Interstitial high-dose-rate brachytherapy in the treatment of keloids: Moving toward a volumetric approach.

PURPOSE: Brachytherapy (BT) after surgical resection of keloids reduces the risk of local recurrence, but standardization of dose/technique is lacking. Typical keloid BT treatment utilizes a single-channel source prescribed to 5-mm depth. We investigated the dosimetry of a volume-based target definition for interstitial high-dose-rate BT treatment of keloids. METHODS AND MATERIALS: We retrospectively identified consecutive 14 patients who had a total of 20 keloids treated with interstitial high-dose-rate BT for keloids at our institution between 2004 and 2014. Keloids were treated with a single 8 Gy fraction prescribed to 5 mm beneath the scar within 36 h of surgery. Retrospectively, a 3-mm skin high-risk clinical target volume (HR-CTV) was contoured under the scar for volume-based dose calculations. RESULTS: Mean (SD) HR-CTV was 3.91 cm3 (3.1) and mean (SD) HR-CTV dose was 11.3 Gy (3.6). Mean D90 (SD) was 62.9% (25.8) and mean V100 (SD) was 56.5% (26.4). The mean V150 (SD), V200 (SD), and V300 (SD) were as follows: 37.6% (19.9), 25.1% (14.4), and 11.3% (6.5), respectively. No local failures were reported at 9 months median followup. There were no Grade 2 or higher late toxicities. CONCLUSIONS: Using a volume-based target definition, a wide range of target coverage was observed. This is likely a consequence of the curvature of the skin and the challenges of keeping the catheter equidistant from the skin across the target. Additional data are needed to define the potential clinical impact on outcomes/toxicities of dosimetric correlates with single-catheter BT keloid treatment.

Palliative Radiation Therapy for Bone Metastases in Neuroendocrine Neoplasms.

PURPOSE: Bone metastases are reported in 10% to 12% of patients with neuroendocrine neoplasms (NENs) and can lead to pain and skeletal-related events (SREs), resulting in diminished quality of life and functional status. In other solid tumors with bone metastases, radiation therapy (RT) is an established treatment approach for SREs, yet few data are available in NENs historically considered to be radioresistant. We hypothesize that RT is effective for pain and other SREs in NENs and aimed to delineate any differences in pain palliation and time until progression of pain between different fractionation and dosing schedules of RT. METHODS AND MATERIALS: We retrospectively reviewed 686 records of patients with NENs treated at the institution between 2011 and 2018 and identified 28 (4.1%) patients treated with RT for 61 cases of SREs. The primary endpoint was change in patient reported pain scores after RT. RESULTS: All 28 patients experienced bone pain. Nineteen sites were treated with a single fraction (doses of 800-1800 cGy) and 42 sites with fractionated regimens (doses of 900-3750 cGy over 3-15 fractions). In 55 of 61 cases (90%), patients experienced improvement in pain after RT. The median time to recurrence or progression of pain was 3.5 months. Significant differences were found between primary site and change in performance status (P = .024), sex, and reported magnitude of pain score decrease after RT (P = .025). There were no differences in the time to the progression of pain, change in performance status, and degree of improvement in pain based on age, chemotherapy received during RT, or radiation site. Outcomes were similar for patients who received single-fraction versus fractionated regimens (P = .545) and between those receiving palliative versus ablative RT regimens (P = .812). CONCLUSIONS: Although the majority of cases in this NEN cohort benefited from RT, additional studies on the use of RT in the treatment of painful bone metastases are warranted.

Effect of Long-Term Hormonal Therapy (vs Short-Term Hormonal Therapy): A Secondary Analysis of Intermediate-Risk Prostate Cancer Patients Treated on NRG Oncology RTOG 9202.

PURPOSE: NRG Oncology RTOG 9202 was a randomized trial testing long-term adjuvant androgen deprivation (LTAD) versus initial androgen deprivation only (STAD) with external beam radiation therapy (RT) in mostly high-risk and some intermediate-risk prostate cancer patients. RTOG 9408 found an overall survival (OS) advantage in patients with cT1b-T2b disease and prostate-specific antigen (PSA) <20 ng/mL, with benefit observed mostly among intermediate-risk patients. It was still unknown whether intermediate-risk patients would experience an additional survival benefit with LTAD; thus, we performed a secondary analysis to explore whether LTAD had any incremental benefit beyond STAD among the intermediate-risk subset of RTOG 9202. The study endpoints were OS, disease-specific survival (DSS), and PSA failure (PSAF). METHODS AND MATERIALS: An analysis was performed for all patients enrolled in RTOG 9202 defined as intermediate-risk (cT2 disease, PSA<10 ng/mL, and Gleason score = 7 or cT2 disease, PSA 10-20 ng/mL, and Gleason score <7). This review yielded 133 patients: 74 (STAD) and 59 (LTAD). The Kaplan-Meier method was used to estimate OS; the cumulative incidence approach was used to estimate DSS and PSAF. A 2-sided test was used, with significance level defined to be .05. RESULTS: With over 11 years of median follow-up, 39 STAD patients were alive and 33 LTAD patients were alive. There was no difference in OS (10-year estimates, 61% STAD vs 65% LTAD; P=.53), DSS (10-year DSS, 96% vs 97%; P=.72), or PSAF (10-year PSAF, 53% vs 55%; P=.99) between groups. CONCLUSION: LTAD did not confer a benefit in terms of OS, DSS, or PSAF rates in the intermediate-risk subset in this study. Whereas the subset was relatively small, treatment assignment was randomly applied, and a trend in favor of LTAD would have been of interest. Given the small number of disease-specific deaths observed and lack of benefit with respect to our endpoints, this secondary analysis does not suggest that exploration of longer hormonal therapy is worth testing in the intermediate-risk prostate cancer subset.