Asal N. Shoushtari

QUANTIFYING THE REPRODUCIBILITY OF HEART POSITION DURING TREATMENT AND CORRESPONDING DELIVERED HEART DOSE IN VOLUNTARY DEEP INHALATION BREATH HOLD FOR LEFT BREAST CANCER PATIENTS TREATED WITH EXTERNAL BEAM RADIOTHERAPY

PURPOSE Voluntary deep inhalation breath hold (VDIBH) reduces heart dose during left breast irradiation. We present results of the first study performed to quantify reproducibility of breath hold using bony anatomy, heart position, and heart dose for VDIBH patients at treatment table. METHODS AND MATERIALS Data from 10 left breast cancer patients undergoing VDIBH whole-breast irradiation were analyzed. Two computed tomography (CT) scans, free breathing (FB) and VDIBH, were acquired to compare dose to critical structures. Pretreatment weekly kV orthogonal images and tangential ports were acquired. The displacement difference from spinal cord to sternum across the isocenter between coregistered planning Digitally Reconstructed Radiographs (DRRs) and kV imaging of bony thorax is a measure of breath hold reproducibility. The difference between bony coregistration and heart coregistration was the measured heart shift if the patient is aligned to bony anatomy. RESULTS Percentage of dose reductions from FB to VDIBH: mean heart dose (48%, SD 19%, p = 0.002), mean LAD dose (43%, SD 19%, p = 0.008), and maximum left anterior descending (LAD) dose (60%, SD 22%, p = 0.008). Average breath hold reproducibility using bony anatomy across the isocenter along the anteroposterior (AP) plane from planning to treatment is 1 (range, 0-3; SD, 1) mm. Average heart shifts with respect to bony anatomy between different breath holds are 2 ± 3 mm inferior, 1 ± 2 mm right, and 1 ± 3 mm posterior. Percentage dose changes from planning to delivery: mean heart dose (7%, SD 6%); mean LAD dose, ((9%, SD 7%)S, and maximum LAD dose, (11%, SD 11%) SD 11%, p = 0.008). CONCLUSION We observed excellent three-dimensional bony registration between planning and pretreatment imaging. Reduced delivered dose to heart and LAD is maintained throughout VDIBH treatment.

Intensity‐modulated radiotherapy outcomes for oropharyngeal squamous cell carcinoma patients stratified by p16 status

Patients with oropharyngeal squamous cell carcinoma (OPSCC) treated with intensity‐modulated radiotherapy (IMRT) were stratified by p16 status, neck dissection, and chemotherapy to correlate these factors with outcomes.

Outcomes of Patients With Head-and-Neck Cancer of Unknown Primary Origin Treated With Intensity-Modulated Radiotherapy

PURPOSE To analyze survival, failure patterns, and toxicity in patients with head-and-neck carcinoma of unknown primary origin (HNCUP) treated with intensity-modulated radiotherapy (IMRT). METHODS AND MATERIALS Records from 27 patients with HNCUP treated during the period 2002-2008 with IMRT were reviewed retrospectively. Nodal staging ranged from N1 to N3. The mean preoperative dose to gross or suspected disease, Waldeyers ring, and uninvolved bilateral cervical nodes was 59.4, 53.5, and 51.0 Gy, respectively. Sixteen patients underwent neck dissection after radiation and 4 patients before radiation. Eight patients with advanced nodal disease (N2b-c, N3) or extracapsular extension received chemotherapy. RESULTS With a median follow-up of 41.9 months (range, 25.3-93.9 months) for non deceased patients, the 5-year actuarial overall survival, disease-free survival, and nodal control rates were 70.9%, 85.2%, and 88.5%, respectively. Actuarial disease-free survival rates for N1, N2, and N3 disease were 100%, 94.1%, and 50.0%, respectively, at 5 years. When stratified by non advanced (N1, N2a nodal disease without extracapsular spread) vs. advanced nodal disease (N2b, N2c, N3), the 5-year actuarial disease-free survival rate for the non advanced nodal disease group was 100%, whereas for the advanced nodal disease group it was significantly lower at 66.7% (p = 0.017). Three nodal recurrences were observed: in 1 patient with bulky N2b disease and 2 in patients with N3 disease. No nodal failures occurred in patients with N1 or N2a disease who received only radiation and surgery. CONCLUSION Definitive IMRT to 50-56 Gy followed by neck dissection results in excellent nodal control and overall and disease-free survival, with acceptable toxicity for patients with T0N1 or non bulky T0N2a disease without extracapsular spread. Patients with extracapsular spread, advanced N2 disease, or N3 disease may benefit from concurrent chemotherapy, targeted therapeutic agents, or accelerated radiation regimens in addition to surgery.

Predicting Residual Neck Disease in Patients With Oropharyngeal Squamous Cell Carcinoma Treated With Radiation Therapy: Utility of p16 Status

OBJECTIVE To identify factors that predict complete response of cervical nodal disease to radiation therapy (RT) in patients with oropharyngeal squamous cell carcinoma (OP-SCCA). DESIGN Histologic analysis of prospectively collected specimens and retrospective medical chart review. SETTING Tertiary referral center. SUBJECTS Sixty-nine patients with OP-SCCA treated from January 1, 2002, through June 1, 2008. INTERVENTION Definitive RT, with or without chemotherapy and with or without neck dissection (ND). MAIN OUTCOME MEASURE Presence of a viable tumor in post-RT ND specimen. RESULTS Tissue specimens from 69 patients with OP-SCCA treated primarily with RT, with or without chemotherapy, were evaluated. Of these, 47 (68.1%) were strongly and diffusely positive for p16 expression by immunohistochemical analysis, signifying human papillomavirus positivity. Patients with p16-positive and p16-negative tumors (hereinafter, p16+ and p16-, respectively) had similarly sized primary tumors on presentation, but p16+ primary tumors were associated with more advanced neck disease (nodal stages N2c-N3; 31.9% vs 4.5% for p16- tumors) and more contralateral nodes (27.7% vs 4.5% for p16- tumors). Forty-seven patients (59.0%) underwent planned posttreatment ND (a total of 55 NDs). The NDs performed for p16- tumors were significantly more likely to have viable tumor in the specimen (50.0% vs 18.0% for p16+ tumors; P = .02). In addition, p16+ necks with residual viable cancer were characterized by incomplete response on post-RT imaging, tobacco and alcohol use, and extracapsular spread on pretreatment imaging. CONCLUSIONS In conjunction with other clinical parameters, p16 status can help predict the need for post-RT ND in patients with OP-SCCA. Although close observation may be warranted in selected patients with p16+ tumors, patients with p16- tumors are at much higher risk for residual neck disease, even when initial nodal disease is less advanced.

Clinical nodal staging of T1-2 tonsillar squamous cell carcinoma stratified by p16 status and implications for ipsilateral neck irradiation.

Background and Purpose:Previous studies have reported <5% incidence of contralateral nodal metastasis in patients with T1-2 tonsillar squamous cell carcinoma. We analyzed the nodal staging of T1-2 tonsillar squamous cell carcinoma stratified for p16 status, a marker of human papillomavirus positivity. Materials and Methods:Clinical and radiographic nodal staging and p16 status of 41 T1-2 tonsillar squamous cell carcinoma patients who were treated between January 2002 and June 2009 were retrospectively analyzed. Patients with a history of prior head and neck cancer, synchronous cancers, base of tongue or soft palate invasion, or distant metastases at diagnosis were excluded. Results:Of the 41 patients, 28 (68.2%) had p16+ tumors and 13 (31.7%) had p16− tumors. Seven patients (17.0%) presented with contralateral cervical nodal disease, all of whom had p16+ tumors. Furthermore, 25.0% of patients with p16+ tumors presented with contralateral cervical nodal disease compared with 0% of patients with p16− tumors. Conclusions:Patients with p16+ T1-2 tonsillar squamous cell carcinoma present with a higher incidence of contralateral nodal spread than those patients with p16− disease. This may have clinical implications when determining which patients are good candidates for ipsilateral cervical nodal irradiation.

Survey on human papillomavirus/p16 screening use in oropharyngeal carcinoma patients in the United States.

Patients with human papillomavirus (HPV)‐positive oropharyngeal carcinoma (OC) have better prognosis than patients with HPV‐negative OC. The objective of the current study was to assess how different practices across the United States treat patients with OC with respect to screening for HPV DNA or p16.

Primary nasopharyngeal interdigitating dendritic cell tumor presentation and response to radiation therapy

We report the case of a primary nasopharyngeal interdigitating dendritic cell tumor (IDDCT). A 25-year old male presented with bilateral decreased hearing, double vision, and ataxia. Flexible nasopharyngoscopy reviewed a large mass obstructing and filling the entire nasopharynx. MRI and PET-CT confirmed the presence of the primary tumor and demonstrated bilateral cervical lymphadenopathy. Biopsy of the nasopharynx revealed a hematolymphoid neoplasm with dendritic cell differentiation, most consistent with an IDDCT. The lesion was unresectable. The patient was treated with definitive radiotherapy to 66 Gy to the primary tumor and 50 Gy to the bilateral cervical lymphatics using an IMRT technique. A complete response was achieved and the patient remains disease free at the primary site 23 months after completion of radiotherapy.

WE‐C‐303A‐04: Quantifying the Reproducibility of Heart Position with Respect to Bony Anatomy in Daily Set Up and the Corresponding Delivered Heart Dose in Voluntary Deep Inhalation Breath Hold for Left Breast Cancer Patients Via External Beam Radiotherapy

Purpose: Voluntary deep inhalation breath hold (DIBH) technique help reduce the heart toxicity during radiation treatment of the left breast. We present the results of the first study performed to quantify the reproducibility of heart position and the heartdose in daily setup for voluntary DIBH patients. Method and Materials: Ten left breast patients undergoing treatment with voluntary DIBH were studied. Each patient had two CT scans, one with free breathing and one with voluntary DIBH, to evaluate the dose under these two conditions to the Heart, anterior most point of left anterior descending (LAD) coronary artery, and left Lung. At the treatment machine, daily and weekly KV orthogonal images were acquired using onboard imaging for each patient. Mosaiq™ software was used to register the full bony anatomy of thorax (including the spine, ribs, anterior chest wall and heart) with KV images to the planning DRRs. Once the patient is aligned on the treatment machine using bony anatomy registration, the difference between the bony anatomy registration and the heart registration is the daily heart position. These differences were transferred into treatment planning system to obtain the delivered dose.Results: The dosimetric evaluation shows clinically significant reduced dose to heart,lung, and LAD in the DIBH case compared to the free breathing case, as previous studies have shown. The weekly heart position shifts are in the order of few mm. Dosimetric evaluations for these shifts indicate that dose to the heart in the daily treatment with DIBH remains low. Conclusion: The setup and breath hold accuracy and the daily delivered dose to the heart was evaluated for voluntary DIBH breast patients. Results indicate a clear reduction of dose delivered to the heart throughout the treatment when voluntary DIBH technique is employed.