Sameer R. Keole

Cine-magnetic resonance imaging assessment of intrafraction motion for prostate cancer patients supine or prone with and without a rectal balloon.

Purpose:Determine prostate intrafraction motion with Cine-magnetic resonance imaging (MRI) and deformable registration. Methods:A total of 68 cine-MRI studies were done in 17 different series with 4 scans per series in 7 patients. In without rectal balloon (WORB) scans, 100 mL of water was infused in the rectum. Each series consisted of supine and prone, with a rectal balloon (WRB) and WORB. Each scan was performed over 4 minutes. Automatic deformable registration software developed by View Ray, Inc., Cleveland, Ohio was employed to segment the prostate for each cine-MRI image. A time-based analysis was done for the different positions and the use of the rectal balloon. Results:The variation/standard deviation of the prostate position during 240 seconds was: supine WRB: 0.55 mm, WORB: 1.2 mm, and prone WRB: 1.48 mm, WORB: 2.15 mm (P < 0.001). A strong relationship was observed between time and prostate motion. For the initial 120 s the standard deviation was smaller than for the second 120 s supine WRB 0.54 mm versus 1.37 mm; supine WORB 0.61 mm versus 1.70 mm; prone WRB 0.85 mm versus 1.85 mm; and prone WORB 1.60 mm versus 2.56 mm. The probabilities for prostate staying within ±2 mm to its initial position are: 94.8% supine WRB; 91.5% supine WORB; 92.3% prone WRB; 79.2% prone WORB. Conclusions:Intrafraction prostate motion was found dependent on time, patient position, and the use of a rectal balloon. Relatively stable positions can be obtained for 4 minutes or less especially in the supine position with a rectal balloon.

Ewing Tumors of the Head and Neck

Purpose:Retrospective review describing the 40-year University of Florida experience treating Ewing tumors of the head-and-neck region with a summary of the pertinent literature. Patients and Methods:Nine patients were diagnosed and treated for Ewing sarcoma of the head and neck at our institution between 1965 and 2007. Primary sites included: mandible (3 patients), calvarium (2 patients), paranasal sinus (2 patients), oral cavity (1 patient), and the extraosseous soft tissue of the neck (1 patient). The median age at diagnosis was 13.0 years (range, 6.3–20.1 years). The median observed follow-up was 10.2 years (range, 1.5–37 years). Results:All patients received multiagent chemotherapy and radiation therapy to a median dose of 55.8 Gy (range, 36–67.2 Gy). Three patients also underwent wide local excision. The actuarial 10-year overall survival, cause-specific survival, event-free survival, and local control probabilities were 66%, 66%, 56%, and 89%, respectively. Late complications included poor dentition, mild xerophthalmia, cataract, and mandibular hypoplasia. A literature search revealed 8 previous series with Ewing tumors of the head and neck analyzed as subsets of larger studies. Conclusions:In the context of limited data on head and neck Ewing tumors, combined modality therapy provides excellent local control with reasonable acute and late toxicity. Large tumors were associated with poor disease control.

DEFINITIVE RADIOTHERAPY FOR EWING TUMORS OF EXTREMITIES AND PELVIS: LONG-TERM DISEASE CONTROL, LIMB FUNCTION, AND TREATMENT TOXICITY

PURPOSE More than 70% of Ewing tumors occur in the extremities and pelvis. This study identified factors influencing local control and functional outcomes after management with definitive radiotherapy (RT). PATIENTS AND METHODS A total of 75 patients with a localized Ewing tumor of the extremity or pelvis were treated with definitive RT at the University of Florida between 1970 and 2006 (lower extremity tumors in 30, pelvic tumors in 26, and upper extremity tumors in 19). RT was performed on a once-daily (40%) or twice-daily (60%) basis. The median dose was 55.2 Gy in 1.8-Gy daily fractions or 55.0 Gy in 1.2-Gy twice-daily fractions. The median observed follow-up was 4.7 years. Functional outcome was assessed using the Toronto Extremity Salvage Score. RESULTS The 10-year actuarial overall survival, cause-specific survival, freedom from relapse, and local control rate was 48%, 48%, 42%, and 71%, respectively. Of the 72 patients, 3 required salvage amputation. Inferior cause-specific survival was associated with larger tumors (81% for tumors <8 cm vs. 39% for tumors >/=8 cm, p <0.05). No patient characteristics or treatment variables were predictive of local failure. No fractures occurred in patients treated with hyperfractionation or with tumors of the distal extremities. Severe late complications were more frequently associated with use of <8-MV photons and fields encompassing the entire bone or hemipelvis. A significantly better Toronto Extremity Salvage Score was associated with a late-effect biologically effective dose of <91.7 Gy(3). CONCLUSIONS Limb preservation was effectively achieved through definitive RT. Treating limited field sizes with hyperfractionated high-energy RT could minimize long-term complications and provides superior functional outcomes.

Impact of local management on long-term outcomes in Ewing tumors of the pelvis and sacral bones: the University of Florida experience.

PURPOSE This retrospective analysis describes our 35-year experience with respect to disease control and functional status. PATIENTS AND METHODS Thirty-five patients with localized Ewing tumors of the pelvis and sacral bones were treated from 1970 to 2005. Twenty-six patients were treated with definitive radiotherapy (RT), and 9 patients were treated with combined local therapy in the form of surgery + RT. The median RT dose was 55.2 Gy. The patients who received RT alone were more likely to be older men with larger tumors exhibiting soft-tissue extension. Patients in the definitive RT group were more likely to receive etoposide and ifosfamide or undergo bone marrow transplant. Median potential follow-up was 19.4 years. RESULTS The 15-year actuarial cause-specific survival, freedom from relapse rate, and local control rates were 26% vs. 76% (p = 0.016), 28% vs. 78% (p = 0.015), and 64% vs. 100% (p = 0.087), respectively, for patients treated with definitive RT and combined therapy. Overall, tumors <8 cm had significantly better cause-specific survival, but this was unrelated to local control. The median Toronto Extremity Salvage Score for the definitive RT and combined therapy groups were 99 and 94, respectively (p = 0.19). Seven definitive RT patients (27%) had serious complications. CONCLUSION Combined modality local therapy should be considered if pelvic Ewing tumors are resectable. However, because of the extent of local disease, most patients have unresectable or partially resectable tumors and therefore require RT in some capacity. For this reason, innovative RT strategies are needed to improve long-term disease outcomes and minimize side effects while maintaining an acceptable functional result.

Pediatric Proton Therapy: Patterns of Care across the United States

Abstract Purpose: Children are particularly prone to the late side effects of normal tissue irradiation. For this reason, pediatric solid tumors are a commonly cited indication for proton therapy worldwide. The aim of this survey was to assess pediatric patterns of care across proton centers in the United States. Patients and Methods: A survey was developed and distributed annually to each clinical proton therapy facility in the United States in operation during the years of 2010, 2011, and 2012. Anonymized patient information including age range, tumor site, and diagnosis were collected annually for each patient 18 years old or younger treated between January 1, 2010 and December 31, 2012. Results: There was a 100% response rate from the United States proton therapy centers in operation for each year surveyed. All facilities treated at least 1 pediatric patient each year. A total of 694 pediatric patients were treated in 2012, an increase from 613 patients in 2011 and 465 patients in 2010. Fifty-seven pe...

Erectile Dysfunction After Radiotherapy for Prostate Cancer

Erectile Dysfunction (ED) is a relatively common complication after radiotherapy for prostate cancer. The etiology of ED is unclear. It is likely related to age, pretreatment erectile function, androgen deprivation therapy, and the volume of tissue irradiated. It is unclear whether the dose to various parts of the penis, such as the penile bulb and corpora cavernosa, is related to the development of ED. Following radiotherapy, the early use of phosphodiesterase inhibitors probably reduces the risk of ED.

Spinal and Paraspinal Ewing Tumors

PURPOSE To perform a review of the 40-year University of Florida experience treating spinal and paraspinal Ewing tumors. PATIENTS AND METHODS A total of 27 patients were treated between 1965 and 2007. For local management, 21 patients were treated with radiotherapy (RT) alone and 6 with surgery plus RT. All patients with metastatic disease were treated with RT alone. The risk profiles of each group were otherwise similar. The median age was 17 years, and the most frequent subsite was the sacral spine (n = 9). The median potential follow-up was 16 years. RESULTS The 5-year actuarial overall survival, cause-specific survival, and local control rate was 62%, 62%, and 90%, respectively. For the nonmetastatic subset (n = 22), the 5-year overall survival, cause-specific survival, and local control rate was 71%, 71%, and 89%, respectively. The local control rate was 84% for patients treated with RT alone vs. 100% for those treated with surgery plus RT. Patients who were >14 years old and those who were treated with intensive therapy demonstrated superior local control. Of 9 patients in our series with Frankel C or greater neurologic deficits at presentation, 7 experienced a full recovery with treatment. Of the 27 patients, 37% experienced Common Toxicity Criteria Grade 3 or greater toxicity, including 2 deaths from sepsis. CONCLUSION Aggressive management of spinal and paraspinal Ewing tumors with RT with or without surgery results in high toxicity but excellent local control and neurologic outcomes. Efforts should be focused on identifying disease amenable to combined modality local therapy and improving RT techniques.

Radiation Treatment for Ewing Family of Tumors in Adults: The University of Florida Experience

PURPOSE To review the clinical characteristics and outcomes of adult patients with Ewing family of tumors treated with radiation at the University of Florida. METHODS AND MATERIALS Clinical features, treatment, and outcomes of 47 patients older than 18 years with Ewing family of tumors treated with combined radiation therapy and chemotherapy from 1970 to 2005 were retrospectively reviewed. Analysis was stratified by age older or younger than 30 years. Patients with metastatic disease at the time of diagnosis were excluded from the study. RESULTS The 29 men and 18 women had a median age of 24 years. Thirty-three patients were 18-30 years old and 14 patients were older than 30 years. Median follow-up of living patients was 8.2 years. The 5-year overall survival rate for all patients was 43% (p = 0.8523). The 5-year local control rate for all patients was 75% (p = 0.9326). The 5-year rate of freedom from distant metastasis for all patients was 45% (p = 0.5471). There were no significant differences in 5-year overall survival, local control, and freedom from distant metastasis rates; patterns of distant failure; or toxicity profiles between older adult patients and younger adult patients. CONCLUSIONS We found that the natural history and treatment outcomes of the Ewing family of tumors were consistently similar in adults (young and old) and children. Thus, aggressive combined modality approaches should be considered for adult patients.

Image guidance based on prostate position for prostate cancer proton therapy.

PURPOSE To determine the target coverage for proton therapy with and without image guidance and daily prebeam reorientation. METHODS AND MATERIALS A total of 207 prostate positions were analyzed for 9 prostate cancer patients treated using our low-risk prostate proton therapy protocol (University of Florida Proton Therapy Institute 001). The planning target volume was defined as the prostate plus a 5-mm axial and 8-mm superoinferior extension. The prostate was repositioned using 5- and 10-mm shifts (anteriorly, inferiorly, posteriorly, and superiorly) and for Points A-D using a combination of 10-mm multidimensional movements (anteriorly or inferiorly; posteriorly or superiorly; and left or right). The beams were then realigned using the new prostate position. The prescription dose was 78 Gray equivalent (GE) to 95% of the planning target volume. RESULTS For small movements in the anterior, inferior, and posterior directions within the planning target volume (< or =5 mm), treatment realignment demonstrated small, but significant, improvements in the clinical target volume (CTV) coverage to the prescribed dose (78 GE). The anterior and posterior shifts also significantly increased the minimal CTV dose (Delta +1.59 GE). For prostate 10-mm movements in the inferior, posterior, and superior directions, the beam realignment produced larger and significant improvements for both the CTV V(78) (Delta +6.4%) and the CTV minimal dose (Delta +8.22 GE). For the compounded 10-mm multidimensional shifts, realignment significantly improved the CTV V(78) (Delta +11.8%) and CTV minimal dose (Delta +23.6 GE). After realignment, the CTV minimal dose was >76.6 GE (>98%) for all points (A-D). CONCLUSION Proton beam realignment after target shift will enhance CTV coverage for different prostate positions.

PROTON THERAPY COVERAGE FOR PROSTATE CANCER TREATMENT

PURPOSE To determine the impact of prostate motion on dose coverage in proton therapy. METHODS AND MATERIALS A total of 120 prostate positions were analyzed on 10 treatment plans for 10 prostate patients treated using our low-risk proton therapy prostate protocol (University of Florida Proton Therapy Institute 001). Computed tomography and magnetic resonance imaging T(2)-weighted turbo spin-echo scans were registered for all cases. The planning target volume included the prostate with a 5-mm axial and 8-mm superoinferior expansion. The prostate was repositioned using 5- and 10-mm one-dimensional vectors and 10-mm multidimensional vectors (Points A-D). The beam was realigned for the 5- and 10-mm displacements. The prescription dose was 78 Gy equivalent (GE). RESULTS The mean percentage of rectum receiving 70 Gy (V(70)) was 7.9%, the bladder V(70) was 14.0%, and the femoral head/neck V(50) was 0.1%, and the mean pelvic dose was 4.6 GE. The percentage of prostate receiving 78 Gy (V(78)) with the 5-mm movements changed by -0.2% (range, 0.006-0.5%, p > 0.7). However, the prostate V(78) after a 10-mm displacement changed significantly (p < 0.003) with different movements: 3.4% (superior), -5.6% (inferior), and -10.2% (posterior). The corresponding minimal doses were also reduced: 4.5 GE, -4.7 GE, and -11.7 GE (p < or = 0.003). For displacement points A-D, the clinical target volume V(78) coverage had a large and significant reduction of 17.4% (range, 13.5-17.4%, p < 0.001) in V(78) coverage of the clinical target volume. The minimal prostate dose was reduced 33% (25.8 GE), on average, for Points A-D. The prostate minimal dose improved from 69.3 GE to 78.2 GE (p < 0.001) with realignment for 10-mm movements. CONCLUSION The good dose coverage and low normal doses achieved for the initial plan was maintained with movements of < or = 5 mm. Beam realignment improved coverage for 10-mm displacements.