Dosimetric and radiobiologic comparison of 3D conformal, IMRT, VMAT and proton therapy for the treatment of early-stage glottic cancer.

BACKGROUND: This study aims to compare dosimetrically and radiobiologically 3D conformal, intensity modulated radiation therapy (IMRT), RapidArc (RA) volumetric modulated arc therapy and proton therapy techniques for early-stage glottic cancer. METHODS: Ten patients were retrospectively selected. Photon treatment planning was performed using Eclipse External Beam Planning, and proton planning was performed using CMS Xio. The minimum, mean and maximum dose values for planning target volume (PTV), mean and maximum dose values for organ at risk, % of volume of PTV receiving at least 95% of the prescription dose, and D20, D50 and D90 of carotid arteries were compared. Biological response models of tumour control probabilities and normal tissue complication probabilities were calculated. RESULTS: IMRT, RA and proton plans versus three-dimensional conformal radiotherapy (3D-CRT) plans consistently provided superior PTV coverage and decreased mean dose to the thyroid and carotid arteries. CONCLUSION: All these three modalities showed superiority with less variation among themselves compared with 3D-CRT plans. Clinical investigation is warranted to determine if these treatment approaches will translate into a reduction in radiation therapy-induced toxicities.

The efficacy of radiation therapy in the treatment of Graves' orbitopathy.

PURPOSE: To review our institutional outcomes of patients treated with radiation therapy (RT) for Graves' orbitopathy (GO), assess the role of orbital reirradiation, and identify prognostic factors of complete response (CR). METHODS AND MATERIALS: This is a retrospective review of 211 patients who presented with a diagnosis of GO and received RT between January 2000-2010. RT dose was 20 Gy in 10 fractions. Patient median age was 51 years (range, 15-84 years), median follow-up was 11 months (range, 1-88 months). Patient symptoms included any combination of proptosis (90.9%), extraocular muscle dysfunction (78.9%), soft tissue signs (68.4%), and diplopia (58.4%). Corticosteroids were used as first-line therapy in 20.6% of patients. Among those who achieved either CR or partial response (PR), prognostic factors were evaluated. RESULTS: Stabilization of disease without recurrence was clinically achieved overall in 202 patients (96.7%). At the completion of RT, 176 patients (84.2%) reported a symptomatic improvement of pretreatment symptoms. CR of GO symptoms was achieved using multiple treatment modalities, including RT by 93 patients (44.5%), of which 32 patients received RT only. Corticosteroids were discontinued in 97.8% of patients who received them as initial therapy. Surgical intervention following radiotherapy was required for 144 (68.9%) of all patients. Fourteen patients received orbital reirradiation for persistent or recurrent symptoms. Five of these achieved a CR, and the other nine achieved disease stabilization but retained persistent ocular symptoms. Long-term side effects of RT included dry eyes (12%). Of the prognostic factors we investigated, only gender predicted CR, which was less common in men (33.9%) than in women (49.7%) p = 0.0471. CONCLUSIONS: Orbital radiation for GO is an established treatment modality for patients. Orbital reirradiation is beneficial for patients who do not respond to initial RT or experience symptom recurrence without an apparent risk of increased morbidity.

Developing a national radiation oncology registry: From acorns to oaks.

PURPOSE: The National Radiation Oncology Registry (NROR) is a collaborative initiative of the Radiation Oncology Institute and the American Society of Radiation Oncology, with input and guidance from other major stakeholders in oncology. The overarching mission of the NROR is to improve the care of cancer patients by capturing reliable information on treatment delivery and health outcomes. METHODS: The NROR will collect patient-specific radiotherapy data electronically to allow for rapid comparison of the many competing treatment modalities and account for effectiveness, outcome, utilization, quality, safety, and cost. It will provide benchmark data and quality improvement tools for individual practitioners. The NROR steering committee has determined that prostate cancer provides an appropriate model to test the concept and the data capturing software in a limited number of sites. The NROR pilot project will begin with this disease-gathering treatment and outcomes data from a limited number of treatment sites across the range of practice; once feasibility is proven, it will scale up to more sites and diseases. RESULTS: When the NROR is fully implemented, all radiotherapy facilities, along with their radiation oncologists, will be solicited to participate in it. With the broader participation of the radiation oncology community, NROR has the potential to serve as a resource for determining national patterns of care, gaps in treatment quality, comparative effectiveness, and hypothesis generation to identify new linkages between therapeutic processes and outcomes. CONCLUSIONS: The NROR will benefit radiation oncologists and other care providers, payors, vendors, policy-makers, and, most importantly, cancer patients by capturing reliable information on population-based radiation treatment delivery.

The role of radiotherapy for T4 non-melanoma skin carcinoma.

INTRODUCTION: To review outcomes of patients treated with radiotherapy (RT) for T4 non-melanoma skin cancer (NMSC). METHODS: A retrospective chart review was performed of 21 patients who received RT for T4 NMSC from 2004 to 2010. Outcomes of treatment efficacy, RT technique and patient morbidity were analysed. Twelve patients (57.1%) were treated definitively without prior treatment, five (23.8%) were recurrent lesions and four (19.1%) were treated postoperatively. Ten patients (47.6%) had evidence of bony erosion at presentation, and four (19.1%) had nodal disease. Intensity-modulated radiotherapy (IMRT), three-dimensional conformal RT and electron treatment were included RT techniques. RESULTS: Median follow-up was 12 months (range, 5-48 months). Twelve patients (57.1%) following RT required no further treatment and had no disease recurrence. Three patients (14.3%) required salvage treatment and are disease-free following all treatment. Tumours treated initially or postoperatively had improved control rates following RT compared with recurrent lesions (58.3% and 100% vs. 20%). Sixty percent of patients treated with IMRT achieved local control following RT, and 80% were disease-free following surgical salvage treatment. Squamous cell carcinoma (SCC) histology, presence of bony erosion and/or nodal disease was associated with a higher incidence of disease recurrence. CONCLUSIONS: Patients presenting with untreated lesions, smaller tumour volumes (<70 cm(3)) postoperatively, basal cell histology and absence of bone erosion or nodal disease have improved local control and outcomes. Basal cell carcinoma and SCC should be staged and treated as two separate disease entities. The use of IMRT for advanced skin cancer warrants further investigation.

Linear accelerator based intracranial and extracranial stereotactic radiation therapy at the University of Oklahoma.

PURPOSE: Review our institutional outcomes with linear accelerator based stereotactic radiation therapy at the University of Oklahoma. METHODS: We retrospectively reviewed all patients treated in our department with linear accelerator based stereotactic radiation therapy since we implemented this modality in 2008. Thirty-seven patients have been treated with a mean follow-up of 8.3 months. Seventeen patients had tumors near critical structures; ten had treatment sites not suited for gamma knife therapy. Outcomes are reviewed for efficacy and toxicity. RESULTS: Acute and long term complications reported are minimal. Stabilization of treatment sites was achieved in 96% of patients on follow-up imaging. Thirteen patients (35%) have died, of which eleven died to systemic disease progression outside of the treatment site. No treatment related deaths occurred. CONCLUSIONS: Stereotactic radiation therapy is a successful treatment modality to achieve local disease control with minimal toxicity. We plan to expand its use and applications in the future.

The efficacy of radiotherapy in the treatment of orbital pseudotumor.

PURPOSE: To review institutional outcomes for patients treated with external-beam radiotherapy (EBRT) for orbital pseudotumor. METHODS AND MATERIALS: This is a single-institution retrospective review of 20 orbits in 16 patients diagnosed with orbital pseudotumor that received EBRT at the University of Oklahoma, Department of Radiation Oncology. Treated patients had a median follow-up of 16.5 months. RESULTS: Fifteen patients (93.7%) were initially treated with corticosteroids. Eight had recurrence after steroid cessation, six were unable to taper corticosteroids completely or partially, and one experienced progression of symptoms despite corticosteroid therapy. Fourteen patients (87.5%) initially responded to radiotherapy indicated by clinical improvement of preradiation symptoms and/or tapering of corticosteroid dose. Mean EBRT dose was 20 Gy (range, 14-30 Gy). Thirteen patients (81.2%) continued to improve after radiation therapy. Patient outcomes were complete cessation of corticosteroid therapy in nine patients (56.3%) and reduced corticosteroid dose in four patients (25%). Radiotherapy did not achieve long-term control for three patients (18.7%), who still required preradiation corticosteroid dosages. Three patients received retreatment(s) of four orbits, of which two patients achieved long-term symptom control without corticosteroid dependence. One patient received retreatment to an orbit three times, achieving long-term control without corticosteroid dependence. No significant late effects have been observed in retreated patients. CONCLUSIONS: Radiotherapy is an effective treatment for acute symptomatic improvement and long-term control of orbital pseudotumor. Orbital retreatment can be of clinical benefit, without apparent increase in morbidity, when initial irradiation fails to achieve complete response.

Radiotherapy in treatment of carcinoma of the parotid gland, an approach for the medically or technically inoperable patient.

INTRODUCTION: Initial surgical resection is considered the standard of care for patients diagnosed with tumours involving the salivary glands. We reviewed our institutional outcomes of patients treated with initial radiation therapy (RT) for diagnosed carcinoma of the parotid gland. METHODS: This review examined seventeen patients that received RT as initial therapy for tumours involving the parotid gland. Fifteen patients had primary salivary gland cancer, and two patients had metastatic carcinoma to the parotid gland. Sixteen patients (94.1%) following surgical evaluation had operative risk of facial nerve impairment or sacrifice with initial surgery, four (23.5%) had clinical objective evidence of nerve involvement at evaluation, five (29.4%) were poor surgical candidates and three (17.6%) refused initial surgery. Primary tumour stages ranged T2-T4b, and disease stages ranged II-IVb. RT median dose was 70 Gy, and median follow-up was 12 months. RESULTS: Eleven patients (64.7%) achieved a clinical complete response (CR) to therapy. Of these CR patients eight (72.7%) received definitive RT and three (27.3%) underwent surgery following RT. Two surgical patients avoided facial nerve impairment while one required nerve sacrifice. The other six patients (35.3%) achieved an unfavourable response to RT and had unresectable or metastatic disease at follow-up. No long-term complications were reported. CONCLUSION: Initial radiation therapy for tumours involving the parotid gland is effective to achieve clinical CR, eliminate surgical resection for many patients, and decrease risk of facial nerve impairment or sacrifice for those patients requiring surgery following RT.

Quantitative evaluation of increase in surface dose by immobilization thermoplastic masks and superficial dosimetry using Gafchromic EBT film and Monte Carlo calculations.

PURPOSE: To investigate the increase in surface dose under immobilization thermoplastic masks by measurements and calculation in the build-up region using Gafchromic films and Monte Carlo simulation. MATERIALS AND METHODS: Surface doses were measured underneath three thermoplastic masks in open fields using 6 and 18 MV photon beams. These masks are used to immobilize patients for head and neck (H&N), pelvis and thoracic treatment. Gafchromic EBT films were placed on the top of the flat surface of a phantom partially underneath the mask and exposed in open 10 x 10 cm2 photon fields. The depth doses were calculated using BEAMnrc Monte Carlo code for water-equivalent film detectors with different layers of thickness ranging from 50 microm to 2.5 mm and compared with film measurements. RESULTS: Surface dose increased by a factor of 3 to 4 underneath the mask relative to the open areas and 6 MV beam delivers more skin dose than 18 MV. H&N mask increased surface dose by a factor of 3 using 18 MV and a factor of 4 using 6 MV. In addition, increase in surface dose depended on the type of the mask, the size of openings, and the amount of stretching performed during the mask preparation. The measured depth doses were compared with BEAMnrc Monte Carlo calculation for water-equivalent detectors using different sizes. The calculated depth dose depended significantly on the thickness of film detector and varies by more than 15% using layer thickness of 2.5 mm compared to 50 microm. Surface doses measured by Gafchromic EBT films agreed within 3% with the Monte Carlo calculations using a small detector layer of 50 microm. CONCLUSION: Thermoplastic masks used for patient immobilization can significantly increase skin doses by up to a factor of 4 more than that without the mask using 6 MV beams. The skin reactions resulting from thermoplastic masks should be monitored and corrective measures should be taken during treatment such as partially removing the mask over skin areas with complications and optimizing the skin dose in IMRT planning. Gafchromic EBT films provide accurate skin dosimetry which agrees within 3% with Monte Carlo calculations. Gafchromic EBT film makes an excellent tool for measuring depth doses in the buildup region and these data can be applied for treatment planning calculations and IMRT optimization.

Using an advanced radiation therapy technique for T4 squamous cell carcinoma of the face.

BACKGROUND: Patients with locally advanced skin cancer often present an uncommon and unique treatment challenge. Surgical resection and reconstruction with an acceptable cosmetic outcome is difficult for larger lesions with deep infiltration into subcutaneous tissues. Radiation therapy has been shown to be an effective treatment modality for advanced non-melanoma skin cancers, with cure rates ranging 50-100%. In this case report, we discuss the efficacy and outcome of treatment using an advanced radiation therapy technique to a large T4 squamous cell carcinoma of the face. MAIN OBSERVATIONS: The patient responded favorably to the advanced radiation treatment course, and achieved a clinical complete response to therapy. No further intervention was required. Advanced radiation therapy techniques offered treatment advantages that resulted in greater tumor dose escalation and minimizing of patient morbidity. CONCLUSIONS: Patients with advanced skin cancers of the head and neck should be considered for definitive radiation therapy using advanced treatment techniques. The use of definitive RT only for tumors deemed unresectable, or for inoperable patients at presentation deserves reconsideration. Further investigation is warranted.

Treatment of base of tongue cancer with paclitaxel, ifosfamide, and cisplatinum induction chemotherapy followed by chemoradiotherapy.

OBJECTIVES/HYPOTHESIS: To assess the efficacy of paclitaxel, ifosfamide, and cisplatinum induction chemotherapy plus concurrent chemoradiation in the treatment of stage III and IV base of tongue cancer. STUDY DESIGN: Subgroup analysis of patients with base of tongue cancer enrolled in a single-institution prospective phase II trial, evaluating an organ-preservation approach in the treatment of locally advanced head and neck cancer. METHODS: Eighteen patients with tumors ranging from stage T2-T4, any N, or M0 were treated with a protocol of induction chemotherapy, with Taxol, ifosfamide, cisplatin every 21 days for up to three cycles. If the primary tumor exhibited a complete or partial response, patients were treated with radiation and weekly taxol and carboplatin for 7 weeks. Surgery was used for those with less than partial response or disease progression. Neck dissection was performed in cases with clinical or radiological evidence of persistent disease in the neck 6 to 8 weeks after completion of treatment. RESULTS: Sixteen patients were male and two were female; the average age was 55 years (range, 43-65). Fifteen patients had stage IV disease and three had stage III disease. Of the 18 patients initially enrolled, 17 patients had a complete response. All 17 patients had no evidence of loco-regional disease at a median follow-up of 29.6 months. Only 1 of them developed distant metastases 30 months after completion of treatment. Three patients required permanent percutaneous endoscopic gastrostomy tubes because of severe dysphagia associated with concurrent chemoradiation. CONCLUSIONS: The treatment regimen studied is remarkably effective in stage III and IV base of tongue cancer with 100% of patients completing the protocol alive to date. Although some patients required persistent percutaneous endoscopic gastrostomy use, no patient experienced significant enough toxicity during the protocol to delay or withdraw from treatment.