Joshua Siglin

Time of Decline in Sexual Function After External Beam Radiotherapy for Prostate Cancer

PURPOSE Erectile dysfunction is one of the most concerning toxicities for patients in the treatment of prostate cancer. The inconsistent evaluation of sexual function (SF) and limited follow-up data have necessitated additional study to clarify the rate and timing of erectile dysfunction after external beam radiotherapy (EBRT) for prostate cancer. METHODS AND MATERIALS A total of 143 men completed baseline data on SF before treatment and at the subsequent follow-up visits. A total of 1187 validated SF inventories were analyzed from the study participants. Multiple domains of SF (sex drive, erectile function, ejaculatory function, and overall satisfaction) were analyzed for < or =8 years of follow-up. RESULTS The median follow-up was 4.03 years. The strongest predictor of SF after EBRT was SF before treatment. For all domains of SF, the only statistically significant decrease in function occurred in the first 24 months after EBRT. SF stabilized 2 years after treatment completion, with no statistically significant change in any area of SF >2 years after the end of EBRT. CONCLUSION These data suggest that SF does not have a continuous decline after EBRT. Instead, SF decreases maximally within the first 24 months after EBRT, with no significant changes thereafter.

Clinical experience transitioning from IMRT to VMAT for head and neck cancer.

To quantify clinical differences for volumetric modulated arc therapy (VMAT) versus intensity modulated radiation therapy (IMRT) in terms of dosimetric endpoints and planning and delivery time, twenty head and neck cancer patients have been considered for VMAT using Nucletron Oncentra MasterPlan delivered via an Elekta linear accelerator. Differences in planning time between IMRT and VMAT were estimated accounting for both optimization and calculation. The average delivery time per patient was obtained retrospectively using the record and verify software. For the dosimetric comparison, all contoured organs at risk (OARs) and planning target volumes (PTVs) were evaluated. Of the 20 cases considered, 14 had VMAT plans approved. Six VMAT plans were rejected due to unacceptable dose to OARs. In terms of optimization time, there was minimal difference between the two modalities. The dose calculation time was significantly longer for VMAT, 4 minutes per 358 degree arc versus 2 minutes for an entire IMRT plan. The overall delivery time was reduced by 9.2 ± 3.9 minutes for VMAT (51.4 ± 15.6%). For the dosimetric comparison of the 14 clinically acceptable plans, there was almost no statistical difference between the VMAT and IMRT. There was also a reduction in monitor units of approximately 32% from IMRT to VMAT with both modalities demonstrating comparable quality assurance results. VMAT provides comparable coverage of target volumes while sparing OARs for the majority of head and neck cases. In cases where high dose modulation was required for OARs, a clinically acceptable plan was only achievable with IMRT. Due to the long calculation times, VMAT plans can cause delays during planning but marked improvements in delivery time reduce patient treatment times and the risk of intra-fraction motion.

Active Breathing Coordinator reduces radiation dose to the heart and preserves local control in patients with left breast cancer: Report of a prospective trial

PURPOSE Incidental radiation dose to the heart and lung during breast radiation therapy (RT) has been associated with an increased risk of cardiopulmonary morbidity. We conducted a prospective trial to determine if RT with the Active Breathing Coordinator (ABC) can reduce the mean heart dose (MHD) by ≥20% and dose to the lung. METHODS AND MATERIALS Patients with stages 0-III left breast cancer (LBC) were enrolled and underwent simulation with both free breathing (FB) and ABC for comparison of dosimetry. ABC was used during the patients RT course if the MHD was reduced by ≥5%. The median prescription dose was 50.4 Gy plus a boost in 77 patients (90%). The primary endpoint was the magnitude of MHD reduction when comparing ABC to FB. Secondary endpoints included dose reduction to the heart and lung, procedural success rate, and adverse events. RESULTS A total of 112 patients with LBC were enrolled from 2002 to 2011 and 86 eligible patients underwent both FB and ABC simulation. Ultimately, 81 patients received RT using ABC, corresponding to 72% procedural success. The primary endpoint was achieved as use of ABC reduced MHD by 20% or greater in 88% of patients (P < .0001). The median values for absolute and relative reduction in MHD were 1.7 Gy and 62%, respectively. RT with ABC provided a statistically significant dose reduction to the left lung. After a median follow up of 81 months, 8-year estimates of locoregional relapse, disease-free, and overall survival were 7%, 90%, and 96%, respectively. CONCLUSIONS ABC was well tolerated and significantly reduced MHD while preserving local control. Use of the ABC device during RT should be considered to reduce the risk of ischemic heart disease in populations at risk.

Radiation Therapy for Locally Recurrent Breast Cancer

Approximately one-third of all breast cancer patients experience local recurrence of their tumor after initial treatment. As initial treatment often employs the use of radiation therapy (RT), the standard of care for local breast cancer recurrence after initial breast conserving therapy has traditionally been surgical intervention with mastectomy. However, recent attempts to preserve the intact breast after recurrence with local excision have revealed a potential need for RT in addition to repeat breast conserving surgery as rates of local failure with resection alone remain high. Additionally, local recurrence following initial mastectomy and chest wall RT can be treated with reirradiation to increase local control. Repeating RT, however, in a previously irradiated area, is a complex treatment strategy, as the clinician must carefully balance maximizing treatment effectiveness while minimizing treatment-related toxicity. As a result, physicians have been hesitant to treat recurrent disease with repeat RT with limited data. Results from the current literature are promising and current clinical trials are underway to explore reirradiation modalities which will provide additional information on treatment-related toxicity and outcomes. This paper will review the current literature on repeat radiation therapy for locally recurrent breast cancer.

Optimizing patient positioning for intensity modulated radiation therapy in hippocampal-sparing whole brain radiation therapy

PURPOSE Sparing the hippocampus during whole brain radiation therapy (WBRT) offers potential neurocognitive benefits. However, previously reported intensity modulated radiation therapy (IMRT) plans use multiple noncoplanar beams for treatment delivery. An optimized coplanar IMRT template for hippocampal-sparing WBRT would assist in clinical workflow and minimize resource utilization. In this study, we sought to determine the optimal patient position to facilitate coplanar treatment planning and delivery of hippocampal-sparing WBRT using IMRT. METHODS AND MATERIALS A variable angle, inclined board was utilized for patient positioning. An anthropomorphic phantom underwent computed tomography simulation at various head angles. The IMRT goals were designed to achieve target coverage of the brain while maintaining hippocampal dose-volume constraints designed to conform to the Radiation Therapy Oncology Group 0933 protocol. Optimal head angle was then verified using data from 8 patients comparing coplanar and noncoplanar WBRT IMRT plans. RESULTS Hippocampal, hippocampal avoidance region, and whole brain mean volumes were 1.1 cm(3), 12.5 cm(3), and 1185.1 cm(3), respectively. The hippocampal avoidance region occupied 1.1% of the whole brain planning volume. For the 30-degree head angle, a 7-field coplanar IMRT plan was generated, sparing the hippocampus to a maximum dose of 14.7 Gy; D100% of the hippocampus was 7.4 Gy and mean hippocampal dose was 9.3 Gy. In comparison, for flat head positioning the hippocampal Dmax was 22.9 Gy with a D100% of 9.2 Gy and mean dose of 11.7 Gy. Target coverage and dose homogeneity was comparable with previously published noncoplanar IMRT plans. CONCLUSIONS Compared with conventional supine positioning, an inclined head board at 30 degrees optimizes coplanar whole brain IMRT treatment planning. Clinically acceptable hippocampal-sparing WBRT dosimetry can be obtained using a simplified coplanar plan at a 30-degree head angle, thus obviating the need for complex and time consuming noncoplanar IMRT plans.

Evaluating changes in radiation treatment volumes from post-operative to same-day planning MRI in High-grade gliomas

BackgroundAdjuvant radiation therapy (RT) with temozolomide (TMZ) is standard of care for high grade gliomas (HGG) patients. RT is commonly started 3 to 5 weeks after surgery. The deformation of the tumor bed and brain from surgery to RT is poorly studied. This study examined the magnitude of volume change in the postoperative tumor bed and the potential impact of RT planning.Method and materialsThis study includes 24 patients with HGG who underwent craniotomy and adjuvant RT with TMZ at our institution. All patients had immediate postoperative MRI and repeat MRI during the day of RT simulation. Gross tumor volumes (GTV), clinical target volumes (CTV) of initial 46 Gy (CTV1) and boost to 60 Gy (CTV2) were contoured on both sets of MRIs according to RTOG (Radiation Therapy Oncology Group) guidelines. For patients who recurred after RT, the recurrence pattern was evaluated.ResultsAn average of 17 days elapsed between immediate and delayed MRIs. GTV1 (FLAIR abnormality and tumor bed) decreased significantly on the delayed MRI as compared to immediate post-operative MRI (mean = 30.96cc, p = 0.0005), while GTV2 (contrast-enhanced T1 abnormality and tumor bed) underwent a non-significant increase (mean = 6.82cc, p = 0.07). Such changes lead to significant decrease of CTV1 (mean decrease is 113.9cc, p<0.01), and significant increase of CTV2 (mean increase is 32.5cc, p=0.05). At a median follow-up of 13 months, 16 patients (67%) progressed, recurred, or died, with a progression-free survival time of 13.7 months. Twelve patients failed within all CTVs based on immediate and delayed MRIs, while one patient recurred outside of CTV2 based on immediate post-operative MRI, but within the CTV2 defined on delayed MRI.ConclusionThe postoperative tumor bed of HGGs undergoes substantial volumetric changes after surgery. Treatment planning based on delayed MRI significantly reduces the volume of treated brain tissue without local control detriment. The marked reduction of volume treated to 46 Gy based on delayed MRI scan, could result in increased sparing of organs at risk. There may be a small risk of inadequate radiation field design if radiation planning is based on immediate post-operative MRI.

Stereotactic Radiotherapy for Trigeminal Schwannomas

BACKGROUND Data on radiotherapy for trigeminal schwannomas (TSs) and comparison of stereotactic radiosurgery (SRS) with fractionated stereotactic radiotherapy (FSRT) are limited. OBJECTIVE We present a large retrospective review of our institutional experience treating TSs with SRS and FSRT. We also describe a flare phenomenon experienced by some patients. METHODS The records of 23 consecutive TSs patients treated with radiotherapy between 1996 and 2011 were reviewed. We investigated radiographic response, tumor control, and toxicity. RESULTS Ten patients underwent SRS and 13 underwent FSRT, with median clinical follow-up of 32 months (range, 3-120 months). Tumor control at 5 and 10 years was 94% overall. Symptom control at 5 years was achieved in 48% of all patients, with nonsignificant improvement in more patients in the FSRT group than those in the SRS group (56% vs 40%, P = .37). Acute toxicity was higher in the FSRT group (38.5 vs 0%, P < .01), although lesions treated with FSRT were larger (mean, 9.5 mL vs 4.8 mL, P < .01). A symptomatic flare phenomenon occurred in 2 patients (8.7% overall) during FSRT, involving transient cystic formation and dramatic size increase. One lesion regressed in size and 1 remained stable on follow-up. CONCLUSION Tumor control rates for TSs are excellent with SRS and FSRT with minimal toxicity. This represents the first documented report of a flare phenomenon after FSRT for TS treatment. Flare risk after FSRT in previously resected large lesions should be discussed with patients before treatment, and prophylactic oral steroids may be considered.

The Responsibilities of a Chief Resident in Radiation Oncology: Results of a National Survey

Received Jun 4, 2013, and in revised form Jun 11, 2013. Accepted for publication Jun 13, 2013Training programs for resident physicians in the United Statesoften have chief residents (CRs) to develop future medical leaderswho will shape clinical practice, medical education, and research.As of 2013, the responsibilities of a CR in radiation oncology areundefined.We asked the program coordinators of 82 radiation oncologyresidencies in the United States for written CR job descriptions inAugust 2012. From all e-mail responses and published literatureon CR job descriptions in other fields (1-6), we compiledresponsibilities, selection criteria, and compensation methods into1 list. The responsibilities were categorized into 4 core groups:clinical skills, research, mentoring/teaching trainees, and leader-ship/administration. Cognitive interviews were conducted totailor the survey (Supplementary material 1, available at www.redjournal.org).The e-mail addresses of radiation oncology CRs and programdirectors (PDs) were obtained from the Association of Residentsin Radiation Oncology directory; programs under probation ornewly formed were excluded (nZ6). Surveys with a 1-time use,unique, anonymous link were e-mailed to individual addresses viasurveymonkey.com to current CRs and PDs. Three remindermessages were sent. Multiple responses from the same internetprotocol address were blocked. For each prompt, the scaled scores(1, strongly disagree; 2, disagree; 3, neutral; 4, agree; 5, stronglyagree) were used to calculate mean Likert scores (MLSs) standard error of the mean (SEM). To compare responses, wecalculated pooled standard deviations, t statistics, and corre-sponding degrees of freedom (with P 90% of programs) and varies among10% of programs depending on the number of residents takenper year.Sixty-four percent of respondents indicate that theirprograms do not have written guidelines for CRs (ie, they do not“agree”/”strongly agree” to the prompt). CRs and PDs believethat the general responsibilities of CRs include clinical (4.80.1), research (4.1 0.1), mentoring/teaching (4.0 0.1), andleadership/administrative (3.5 0.1) duties; both parties rankthe duties in this order. Specific responsibilities (Fig. 1) includeattending events, scheduling/coordinating events, seeingpatients with the attending they are covering, mentoring

Correction to: Salvage fractionated stereotactic re-irradiation (FSRT) for patients with recurrent high grade gliomas progressed after bevacizumab treatment

The fourth author’s name was incorrect in the initial online publication. The original article has been corrected.

Dose Reduction to the Scalp with Hippocampal Sparing Is Achievable with Intensity Modulated Radiotherapy

We evaluated the feasibility of combined hippocampal- and scalp-sparing intensity-modulated radiotherapy (IMRT) plans. This study included 7 patients who received conventional palliative whole brain radiation treatment (WBRT) for brain metastasis. The brain, hippocampus, and scalp were contoured and replanned with intensity modulated radiation therapy. The prescription dose was 30 Gray (Gy) in 10 fractions with hippocampus and normal structure constraints per the Radiation Therapy Oncology Group (RTOG) 0933 protocol. Further planning was done to minimize the scalp dose while maintaining the dose constraints for the hippocampus. Dose volume histograms were obtained from conventional opposed lateral fields, IMRT and compared. Planning target volume (PTV) coverage for all plans fell within the RTOG 0933 critical structure acceptable variation category. When compared to traditional opposed lateral fields, the IMRT plan with combined hippocampal- and scalp-sparing constraints was able to significantly reduce the max and mean scalp dose as well as the percentage of scalp receiving 10 and 20 Gy by 46% and 35%, respectively, while maintaining acceptable RTOG 0933 hippocampal dose variations. We conclude that acceptable PTV coverage and sparing of the scalp and hippocampus can be accomplished using a 9-field non-coplanar IMRT plan. Prospective study is warranted to understand the impact on radiation induced alopecia.