluation of post-treatment residual masses

Among the 193 patients (82 female, 111 male) treated primarily for Hodgkin's disease at our clinic between 1990 and 2001 and followed up until 2003, 42 (22%) had mediastinal bulky tumours (MBTs) by the Cotswolds criteria. The rate of MBT diagnosis was significantly greater in the early stage of the disease, these patients were younger and--in contrast to the other group--they all received combined therapy. No significant differences were found in the overall and relapse-free survival rate in the two groups, but relapse and death rates were lower in the patients with bulky tumours. Of the total number of patients, 27 underwent a total of 31 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) examinations, mainly for the evaluation of post-treatment residual mass viability. In the 12 positive cases, the majority of patients received further therapy. During the mean follow-up time of 58 months (range 5-98 months) after obtaining negative results, progression of the disease was found in 2 cases 14 and 23 months later, respectively. Based on our results, we conclude that FDG-PET examinations show a good correlation with clinical follow-up results.

Phase I study of involved-field radiotherapy preceding autologous stem cell transplantation for patients with high-risk lymphoma or Hodgkin's disease

PURPOSE

This Phase I study was designed to evaluate the tolerability of involved-field radiotherapy (IFRT) to areas of persistent disease in patients with high-risk Hodgkin's disease and non-Hodgkin's lymphomas before autologous stem cell transplantation (ASCT).

METHODS AND MATERIALS

Thirty-one patients with primary refractory or relapsed Hodgkin's disease (n = 13) and non-Hodgkin's lymphoma (n = 18) were treated with IFRT followed by high-dose chemotherapy and ASCT. All patients had bulky disease (> or =5 cm) and/or an inadequate response to salvage chemotherapy. The IFRT dose was escalated to a maximum of 36 Gy. Dose-limiting toxicity was defined as Grade 3-4 Bearman toxicity (life-threatening/fatal toxicity occurring within 28 days of ASCT). The chemotherapy regimen consisted of cyclophosphamide, etoposide, and carmustine.

RESULTS

The delivered dose of IFRT was 20 Gy in 9 patients, 28-30 Gy in 20, and 32-36 Gy in 2 patients to mediastinal (n = 19) and nonmediastinal (n = 12) sites. The median interval between IFRT completion and ASCT was 19 days. One patient developed Bearman Grade 3 hepatic toxicity. No other Grade 3 or 4 Bearman toxicity was observed. An increased requirement for i.v. narcotics was observed in patients treated with mediastinal IFRT vs. nonmediastinal IFRT (p = 0.02). A trend toward increased mucositis severity was seen in patients previously treated with a larger number of chemotherapy agents (p = 0.09) and in those with a shorter interval between IFRT and ASCT (p = 0.12). Pulmonary toxicity was more common in patients treated with mediastinal IFRT than in those treated with nonmediastinal IFRT (21% vs. 0%, p = 0.13). The 2-year overall and progression-free survival rate was 70% and 49% for all patients, 84% and 50% for patients with Hodgkin's disease, and 59% and 47% for patients with non-Hodgkin's lymphoma, respectively.

CONCLUSION

The maximal tolerated dose of IFRT was not reached when Grade 3-4 Bearman toxicity was dose limiting. Increased pulmonary toxicity and mucositis severity was seen after mediastinal IFRT compared with nonmediastinal IFRT. Because local control was excellent, higher doses of IFRT are not recommended. The absolute benefit of IFRT in this patient population needs investigation in future studies.

Analysis of in-field control and late toxicity for adults with early-stage Hodgkin's disease treated with chemotherapy followed by radiotherapy

PURPOSE

We analyzed in-field (IF) control in adults with early-stage Hodgkin's disease who received chemotherapy followed by radiotherapy (RT) in terms of the (1) chemotherapeutic regimen used and number of cycles delivered, (2) response to chemotherapy, and (3) initial tumor size. Cardiac toxicity and second malignancies, particularly the incidence of solid tumors in terms of the RT field size treated, were also examined.

METHODS AND MATERIALS

From 1980 to 1995, 286 patients ranging in age from 16 to 88 years (median: 28 years) with Ann Arbor clinical Stage I or II Hodgkin's disease underwent chemotherapy followed 3 to 4 weeks later by RT. There were 516 nodal sites measuring 0.5 to 19.0 cm at the start of chemotherapy, including 134 cases of bulky mediastinal disease. NOVP, MOPP, ABVD, CVPP/ABDIC, and other chemotherapeutic regimens were given to 161, 67, 19, 18, and 21 patients, respectively. Patients received 1-8 (median: 3) cycles of induction chemotherapy. All 533 gross nodal and extranodal sites of disease were included in the RT fields. The median prescribed RT dose for gross disease was 40.0 Gy given in 20 daily 2.0-Gy fractions. There was little variation in the RT dose. Eighty-five patients were treated with involved-field or regional RT (to one side of the diaphragm), and 201 patients were treated with extended-field RT (to both sides of the diaphragm), based on the protocol on which they were enrolled.

RESULTS

Follow-up of surviving patients ranged from 1.3 to 19.9 years (median: 7.4 years). Based on a review of simulation films, there were 16 IF, 8 marginal, and 15 out-of-field recurrences. The chemotherapeutic regimen used and the number of cycles of chemotherapy delivered did not significantly affect IF control. IF control also did not significantly depend on the response to induction chemotherapy. In cases where there was a confirmed or unconfirmed complete response as opposed to a partial response or stable disease in response to induction chemotherapy for bulky nodal disease, the 5-year IF control rates were 99% and 92%, respectively (p = 0.0006). The 15-year actuarial risks of coronary artery disease requiring surgical intervention and of solid tumors were 4.1% and 16.8%, respectively. There was a trend toward a greater risk of solid tumors in patients who received extended-field RT rather than involved-field or regional RT (p = 0.08).

CONCLUSIONS

In patients with nonbulky disease, induction chemotherapy followed by RT to a median dose of 40.0 Gy resulted in excellent IF control, regardless of the chemotherapeutic regimen used, the fact that only 1-2 cycles of chemotherapy were delivered, and the response to chemotherapy. There was a trend toward a higher incidence of solid tumors in patients who received consolidation RT to both sides rather than only one side of the diaphragm. Ongoing Phase III trials will help clarify whether lower RT doses and smaller RT fields after chemotherapy can maintain the IF control seen in our study, but with a lower incidence of late complications in patients with Stage I or II Hodgkin's disease.