Sheen Cherian

Stereotactic body radiotherapy for the treatment of spinal metastases

IntroductionSpine stereotactic body radiation therapy (sSBRT) allows for the delivery of a high dose of radiation to spine metastases while respecting the dose limits of the adjacent spinal cord. In contrast with conventional radiation, the dose to spine metastases is limited by the spinal cord tolerance since the spinal cord is in the treatment field. sSBRT allows for reirradiation of spinal metastases, as well as higher doses to be delivered particularly for radioresistant metastases. It is also being used post laminectomy and decompressive surgery as primary treatment for malignant spinal cord compression instead of conventional external beam radiation therapy. Although experience and evidence are growing, variations in practice remain.PurposeWe review the technical considerations and clinical applications of sSBRT.

Evaluating Candidacy for Hypofractionated Radiation Therapy, Accelerated Partial Breast Irradiation, and Endocrine Therapy After Breast Conserving Surgery: A Surveillance Epidemiology and End Results (seer) Analysis

Purpose/Objective(s): After breast conserving surgery, adjuvant radiation therapy represents the standard of care for most patients. However, multiple options exist beyond standard fractionated whole breast irradiation including hypofractionated whole breast irradiation (HFRT), accelerated partial breast irradiation (APBI), and endocrine therapy (ET) alone, which can limit treatment duration, and potentially reduce morbidity and cost. Limited data are available on the percentage of patients eligible for these alternatives; therefore, a Surveillance Epidemiology and End Results (SEER) analysis was performed to assess candidacy for these alternative options in women with early stage breast cancer. Materials and Methods: Women treated for breast cancer between the years of 2010 and 2012 were identified in the SEER database. Patients with unknown staging, metastatic disease, T3/T4 disease, and ≥N1 disease were excluded. Patients were defined as eligible for HFRT based on the American Society for Radiation Oncology (ASTRO) consensus guidelines and randomised trial testing intensity modulated and partial organ radiotherapy following breast conservation surgery for early breast cancer (IMPORT LOW) trial criteria, APBI based on the ASTRO, American Brachytherapy Society and the Groupe Européen de Curiethérapie of European Society for Therapeutic Radiotherapy and Oncology (GEC-ESTRO) consensus guidelines, and GEC-ESTRO APBI and IMPORT LOW trial criteria, and ET alone based on the Cancer and Leukemia Group B 9343 and Post-operative Radiotherapy in Minimum Risk Elderly II inclusion criteria. Results: A total of 108,484 women with early stage breast cancer who met the aforementioned inclusion criteria were identified. Of these patients, 86,896 (80.1%) were eligible for HFRT based on ASTRO consensus guidelines and 81,459 (75.0%) based on IMPORT LOW trial criteria. Regarding APBI, 44,797 (41.2%), 81,020 (74.6%), 81,020 (74.6%) were eligible according to ASTRO, ABS, GEC-ESTRO consensus guidelines, respectively, 97,301 (89.7%) patients according to the GEC-ESTRO trial criteria, and 81,459 (75.0%) patients according to the IMPORT LOW trial criteria. For ET alone, 23,006 (21.2%) were eligible according to Cancer and Leukemia Group B 9343 criteria and 42,104 (38.8%) according to Post-operative Radiotherapy in Minimum Risk Elderly II criteria. Conclusions: This SEER analysis demonstrates that a substantial proportion of women with early stage breast cancer are eligible for HFRT, APBI, or ET alone after breast conserving surgery according to consensus guidelines and prospective trial criteria. With incorporation of additional pathologic, dosimetric, and chemotherapy data, quality assurance pathways may use such data to help ensure patients are receiving appropriate risk stratified treatment recommendations.

Safety and efficacy of iodine-125 permanent prostate brachytherapy in patients with J-pouch anastomosis after total colectomy for ulcerative colitis

PURPOSE To ascertain the safety and efficacy of permanent prostate brachytherapy (PPB) in early prostate cancer patients who have undergone previous total proctocolectomy and J-pouch anastomosis for inflammatory bowel disease. METHODS AND MATERIALS We identified 10 patients with a previous history of prostate cancer and J-pouch anastomosis from our institutional review board-approved database. Seven patients had PPB and 3 had prostatectomy. Only patients treated with PPB were included. Patient records were reviewed to collect data on treatment-related toxicity and oncological outcomes. RESULTS All 7 patients who underwent PPB had low- to intermediate-risk prostate cancer. The mean prostatic volume was 24.40 mL and the average number of iodine-125 seeds implanted was 84. Postimplant dosimetric calculations showed a mean prostate volume receiving 100% of the prescribed dose (V100) of 88.76%, V150 of 45.23%, V200 of 16.79%, radiation dose delivered to 90% of the prostate of 147.89 Gy, volume of ileal pouch receiving 100% of the prescribed dose of 0.164 mL, and volume of ileal pouch receiving 50% of the prescribed dose of 1.38 mL. After a mean follow-up of 19 months, none of the patients had evidence of biochemical failure or clinical failure. There were no long-term genitourinary side effects detected. Two patients had Common Terminology Criteria for Adverse Events version 4.0 grade II gastrointestinal side effects, of which symptoms resolved to baseline in 1 patient, whereas the other patient progressed to chronic active enteritis (pouchitis). CONCLUSION Low- to intermediate-risk prostate cancer patients with J-pouch anastomosis after total colectomy for inflammatory bowel disease are candidates for definitive treatment with PPB. Caution should be exercised while deploying the most posterior row of seeds to minimize enteral pouch radiation doses.

Principles and practice of high-dose rate penile brachytherapy: Planning and delivery techniques

PURPOSE To allow for organ preservation, high-dose rate (HDR) brachytherapy may be used in the treatment of localized penile cancer. Penile cancer is a rare malignancy that accounts for <1% of cancers in men in the United States. The standard treatment for localized disease is partial amputation of the penis. However, patients with T1b or T2 disease <4 cm in maximum dimension and confined to the glans penis may be treated with brachytherapy as an organ-sparing approach. Previous works have described the technique involved for low-dose rate brachytherapy; however, we detail the techniques involved with HDR brachytherapy. METHODS AND MATERIALS Circumcision should precede brachytherapy. Interstitial brachytherapy needles are placed in the operating room under general anesthesia with the goal to allow for appropriate target coverage. Target definition is done via computed tomography-based simulation and planning. Radiation is delivered using a prescription dose of 3840 cGy in 12 fractions twice daily over a course of 6 days. RESULTS Acute toxicities peak upon completion of the radiation therapy and may include dermatitis, sterile urethritis, and adhesions in the urethra. These toxicities are reversible and generally take 2 to 3 months to heal. The two most common and significant late complications of radiation therapy for penile cancer are soft tissue necrosis and meatal stenosis. An increased risk of necrosis has been reported with T3 tumors and higher-volume implants (>30 cm3). Erectile function is generally maintained because the erectile tissues including the penile shaft and corpora have not been irradiated. CONCLUSIONS Organ preservation is feasible using HDR brachytherapy with favorable acute and late toxicities.

Oncotype testing in patients undergoing intraoperative radiation for breast cancer

Oncotype DX recurrence score (RS) predicts risk of distant disease recurrence, and can guide chemotherapy recommendations in hormone positive, human epidermal growth factor 2-negative, early stage breast cancer. The present study aimed to evaluate the pattern of oncotype testing, RS and adjuvant treatment in patients undergoing intraoperative radiotherapy (IORT). Single center prospective data registry was queried for patients receiving IORT between October 2011 and February 2017. Patient demographics, tumor characteristics, RS, systemic therapy and recurrence information were analyzed. A total of 150 women with mean age of 70.8 years were included. The majority had invasive ductal cancer (60.6%) with 1.0 cm average tumor size and no lymph node involvement (99%). Oncotype testing was performed in 36 patients (24.3%). Low risk score (<18) was confirmed in 19 women (53%); intermediate risk score (18-30) in 16 women (44%); and high risk score (>30) in one woman (3%). Patients with RS testing had significantly increased tumor sizes (1.2 vs. 1.0 cm; P<0.001) and were younger (68.5 vs. 71.3 years; P=0.02) compared with those not tested. A total of 4/150 patients (2.6%) received chemotherapy; two received chemotherapy based on RS testing. Based on the current selection criteria for IORT, oncotype testing rarely results in a high-risk score or utilization of chemotherapy for IORT patients. The present study supports selective use of RS testing in IORT patients and confirms that biologically low-risk patients are being selected for IORT based on current guidelines.

Dosimetric differences between local failure and local controlled non-small cell lung cancer patients treated with stereotactic body radiotherapy: A matched-pair study

Concerns were raised about the accuracy of pencil beam (PB) calculation and potential underdosing of medically inoperable non‐small cell lung cancer (NSCLC) treated with stereotactic body radiation therapy (SBRT). From our institutional series, we designed a matched‐pair study where each local failure and controlled patient was matched based upon several clinical factors, to investigate the dose difference between the matched‐pair.

Most patients are eligible for an alternative to conventional whole breast irradiation for early-stage breast cancer: A National Cancer Database Analysis

We evaluated the proportion of patients eligible for alternatives to standard whole breast irradiation (WBI) following breast‐conserving surgery using the National Cancer Database (NCDB). Using the 2016 dataset, Stage I‐III patients were identified. Eligibility for hypofractionated WBI (HFRT), accelerated partial breast irradiation (APBI) and endocrine therapy (ET‐alone) was defined using eligibility from large clinical trials as well as consensus guidelines. For patients with pN0 breast cancer, 20.6% and 37.0% were eligible for ET‐alone based on the CALGB 9343/PRIME‐II trials, respectively. In terms of HFRT, 72.5% and 50.4% were eligible based on IMPORT LOW/ASTRO HFRT guidelines, respectively. Based on IMPORT LOW/GEC‐ESTRO trial/ASTRO guidelines/ABS guidelines/GEC‐ESTRO guidelines, 72.5%, 86.1%, 39.0%, 72.5%, 45.7%, respectively, were eligible for APBI. Of those who qualify for HFRT per ASTRO guidelines, approximately 90% were eligible for APBI and 50% for ET‐alone. This analysis shows that a large proportion of patients with node‐negative breast cancer are eligible for HFRT, APBI and/or ET‐alone after breast‐conserving surgery.

Are Patients Traveling for Intraoperative Radiation Therapy

Purpose One benefit of intraoperative radiation therapy (IORT) is that it usually requires a single treatment, thus potentially eliminating distance as a barrier to receipt of whole breast irradiation. The aim of this study was to evaluate the distance traveled by IORT patients at our institution. Methods Our institutional prospective registry was used to identify IORT patients from 10/2011 to 2/2017. Patients home zip code was compared to institution zip code to determine travel distance. Characteristics of local (<50 miles), regional (50–100 miles), and faraway (>100 miles) patients were compared. Results 150 were patients included with a median travel distance of 27 miles and mean travel distance of 121 miles. Most were local (68.7%), with the second largest group living faraway (20.0%). Subset analysis of local patients demonstrated 20.4% traveled <10 miles, 34.0% traveled 10–20 miles, and 45.6% traveled 20–50 miles. Six patients traveled >1000 miles. The local, regional, and faraway patients did not differ with respect to age, race, tumor characteristics, or whole breast irradiation. Conclusions Breast cancer patients are traveling for IORT, with 63% traveling >20 miles for care. IORT is an excellent strategy to promote breast conservation in selected patients, particularly those who live remote from a radiation facility.

Intraoperative Radiation for Breast Cancer with Intrabeam™: Factors Associated with Decreased Operative Times in Patients Having IORT for Breast Cancer

Introduction Intraoperative radiation with Intrabeam™ (IORT) for breast cancer is a newer technology recently implemented into the operating room (OR). This procedure requires time and coordination between the surgeon and radiation oncologist, who both perform their treatments in a single operative setting. We evaluated the surgeons at our center, who perform IORT and their OR times to examine changes in OR times following implementation of this new surgical procedure. We hypothesized that IORT is a technique for which timing could be improved with the increasing number of cases performed. Methods A prospectively maintained IRB approved database was queried for OR times (incision and close) in patients who underwent breast conserving surgery (BCS), sentinel lymph node biopsy with and without IORT using the Intrabeam™ system at our institution from 2011 to 2015. The total OR times were compared for each surgeon individually and over time. Next, the OR times of each surgeon were compared to each other. Continuous variables were summarized and then a prediction model was created using IORT time, OR time, surgeon, and number of cases performed. Results There were five surgeons performing IORT at our institution during this time period with a total of 96 cases performed. There was a significant difference observed in baseline surgeon-specific OR time for BSC (p = 0.03) as well as for BCS with IORT (p < 0.05), attributable to surgeon experience. The average BCS times were faster than the BCS plus IORT procedure times for all surgeons. The overall mean OR time for the entire combined surgical and radiation procedure was 135.5 min. The most common applicator sizes used were the 3.5 and 4 cm, yielding an average 21 min IORT time. Applicator choice did not differ over time (p = 0.189). After adjusting for IORT time and surgeon, the prediction model estimated that surgeons decreased the total BCS plus IORT OR time at a rate of −4.5 min per each additional 10 cases performed. Conclusion Surgeon experience and applicator size are related to OR times for performing IORT for breast cancer. OR time for IORT in breast cancer treatment can be improved over time, even among experienced surgeons.

Locoregional Therapy Following Neoadjuvant Therapy for HER-2+ Breast Cancer: Opportunities and Challenges

Advances in the management of patients with HER-2+ breast cancer with combinatorial targeted therapies are leading to unprecedented rates of pathologic complete response. The high rates of complete pathologic response in the breast and the axillary lymph nodes following neoadjuvant therapy are raising new questions about the role of local therapies (surgery and radiation therapy) in treating these patients. The safe elimination of surgery and radiation therapy for selected breast cancer patients would ultimately reduce the short- and long-term morbidity associated with traditional breast cancer treatments and would represent a major step forward. However, numerous technical and clinical challenges remain which will be discussed in this chapter. Collaborative efforts to address these challenges are essential to improving current therapeutic approaches for patients with HER-2+ breast cancer.