Modulated Radiation Therapy Treatment Research Articles

Measurement and Comparison of Surface Dose outside Treatment Area for Different Radiation Treatment Modalities in Breast Cancer Patients Using Thermoluminescence Dosimeters

Purpose: We propose a new intra-uterine tandem design that are capable of creating non-isotropic 192-Ir dose distributions and give unprecedented dose conformality for treatment of cervical cancer. Materials and Methods: The MRI-compatible DMBT tandem design has 6 peripheral holes of 1mm diameter, on a non-magnetic tungsten-alloy rod (18.0 g/cc), enclosed in a polyoxymethylene tube (1.41 g/cc), with a total diameter of 6mm. The tungsten-alloy shield has a diameter of 5mm and the grooves are evenly distributed (60 ) on the surface of tungsten-alloy shield. A VariSource iX HDR source was used for delivering radiation dose. MCNPX Monte Carlo was used to simulate the resulting nonisotropic dose distributions. An in-house developed HDR brachytherapy planning platform, with intensity modulated planning capability using Simulated Annealing and Constrained-Gradient Optimization algorithms, was used to re-plan 75 plans (5 fractions (fx) of 15 patient cases) treated with a conventional tandem & ovoids (T&O) applicator. For the proposed tandem designs, the plans were optimized with the same ovoids in place, as the conventional T&O plans. All DMBT plans were normalized to match the HRCTV V100 coverage of the original T&O plans. Results: Generally, the plan qualities were markedly better using DMBT. Mean 2cc doses to the bladder were 4.0 0.2Gy and 3.37 0.19Gy, for T&O and DMBT, respectively. For the rectum, they were 2.30 0.17Gy and 1.82 0.1Gy. For the sigmoid, they were 1.58 0.19Gy and 1.48 0.17Gy. The best single plan reduction was in the bladder dose, 0.32Gy (40.8%), and this was due to the horseshoe-like wrapping of the bladder around the CTV, thus benefitting the most with the dose conformation enhancements achieved by the proposed designs. The best sigmoid improvement, 0.13Gy (27.5%), was shown for endophytic growth type cervical cancer. The HRCTV dose heterogeneity index (DHI) was 2.56 0.24 and 2.36 0.22 for T&O and DMBT, respectively. Conclusions: We have shown the new tandem designs that advance the conformality of image-guided cervix HDR, in congruence with the current trend of 3D image based planning to maximize the therapeutic ratio.

Stereotactic Radiosurgery/Radiotherapy: A Historical Review

is an exact radiotherapy treatment modality which implements invasive and non-invasive facilities for improving precise dose delivery. Stereotactic refers to three-dimensi onal localization of a specific point in space by a unique set of coordinates that relate to a fixed external reference frame. An accurate delivery of radiation is attainable using these techniques with high precision (1-2 mm) which leads to dose reduction in critical organs and adjacent normal tissues while delivering the highest dose to tumoral tissue. Stereotactic irradiation consists of two techniques of delivery: Stereotactic RadioSurgery (SRS) which is an accurate single fractionated delivery of radiation to intracranial lesions and is attained by converging series of radiation beams on a target from various angles. Stereotactic Radiotherapy (SRT) which is a fractionated irradiation of intra and extra cranial lesions. This review article intends to highlight the radiobiological and physical aspects of these techniques and also introduces three commercially available stereotactic machines systematically and functionally.

Endoscopic Surgery of Nasopharyngeal Angiofibroma

Introduction: Juvenile nasopharyngeal angiofibroma (NAJ) is a tumor with vascular component, slow growing, benign but very aggressive because of its local invasiveness. The NAJ is rare, accounting for 0.05% of all head and neck cancers. The classic triad of epistaxis, unilateral nasal obstruction and a mass in the nasopharynx suggests the diagnosis of NAJ and is then supplemented by imaging. Over the past 10 years the treatment of this disease has been discussed with the aim of designing a management protocol. Currently, surgery appears to be the best treatment of the NAJ. Other methods such as hormone therapy, radiotherapy and chemotherapy treatment modalities are now used occasionally as complementary treatments. Objective: To present the cases of this disease in the Hospital Infantil between October 2007 and August 2008. Methods: A retrospective case study of five cases of NAJ underwent surgery solely with endoscopic technique of two surgeons. Classifieds between IIA and IIIA. All patients underwent angiography with embolization of the tumor 3-4 days before surgery. Follow-up after surgery to detect recurrence. Results: There were two relapses in the following two years after surgery. Conclusion: Given the short period of patient follow-up, there were only two relapses in one year. So there is need for further action to claim that this technique has a low recurrence rate, since the recurrence is probably related to incomplete resection the initial tumor.

OC-0581: Dosimetry of 100 ñ 250 MeV Very High Energy Electrons (VHEE) as a new treatment modality for radiotherapy

OC-0581: Dosimetry of 100 ñ 250 MeV Very High Energy Electrons (VHEE) as a new treatment modality for radiotherapy

Clinical implementation of a new electronic brachytherapy system for skin brachytherapy.

Although surgery is usually the first-line treatment for nonmelanoma skin cancers, radiotherapy (RT) may be indicated in selected cases. Radiation therapy as primary therapy can result in excellent control rates, cosmetics, and quality of life. Brachytherapy is a radiation treatment modality that offers the most conformal option to patients. A new modality for skin brachytherapy is electronic brachytherapy. This involves the placement of a high dose rate X-ray source directly in a skin applicator close to the skin surface, and therefore combines the benefits of brachytherapy with those of low energy X-ray radiotherapy. The Esteya electronic brachytherapy system is specifically designed for skin surface brachytherapy procedures. The purpose of this manuscript is to describe the clinical implementation of the new Esteya electronic brachytherapy system, which may provide guidance for users of this system. The information covered includes patient selection, treatment planning (depth evaluation and margin determination), patient marking, and setup. The justification for the hypofractionated regimen is described and compared with others protocols in the literature. Quality assurance (QA) aspects including daily testing are also included. We emphasize that these are guidelines, and clinical judgment and experience must always prevail in the care of patients, as with any medical treatment. We conclude that clinical implementation of the Esteya brachytherapy system is simple for patients and providers, and should allow for precise and safe treatment of nonmelanoma skin cancers.

A dosimetric comparison of 3D-CRT, IMRT, and static tomotherapy with an SIB for large and small breast volumes

Radiation therapy to the breast is a complex task, with many different techniques that can be employed to ensure adequate dose target coverage while minimizing doses to the organs at risk. This study compares the dose planning outcomes of 3 radiation treatment modalities, 3 dimensional conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), and static tomotherapy, for left-sided whole-breast radiation treatment with a simultaneous integrated boost (SIB). Overall, 20 patients with left-sided breast cancer were separated into 2 cohorts, small and large, based on breast volume. Dose plans were produced for each patient using 3D-CRT, IMRT, and static tomotherapy. All patients were prescribed a dose of 45Gy in 20 fractions to the breast with an SIB of 56Gy in 20 fractions to the tumor bed and normalized so that D98% > 95% of the prescription dose. Dosimetric comparisons were made between the 3 modalities and the interaction of patient size. All 3 modalities offered adequate planning target volume (PTV) coverage with D98% > 95% and D2% < 107%. Static tomotherapy offered significantly improved (p = 0.006) dose homogeneity to the PTVboost eval (0.079 ± 0.011) and breast minus the SIB volume (BreastSIB) (p < 0.001, 0.15 ± 0.03) compared with the PTVboost eval (0.085 ± 0.008, 0.088 ± 0.12) and BreastSIB (0.22 ± 0.05, 0.23 ± 0.03) for IMRT and 3D-CRT, respectively. Static tomotherapy also offered statistically significant reductions (p < 0.001) in doses to the ipsilateral lung mean dose of 6.79 ± 2.11Gy compared with 7.75 ± 2.54Gy and 8.29 ± 2.76Gy for IMRT and 3D-CRT, respectively, and significantly (p < 0.001) reduced heart doses (mean = 2.83 ± 1.26Gy) compared to both IMRT and 3D-CRT (mean = 3.70 ± 1.44Gy and 3.91 ± 1.58Gy). Static tomotherapy is the dosimetrically superior modality for the whole breast with an SIB compared with IMRT and 3D-CRT. IMRT is superior to 3D-CRT in both PTV dose conformity and reduction of mean doses to the ipsilateral lung.

Feasibility and outcome of re-irradiation in the treatment of multiply recurrent pituitary adenomas

This study evaluates the toxicity and outcomes of re-irradiation to the sella for pituitary adenomas. Patients diagnosed with a pituitary adenoma and treated with two or more courses of radiation treatment (RT) to the sella were retrospectively analyzed for: initial diagnosis, including histological type and functional status; RT modality, technique, dose, and fractionation; treatment with surgery, endocrine agents, and chemotherapy; toxicity of RT including radiation-induced optic neuropathy, radionecrosis, and radiation-induced neoplasms; and outcomes including local control, distant metastasis, biochemical control of functional tumors, and vital status at last follow-up. We identified 15 patients with non-functioning pituitary adenoma (n = 6), Cushing's disease (CD) (n = 5), acromegaly (n = 3), and prolactinoma (n = 1). Initial RT was delivered using opposed lateral fields in 8 (53%), intensity-modulated radiation therapy (IMRT) in 4 (27%), fractionated stereotactic radiation therapy (FSRT) in 1 (6.7%), and stereotactic radiosurgery (SRS) in 2. The median dose was 49.5 Gy for fractionated RT and 15-25 Gy for SRS. Re-irradiation was performed a median of 5.8 years after initial RT, and delivered using lateral opposed beams (n = 1), IMRT (n = 4), linear-accelerator based SRS (n = 3), FSRT (n = 3), gamma knife surgery (n = 2), and yttrium-90 brachytherapy (n = 1). The median dose of re-irradiation was 45 Gy (range 27.9-54 Gy) for fractionated RT and 18 Gy for SRS. Radiation-induced optic neuropathy (RION) was observed in 2 (13.3%) patients, 6 months and 14 years after re-irradiation; the 5-year rate of RION was 9 %. Temporal lobe necrosis (TLN) occurred in two patients (13.3%), both of whom had received SRS. The 2- and 5-year rates of TLN were 10 and 28%. Actuarial local control rates at 2 and 5 years were 80 and 58%, respectively. Biochemical remission occurred in one of three patients with CD. Four patients (27%) ultimately developed pituitary carcinoma. Re-irradiation is a feasible treatment option for local control in patients with recalcitrant pituitary adenomas, with acceptable rates of RION and TLN given the lack of options that may be available otherwise. Re-irradiation, however, did not control hormonal hypersecretion.

Biocompatibility of functionalized boron phosphate (BPO4) nanoparticles for boron neutron capture therapy (BNCT) application

Boron neutron capture therapy (BNCT) is a radiotherapy treatment based on the accumulation in the tumor of a 10B-containing drug and subsequent irradiation with low energy neutrons, which bring about the decay of 10B to 7Li and an α particle, causing the death of the neoplastic cell. The effectiveness of BNCT is limited by the low delivery and accumulation of the used boron-containing compounds. Here we report the development and the characterization of BPO4 nanoparticles (NPs) as a novel possible alternative drug for BNCT. An extensive analysis of BPO4 NP biocompatibility was performed using both mature blood cells (erythrocytes, neutrophils and platelets) and a model of hematopoietic progenitor cells. A time- and concentration-dependent cytotoxicity study was performed on neoplastic coloncarcinoma and osteosarcoma cell lines. BPO4 functionalization with folic acid, introduced to improve the uptake by tumor cells, appeared to effectively limit the unwanted effects of NPs on the analyzed blood components. From the Clinical EditorBoron neutron capture therapy (BNCT) is a radiotherapy treatment modality based on the accumulation of a 10B-containing drug and subsequent irradiation with low energy neutrons, inducing the decay of 10B to 7Li and an α particle, causing neoplastic cell death. This team of authors reports on a folic acid functionalized BPO4 nanoparticle with improved characteristics compared with conventional BNCT approaches, as demonstrated in tumor cell lines, and hopefully to be followed by translational human studies.

Correcting radiation survey data to account for increased leakage during intensity modulated radiotherapy treatments

Intensity modulated radiotherapy (IMRT) treatments require more beam-on time and produce more linac head leakage to deliver similar doses to conventional, unmodulated, radiotherapy treatments. It is necessary to take this increased leakage into account when evaluating the results of radiation surveys around bunkers that are, or will be, used for IMRT. The recommended procedure of applying a monitor-unit based workload correction factor to secondary barrier survey measurements, to account for this increased leakage when evaluating radiation survey measurements around IMRT bunkers, can lead to potentially costly overestimation of the required barrier thickness. This study aims to provide initial guidance on the validity of reducing the value of the correction factor when applied to different radiation barriers (primary barriers, doors, maze walls, and other walls) by evaluating three different bunker designs. Radiation survey measurements of primary, scattered, and leakage radiation were obtained at each of five survey points around each of three different radiotherapy bunkers and the contribution of leakage to the total measured radiation dose at each point was evaluated. Measurements at each survey point were made with the linac gantry set to 12 equidistant positions from 0° to 330°, to assess the effects of radiation beam direction on the results. For all three bunker designs, less than 0.5% of dose measured at and alongside the primary barriers, less than 25% of the dose measured outside the bunker doors and up to 100% of the dose measured outside other secondary barriers was found to be caused by linac head leakage. Results of this study suggest that IMRT workload corrections are unnecessary, for survey measurements made at and alongside primary barriers. Use of reduced IMRT workload correction factors is recommended when evaluating survey measurements around a bunker door, provided that a subset of the measurements used in this study are repeated for the bunker in question. Reduction of the correction factor for other secondary barrier survey measurements is not recommended unless the contribution from leakage is separately evaluated.

Nutrition and cancer: issues related to treatment and survivorship

This paper reviews nutritional issues related to cancer treatment and further explores nutritional needs pertinent to cancer survivorship. It examines the major problems with nutrition when patients undergo the main cancer treatment modalities of chemotherapy, radiotherapy and surgery. Particular attention is paid to long-term dietary advice in acknowledgement of the improved effectiveness of cancer treatment and the chronic nature of the condition.

Novel Parameter Predicting Grade 2 Rectal Bleeding After Iodine-125 Prostate Brachytherapy Combined With External Beam Radiation Therapy

To propose a novel parameter predicting rectal bleeding on the basis of generalized equivalent uniform doses (gEUD) after (125)I prostate brachytherapy combined with external beam radiation therapy and to assess the predictive value of this parameter. To account for differences among radiation treatment modalities and fractionation schedules, rectal dose-volume histograms (DVHs) of 369 patients with localized prostate cancer undergoing combined therapy retrieved from corresponding treatment planning systems were converted to equivalent dose-based DVHs. The gEUDs for the rectum were calculated from these converted DVHs. The total gEUD (gEUDsum) was determined by a summation of the brachytherapy and external-beam radiation therapy components. Thirty-eight patients (10.3%) developed grade 2+ rectal bleeding. The grade 2+ rectal bleeding rate increased as the gEUDsum increased: 2.0% (2 of 102 patients) for <70 Gy, 10.3% (15 of 145 patients) for 70-80 Gy, 15.8% (12 of 76 patients) for 80-90 Gy, and 19.6% (9 of 46 patients) for >90 Gy (P=.002). Multivariate analysis identified age (P=.024) and gEUDsum (P=.000) as risk factors for grade 2+ rectal bleeding. Our results demonstrate gEUD to be a potential predictive factor for grade 2+ late rectal bleeding after combined therapy for prostate cancer.

SU-E-T-75: Application of Film Dosimetry and Comparison to Delta4 to Patient-Specific Preclinical Dosimetric Verification of RapidArc

Purpose: Radiotherapy treatment modalities are becoming more complex in order to enable advanced patient treatments with a higher dose to irregularly shaped tumor volumes while sparing nearby organs at risk. VMAT as well as RapidArc incorporate capabilities such as variable doserate, variable gantry speed, and accurate and fast dynamic multileaf collimators (DMLC), to optimize dose conformity, delivery efficiency, accuracy and reliability. There is very little information on QA systems and techniques regarding the patient‐specific QA. Therefore, we compared the results obtained with radiographic film to those from the Delta4 phantom. Methods: RapidArc treatment plans were generated using the Varian Eclipse treatment planning software version 8.9 (Varian Medical Systems, Palo Alto, CA). A single but complete (358°) RapidArc was planned. RapidArc treatment plans were delivered to the Delta4 (Delta4) cylindrical (1069 p‐Si Silicon diodes) phantom from Scandidos Uppsala, Sweden, as well as to an equivalent home‐made polyethylene (HD 1000) cylindrical phantom (two longitudinal halves, density 0.94 g/cm3) for EDR2 film dosimetry. Results: The correspondence between D4 and cylindrical phantom measured were analyzed in radial and longitudinal (GT) profiles. The film in the 40° plane displayed a ±3.1% agreement in radial and a 2.2% agreement in GT direction with Delta4 phantom. A small difference was found between the planes because the cylindrical phantom joining the two halves parts has some gaps which might generate the discrepancy between radial and GT direction. The film‐measured dose in the isocenter of the 50° radial and GT plane showed an agreement within ±2.7% with the Delta4 phantom. Conclusion: Film dosimetry validated the Delta4 measurements and it clearly provided more useful information than single point dose measurement. GHENT UNIVERSITY BOF08/DOS/052

TU-A-108-01: Four-Dimensional Monte Carlo Using the TOPAS TOol for PArticle Simulation

Purpose: As the number and diversity of 4D radiation therapy treatment modalities increases, with techniques from IMRT, VMAT, SBRT, IGRT and IMPT to proton and ion beam scanning, the value of a comprehensive 4D Monte Carlo dose calculation tool has become evident. In silico experiments provide a powerful platform to study sensitivity of dose calculation techniques to motion errors, beam instabilities and interplay effects. We present a comprehensive system to meet this growing need. Methods: We have provided rich 4D capabilities within the TOPAS TOol for PArticle Simulation. TOPAS allows any one or more simulation parameter to vary over time, such as a beam current, the geometrical position of a treatment head component, a magnetic field, a 4D CT time slice or a gating signal for scoring. In use at 25 research institutions, TOPAS has been brought to bear on a wide range of 4D problems. We present 4D capabilities, including modulator wheel rotation during beam current modulation, beam scanning, MLC leaf motion, gantry rotation and 4D CT. Results: It is imperative that 4D simulation tools provide 4D-scoring capabilities, such as scorers that can be gated by time, or phase space output that can associate time to each saved particle. Only with such tools can one confirm that the simulation is accurate in not just three dimensions but four. We show such results that confirm TOPAS 4D performance, both as time-sliced histograms and through simulated 4D radiography (simulated films darkening as dose accumulates over time). Conclusion: TOPAS has proven to be a comprehensive 4D simulation tool. While current users are mainly in proton therapy, TOPAS is being extended for use in ion, x-ray, electron and brachytherapy. While there are many excellent MC tools already for some of these modalities, TOPAS is unique in the 4D domain.

Intensity modulated radiotherapy treatment (IMRT) in bilateral breast

Intensity modulated radiotherapy treatment (IMRT) in bilateral breast

SU‐E‐T‐640: Using An Open Source Interior Point Optimization Solver for Intensity Modulated Radiotherapy Treatment Planning

Purpose: To support IMRT research, we developed an open‐source, computationally efficient, and flexible optimization solver that can solve a wide range of problem formulations, including constrained optimization, convex and non‐convex polynomial functions, and hierarchical optimization formulations. Methods: The solver is an adaptation and modification of the open‐source Interior Point Optimization Solver (IPOPT), with some performance enhancements. Previously, we implemented the IMRT optimization based on the commercial Mosek solver. Mosek can solve convex linear and quadratic problems but cannot solve convex or non‐convex polynomials of higher orders. This limits the ability to model IMRT optimization using more appropriate metrics like gEUD. Therefore, we implemented the optimization problem using C++ interface of IPOPT. IPOPT can use the Newton or Quasi‐Newton method to solve the optimization problem. In the Newton method, the exact Hessian matrix provided by the user is used to find the direction in each iteration while in the Quasi‐Newton method the Hessian matrix is approximated from the Jacobian matrix. After integrating IPOPT with CERR, we found that the Newton method converges more quickly than the Quasi‐Newton method. To increase the computational efficiency, we incorporated the uBLAS matrix library. Results: Few compared the modified IPOPT code to Mosek for a set of convex quadratic problems using realistic, anonymized treatment planning data and dose data accessed using CERR. These problems have a unique global minimum and both solvers were observed to give the same results for eight head and neck planning datasets. The median speedup of IPOPT compared to Mosek was a factor of 3.5. Conclusion: Our IPOPT implementation provides an open‐source framework to model the IMRT optimization using complex objective functions; is integrated with CERR; and our C++ implementation of the optimization problem gives increased control over the optimization process. This tool provides a basis for future IMRT treatment planning research. Memorial Sloan‐Kettering Cancer Center

Complex aberrations in lymphocytes exposed to mixed beams of 241Am alpha particles and X-rays

Modern radiotherapy treatment modalities are associated with undesired out-of-field exposure to complex mixed beams of high and low energy transfer (LET) radiation that can give rise to secondary cancers. The biological effectiveness of mixed beams is not known. The aim of the investigation was the analysis of chromosomal damage in human peripheral blood lymphocytes (PBL) exposed to a mixed beam of X-rays and alpha particles. Using a dedicated exposure facility PBL were exposed to increasing doses of alpha particles (from 241Am), X-rays and a mixture of both. Chromosomal aberrations were analysed in chromosomes 2, 8 and 14 using fluorescence in situ hybridisation. The found and expected frequencies of simple and complex aberrations were compared. Simple aberrations showed linear dose–response relationships with doses. A higher than expected frequency of simple aberrations was only observed after the highest mixed beam dose. A linear-quadratic dose response curve for complex aberrations was observed after mixed-beam exposure. Higher than expected frequencies of complex aberrations were observed for the two highest doses. Both the linear-quadratic dose–response relationship and the calculation of expected frequencies show that exposure of PBL to mixed beams of high and low LET radiation leads to a higher than expected frequency of complex-type aberrations. Because chromosomal changes are associated with cancer induction this result may imply that the cancer risk of exposure to mixed beams in radiation oncology may be higher than expected based on the additive action of the individual dose components.

Dosimetric Performance of Single-Crystal Diamond X-Ray Schottky Photodiodes

Single-crystal diamond Schottky photodiodes have been developed following a WC–diamond–TiC/Ti/Ag vertical structure for X-ray dosimetry with characteristics of low leakage current and the capability of zero-bias operations. Continuous and modulated X-ray measurements show that the devices developed provide a linear response to dose rate at low bias voltages $({ and at modulation frequencies ${>}{\rm 130}~{\rm Hz}$ . This supports their application in modulated radiotherapy treatments.

Targeting Tumors Using Nanoparticle Platforms: A Phase I Study of a Systemically Administered Gene Therapy System

The potential for nonviral gene therapy to treat cancer has been limited by the difficulty of targeting therapeutic genes to tumors. In this issue of Molecular Therapy, Senzer et al.1 show evidence of specific tumor targeting as well as clinical efficacy in a phase I trial of a nonviral vector. This is the first phase I clinical trial to demonstrate tumor specificity and uptake by metastatic tumors of a systemically delivered liposomal nanoparticle. Importantly, the therapeutic nanoparticle elicited minimal side effects and the majority of patients demonstrated stable disease. This phase I trial has shown this delivery system to be a safe, stable, efficient, and tumor-specific drug delivery platform for systemic administration.

Practice-based evidence to evidence-based practice: building the National Radiation Oncology Registry.

The National Radiation Oncology Registry (NROR), sponsored by the Radiation Oncology Institute and the American Society for Radiation Oncology, is designed to collect standardized information on cancer care delivery among patients treated with radiotherapy in the United States and will focus on patients with prostate cancer. Stakeholders were engaged through a forum that emphasized the need for patient-centered outcomes, minimal data burden, and maximal connectivity to existing registries and databases. An electronic infrastructure is under development to provide connectivity across radiation oncology and hospital information systems. The NROR Gateway features automatic abstraction as well as aggregation of treatment and outcome data. The prostate cancer data dictionary provides standardized elements in four domains: facility, physician, patient, and treatment. The pilot phase will consist of clinical centers chosen to provide a representative mix of radiation treatment modalities, facility types, population-based settings, and regional locations. The initial set of radiation practice metrics includes physician board certification and maintenance, ordering of staging scans, active surveillance discussion, dose prescriptions for low-risk/high-risk disease, radiation fields for low-risk/high-risk disease, image-guided radiation therapy use, androgen deprivation therapy use, post-brachytherapy implant computed tomography dosimetry, collection of toxicity assessments, and longitudinal patient follow-up. The NROR pilot study will provide the framework for expansion to a nationwide electronic registry for radiation oncology.

Organ Preservation for Adenoid Cystic Carcinoma of the Larynx

Two cases of adenoid cystic carcinoma (ACC) of the larynx were treated with chemoradiotherapy (CRT) for organ preservation. We reviewed case series and current literature to contrast the potential role of primary CRT as an organ-sparing modality with standard laryngectomy and radiotherapy in patients with laryngeal ACC. Two treatment-naïve patients with laryngeal ACC treated at Dana-Farber Cancer Institute between 2002 and 2007 were identified. Both patients were offered standard laryngectomy followed by adjuvant radiotherapy or organ-sparing treatment modality. Both patients were males, aged 57 and 73. The patients completed a course of combined chemoradiotherapy with weekly carboplatin and paclitaxel and 7-8 weeks of radiotherapy to a total dose of 6,600 and 7,000 cGy over 50 and 57 days, respectively. There were no treatment breaks or delays because of toxicity. The major toxicities reported by both patients, as anticipated, were Grade 3 mucositis, desquamative dermatitis, and severe dysphagia, all of which resolved. Both patients are alive with local regional control and functional larynx; one at 112+ months with pulmonary metastases at 54 months, and the other disease free at 60+ months. Definitive chemoradiation with weekly carboplatin and paclitaxel may be a potential alternative to the current standard of surgery and radiation for patients with locally advanced laryngeal ACC who request an organ-sparing approach. In this group of patients, salvage laryngectomy may be reserved for those who are locally recurrent or chemoradiotherapy resistant. Although CRT provided long-term local regional control in our two patients, there are evident limitations in obtaining evidence for a determination of treatment of rare diseases. This report provides support for following an organ preservation plan in selected patients.