Long-term results of therapy for stage C neuroblastoma

Patterns of recurrence after radiotherapy for high-risk neuroblastoma: Implications for radiation dose and field

BACKGROUND

Prognosis for patients with high-risk neuroblastoma (HR-NBL) is guarded despite aggressive therapy, and few studies have characterized outcomes after radiotherapy in relation to radiation treatment fields.

METHODS

Multi-institutional retrospective cohort of 293 patients with HR-NBL who received autologous stem cell transplant (ASCT) and EBRT between 1997-2021. LRR was defined as recurrence at the primary site or within one nodal echelon beyond disease present at diagnosis. Follow-up was defined from the end of EBRT. Event-free survival (EFS) and OS were analyzed by Kaplan-Meier method. Cumulative incidence of locoregional progression (CILP) was analyzed using competing risks of distant-only relapse and death with Gray's test.

RESULTS

Median follow-up was 7.0 years (range: 0.01-22.4). Five-year CILP, EFS, and OS were 11.9 %, 65.2 %, and 77.5 %, respectively. Of the 31 patients with LRR and imaging review, 15 (48.4 %) had in-field recurrences (>12 Gy), 6 (19.4 %) had marginal failures (≤12 Gy), and 10 (32.3 %) had both in-field and marginal recurrences. No patients receiving total body irradiation (12 Gy) experienced marginal-only failures (p = 0.069). On multivariable analyses, MYCN amplification had higher risk of LRR (HR: 2.42, 95 % CI: 1.06-5.50, p = 0.035) and post-consolidation isotretinoin and anti-GD2 antibody therapy (HR: 0.42, 95 % CI: 0.19-0.94, p = 0.035) had lower risk of LRR.

CONCLUSIONS

Despite EBRT, LRR remains a contributor to treatment failure in HR-NBL with approximately half of LRRs including a component of marginal failure. Future prospective studies are needed to explore whether radiation fields and doses should be defined based on molecular features such as MYCN amplification, and/or response to chemotherapy.

Prospective Evaluation of Radiation Dose Escalation in Patients With High-Risk Neuroblastoma and Gross Residual Disease After Surgery: A Report From the Children's Oncology Group ANBL0532 Study

PURPOSE

A primary objective of the Children's Oncology Group (COG) ANBL0532 phase III study was to assess the effect of increasing local dose of radiation to a residual primary tumor on the cumulative incidence of local progression (CILP) in patients with high-risk neuroblastoma.

PATIENTS AND METHODS

Newly diagnosed patients with high-risk neuroblastoma were randomly assigned or assigned to receive single or tandem autologous stem-cell transplantation (SCT) after induction chemotherapy. Local control consisted of surgical resection during induction chemotherapy and radiotherapy after last SCT. Patients received 21.6 Gy to the preoperative primary tumor volume. For patients with incomplete surgical resection, an additional boost of 14.4 Gy was delivered to the gross residual tumor, for a total dose of 36 Gy. CILP (primary end point) and event-free (EFS) and overall survival (OS; secondary end points) were compared with the COG A3973 historical cohort, in which all patients received single SCT and 21.6 Gy without a boost.

RESULTS

For all patients in ANBL0532 receiving radiotherapy (n = 323), 5-year CILP, EFS, and OS rates were 11.2% ± 1.8%, 56.2% ± 3.4%, and 68.4% ± 3.2% compared with 7.1% ± 1.4% (P = .0590), 47.0% ± 3.5% (P = .0090), and 57.4% ± 3.5% (P = .0088) for all patients in A3973 receiving radiotherapy (n = 328), respectively. Five-year CILP, EFS, and OS rates for patients in A3973 with incomplete resection and radiotherapy (n = 47) were 10.6% ± 4.6%, 48.9% ± 10.1%, and 56.9% ± 10.0%, respectively. In comparison, 5-year CILP, EFS, and OS rates for patients in ANBL0532 who were randomly assigned or assigned to single SCT and received boost radiotherapy (n = 74) were 16.3% ± 4.3% (P = .4126), 50.9% ± 7.0% (P = .5084), and 68.1% ± 6.7% (P = .2835), respectively.

CONCLUSION

Boost radiotherapy to gross residual tumor present at the end of induction did not significantly improve 5-year CILP. These results highlight the need for new strategies to decrease the risk of locoregional failure.

Patterns of recurrence after radiation therapy for high-risk neuroblastoma

Purpose

To investigate the patterns of recurrence in patients with neuroblastoma treated with radiation therapy to the primary tumor site.

Materials and Methods

We retrospectively analyzed patients with high-risk neuroblastoma managed with definitive treatment with radiation therapy to the primary tumor site between January 2003 and June 2017. These patients underwent three-dimensional conformal radiation therapy or intensity-modulated radiation therapy. A total of 14–36 Gy was delivered to the planning target volume, which included the primary tumor bed and the selected metastatic site. The disease stage was determined according to the International Neuroblastoma Staging System (INSS). We evaluated the recurrence pattern (i.e., local or systemic), progression-free survival, and overall survival.

Results

A total of 40 patients with high-risk neuroblastoma were included in this study. The median patient age was 4 years (range, 1 to 11 years). Thirty patients (75%) had INSS stage 4 neuroblastoma. At the median follow-up of 58 months, there were 6 cases of local recurrence and 10 cases of systemic recurrence. Among the 6 local failure cases, 4 relapsed adjacent to the radiation field. The other 2 relapsed in the radiation field (i.e., para-aortic and retroperitoneal areas). The main sites of distant metastasis were the bone, lymph nodes, and bone marrow. The 5-year progression-free survival was 70.9% and the 5-year overall survival was 74.3%.

Conclusion

Radiation therapy directed at the primary tumor site provides good local control. It seems to be adequate for disease control in patients with high-risk neuroblastoma after chemotherapy and surgical resection.

Role of the extent of prophylactic regional lymph node radiotherapy on survival in high-risk neuroblastoma: A report from the COG A3973 study

PURPOSE

Neuroblastoma is the most common extracranial solid pediatric malignancy, with poor outcomes in high-risk disease. Standard treatment approaches employ an increasing array of aggressive multimodal therapies, of which local control with surgery and radiotherapy remains a backbone; however, the benefit of broad regional nodal irradiation remains controversial. We analyzed centrally reviewed radiation therapy data from patients enrolled on COG A3973 to evaluate the impact of primary site irradiation and the extent of regional nodal coverage stratified by extent of surgical resection.

METHODS

Three hundred thirty high-risk neuroblastoma patients with centrally reviewed radiotherapy plans were analyzed. Outcome was evaluated by the extent of nodal irradiation. For the 171 patients who also underwent surgery (centrally reviewed), outcome was likewise analyzed according to the extent of resection. Overall survival (OS), event-free survival (EFS), and cumulative incidence of local progression (CILP) were examined by Kaplan-Meier, log-rank test (EFS, OS), and Grey test (CILP).

RESULTS

The five-year CILP, EFS, and OS for all 330 patients receiving radiotherapy on A3973 were 8.5% ± 1.5%, 47.2% ± 3.0%, and 59.7% ± 3.0%, respectively. There were no significant differences in outcomes based on the extent of lymph node irradiation regardless of the degree of surgical resection (< 90% or ≥90%).

CONCLUSION

Although local control remains a significant component of treatment of high-risk neuroblastoma, our results suggest there is no benefit of extensive lymph node irradiation, irrespective of the extent of surgical resection preceding stem cell transplant.

Pregnancy Incidence in Female Nasopharyngeal Carcinoma Survivors of Reproductive Age: A Population-Based Study

This study evaluated the pregnancy incidence in female nasopharyngeal carcinoma (NPC) survivors of reproductive age.In a nationwide cohort, 2816 female patients 15 to 50 years of age from 1998 to 2010 were identified from the Taiwan National Health Insurance Research database. Comorbidities, complications during pregnancy, and delivery status were recorded. All patients were followed up until a diagnosis of pregnancy, withdrawal from the National Health Insurance system, or December 31, 2011.Overall, 155 patients (incidence rate [IR] = 9.50) were pregnant in the NPC group, whereas 251 patients (IR = 12.80) were pregnant in the non-NPC group. The cumulative incidence of pregnancy in the NPC group was lower than that in the non-NPC group (incidence rate ratio = 0.74, 95% CI = 0.61-0.91). The adjusted hazard ratio of pregnancy in the NPC group was 0.79 with 95% CI = 0.61-0.96, compared with the non-NPC group.The incidence of pregnancy is significantly lower among female NPC survivors of reproductive age than among those without NPC.

Combination of external-beam radiotherapy with intraoperative electron-beam therapy is effective in incompletely resected pediatric malignancies

PURPOSE

Intraoperative electron-beam radiotherapy (IOERT) has been applied for local dose escalation in over 1,400 patients in Heidelberg since 1991. Among these were 30 children, in 18 of whom IOERT was employed in radiation treatment with external-beam radiotherapy (EBRT) on account of incomplete resection. We address the question whether IOERT is able to compensate for microscopic or macroscopic tumor residue if employed in the overall radiation regimen.

METHODS AND MATERIALS

The data of the aforementioned 18 children were analyzed with regard to local recurrence, overall survival, and complication rates. All children suffered from either sarcomas or neuroblastomas. In all children, IOERT was employed for local dose escalation after or before EBRT.

RESULTS

After a median follow-up of 60.5 months, 15 of the treated children are alive. One local failure has been observed. Six children show clinically significant late morbidity, including the loss of a treated limb (Radiation Therapy Oncology Group Grade 4 [RTOG 4]), a severe nerve lesion (RTOG 3), an orthopedic complication (RTOG 2), a ureteral stenosis (not clinically significant), and a kidney hypotrophy (not clinically significant). In 1 child a fracture due to radionecrosis (RTOG 4) was diagnosed; however, in the follow-up, local tumor relapse was diagnosed as another possible reason for the fracture.

CONCLUSIONS

Regarding the low incidence of local failure, IOERT seems to be able to compensate incomplete tumor resection in childhood sarcoma and neuroblastoma patients. The incidence of late morbidity is low enough to justify the employment of IOERT as part of the radiation treatment regimen for pediatric patients.

Excellent local tumor control regardless of extent of surgical resection after treatment on the Chicago Pilot II protocol for neuroblastoma

BACKGROUND

Our aim was to investigate the impact of the extent of surgical resection on local recurrence and survival in high-risk patients treated with the Chicago Pilot II protocol.

METHODS

Retrospective chart review was performed on 30 patients enrolled in the Chicago Pilot II protocol between 1995 and 2003. Variables studied were location of tumor, extent of resection, timing and location of recurrence, MYCN amplification, surgical complications, event-free survival, and overall survival (OS). Operative reports and postoperative meta-iodobenzylguanidine scans were used to assess extent of resection. Complete resection (CR) was defined as no gross residual tumor including primary and nodal disease.

RESULTS

Three-year event-free survival and OS of this cohort of 30 patients was 58% and 82%, respectively. Only 1 patient developed a local recurrence, whereas metastatic recurrent disease was observed in 13 (43%) of the 30; and this subset had a significantly worse OS (23% vs 94%, P = .001). The most common relapse location was in bone. Patients with incomplete resection (IR) (11/30) and CR (19/30) had recurrence rates of 64% (7/11) and 32% (6/19, P = .12), respectively. Event-free survival was significantly better for patients with CR (68%) vs IR (27%; P = .05; odds ratio, 2.9). Overall survival rates for patients with CR vs IR were 68% vs 55%, respectively (P = .25).

CONCLUSIONS

Recurrence rate was the significant determinant of survival. Patients with CR had lower recurrence rates; however, they did not have improved local control. Final outcome of patients with unfavorable neuroblastoma will be determined by metastatic recurrence, not by extent of resection.

Risk factors for scoliosis in children with neuroblastoma

PURPOSE

To determine the risk factors for scoliosis in children treated for neuroblastoma.

METHODS AND MATERIALS

From 1957 to 1997, 58 children with neuroblastoma were treated at one institution and have survived a minimum of 5 years. There were 35 boys and 23 girls with a median age of 6 months (range, 2 weeks to 15 years) at initial diagnosis. Primary site was located in the adrenal gland in 25 (43.1%), abdominal/nonadrenal in 16 (27.6%), thoracic in 12 (20.7%), cervical in 3 (5.3%), and pelvic region in 2 (3.5%). The International Neuroblastoma Staging System (INSS) stage was Stage 1 in 10 (17.2%), Stage 2A in 7 (12.1%), Stage 2B in 5 (8.6%), Stage 3 in 22 (37.9%), Stage 4 in 4 (6.9%), and Stage 4S in 10 (17.2%). Thirty-three (56.9%) received chemotherapy whereas 5 (8.6%) had a laminectomy as part of the surgical procedure. Twenty-seven (46.6%) received radiotherapy (RT). Beam energy was 1.25 MV in 11 (41%), 250 kV in 10 (37%), 4 MV in 4 (15%), and 6-MV photons in 1 patient. One patient received 300 cGy in 1 fraction total skin RT using 6-MeV electrons. For the remaining patients, fraction size was 100 cGy in 6 (22%), 150-180 cGy in 11 (41%), 200 cGy in 4 (15%), and 250-300 cGy in 3. Three patients had total body irradiation at 333 cGy for 3 fractions. For all children who received RT, median total dose was 2000 cGy (range, 300-3900 cGy). Patients who were treated with RT had plain films of the irradiated area every 1 to 2 years until at least the age of puberty. Median follow-up was 10 years (range, 5-46 years).

RESULTS

The overall 5-, 10-, and 15-year scoliosis-free rates were 87.6%, 79.0%, and 76.0% respectively. Twelve (21%) developed scoliosis at a median time of 51 months (range, 8-137 months). The degree of scoliosis was mild (< or =20 degrees ) in 8 (67%). Four had scoliosis ranging from 30 degrees to 66 degrees ; 3 of these patients required surgical intervention, whereas 1 had an underlying Duchenne muscular dystrophy which manifested itself 8 years after diagnosis of neuroblastoma. Median time to scoliosis was 23 months (range, 8-54 months) in children who had a laminectomy. On multivariate analysis, both history of laminectomy (p = 0.0005) and use of RT (p = 0.0284) were found to be risk factors for development of scoliosis. Gender, age at diagnosis, INSS stage, primary site, and use of chemotherapy were not found to be significant. Both RT fraction size and beam energy were also not significant, but increasing total RT dose was found to be significant (p = 0.0039). The 15-year scoliosis-free rates were 20% for children who had a laminectomy and 81.3% for those who did not have a laminectomy. The 15-year scoliosis-free rates for children treated with RT doses 0 cGy, 1-1750 cGy, 1751-2300 cGy, and >2300 cGy were 91.7%, 87.5%, 51.4%, and 44.4% respectively.

CONCLUSIONS

Treatment-related factors, namely laminectomy and radiotherapy, were found to increase the risk of scoliosis in patients with neuroblastoma. Children who had a laminectomy were more likely to manifest scoliosis earlier. Increasing RT dose was found to impact adversely on the development of scoliosis.

Primary tumor control in patients with stage 3/4 unfavorable neuroblastoma treated with tandem double autologous stem cell transplants

OBJECTIVE

To assess the efficacy and toxicity of local radiotherapy in achieving local control in patients with stage 4 or high-risk stage 3 neuroblastoma treated with induction chemotherapy and tandem stem cell transplants.

METHODS

Fifty-two children with stage 4 or high-risk stage 3 neuroblastoma were treated on a standardized protocol that included five cycles of induction chemotherapy, surgical resection of the primary tumor when feasible, local radiotherapy, and then consolidation with tandem myeloablative cycles with autologous peripheral blood stem cell rescue. Local radiotherapy (10.5-18 Gy) was administered to patients with gross or microscopic residual disease prior to the myeloablative cycles. Thirty-seven patients received local radiotherapy to the primary tumor or primary tumor bed. Two patients with unknown primaries each received radiotherapy to single, unresectable, bulky metastatic sites. The second of the myeloablative regimens included 12 Gy of total body irradiation.

RESULTS

Of the 52 consecutively treated patients analyzed, 44 underwent both transplants, 6 underwent a single transplant, and 2 progressed during induction. Local radiotherapy did not prolong recovery of hematopoiesis following transplants, did not increase peritransplant morbidity, and did not prolong the hospital stay compared with patients who had not received local radiotherapy. Local control was excellent. Of 11 patients with disease recurrence after completion of therapy, 9 failed in bony metastatic sites 3 to 21 months after the completion of therapy, 1 recurred 67 months following therapy in the previously bulky metastatic site that had been irradiated, and 1 had local recurrence concurrent with distant progression 15 months following the second transplant. The three-year event-free survival was 63%, with a median follow-up of 29.5 months. The actuarial probability of local control was 97%.

CONCLUSIONS

The use of induction chemotherapy, aggressive multimodality therapy for the primary tumor, followed by tandem myeloablative cycles with stem cell transplant in patients with stage 4 or high risk stage 3 neuroblastoma has resulted in acceptable toxicity, a very low local recurrence risk, and an improvement in survival.

Long-term risk of second malignant neoplasms after neuroblastoma in childhood: Role of treatment

The aim of our study was to quantify the risk of second malignant neoplasms (SMNs) among long-term survivors of neuroblastoma and to study the influence of treatment on this risk. We studied data from 544 5-year survival patients diagnosed with neuroblastoma before age 16 years at 8 French and British treatment centres from 1948 to 1986. After an average follow-up of 15 years (range, 5-38 years), 12 children developed a total of 13 SMNs, whereas 1.19 were expected from general population rates. Among these SMNs, there were 5 thyroid and 3 breast cancers. Increases of the risks of SMN were observed with time since neuroblastoma diagnosis and attained age. In a multivariate analysis, the relative risk of SMN associated with radiotherapy was 4.3 (95% CI 0.8-78), whereas no increased risk of SMN was associated with the administration of chemotherapy as a whole (RR = 0.4, 95% CI 0.1-1.9). Young children treated for a neuroblastoma have significantly increased risks of SMN over 3 decades of follow-up. Radiotherapy treatment was found to be an important risk factor for developing SMNs, whereas no effect of chemotherapy was evidenced. Although our findings reflect the late effects of past therapeutic modalities, they underscore the importance of long-term surveillance of young children treated for a neuroblastoma. For these patients, many more years of follow-up are required to appreciate their overall risks of treatment-related SMNs.

Impact of radiotherapy for high-risk neuroblastoma: a Children's Cancer Group study

PURPOSE

To assess the effect of local radiation administered to primary disease sites in children with high-risk neuroblastoma.

MATERIALS AND METHODS

A total of 539 eligible patients were entered on protocol CCG-3891, consisting of chemotherapy, primary surgery, and 10 Gy of external beam radiation therapy (EBRT) to gross residual disease, followed by randomized assignment to continuation chemotherapy (CC) or autologous bone marrow transplantation (ABMT). ABMT patients received total body irradiation (TBI).

RESULTS

Estimated event-free survival and overall survival at 5 years were 25% +/- 2% and 35% +/- 2%, respectively. Estimated 5-year locoregional recurrence rates were 51% +/- 5% and 33% +/- 7% for CC and ABMT patients (p = 0.004). For patients who received 10 Gy of EBRT to the primary, the addition of 10 Gy of TBI and ABMT decreased local recurrence compared with CC (22% +/- 12% and 52% +/- 8%, p = 0.022). EBRT did not increase acute toxicity, except for increased total parenteral nutrition administration.

CONCLUSIONS

In combination with EBRT to the primary tumor site, the addition of 10 Gy of TBI as a component of high-dose chemotherapy with ABMT improved local control compared with CC without TBI. Results suggest a dose-response relationship for local EBRT. Short-term toxicity of local EBRT is limited.

Locoregional control in infants with neuroblastoma: role of radiation therapy and late toxicity

PURPOSE

To review patterns of failure in infants with neuroblastoma and determine late toxicity and efficacy of radiotherapy (RT) on locoregional control.

MATERIALS AND METHODS

From 1955 to 1998, 53 children (35 males and 18 females) <1 year old with neuroblastoma were seen at our institution. Twenty-one (40%) were </=1 month of age (neonates). Seven congenital anomalies were seen in 4 children (atrial septal defect, pulmonary valve stenosis, and absent corpus callosum were seen in 1 patient each; the other child had atrial and ventricular septal defect, aortic arch hypoplasia, and mitral valve stenosis). Primary tumor was located in the adrenal gland in 26 (49%), abdomen/nonadrenal in 14 (26%), thorax in 9 (17%), neck in 2 (4%), and pelvis in 2 (4%). All infants were retrospectively staged according to the International Neuroblastoma Staging System (INSS); 8 had Stage 1, 7 Stage 2A, 6 Stage 2B, 15 Stage 3, 6 Stage 4, and 11 Stage 4S. All patients, except 11 with Stage 4S and 4 with Stage 4, had resection of the primary tumor. Sixteen infants had pathologic involvement of regional lymph nodes (LN+). Twenty patients received RT. Kilovoltage beams were used in 10, megavoltage photons in 9, and electrons in 1 child. Fifteen received RT to the primary site and regional nodes (postoperative 8, preoperative 7). Postoperative doses ranged from 15 to 25 Gy whereas preoperative doses ranged from 12 to 31 Gy using a median fraction size of 1.5 Gy. Chemotherapy was employed in 22 of 53 patients (42%) with the most common agents being cyclophosphamide in 22 and doxorubicin in 11. Median follow-up was 13.1 years (range, 2-41 years).

RESULTS

Tumor control: The 5-year overall and freedom from progression rates were 79 +/- 9% and 81 +/- 11%; the locoregional control rate was 88 +/- 9%. INSS Stage was a prognostic factor for overall survival (p = 0.03) and freedom from progression (p = 0.035). Gender, age (</=1 month vs. >1 month), and primary site were not found to impact on survival or progression. None of the Stage 1, 2A, or 2B patients recurred. One of 15 Stage 3 and 5 of 6 Stage 4 children recurred (6 distant metastases, 4 local failure). Four of 6 (67%) LN+ patients treated with locoregional RT and 8 of 10 (80%) LN+ patients treated without RT were locally controlled. There was no isolated locoregional relapse. Two Stage 4S patients died of respiratory compromise secondary to hepatomegaly. RT toxicity: For the 20 infants who received RT, 13 are alive with long-term follow-up ranging from 9.3 to 41 years, median 23 years. The 10 and 15-year musculoskeletal toxicity rates were 38.5% and 47.3% for those receiving RT and 3.3% for no RT (p = 0.02, log-rank test). Five of 6 infants <6 months of age and 1 of 7 >/=6 months developed musculoskeletal toxicity. Musculoskeletal effects were seen in 6 RT patients and included bony hypoplasia in 6, scoliosis in 5, soft tissue hypoplasia in 3, slipped capital femoral epiphysis in 2, kyphosis in 1, and osteochondroma in 1. Three required orthopedic intervention, all receiving >/=20 Gy. One child developed bowel obstruction at 21 months and another developed a leiomyosarcoma in the treatment field 34 years after RT.

CONCLUSION

Our study shows that most LN+ infants achieve locoregional control without RT. Infants <6 months receiving RT were the most susceptible to musculoskeletal abnormalities. Further studies are needed to determine if cardiovascular anomalies are more frequently seen in children with neuroblastoma.

Intraoperative radiation therapy for high-risk pediatric neuroblastoma

PURPOSE

To evaluate the efficacy of intraoperative radiation therapy (IORT) in the treatment of high-risk pediatric neuroblastoma.

METHODS AND MATERIALS

Between 1986 and 1998, 23 children received IORT for pediatric neuroblastoma. Electron beam energies ranged from 4 MeV to 16 MeV and median dose was 10 Gy (7-16 Gy).

RESULTS

Twenty-one of 23 patients were classified as high-risk. A gross total resection (GTR) was achieved in 18 patients, of whom 6 experienced disease recurrence, 2 of which included a locoregional relapse as a component of failure. Fourteen of 18 patients receiving IORT after a GTR are disease-free survivors. A second subset of 5 patients had a subtotal resection (STR), with gross residual disease remaining after surgery. All 5 patients recurred locally, and all died of their disease. IORT was extremely well-tolerated in our cohort. Surgical resection and IORT resulted in the narrowing of the abdominal aorta and an atrophic kidney in 1 patient.

CONCLUSIONS

For high-risk neuroblastoma patients, IORT as the only radiotherapy to the primary, produced excellent local control after a GTR. However, IORT as the sole radiotherapy to the primary was inadequate for patients with extensive adenopathy or an STR. In this setting, we are exploring the use of IORT as a boost in conjunction with external beam radiation therapy.

Local control with multimodality therapy for stage 4 neuroblastoma

PURPOSE

To evaluate the efficacy of 21 Gy hyperfractionated radiotherapy for local control in conjunction with surgery and intensive systemic therapy for patients with Stage 4 neuroblastoma.

METHODS AND MATERIALS

After achieving a partial or complete remission, 47 children, ages 1-10 years, with Stage 4 neuroblastoma were treated on four consecutive institutional protocols (N4-N7) with dose-intensive multi-agent chemotherapy, maximal surgical debulking, and hyperfractionated radiotherapy (1.5 Gy twice a day to 21 Gy). Radiotherapy fields encompassed the initial tumor volume and regional lymph nodes plus a 3-cm margin. This was followed by consolidation with either autologous bone marrow transplantation (N4 and N5) or immunotherapy (N6 and N7).

RESULTS

Forty-five of 47 patients had a complete response to surgery and chemotherapy prior to radiotherapy. Five-year actuarial rates of local control, progression-free survival, and overall survival were 84%, 40%, and 45%, respectively. Among 26 patients who relapsed, 1 failed only at the primary site, 22 developed distant metastases exclusively, and 3 had both local and distant failures. There were no acute complications of radiotherapy.

CONCLUSION

Hyperfractionated radiotherapy to 21 Gy, in conjunction with dose-intensive systemic therapy and aggressive surgical resection, is well tolerated and is associated with durable local control for most patients with Stage 4 neuroblastoma.