B Micaily

Total skin electron beam therapy may be associated with improvement of peripheral blood disease in Sézary syndrome.

Total skin electron beam radiation is an effective therapy for palliation of the cutaneous symptoms of the most common types of cutaneous T-cell lymphomas, mycosis fungoides and Sézary syndrome. We report 4 cases of patients with Sézary syndrome who had significant improvement in their blood burden of malignant cells in addition to complete cutaneous responses to total skin electron beam therapy. The data from these 4 patients illustrate the potential for total skin electron beam to be used as both a skin and blood tumor debulking agent, and not merely as a palliation for skin symptoms.

Total skin electron beam and total nodal irradiation for treatment of patients with cutaneous t-cell lymphoma

Sixteen patients with advanced cutaneous T-cell lymphoma (CTCL) with or without lymph node involvement, but without evidence of extranodal manifestations, were treated with a combination of total skin electron beam therapy (TSEB) and total nodal irradiation (TNI). Fourteen (87%) patients achieved a complete response (CR) lasting from 1 to 84+ months (median, 8+ months) from the completion of treatment. The best results occurred in 6 patients with pretumorous intracutaneous CTCL (Stages IB and IIA) where the CR has lasted in all patients from 8 to 84+ months (median about 27+ months). Conversely, a long-term CR occurred in only one of five patients with tumor-phase intracutaneous CTCL (Stage IIB) and in none of the 5 patients with histopathologically proven nodal involvement (Stage IVA). Radiotherapy was well tolerated with the major toxicity being bone marrow suppression. We conclude that combined TSEB and TNI is a relatively safe and effective treatment for patients with CTCL prior to the development of lymph node involvement. Long-term follow-up is needed to assess the curative potential of this treatment.

Repeat stereotactic body radiation therapy for patients with pulmonary malignancies who had previously received SBRT to the same or an adjacent tumor site.

OBJECTIVES Retrospective analysis of patients with recurrences at or closely adjacent to the site of prior lung stereotactic body radiation therapy (SBRT) who received repeat SBRT. MATERIALS AND METHODS Nine patients with non-small cell lung cancer (n = 8) or oligometastatic colonic adenocarcinoma (n = 1) were treated with image-guided lung SBRT to a median of 60 Gy (range, 30-60) in a median of 3 fractions (3-5). Patients developed in-field relapse (n = 3) or recurrence adjacent (≤ 3.5 cm away) to the previous tumor location (n = 6) and received 2 nd lung SBRT to a median of 60 Gy. RESULTS Median follow-up after 2 nd SBRT was 22 months (4-40). All completed prescribed course of repeat SBRT and acute toxicity was limited. There was no grade >3 late toxicity. 3 (33.3%) patients developed Grade 3 late reactions: 2 pulmonary and 1 chest wall pain. Late pulmonary toxicity included 2 (22.2%) patients with Grade 3 and 3 (33.3%) with Grade 2. One patient (11.1%) had late Grade 3 and 1 (11.1%) Grade 2 chest wall pain. 1 (11.1%) developed Grade 2 late brachial plexopathy. No myelopathy was observed. Two patients developed progression of tumors treated by 2 nd SBRT. Local recurrence free survival and overall survival was 75% and 68.6%, respectively at 2 years. Relative volume of ipsilateral lung receiving 5 Gy (V5) and V10 were lower for 2 nd SBRT. CONCLUSION Repeat image-guided SBRT for patients with small peripheral recurrences was feasible and severe toxicity was not observed. Additional studies are needed to evaluate the safety and efficacy of lung reirradiation using 2 nd SBRT.

Improvement in peripheral blood disease burden in patients with Sézary syndrome and leukemic mycosis fungoides after total skin electron beam therapy

BACKGROUND There is a paucity of effective therapies for patients with Sézary syndrome and advanced mycosis fungoides with peripheral blood involvement. Total skin electron beam (TSEB) radiation therapy is an extremely effective skin-directed therapy for these patients, but, until recently, it was thought not to signifcantly affect the peripheral blood malignant T-cell population. OBJECTIVE We conducted this study to determine if TSEB has therapeutic effect on the peripheral blood in patients with advanced mycosis fungoides and Sézary syndrome. METHODS All patients on stable medication regimens seen in our photopheresis facility who received TSEB therapy between January 2008 and October 2011 at Temple University Hospital, Philadelphia, PA, were analyzed retrospectively for improvement in the peripheral blood, as documented by flow cytometry. RESULTS Six of 11 patients achieved 50% or greater decrease in their peripheral blood malignant T-cell population after TSEB therapy, for an overall response rate of 55%. Within the group of patients who had a response in the skin, 67% also had a response in the peripheral blood. LIMITATIONS This analysis is limited in 3 ways. First, the sample described is small. Second, the results may be confounded by the fact that each patient was on other systemic therapies in addition to TSEB, albeit stable pre-existing regimens. The time interval between completion of TSEB therapy and repetition of flow cytometry was not standardized among patients, which may result in an underestimation of the overall response to TSEB therapy. CONCLUSION In patients with advanced mycosis fungoides and Sézary syndrome, the peripheral blood tumor burden may improve after treatment with TSEB.

Use of image-guided stereotactic body radiation therapy in lieu of intracavitary brachytherapy for the treatment of inoperable endometrial neoplasia

PURPOSE Retrospective analysis of patients with invasive endometrial neoplasia who were treated with external beam radiation therapy followed by stereotactic body radiation therapy (SBRT) boost because of the inability to undergo surgery or brachytherapy. METHODS AND MATERIALS We identified 11 women with stage I-III endometrial cancer with a median age of 78 years that were not candidates for hysterectomy or intracavitary brachytherapy secondary to comorbidities (91%) or refusal (9%). Eight patients were American Joint Committee on Cancer (AJCC) stage I (3 stage IA, 5 stage IB), and 3 patients were AJCC stage III. Patients were treated to a median of 4500 cGy at 180 cGy per fraction followed by SBRT boost (600 cGy per fraction×5). RESULTS The most common side effect was acute grade 1 gastrointestinal toxicity in 73% of patients, with no late toxicities observed. With a median follow-up of 10 months since SBRT, 5 patients (45%) experienced locoregional disease progression, with 3 patients (27%) succumbing to their malignancy. At 12 and 18 months from SBRT, the overall freedom from progression was 68% and 41%, respectively. Overall freedom from progression (FFP) was 100% for all patients with AJCC stage IA endometrial carcinoma, whereas it was 33% for stage IB at 18 months. The overall FFP was 100% for International Federation of Obstetrics and Gynecology grade 1 disease. The estimated overall survival was 57% at 18 months from diagnosis. CONCLUSION In this study, SBRT boost to the intact uterus was feasible, with encouragingly low rates of acute and late toxicity, and favorable disease control in patients with early-stage disease. Additional studies are needed to provide better insight into the best management of these clinically challenging cases.

Three-Dimensional Conformal Radiotherapy for Treatment of Extensive Juvenile Angiofibroma: Report on Two Cases

These case reports describe the application of three-dimensional conformal radiotherapy for the treatment of extensive juvenile angiofibroma. The affected areas included the pterygomaxillary fossa, infratemporal fossa, orbit, middle cranial fossa and maxillary sinus. Three-dimensional conformal radiotherapy was used to deliver the tumor dose of 3,800–4,140 cGy. The radiation dose to the surrounding normal structures including the optic nerve, optic chiasm, spinal cord, parotid and brain was limited. The tumor showed an excellent clinical and radiological response in both patients. There was no appreciable late toxicity. In conclusion, three-dimensional conformal radiotherapy provides several advantages over conventional radiotherapy in the treatment of extensive juvenile angiofibroma.

SU-E-T-191: Commissioning and Dosimetric Characteristics of Elekta Agility for Total Skin Electron Beam (TSEB) Therapy

Purpose The purpose of this work is to publish beam data from Elekta Synergy(R) linear accelerators with Agility(TM) MLC for total skin electron beam (TSEB) therapy using the HDRE1 (High Dose Rate Electron 6MeV) energy. Method & Materials The optimal gantry angles for TSEB were determined using ion chamber measurements along a vertical profile at 450cm SSD. After gantry angles were chosen, field uniformity was measured over the entire treatment area. Uniformity was measured with and without the patient support device, allowing the dosimetric effect of the support device to be determined. Beam output and PDD were measured at the calibration point (450cm SSD) for a dual beam using a parallel plate chamber in solid water. These measurements were repeated with the chamber and phantom rotated about the patient isocenter at various angles, in order to measure the contribution from oblique beams. This technique provides a precise measurement of the treatment skin dose (TSD). Lastly, ion chamber measurements were verified by film and diodes. Results The optimal gantry angle for 450 cm SSD was determined to be 90±16°. This achieved uniformity better than 96% on the vertical axis, and 92% along the horizontal axis. HDRE1 was calibrated to deliver 10 cGy/MU at standard geometry (100 cm SSD, 1.2 cm depth). Thus at TSEB geometry (450 cm SSD, 0.1 cm depth) the output of the AP dual field was measured to be 0.35 cGy/MU. The TSD of a 20 cm radius cylinder for six (equally, 60° spaced) dual fields was measured to be 1.19 cGy/MU. Percent Depth Dose data for the AP dual field and TSD are shown in Figure 2. Conclusion This paper provides a modern procedure for commissioning TSEB therapy on a linear accelerator, and clinical beam data for the Elekta Synergy(R) with Agility(TM) MLC.

Spatial and Temporal Thermal Dose Distribution in Hyperthermia Therapy

Introduction: A recent report of EORTC-STBSG phase III randomized trial (2010) describes that regional hyperthermia can improve chemotherapy results for patients with high-risk soft-tissue sarcoma and Krawczyk et al. (PNAS, 2011) have just discovered that mild high temperature can prohibit homologous recombination - a process to repair double strand breaks. The clinical outcomes and laboratory findings support the combination use of hyperthermia therapy (HT) with chemotherapy or radiotherapy. However, uncontrolled heating can cause severe burns of bones and other critical structures. Thus, it is extremely important to quantify heat transport and thermal dose in the human body for safe and accurate HT. Materials and Methods: Custom phantoms were made of materials with relative permittivity equivalent to soft tissue and shapes similar to the patient body with embedded heat reflectors simulating bones and heat exchangers simulating the blood streams. Eight thermistors were placed at various depths to monitor temperature changes during the heating process. The phantoms were heated by microwave surface heaters with adjustable heat power and water bolus. At therapeutic temperatures, thermographs and 3D surfaces at depths of interest were captured using an infrared camera and a 3D camera. Results and Discussion: Initial results without heat exchangers show that spatial temperature distribution varies greatly with the heat power, heating duration, treatment depth, surface shape, bolus thickness, and presence of heat reflectors. Understanding effects of the controllable variables of the heat power, heating duration, and bolus thickness and the intrinsic variables of the body shape, bone, and blood flow on the temporal and spatial temperature distributions in patients would allow us to optimize the heating process and to calculate the effective thermal doses.

4D-Video Usefulness For Tracking Respiration Motion in 4DCT Scans and Targeting Small Mobile Tumors

4DCT-based treatment plan, 4DCBCT-guided patient setup, and real-time tracking of target motion are essential for accurate stereotactic body radiotherapy (SBRT) of small mobile tumors. However, there is lack of correlation between 4DCT-4DCBCT data in phases of regular respiration cycles and the real-time monitored irregular respiration motion data. We are now proposing a real-time 4D video technique to synchronize respiration patterns in 4DCT, 4DCBCT, and real-time target motion during the dose delivery. Results of feasibility studies with sequential surface images on several patients and volunteers demonstrated the capability of detecting the breathing patterns by the movements of the frontal surfaces of the thorax and abdomen. The deep breathing concurs with larger thorax surface shifts of > 5-mm or tilt angles of > 2-degrees and longer respiratory cycles with periods of >6- seconds. Normal breathing usually has small thorax surface shifts of < 2-mm and angles of < 2-degrees but wide ranges of abdomen surface shifts from 2 to 30-mm and angles from 1 to 5 degrees. At free breathing conditions, we also find that patient respiration cycles and abdomen surface movements are frequently changed with time. More importantly, the personal respiration patterns are predictable with the dynamic volumetric curves determined by the abdomen and thorax surface movements. The surface movements and changes of surface covered volume can be correlated with dynamic volumetric changes in 4DCT and 4DCBCT scans. Thus, the 4D video technique is potentially useful for real-time tracking of small mobile targets in SBRT through synchronization with 4DCT or 4DCBCT.

WE‐C‐WAB‐08: Measurements and Quantifications for the Lung Nodule Motion Using 4DCBCT Scans Prior to Each SBRT Treatment

PURPOSE To measure the lung nodule motion using 4D CBCT, to quantify any potential influences on the motion trajectory, and to derive an analytical approximation for motion trajectory in order to synchronize with external real-time respiratory motion tracking. METHODS GTV from fast CT and ITV from CT-PET obtained from rigid or deformable co-registration with simulation CT are used for SBRT planning. Pretreatment 4D CBCT with ten phases are automatically registered according to the GTV mask. The nodule motion trajectory is quantified by the center, amplitudes, swiping area, major and minor axes in the principal plane (PP), and the PP normal vector. The setup errors and motion margins are assessed by the trajectory center and amplitude, respectively. Detected motion in the PP is analytically approximated by an ellipse with time parameter and the trajactory shape or axes and orentation may be correlated with the lung volume, nodule location, abdominal compression, and restriction force from the neighboring chest wall or other rigid tissue. Those variables in seventy-two 4D CBCT scans from 34 patients are retrospectively analyzed. RESULTS After 4D CBCT-guided setup adjustments of 10±8 mm, the remaining setup errors in any directions increase from 1±1 mm for upper and middle lobes to 1± 2 mm for the lower lobes while the average motion margins in the lateral, longitudinal, and posterior-anterior directions increase from (1, 2, 1) to (1, 6, 1) mm. No significant difference is observed between the left and right lungs and between the groups with and without abdominal compression. Importantly, most motion trajectories can be analytically approximated and its PP is predicable with the local force. CONCLUSION The clinical measurements and detail analysis validate the geometric accuracy and precision of current SBRT and our analytical approximation is potentially useful for synchronization with real-time respiratory motion tracking for future gated SBRT.