Intensity-modulated radiotherapy for head-and-neck rhabdomyosarcoma

Non-inferior efficacy of non-surgical treatment to surgical treatment in patients with nonmetastatic head and neck rhabdomyosarcoma: a SEER-based study

PURPOSE

Head and neck rhabdomyosarcoma (HNRMS) is a rare but aggressive malignant neoplasm. Given the young patient age and critical anatomy of the head and neck, performing surgery on the primary tumor still remains debatable. This study aimed to evaluate the impact of the non-surgery-based treatment versus surgery-based treatment on patients with nonmetastatic HNRMS.

METHODS

Patients diagnosed with nonmetastatic HNRMS between 2004 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database were enrolled in our study. Inverse probability treatment weighting (IPTW) method was employed to balance confounding factors between surgery and non-surgery groups. Kaplan-Meier methods and COX regression analyses were used to analyze survival outcomes of overall survival (OS) and cancer-specific survival (CSS). Prognostic nomogram was established to predict survival.

RESULTS

A total of 260 eligible patients were extracted from the SEER database. Kaplan-Meier survival curves revealed that there was no significant difference in OS and CSS between the surgery and non-surgery groups both before and after IPTW (p > 0.05). Cox regression analyses and IPTW-adjusted Cox regression analyses for both OS and CSS showed similar survival between the two groups. Prognostic factors were explored and a nomogram for patients in the surgery group was constructed. Risk stratification based on the nomogram indicated that patients in surgery-high-risk group did not benefit from primary surgery. While those in surgery-low-risk group had an equal survival outcome to those in non-surgery group.

CONCLUSIONS

Our study revealed that compared to patients receiving surgery, those not receiving surgery had similar survival outcomes for nonmetastatic HNRMS. Our established nomogram may serve as a practical tool for individual prognostic evaluations.

Proton Radiotherapy to Reduce Late Complications in Childhood Head and Neck Cancers

In most childhood head and neck cancers, radiotherapy is an essential component of treatment; however, it can be associated with problematic long-term complications. Proton beam therapy is accepted as a preferred radiation modality in pediatric cancers to minimize the late radiation side effects. Given that childhood cancers are a rare and heterogeneous disease, the support for proton therapy comes from risk modeling and a limited number of cohort series. Here, we discuss the role of proton radiotherapy in pediatric head and neck cancers with a focus on reducing radiation toxicities. First, we compare the efficacy and expected toxicities in proton and photon radiotherapy for childhood cancers. Second, we review the benefit of proton radiotherapy in reducing acute and late radiation toxicities, including risks for secondary cancers, craniofacial development, vision, and cognition. Finally, we review the cost effectiveness for proton radiotherapy in pediatric head and neck cancers. This review highlights the benefits of particle radiotherapy for pediatric head and neck cancers to improve the quality of life in cancer survivors, to reduce radiation morbidities, and to maximize efficient health care use.

Management of Rhabdomyosarcoma in Pediatric Patients

Rhabdomyosarcoma is the commonest soft tissue sarcoma in children. Clinicians need vigilance to recognize the different signs and symptoms this tumor can present with because of variable sites of origin. Diagnosis requires a safe biopsy that obtains sufficient tissue for pathologic, genetic, and biological characterization of the tumor. Treatment depends on accurate staging with imaging and surgical sampling of draining lymph nodes. A multidisciplinary team assigns patients to risk-based therapy. Patients require chemotherapy and usually a combination of complex, site-specific surgery and/or radiotherapy. Outcomes for localized rhabdomyosarcoma continue to improve but new treatments are required for metastatic and relapsed disease.

Adult parameningial alveolar rhabdomyosarcoma: Case report and literature review

Alveolar rhabdomyosarcoma (ARMS) represents the most common childhood soft tissue sarcoma, but they are rarely seen among adults. Most of the protocols for adults are adapted from pediatric protocols. Here we report a case of a 53-year-old woman diagnosed with a nasal alveolar rhabdomyosarcoma, stage IV at diagnosis, treated by chemotherapy (a regimen inspired from the pediatric protocole pEpSSG RMS 2005) which led to partial response followed by chemo-radiotherapy. We performed a systematic review of adult head and neck ARMS and found 29 cases. Primary chemotherapy with different protocols (VAC, VAI or VIE) should be done followed by surgery and/or external beam radiotherapy (preferably with IMRT). EBRT seems beneficial to every ARMS with a dose around 50Gy in a conventional fractionation, eventually completed with a boost on residual tumor. The target volume must be defined on pre-chemotherapy imaging. Brachytherapy and proton therapy are under evaluation.

The role of proton therapy in pediatric malignancies: Recent advances and future directions

Proton radiotherapy has promised an advantage in safely treating pediatric malignancies with an increased capability to spare normal tissues, reducing the risk of both acute and late toxicity. The past decade has seen the proliferation of more than 30 proton facilities in the United States, with increased capacity to provide access to approximately 3,000 children per year who will require radiotherapy for their disease. We provide a review of the initial efforts to describe outcomes after proton therapy across the common pediatric disease sites. We discuss the main attempts to assess comparative efficacy between proton and photon radiotherapy concerning toxicity. We also discuss recent efforts of multi-institutional registries aimed at accelerating research to better define the optimal treatment paradigm for children requiring radiotherapy for cure.

Outcome and Patterns of Relapse in Childhood Parameningeal Rhabdomyosarcoma Treated With Proton Beam Therapy

PURPOSE

The standard of care of childhood parameningeal rhabdomyosarcoma (pRMS) is chemotherapy and local radiation therapy. Protons are increasingly being used to decrease late effects. The aim of the present study is to analyze the pattern of relapse and the correlation with dosimetric factors in pRMS treated with proton therapy.

METHODS AND MATERIALS

This retrospective evaluation includes children treated in our institution for pRMS. Information on demographics, treatment, tumor characteristics, and toxicities and outcome was prospectively collected within the in-house registry. For patients presenting with local relapse, a fusion of the dosimetry with magnetic resonance imaging displaying site and geometry of recurrence was performed.

RESULTS

Median follow-up time was 2.9 years (0.5-4.7). Forty-six patients were identified in our institution between July 2013 and November 2017. Main characteristics of patients were as follows: 56.5% male, median age 5.1 years (1.3-17.5), 39.1% alveolar histology, 26.1%, 52.2%, 8.7%, and 13% patients with subgroup risk classification D, E/F/G, H, or metastatic, respectively, median total prescribed dose 55.8 Gy (50.4-56.4). Estimated 2-year local control, metastasis-free survival, event-free survival, and overall survival were 83.8%, 87.8%, 76.9%, and 88.9%, respectively. No acute or late local toxicity exceeding grade 3 was observed. Risk-group was identified as prognostic factor for metastasis-free survival in univariate analysis but not in multivariate analysis (trend: P = .09). In this cohort, dosimetric factors did not correlate with outcome. Isolated local failure happened in 5 of the 11 relapses. Local relapses were matched with dosimetry for 6 patients: 4 of them occurred in the high dose volume and 2 in the intermediate or low dose volume.

CONCLUSIONS

Proton therapy was effective and well feasible even in a critical cohort. Still, local relapse within the target volume of the radiation therapy remains an important issue in pRMS and new treatment strategies are needed.

Using Image-guided Intensity-modulated Radiotherapy on Patients With Head and Neck Soft-tissue Sarcoma

BACKGROUND

Image-guided intensity-modulated radiotherapy (IG-IMRT) is increasingly being used to treat patients with soft-tissue sarcoma (STS) of the head and neck. Although there is no comparison between IMRT and conventional radiation therapy (CRT) concerning their efficacy. In this analysis, we compared CRT and IMRT outcomes for head and neck STS.

PATIENTS AND METHODS

Sixty-seven patients who underwent radiotherapy between 1994 and 2017 were identified.

RESULTS

The median follow-up was 31 months. Of the 67 patients, 34% were treated with CRT technique and 66% with IG-IMRT. The locoregional relapse rate following IMRT was 21% versus 70% with CRT (p<0.001) and the 5-year locoregional control was 69% versus 28%, respectively (p=0.01). IG-IMRT was associated with non-significant, less acute, and chronic adverse events. In the multivariate analysis, a significant influence of radiation technique on locoregional control was confirmed (p=0.04).

CONCLUSION

IG-IMRT seems to be associated both with higher locoregional control as well as lower acute and chronic toxicities.

Worse Outcomes for Head and Neck Rhabdomyosarcoma Secondary to Reduced-Dose Cyclophosphamide

PURPOSE

Recent trends, including the use of proton therapy and administration of reduced doses of cyclophosphamide, have been adapted in head and neck (HN) rhabdomyosarcoma (RMS) to reduce late morbidity. Our primary goal was to analyze local control and survival outcomes after photon versus proton irradiation in pediatric patients with HN-RMS, with the secondary goal of analyzing the effect of cyclophosphamide dose on disease outcomes.

METHODS AND MATERIALS

This single-institution cohort study comprised 76 pediatric HN-RMS patients treated with definitive chemoradiation from 2000 to 2018. Fifty-one patients (67%) received intensity modulated photon radiation therapy, and 25 (33%) received proton therapy.

RESULTS

Local failure (LF) at 2 years was 12.5% for parameningeal RMS and 0% for orbital RMS and other head and neck sites (P = .24). Patients treated with protons were more likely to have received reduced-dose cyclophosphamide (P < .0001). The 2-year LF was 7.9% in the intensity modulated photon radiation therapy cohort versus 14.6% in the proton cohort (P = .07), with no difference in survival outcomes. Cumulative cyclophosphamide dose was significantly associated with 2-year LF: 0% for cumulative dose of >20 g/m2 versus 15.3% for ≤20 g/m2 (P = .04). In parameningeal RMS patients (n = 59), both cumulative cyclophosphamide dose and dose intensity were associated with LF (P = .01). There was a trend toward worse event-free survival for parameningeal RMS patients who received reduced-dose-intensity cyclophosphamide (59.2% vs 70.6%, P = .11).

CONCLUSIONS

Both dose-intensity and cumulative cyclophosphamide dose seem to play an important role in achieving local control for HN-RMS patients treated with either protons or photons. Longer follow-up is needed to further assess disease outcomes with proton therapy.

Proton therapy for pediatric malignancies: Fact, figures and costs. A joint consensus statement from the pediatric subcommittee of PTCOG, PROS and EPTN

Radiotherapy plays an important role in the management of childhood cancer, with the primary aim of achieving the highest likelihood of cure with the lowest risk of radiation-induced morbidity. Proton therapy (PT) provides an undisputable advantage by reducing the radiation 'bath' dose delivered to non-target structures/volume while optimally covering the tumor with tumoricidal dose. This treatment modality comes, however, with an additional costs compared to conventional radiotherapy that could put substantial financial pressure to the health care systems with societal implications. In this review we assess the data available to the oncology community of PT delivered to children with cancer, discuss on the urgency to develop high-quality data. Additionally, we look at the advantage of combining systemic agents with protons and look at the cost-effectiveness data published so far.

Proton therapy for pediatric head and neck malignancies

PURPOSE

Pediatric head and neck malignancies are managed with intensive multimodality therapy. Proton beam therapy (PBT) may reduce toxicity by limiting exposure of normal tissue to radiation. In this study, we report acute toxicities and early outcomes following PBT for pediatric head and neck malignancies.

MATERIALS AND METHODS

Between 2010 and 2016, pediatric patients with nonhematologic malignancies of the head and neck were treated with PBT. Clinical and dosimetric data were abstracted from the medical record and treatment planning system with institutional review board approval.

RESULTS

Sixty-nine consecutive pediatric patients were treated with proton-based radiotherapy for head and neck malignancies. Thirty-five were treated for rhabdomyosarcoma to a median dose of 50.4 Gy relative biological effectiveness [RBE]. Ten patients were treated for Ewing sarcoma to a median dose of 55.8 Gy[RBE]. Twenty-four patients were treated for other histologies to a median dose of 63.0 Gy[RBE]. Grade 3 oral mucositis, anorexia, and dysphagia were reported to be 4, 22, and 7%, respectively. Actuarial 1-year freedom from local recurrence was 92% (95% CI 80-97). Actuarial 1-year overall survival was 93% (95% CI 79-98) in the entire cohort. Oral cavity mucositis was significantly correlated with oral cavity dose (D80 and D50 [P < 0.05], where D80 and D50 are dose to 50% of the volume and dose to 80% of the volume, respectively).

CONCLUSIONS

In this study, we report low rates of acute toxicity in a cohort of pediatric patients with head and neck malignancies. PBT appears safe for this patient population, with local control rates similar to historical reports. Longer follow-up will be required to evaluate late toxicity and long-term disease control.

Rhabdomyosarcoma of the Head and Neck: A Multimodal Approach

Head and neck rhabdomyosarcoma (HNRMS) is a uniquely challenging site to treat given the young patient age and critical anatomy of the head and neck region. We review the characteristics, management, and future directions in the treatment of HNRMS. Most patients who present with HNRMS have unresectable disease due to functional and/or cosmetic constraints. However, surgical resection and brachytherapy serve a critical role in select patients. The treatment paradigm for the majority of patients with HNRMS consists of definitive chemotherapy and radiation therapy. As the incidence of late toxicities increases with improved survival, modern efforts must focus on ways to decrease long-term morbidity. We recommend a multimodal approach emphasizing the preservation of form and function for the treatment of HNRMS.

A Dosimetric Comparison of Intensity-Modulated Proton Therapy, Volumetric-Modulated Arc Therapy, and 4π Non-Coplanar Intensity-Modulated Radiation Therapy for a Patient with Parameningeal Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and manifests as two major histological subtypes: embryonal and alveolar. The five-year local failure rate for RMS at parameningeal sites (middle ear, mastoid region, nasal cavity, etc.) is around 17% despite multiple Intergroup Rhabdomyosarcoma Study Group (IRS) trials conducted to determine the optimal radiation treatment regimen. This case report explores the use of intensity-modulated proton therapy (IMPT) for a 10-year-old child who presented with left eye irritation, facial pain, and headaches and was found to have an alveolar parameningeal rhabdomyosarcoma. He received systemic therapy as well as radiation therapy to 5,640 cGy and 4,320 cGy over 24 fractions, prescribed for gross tumor extension and adjacent high-risk involved sites, respectively, via simultaneous integrated boost. Approximately two years following treatment, the patient has had no recurrence of his RMS with no distant metastases. In addition, his presenting symptom of left eye irritation has improved. His only side effect from radiation at this point is short stature, possibly due to growth hormone deficiency. The patient’s IMPT plan was compared with volumetric-modulated arc therapy (VMAT) and 4π non-coplanar intensity-modulated radiation therapy (IMRT) plans, and comparisons of isodose lines show decreased dose to the distal brain tissue with preserved target conformality by IMPT. IMPT also allowed for increased sparing of the patient's retina, lens, and lacrimal gland. All radiation plans achieved conformal dose coverage to the planning/scanning target volumes, while the IMPT plan is potentially better at sparing the patient from developing long-term optic apparatus side effects and neurocognitive defects. In this case, IMPT is comparable, if not favorable, when long-term side effects can be reduced while maintaining dose conformality and local control.

45 Gy is not sufficient radiotherapy dose for Group III orbital embryonal rhabdomyosarcoma after less than complete response to 12 weeks of ARST0331 chemotherapy: A report from the Soft Tissue Sarcoma Committee of the Children's Oncology Group

BACKGROUND

Recent Children's Oncology Group (COG) trials tested the efficacy of reduced therapy in an effort to lessen late effects compared to the Intergroup Rhabdomyosarcoma Study (IRS) IV regimen with associated hematologic and hepatic toxicity, and infertility. Here, we analyze the efficacy of 45 Gray (Gy) local radiotherapy (RT) in patients with Group III orbital embryonal rhabdomyosarcoma (ERMS) enrolled on the COG low-risk study ARST0331.

PROCEDURE

Sixty-two patients with Group III orbital ERMS were treated on ARST0331 with four cycles of vincristine (VCR), dactinomycin (DACT), and cyclophosphamide (CPM; VAC, total cumulative CPM dose 4.8 g/m2 ) followed by four cycles of VCR and DACT over 22 weeks. Forty-five Gray of radiation was administered in 25 fractions beginning at week 13 of therapy.

RESULTS

Fifty-three patients were evaluable for this response analysis; seven had missing week 12 response evaluation data and two had progressive disease prior to starting RT. Median follow-up was 7.8 years. None of the 15 patients with radiographic complete response (CR) compared to 6 of the 38 patients with

CONCLUSIONS

For patients with Group III orbital ERMS achieving a CR following VAC chemotherapy that includes modest dose CPM, 45 Gy may be sufficient for durable failure-free survival. However, for those with Collapse

Key Words

• orbital rhabdomyosarcoma
• radiotherapy
• response based

Collapse

MESH Headings

• Antineoplastic Combined Chemotherapy Protocols/therapeutic use
• Child
• Child, Preschool
• Combined Modality Therapy
• Female
• History, Ancient
• Humans
• Kaplan-Meier Estimate
• Male
• Orbital Neoplasms/drug therapy
• Orbital Neoplasms/mortality
• Orbital Neoplasms/radiotherapy
• Radiation Dosage
• Radiotherapy/methods
• Rhabdomyosarcoma, Embryonal/drug therapy
• Rhabdomyosarcoma, Embryonal/mortality
• Rhabdomyosarcoma, Embryonal/radiotherapy

Collapse

Grants

• U10 CA098413 NCI NIH HHS
• U10 CA098543 NCI NIH HHS
• U10 CA180899 NCI NIH HHS

Collapse

Affiliation(s)

Ralph P. Ermoian Department of Radiation Oncology, University of Washington, Washington
John Breneman Department of Radiation Oncology, University of Cincinnati, Ohio
David O. Walterhouse Department of Pediatrics-Hematology, Oncology and Stem Cell Transplantation, Northwestern University, Illinois
Yueh-Yun Chi Department of Biostatistics, University of Florida, Florida
Jane Meza Department of Biostatistics, University of Nebraska, Nebraska
James Anderson Department of Biostatistics, University of Nebraska, Nebraska
Douglas S. Hawkins Department of Pediatrics, University of Washington, Washington
Andrea A. Hayes-Jordan Department of Pediatric Surgery, The University of Texas Health Science Center at Houston, Texas
David M. Parham Department of Pathology and Laboratory Medicine, Children’s Hospital Los Angeles and Keck School of Medicine, University of Southern California, California
Torunn I. Yock Department of Radiation Oncology, Massachusetts General Hospital, Massachusetts
Sarah S. Donaldson Department of Radiation Oncology, Stanford University School of Medicine, California
Suzanne L. Wolden Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York

Collapse

Strategies to Overcome Late Complications from Radiotherapy for Childhood Head and Neck Cancers

Most pediatric head and neck cancers are treated with radiotherapy, but the morbidity associated with radiotherapy has become a prominent issue. This article discusses the common long-term complications associated with head and neck radiotherapy for childhood cancers. It reviews approaches to minimize toxicity and details the toxicities that head and neck radiation inflicts on relevant functional measures. In addition, it discusses the risk of radiation-induced secondary cancers in childhood cancer survivors, as well as strategies to reduce them. Thus, this article addresses approaches to minimize long-term radiation toxicities in order to improve the quality of life for childhood cancer survivors.

Pencil Beam Scanning Proton Therapy for Pediatric Parameningeal Rhabdomyosarcomas: Clinical Outcome of Patients Treated at the Paul Scherrer Institute

BACKGROUND

Parameningeal rhabdomyosarcomas (PM-RMSs) represent approximately 25% of all rhabdomyosarcoma (RMS) cases. These tumors are associated with early recurrence and poor prognosis. This study assessed the clinical outcome and late toxicity of pencil beam scanning (PBS) proton therapy (PT) in the treatment of children with PM-RMS.

PROCEDURES

Thirty-nine children with PM-RMS received neoadjuvant chemotherapy followed by PBS-PT at the Paul Scherrer Institute, with concomitant chemotherapy. The median age was 5.8 years (range, 1.2-16.1). Due to young age, 25 patients (64%) required general anesthesia during PT. The median time from the start of chemotherapy to PT was 13 weeks (range, 3-23 weeks). Median prescription dose was 54 Gy (relative biologic effectiveness, RBE).

RESULTS

With a mean follow-up of 41 months (range, 9-106 months), 10 patients failed. The actuarial 5-year progression-free survival (PFS) was 72% (95% CI, 67-94%) and the 5-year overall survival was 73% (95% CI, 69-96%). On univariate analysis, a delay in the initiation of PT (>13 weeks) was a significant detrimental factor for PFS. Three (8%) patients presented with grade 3 radiation-induced toxicity. The estimated actuarial 5-year toxicity ≥grade 3 free survival was 95% (95% CI, 94-96%).

CONCLUSIONS

Our data contribute to the growing body of evidence demonstrating the safety and effectiveness of PT for pediatric patients with PM-RMS. These preliminary results are encouraging and in line with other combined proton-photon and photons series; observed toxicity was acceptable.

The impact of radiotherapy on clinical outcomes in parameningeal rhabdomyosarcoma

PURPOSE

Radiotherapy (RT) is considered a mainstay of treatment in parameningeal rhabdomyosarcoma (PM-RMS). We aim to determine the treatment outcomes and prognostic factors for PM-RMS patients who treated with RT. In addition, we tried to evaluate the adequate dose and timing of RT.

MATERIALS AND METHODS

Twenty-two patients with PM-RMS from 1995 to 2013 were evaluated. Seven patients had intracranial extension (ICE) and 17 patients had skull base bony erosion (SBBE). Five patients showed distant metastases at the time of diagnosis. All patients underwent chemotherapy and RT. The median radiation dose was 50.4 Gy (range, 40.0 to 56.0 Gy).

RESULTS

The median follow-up was 28.7 months. Twelve patients (54.5%) experienced failure after treatment; 4 local, 2 regional, and 6 distant failures. The 5-year local control (LC) and overall survival (OS) were 77.7% and 38.5%, respectively. The 5-year OS rate was 50.8% for patients without distant metastases and 0% for patients with metastases (p < 0.001). Radiation dose (<50 Gy vs. ≥50 Gy) did not compromise the LC (p = 0.645). However, LC was affected by ICE (p = 0.031). Delayed administration (>22 weeks) of RT was related to a higher rate of local failure (40.0%).

CONCLUSION

RT resulted in a higher rate of local control in PM-RMS. However, it was not extended to survival outcome. A more effective treatment for PM-RMS is warranted.

A clinicopathologic study of head and neck rhabdomyosarcomas showing FOXO1 fusion-positive alveolar and MYOD1-mutant sclerosing are associated with unfavorable outcome

BACKGROUND

Based on their distinctive histologic and genetic features, the latest WHO classification of soft tissue tumors includes four pathologic variants of rhabdomyosarcoma (RMS): embryonal (ERMS), alveolar (ARMS), spindle cell-sclerosing (SRMS-ScRMS) and pleomorphic RMS. The aim of this study focused on a detailed clinicopathologic and survival analysis of head and neck RMS (HNRMS) using the latest pathologic and molecular criteria reflecting this new subclassification in a large cohort.

PATIENTS AND METHODS

Patients managed for HNRMS in our institution (1996-2015) were analyzed. The presence of a FOXO1 fusion was required for the classification of ARMS. MYOD1 mutations in SRMS-ScRMS were tested when material available. Univariate and multivariate analyses were performed to evaluate variables related to overall survival (OS).

RESULTS

Ninety-nine HNRMS patients (52 males and 47 females, mean of 16years) were included in the study after pathologic re-review. The most common location was parameningeal (PM) (n=64), followed by non-orbital/non-PM (n=25) and orbital (n=10). There were 53 ERMS, 33 fusion-positive ARMS and 13 SRMS-ScRMS [SRMS (8); ScRMS (5)]. The 5-year OS rate for ERMS patients was significantly higher (82%) compared to ARMS (53%) and SRMS-ScRMS (50%) [SRMS (75%); ScRMS (30%)]. Univariate analysis showed that survival was dependent on histology (P=0.012), tumor size >5cm (P<0.001), regional lymph node involvement (P=0.002), metastasis at initial presentation (P<0.001), stage (P<0.001), and recurrence (P=0.002). Multivariate analysis confirmed histologic subtype to be significant (P=0.043).

CONCLUSION

Our findings reinforce that HNRMS is a heterogenous disease with ARMS and SRMS-ScRMS having an equally unfavorable outcome.

Late Toxicities of Intensity-Modulated Radiation Therapy for Head and Neck Rhabdomyosarcoma

PURPOSE/OBJECTIVES

To examine the late effects of intensity-modulated radiation therapy (IMRT) in pediatric patients with rhabdomyosarcoma of the head and neck.

MATERIALS/METHODS

All 1-year survivors of pediatric head and neck rhabdomyosarcoma treated with IMRT at a single institution from 1999 to 2014 were assessed for long-term complications. Late toxicities were graded according to CTCAE version 4.03.

RESULTS

Among 30 patients, median age at IMRT was 7.4 (1.5-20.8) years, median follow-up was 7.7 (1.2-14.4) years, and median IMRT dose was 50.4 (36-50.4) Gy. Tumor subsites included parameningeal (80%), orbit (13%), and other (7%). Common late toxicities were facial disfigurement (n = 23, 77%), growth hormone deficiency (n = 11, 37%), cataract (n = 10, 34%), and dental problems (n = 10, 33%). Twenty-two patients (73%) had ≥2 late toxicities and 14 patients (47%) had ≥3 late toxicities. Seventeen patients (57%) experienced grade 2 toxicity and 10 patients (33%) had grade 3 toxicity. Grade 3 toxicities included visual disturbance, cataract, facial disfigurement, chronic sinusitis/otitis, and hearing loss. Severe facial deformity was noted in nine patients (30%), and three patients underwent cosmetic surgery. Patients with severe facial deformity were treated at younger ages (median 6.0 years vs. 8.1 years for patients with no/nonsevere facial deformity) and more likely to have infratemporal fossa tumors. There were no secondary solid malignancies.

CONCLUSIONS

Late radiation toxicities are common in survivors of pediatric head and neck rhabdomyosarcoma treated with IMRT. While the majority of late effects are mild-moderate, they can significantly impact quality of life, particularly facial disfigurement.

High-dose-rate brachytherapy of rhabdomyosarcoma limited to the external auditory canal

PURPOSE

To report on the single-catheter high-dose-rate brachytherapy treatment of a 21-month-old girl child with an embryonal, botryoid-type, rhabdomyosarcoma limited to the external auditory canal (EAC).

METHODS AND MATERIALS

A 2.4-mm diameter catheter was inserted into the right EAC and placed against the tympanic membrane. A computed tomography simulation scan was acquired. A brachytherapy treatment plan, in which 21 Gy in seven fractions was prescribed to a 1-mm depth along the distal 2 cm of the catheter, was generated. Treatments were delivered under anesthesia without complication. A dosimetric comparison between this plan and an intensity-modulated radiation therapy (IMRT) plan was then conducted. A clinical target volume (CTV), which encompassed a 1-mm margin along the distal 2 cm of the catheter, was delineated for both plans. Given positioning uncertainty under image guidance, a planning target volume (PTV = CTV + 3-mm margin) was defined for the IMRT plan. The IMRT plan was optimized for maximal CTV coverage but subsequently normalized to the same CTV volume receiving 100% of the prescription dose (V₁₀₀) of the brachytherapy plan.

RESULTS

The IMRT plan was normalized to the brachytherapy CTV V₁₀₀ of 82.0%. The PTV V₁₀₀ of this plan was 34.1%. The PTV exhibited dosimetric undercoverage within the middle ear and toward the external ear. Mean cochlea doses for the IMRT and brachytherapy plans were 26.7% and 10.5% of prescription, respectively.

CONCLUSIONS

For rhabdomyosarcomas limited to the EAC, a standard brachytherapy catheter can deliver a highly conformal radiation plan that can spare the nearby cochlea from excess radiation.

Non-rhabdomyosarcoma soft-tissue sarcomas in children: Contemporary appraisal and experience from a single centre

Nonrhabdmyosarcoma soft tissue sarcomas (NRSTS) include a cluster of different types of soft tissue sarcomas clubbed together due to the rarity of individual subtypes. The diagnostic accuracy is lately reinforced due to the availability of immunohistochemical and molecular markers. Surgery is the central modality of treatment since many of them are insensitive to chemotherapy. With the availability of rational risk stratification system, efforts are in progress to evaluate the role of neoadjuvant chemotherapy and radiotherapy to improve outcomes especially for the locally advanced disease. The survival remains dismal for metastatic disease. This review highlights the current status of NRSTS and also describes the experience from a single centre in treatment of NRSTS.

Ethical analysis as a tool for addressing treatment controversies: radiotherapy timing in children with orbital rhabdomyosarcoma as a case example

PURPOSE

The treatment of orbital rhabdomyosarcoma is a topic of debate between North American and European clinicians, with the utility of radiation therapy as part of initial management in question. Despite differences in philosophy, the dominant North American approach of upfront radiation and the dominant European approach of radiation only in the event of recurrence yield a similar rate of overall survival. We sought to identify the ethical arguments for each approach.

METHODS

Established moral principles and appeals in contemporary medical ethics were utilized to identify the ethical arguments supporting each treatment approach. The potential for technologic advances to alter the analysis was considered.

RESULTS

Emphasizing the principle of beneficence, the North American approach seeks to reduce recurrence rates. In contrast, the European approach seeks to avoid radiation-induced sequelae, emphasizing the principle of nonmaleficence. Both approaches are based on well-established ethical principles, evidence, and clinical experience. Thus, both approaches currently appear to have legitimacy and should be included in the informed consent process. However, if treatment-related toxicity is reduced through improvements in radiation delivery, the North American approach could emerge as ethically superior.

CONCLUSIONS

Ethical analysis can aid in addressing challenges that arise when professional practices and perspectives differ in the management of cancer patients.

Preliminary results of a phase II trial of proton radiotherapy for pediatric rhabdomyosarcoma

PURPOSE

This prospective phase II study was designed to assess disease control and to describe acute and late adverse effects of treatment with proton radiotherapy in children with rhabdomyosarcoma (RMS).

PATIENTS AND METHODS

Fifty-seven patients with localized RMS (age 21 years or younger) or metastatic embryonal RMS (age 2 to 10 years) were enrolled between February 2005 and August 2012. All patients were treated with chemotherapy based on either vincristine, actinomycin, and cyclophosphamide or vincristine, actinomycin, and ifosfamide-based chemotherapy and proton radiation. Surgical resection was based on tumor site and accessibility. Common Terminology Criteria for Adverse Events, Version 3.0, was used to assess and grade adverse effects of treatment. Concurrent enrollment onto Children's Oncology Group or European Pediatric Sarcoma Study Group protocols was allowed. All pathology and imaging were reviewed at the treating institution.

RESULTS

Median follow-up was 47 months (range, 14 to 102 months) for survivors. Five-year event-free survival (EFS), overall survival (OS), and local control (LC) were 69%, 78%, and 81%, respectively, for the entire cohort. The 5-year LC by risk group was 93% for low-risk and 77% for intermediate-risk disease. There were 13 patients with grade 3 acute toxicity and three patients with grade 3 late toxicity. There were no acute or late toxicities higher than grade 3.

CONCLUSION

Five-year LC, EFS, and OS rates were similar to those observed in comparable trials that used photon radiation. Acute and late toxicity rates were favorable. Proton radiation appears to represent a safe and effective radiation modality for pediatric RMS.

Orbital tumors in USA: difference in survival patterns

INTRODUCTION

There is a wide range of tumors affecting the orbital adnexa. Key such tumors include lymphomas, carcinomas, melanomas and rhabdomyosarcomas. Several studies have proposed that these histological subtypes differ in their survival outcomes. In this study we aim to describe the difference in survival outcomes between such subtypes.

METHODS

The SEER database was used to gather patient information. All 18 SEER registries were used. Patients diagnosed from 1996 to 2005 were included in the analysis. Observed five-year survival rate was calculated using the SEER*Stat software version 8.1.2. Data were extracted into IBM SPSS version 20 to generate Kaplan Meier curve for each group.

RESULTS

There were 2180 patients in the SEER databases who met the selection criteria. Lymphomas were the most common histology in adults. The overall five-year observed survival for all lymphoma patients was 75.9% (95% CI: 73.7-78.1). There was statistically significant difference between observed survival rates of lymphoma subtypes. Carcinomas were the second most common tumors. Their five-year observed survival rate in our study was 60.4%. There was no statistically significant difference between carcinoma subtypes' observed survival rates in the 20-49 age group, while, in the older age group, the difference was found to be statistically significant. Rhabdomyosarcomas were the most common tumors in children. The overall five-year observed survival rate for rhabdomyosarcomas patients was 89.8%. There was no statistically significant difference between observed survival rates of rhabdomyosarcomas subtypes. There was no statistically significant difference between relative survival rates according to gender and treatment received except within melanomas.

CONCLUSION

In adults, lymphomas have better survival rates than carcinomas. Whereas the lymphoma subtype can be used as a determinant prognostic factor in any age, the carcinoma subtype can be used as such a determinant in older age groups only. In children, rhabdomyosarcomas are the predominant tumors affecting the orbital adnexa. Further studies are needed to determine if the difference between embryonal rhabdomyosarcoma and alveolar rhabdomyosarcoma observed survival rates are statistically significant.

Proton radiotherapy for pediatric sarcoma

Pediatric sarcomas represent a distinct group of pathologies, with approximately 900 new cases per year in the United States alone. Radiotherapy plays an integral role in the local control of these tumors, which often arise adjacent to critical structures and growing organs. The physical properties of proton beam radiotherapy provide a distinct advantage over standard photon radiation by eliminating excess dose deposited beyond the target volume, thereby reducing both the dose of radiation delivered to non-target structures as well as the total radiation dose delivered to a patient. Dosimetric studies comparing proton plans to IMRT and 3D conformal radiation have demonstrated the superiority of protons in numerous pediatric malignancies and data on long-term clinical outcomes and toxicity is emerging. In this article, we review the existing clinical and dosimetric data regarding the use of proton beam radiation in malignant bone and soft tissue sarcomas.

Orbital rhabdomyosarcomas: A review

Rhabdomyosarcoma (RMS) is a highly malignant tumor and is one of the few life-threatening diseases that present first to the ophthalmologist. It is the most common soft-tissue sarcoma of the head and neck in childhood with 10% of all cases occurring in the orbit. RMS has been reported from birth to the seventh decade, with the majority of cases presenting in early childhood. Survival has changed drastically over the years, from 30% in the 1960's to 90% presently, with the advent of new diagnostic and therapeutic modalities. The purpose of this review is to provide a general overview of primary orbital RMS derived from a literature search of material published over the last 10 years, as well as to present two representative cases of patients that have been managed at our institute.

Concurrent radiation with irinotecan and carboplatin in intermediate- and high-risk rhabdomyosarcoma: a report on toxicity and efficacy from a prospective pilot phase II study

BACKGROUND

Irinotecan is highly active against rhabdomyosarcoma (RMS), yet its tolerability and efficacy in combination with radiation is unknown. We examined local control and toxicities in RMS patients treated with radiotherapy (RT) in combination with radiosensitizing agents irinotecan + carboplatin (I + C).

PROCEDURE

From 11/2003 to 1/2011, 60 patients were enrolled on a pilot phase II protocol with newly diagnosed intermediate- or high-risk RMS at Memorial Sloan-Kettering Cancer Center. Induction therapy consisted of two cycles of I + C followed by three cycles of vincristine, doxorubicin, and cyclophosphamide. At week 13, 47 patients received definitive primary-site RT or post-operative RT with two concurrent cycles of I + C. Median RT dose was 50.4 Gy (range 30.6-50.4 Gy). Radiation-related toxicities were evaluated according to the Common Terminology Criteria for Adverse Events, version 3.0.

RESULTS

Median age of the cohort was 9 years. With median follow-up of 32 months, 2.5 year actuarial local control was 89%. Among all patients, grades 3 and 4 dermatitis were observed in 11% and 4%, respectively. Among parameningeal, orbit, and other head/neck sites, rates of grades 3 and 4 mucositis were 20% and 10%, respectively. Among abdomen/pelvis sites, 12% developed grade 3 diarrhea and 6% developed grade 3 cystitis. No treatment breaks were necessary.

CONCLUSIONS

Preliminary results of irinotecan and carboplatin administered with concurrent RT in intermediate- and high-risk RMS demonstrated favorable tolerability, efficacy, and local control. Reduced rates of acute grades 3-4 mucositis were observed when compared with historical results.

Parameningeal rhabdomyosarcoma: outcomes and opportunities

PURPOSE

To examine patterns of failure in patients with parameningeal rhabdomyosarcoma (PM-RMS) treated with intensity modulated radiation therapy (IMRT).

METHODS AND MATERIALS

Forty-seven patients with PM-RMS received chemotherapy and IMRT for definitive treatment. The median age was 9 years (range, 0.5-35 years). The high-risk features were as follows: 40% alveolar histology, 72% group III and 26% group IV disease, 57% either intracranial extension (ICE) (n=25) or cranial neuropathy (n=21). The median time to RT from the start of chemotherapy was 15 weeks (range, 2-54 weeks). Patients received 50.4 Gy in 1.8-Gy fractions to the primary tumor by use of IMRT. Thirteen patients aged≥14 years with alveolar histology received 36 Gy prophylactic nodal irradiation (PNI) to bilateral cervical nodes. Events were defined as local, regional (nodal), central nervous system (CNS), or distant failures.

RESULTS

With a median follow-up time of 3.3 years (range, 0.5-12.8 years), 18 patients experienced failure: 5 local, 2 regional, 6 distant, and 7 CNS. The 5-year local failure-free survival was 86%. Age, histology, and time to RT did not influence the risk of local failure. The 5-year regional failure-free survival was 92%: 100% for embryonal and 74% for alveolar (P=.03). However, there were no lymph node failures in patients with alveolar histology who were given PNI. The 5-year CNS failure-free survival was 83%: 100% without and 70% with ICE (P=.01); 95% without and 69% with cranial neuropathy (P=.02). The estimated 5-year event-free survival and overall survival were 61% for group III and 58% for group IV patients.

CONCLUSIONS

Distant failure was the most common type of failure among group IV patients. Patients with alveolar histology seem to benefit from PNI. The presence of ICE or cranial neuropathy portends a high risk of CNS failure, the most common pattern of failure among non-group IV patients. These patients may benefit from the addition of novel CNS-directed therapy.

Radiotherapy for rhabdomyosarcoma: indications and outcome

Rhabdomyosarcoma is the most common soft tissue sarcoma of childhood. Improvements in the clinical outcomes of rhabdomyosarcoma have been secondary to the intensification and refinement of treatment investigated by the Intergroup Rhabdomyosarcoma Study Group. Advances in diagnostic imaging techniques have led to improvements in staging and contribute to precision in radiation field design. Radiation treatment has been integrated into the primary treatment of most patients with rhabdomyosarcoma. Each treatment site has special considerations with regards to prognosis, outcomes and potential morbidities that affect the choice of local therapy. Advanced radiotherapy techniques using conformal treatment with intensity-modulated radiotherapy and proton therapy are particularly advantageous for the treatment of sites close to critical structures, such as the head and neck and genitourinary system. Active investigation is underway to develop strategies to reduce the radiation dose and volume in an effort to minimise late toxicity and improve the therapeutic ratio.

Cardiac-sparing whole lung IMRT in children with lung metastasis

PURPOSE

To demonstrate the dosimetric advantages of cardiac-sparing (CS) intensity modulated radiation therapy (IMRT) in children undergoing whole lung irradiation (WLI).

METHODS AND MATERIALS

Chest CT scans of 22 children who underwent simulation with 3-dimensional (n=10) or 4-dimensional (n=12) techniques were used for this study. Treatment planning was performed using standard anteroposterior-posteroanterior (S-RT) technique and CS-IMRT. Left and right flank fields were added to WLI fields to determine whether CS-IMRT offered any added protection to normal tissues at the junction between these fields. The radiation dose to the lung PTV, cardiac structures, liver, and thyroid were analyzed and compared.

RESULTS

CS-IMRT had 4 significant advantages over S-RT: (1) superior cardiac protection (2) superior 4-dimensional lung planning target volume coverage, (3) superior dose uniformity in the lungs with fewer hot spots, and (4) significantly lower dose to the heart when flank RT is administered after WLI.

CONCLUSIONS

The use of CS-IMRT and 4-dimensional treatment planning has the potential to improve tumor control rates and reduce cardiac toxicity in children receiving WLI.

Advantages of whole-liver intensity modulated radiation therapy in children with Wilms tumor and liver metastasis

PURPOSE

To demonstrate the dosimetric advantages of intensity modulated radiation therapy (IMRT) in children with Wilms tumor (WT) undergoing whole-liver (WL) RT.

METHODS AND MATERIALS

Computed tomography simulation scans of 10 children, either 3 (3D) or 4-dimensional (4D), were used for this study. The WL PTV was determined by the 3D or 4D liver volumes, with a margin of 1 cm. A total of 40 WL RT plans were performed: 10 each for left- and right-sided WT with IMRT and anteroposterior-posteroanterior (AP-PA) techniques. The radiation dose-volume coverage of the WL planning target volume (PTV), remaining kidney, and other organs were analyzed and compared.

RESULTS

The 95% dose coverage to WL PTV for left and right WT were as follows: 97% ± 4% (IMRT), 83% ± 8% (AP-PA) (P<.01) and 99% ± 1% (IMRT), 94% ± 5% (AP-PA) (P<.01), respectively. When 3D WL PTV was used for RT planning, the AP-PA technique delivered 95% of dose to only 78% ± 13% and 88% ± 8% of 4D liver volume. For left WT, the right kidney V15 and V10 for IMRT were 29% ± 7% and 55% ± 8%, compared with 61% ± 29% (P<.01) and 78% ± 25% (P<.01) with AP-PA. For right WT, the left kidney V15 and V10 were 0 ± 0 and 2% ± 3% for IMRT, compared with 25% ± 19% (P<.01) and 40% ± 31% (P<.01) for AP-PA.

CONCLUSIONS

The use of IMRT and 4D treatment planning resulted in the delivery of a higher RT dose to the liver compared with the standard AP-PA technique. Whole-liver IMRT also delivered a significantly lower dose to the remaining kidney.

Intensity modulated radiation therapy with dose painting to treat rhabdomyosarcoma

PURPOSE

To examine local control and patterns of failure in rhabdomyosarcoma patients treated with intensity modulated radiation therapy (RT) with dose painting (DP-IMRT).

PATIENTS AND METHODS

A total of 41 patients underwent DP-IMRT with chemotherapy for definitive treatment. Nineteen also underwent surgery with or without intraoperative RT. Fifty-six percent had alveolar histologic features. The median interval from beginning chemotherapy to RT was 17 weeks (range, 4-25). Very young children who underwent second-look procedures with or without intraoperative RT received reduced doses of 24-36 Gy in 1.4-1.8-Gy fractions. Young adults received 50.4 Gy to the primary tumor and lower doses of 36 Gy in 1.8-Gy fractions to at-risk lymph node chains.

RESULTS

With 22 months of median follow-up, the actuarial local control rate was 90%. Patients aged ≤7 years who received reduced overall and fractional doses had 100% local control, and young adults had 79% (P=.07) local control. Three local failures were identified in young adults whose primary target volumes had received 50.4 Gy in 1.8-Gy fractions.

CONCLUSIONS

DP-IMRT with lower fractional and cumulative doses is feasible for very young children after second-look procedures with or without intraoperative RT. DP-IMRT is also feasible in adolescents and young adults with aggressive disease who would benefit from prophylactic RT to high-risk lymph node chains, although dose escalation might be warranted for improved local control. With limited follow-up, it appears that DP-IMRT produces local control rates comparable to those of sequential IMRT in patients with rhabdomyosarcoma.

Helical tomotherapy in the treatment of pediatric malignancies: a preliminary report of feasibility and acute toxicity

Background

Radiation therapy plays a central role in the management of many childhood malignancies and Helical Tomotherapy (HT) provides potential to decrease toxicity by limiting the radiation dose to normal structures. The aim of this article was to report preliminary results of our clinical experience with HT in pediatric malignancies.

Methods

In this study 66 consecutive patients younger than 14 years old, treated with HT at our center between January 2006 and April 2010, have been included. We performed statistical analyses to assess the relationship between acute toxicity, graded according to the RTOG criteria, and several clinical and treatment characteristics such as a dose and irradiation volume.

Results

The median age of patients was 5 years. The most common tumor sites were: central nervous system (57%), abdomen (17%) and thorax (6%). The most prevalent histological types were: medulloblastoma (16 patients), neuroblastoma (9 patients) and rhabdomyosarcoma (7 patients). A total of 52 patients were treated for primary disease and 14 patients were treated for recurrent tumors. The majority of the patients (72%) were previously treated with chemotherapy. The median prescribed dose was 51 Gy (range 10-70 Gy). In 81% of cases grade 1 or 2 acute toxicity was observed. There were 11 cases (16,6%) of grade 3 hematological toxicity, two cases of grade 3 skin toxicity and one case of grade 3 emesis. Nine patients (13,6%) had grade 4 hematological toxicity. There were no cases of grade 4 non-hematological toxicities. On the univariate analysis, total dose and craniospinal irradiation (24 cases) were significantly associated with severe toxicity (grade 3 or more), whereas age and chemotherapy were not. On the multivariate analysis, craniospinal irradiation was the only significant independent risk factor for grade 3-4 toxicity.

Conclusion

HT in pediatric population is feasible and safe treatment modality. It is characterized by an acceptable level of acute toxicity that we have seen in this highly selected pediatric patient cohort with clinical features of poor prognosis and/or aggressive therapy needed. Despite of a dosimetrical advantage of HT technique, an exhaustive analysis of long-term follow-up data is needed to assess late toxicity, especially in this potentially sensitive to radiation population.

Effect of radiotherapy techniques (IMRT vs. 3D-CRT) on outcome in patients with intermediate-risk rhabdomyosarcoma enrolled in COG D9803--a report from the Children's Oncology Group

PURPOSE

To compare the dosimetric parameters of intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3D-CRT) in patients with intermediate-risk rhabdomyosarcoma and to analyze their effect on locoregional control and failure-free survival (FFS).

METHODS AND MATERIALS

The study population consisted of 375 patients enrolled in the Children's Oncology Group protocol D9803 study, receiving IMRT or 3D-CRT. Dosimetric data were collected from 179 patients with an available composite plan. The chi-square test or Fisher's exact test was used to compare the patient characteristics and radiotherapy parameters between the two groups. The interval-to-event outcomes were estimated using the Kaplan-Meier method and compared using log-rank tests. Cox proportional hazards regression analysis was used to examine the effect of the treatment technique on FFS after adjusting for primary site and risk group.

RESULTS

The median follow-up time was 5.7 and 4.2 years for patients receiving 3D-CRT and IMRT, respectively. No differences in the 5-year failure of locoregional control (18% vs. 15%) or FFS (72% vs. 76%) rates were noted between the two groups. Multivariate analysis revealed no association between the two techniques and FFS. Patients with primary tumors in parameningeal sites were more likely to receive IMRT than 3D-CRT. IMRT became more common during the later years of the study. Patients receiving IMRT were more likely to receive >50 Gy, photon energy of ≤6 MV, and >5 radiation fields than those who received 3D-CRT. The coverage of the IMRT planning target volume by the prescription dose was improved compared with the coverage using 3D-CRT with similar target dose heterogeneity.

CONCLUSIONS

IMRT improved the target dose coverage compared with 3D-CRT, although an improvement in locoregional control or FFS could not be demonstrated in this population. Future studies comparing the integral dose to nontarget tissue and late radiation toxicity between the two groups are warranted.

Proton radiotherapy for parameningeal rhabdomyosarcoma: clinical outcomes and late effects

PURPOSE

To report the clinical outcome and late side effect profile of proton radiotherapy in the treatment of children with parameningeal rhabdomyosarcoma (PM-RMS).

METHODS AND MATERIALS

Seventeen consecutive children with PM-RMS were treated with proton radiotherapy at Massachusetts General Hospital between 1996 and 2005. We reviewed the medical records of all patients and asked referring physicians to report specific side effects of interest.

RESULTS

Median patient age at diagnosis was 3.4 years (range, 0.4-17.6). Embryonal (n = 11), alveolar (n = 4), and undifferentiated (n = 2) histologies were represented. Ten patients (59%) had intracranial extension. Median prescribed dose was 50.4 cobalt gray equivalents (GyRBE) (range, 50.4-56.0 GyRBE) delivered in 1.8-2.0-GyRBE daily fractions. Median follow-up was 5.0 years for survivors. The 5-year failure-free survival estimate was 59% (95% confidence interval, 33-79%), and overall survival estimate was 64% (95% confidence interval, 37-82%). Among the 7 patients who failed, sites of first recurrence were local only (n = 2), regional only (n = 2), distant only (n = 2), and local and distant (n = 1). Late effects related to proton radiotherapy in the 10 recurrence-free patients (median follow-up, 5 years) include failure to maintain height velocity (n = 3), endocrinopathies (n = 2), mild facial hypoplasia (n = 7), failure of permanent tooth eruption (n = 3), dental caries (n = 5), and chronic nasal/sinus congestion (n = 2).

CONCLUSIONS

Proton radiotherapy for patients with PM-RMS yields tumor control and survival comparable to that in historical controls with similar poor prognostic factors. Furthermore, rates of late effects from proton radiotherapy compare favorably to published reports of photon-treated cohorts.

Sarcomas across the age spectrum

In most cancers, the age of the affected patient has a significant influence on how that cancer is approached. This is less often the case in sarcomas in that both children and adults are treated similarly. However, different types of sarcomas are most typical in these populations, and our understanding of these cancers in one group has provided direction for understanding them in the other group. For example, advances at the molecular level in Ewing sarcoma, a disease that affects predominantly children, helped spearhead the uncovering of several signature translocations in adult sarcomas, such as synovial sarcoma and myxoid liposarcomas. The success of chemotherapy in pediatric sarcomas continues to be a benchmark for adult sarcomas to emulate. Conversely, the demonstration of the viability of limb-sparing surgery combined with adjuvant radiation in adult extremity sarcomas helped advance that treatment approach in pediatric sarcomas. To illustrate some of these concepts and to enhance our understanding of sarcomas across the age spectrum, 4 types of sarcoma are discussed. The first 2 are Ewing sarcoma and rhabdomyosarcoma seen mainly, but not exclusively, in children. The other 2 are synovial sarcoma, which can be looked at as a bridge between pediatric and adult sarcomas as it affects mainly young adults, and liposarcoma that is almost exclusively an adult sarcoma.

Intensity modulated radiotherapy (IMRT) in the treatment of children and adolescents--a single institution's experience and a review of the literature

Background

While IMRT is widely used in treating complex oncological cases in adults, it is not commonly used in pediatric radiation oncology for a variety of reasons. This report evaluates our 9 year experience using stereotactic-guided, inverse planned intensity-modulated radiotherapy (IMRT) in children and adolescents in the context of the current literature.

Methods

Between 1999 and 2008 thirty-one children and adolescents with a mean age of 14.2 years (1.5 - 20.5) were treated with IMRT in our department. This heterogeneous group of patients consisted of 20 different tumor entities, with Ewing's sarcoma being the largest (5 patients), followed by juvenile nasopharyngeal fibroma, esthesioneuroblastoma and rhabdomyosarcoma (3 patients each). In addition a review of the available literature reporting on technology, quality, toxicity, outcome and concerns of IMRT was performed.

Results

With IMRT individualized dose distributions and excellent sparing of organs at risk were obtained in the most challenging cases. This was achieved at the cost of an increased volume of normal tissue receiving low radiation doses. Local control was achieved in 21 patients. 5 patients died due to progressive distant metastases. No severe acute or chronic toxicity was observed.

Conclusion

IMRT in the treatment of children and adolescents is feasible and was applied safely within the last 9 years at our institution. Several reports in literature show the excellent possibilities of IMRT in selective sparing of organs at risk and achieving local control. In selected cases the quality of IMRT plans increases the therapeutic ratio and outweighs the risk of potentially increased rates of secondary malignancies by the augmented low dose exposure.

Intensity-modulated radiation therapy for orbital lymphoma

PURPOSE

Orbital manifestations of non-Hodgkin's lymphoma (NHL) are rare and accounts for only 1% of all cases of NHL. There have been no reports of treating orbital lymphoma using intensity-modulated radiotherapy (IMRT).

MATERIALS AND METHODS

Four patients were treated at our institution for orbital lymphoma using IMRT. Radiotherapy (RT) plans using wedged pair fields were developed for comparison. Clinical results using IMRT are presented and a dosimetric analysis between IMRT and RT was performed.

RESULTS

All patients had a complete response based on their physical examinations and post-IMRT imaging. Symptoms that had been present at initial presentation resolved in all patients during the course of the treatment. All four patients experienced only grade 1 dry eye syndrome and keratitis. The average dose to the contralateral orbit, lacrimal gland, and lens were all significantly reduced (P < 0.01) in IMRT patients as compared to the RT patients. IMRT reduced the V5 and V10 for the contralateral lens, orbit, and lacrimal gland and the optic chiasm (P < 0.05).

CONCLUSION

IMRT is feasible when treating orbital lymphoma and reduces dose to critical structures while providing excellent dose coverage of target volumes. IMRT offers patients with orbital lymphoma excellent clinical outcomes, similar to conventional RT, with no increased toxicity.