Jay Reiff

Plaque Radiotherapy for Juxtapapillary Choroidal Melanoma: Tumor Control in 650 Consecutive Cases

PURPOSE To evaluate treatment of juxtapapillary choroidal melanoma with plaque radiotherapy and to investigate the role of supplemental transpupillary thermotherapy (TTT). DESIGN Retrospective, comparative case series. PARTICIPANTS We included 650 consecutive eyes with juxtapapillary choroidal melanoma within 1 mm of the optic disc. METHODS Eyes with juxtapapillary choroidal melanoma receiving plaque radiotherapy over a 31-year period from October 1974 to November 2005 were included in the study. The TTT and no TTT groups were analyzed separately and compared. MAIN OUTCOME MEASURES Local tumor control, metastasis, and tumor-related mortality. RESULTS The median basal tumor diameter was 10 mm (range, 1.5-21) and median thickness was 3.5 mm (range, 0.5-14.8). In 481 eyes (74%), the tumor was directly adjacent to the optic disc and in 169 eyes (26%) the posterior tumor margin was between 0.1 and 1.0 mm from the optic disc. The circumpapillary extent of the tumor was <4 clock-hours in 321 eyes (50%), 4-8 clock-hours in 250 eyes (38%), and >8 clock-hours in 79 eyes (12%). Plaque radiotherapy using iodine-125 in 616 eyes (95%), cobalt-60 in 19 eyes (3%), iridium-192 in 12 eyes (2%), and ruthenium-106 in 3 eyes (<1%) delivered a median radiation dose of 8000 cGy (range, 3600-15 500) to the tumor apex and adjunctive TTT was used in 307 eyes (56%). Kaplan-Meier estimates for tumor recurrence, metastasis, and death were 14%, 11%, and 4% at 5 years and 21%, 24%, and 9% at 10 years, respectively. Eyes treated with additional TTT showed slight (statistically nonsignificant) reduction in recurrence and metastasis. Using multivariable analysis, factors predictive of tumor recurrence included foveolar tumor requiring TTT (hazard ratio, 5.07; P<0.001) and greater tumor thickness (hazard ratio, 1.29 per mm increase; P<0.001). Factors predictive of metastasis included greater tumor base (hazard ratio, 1.21 per mm increase; P<0.001) and increasing intraocular pressure (hazard ratio, 1.11 per mmHg increase; P = 0.020). CONCLUSIONS Plaque radiotherapy for juxtapapillary melanoma provides local tumor control in approximately 80% of eyes at 10 years. In subjects who received TTT, there was slight but nonsignificant improved local tumor control and lower metastatic rate.

Plaque radiotherapy for juxtapapillary choroidal melanoma overhanging the optic disc in 141 consecutive patients.

OBJECTIVE To evaluate tumor control with plaque radiotherapy for juxtapapillary choroidal melanoma that overhangs the optic disc. METHODS Retrospective medical record review of 141 consecutive patients with data on complications of treatment, final visual acuity, visual loss, enucleation, tumor recurrence, metastasis, and death. RESULTS The median patient age was 61 years. Presenting symptoms included reduced visual acuity in 72 eyes (51%), photopsia in 14 (10%), and visual field defect in 18 (13%); 35 patients (25%) were asymptomatic. The median tumor basal diameter was 11 mm and the median thickness was 5.2 mm. The tumor overhung 50% or less of the disc in 88 eyes (62%) and more than 50% of the disc in 53 eyes (38%). In 19 cases (13%), the tumor overhung the entire disc. All patients were treated with plaque radiotherapy, using a notched design in 126 eyes (89%) and a round design in 14 eyes (10%), with iodine 125 in 132 eyes (94%) and cobalt 60 in 9 eyes (6%). The median radiation dose to the tumor apex was 8500 cGy. Adjuvant transpupillary thermotherapy was used in 54 eyes (39%). During a mean follow-up of 56 months, complications included nonproliferative retinopathy in 61 eyes (51%), proliferative retinopathy in 26 (22%), maculopathy in 44 (37%), papillopathy in 57 (48%), neovascular glaucoma in 23 (19%), and vitreous hemorrhage in 48 (40%). A final visual acuity of 20/200 or worse was measured in 72 eyes (77%), and visual loss of more than 5 Snellen lines occurred in 59 eyes (63%). Enucleation was necessary in 27 eyes (23%). Tumor recurrence was found in 12 eyes (10%). Metastasis developed in 15 patients (13%) and death in 4 cases (3%). CONCLUSIONS Using plaque radiotherapy for choroidal melanoma overhanging the optic disc, local tumor control was achieved in 90% of cases. Tumor and radiation effects led to poor visual acuity in 77% of eyes. The metastatic rate was 13% and the mortality rate was 3%.

Dosimetric properties of megavoltage grid therapy

PURPOSE Grid therapy is a technique used to deliver a high dose of radiation (15-20 Gy) in a single fraction to many small volumes within a large treatment field. This treatment modality is used for the palliative treatment of large, deeply seated tumors, which have either been treated to tolerance with conventional radiation, or, due to massive tumor bulk, would most likely not benefit from a conventional course of radiation therapy. As the dose distribution from megavoltage grid therapy differs significantly from that of conventional radiation therapy (i.e., many large dose gradients exist within the tumor volume), we have measured various dosimetric properties inherent in this unique treatment modality. METHODS AND MATERIALS The grid is a 16 x 16 array of 1-cm diameter holes in a 7-cm thick piece of custom blocking material. The ratio of shielded to open surface area is 1:1. Depth dose, valley-to-peak ratios, and output factors for this square array grid were measured in a water phantom for several field sizes, as well as for a 1-cm diameter narrow beam using 6 MV and 25 MV photon beams. RESULTS The depth dose curves for the grid fields lie between those for an open portal and a narrow beam. For the 6-MV beam at dmax, the ratios of the doses delivered to the center of the shielded regions to that under the center of the holes, expressed as valley-to-peak ratios, range from 15 to 40%. At 10 cm, the ratios increase to between 25 and 45%. At 25 MV at both dmax and 10 cm, the valley-to-peak ratios are between 40 and 60%. The output factors, 0.89 for 6 MV and 0.77 for 25 MV, do not depend on field size. CONCLUSION Megavoltage grid therapy is a unique treatment modality where the dose is delivered differentially to a large volume in one fraction. Characterization of the dosimetric properties has allowed clinical implementation of the grid.

Tumor bed-to-skin distance using accelerated partial-breast irradiation with the strut-adjusted volume implant device.

PURPOSE Because of the risk of skin toxicity with single dwell position, single-lumen brachytherapy devices are sometimes contraindicated for tumor cavities 5-7mm from the skin surface. We discuss the use of multicatheter device to treat patients with tumor bed-to-skin distances <7mm. METHODS AND MATERIALS We treated 117 patients with accelerated partial-breast irradiation brachytherapy: 77 single-lumen and 40 multicatheter devices. A subset of 12 patients treated with SAVI(®) had bed-to-skin spacing <7mm. All patients had Tis-2N0 ductal carcinoma with negative margins. A total dose of 34.0Gy in 10 fractions was delivered twice daily. Planning target volume was created using computed tomography-based three-dimensional planning with a 1.0-cm expansion of the lumpectomy cavity. Skin dose was measured dosimetrically, with skin constraints <125% of the prescription. Toxicities were graded, and patients were assessed at various intervals. RESULTS Of the patients treated with the multicatheter device, 0% (0/12) had their device pulled. At 2 weeks after treatment, fewer than 50% of the patients had skin toxicities of Grades 1-2, all of which resolved by 6 months. The cosmetic outcome was good to excellent at followup. CONCLUSIONS Multicatheter devices permit well-tolerated accelerated partial-breast irradiation in patients with tumor cavities near the skin surface for which the single-lumen device may not be appropriate.

SU‐E‐T‐768: Treatment Time Nomogram for Strut‐Based Accelerated Partial Breast Applicators

Purpose: The purpose of this work was to generate a tabular nomogram of treatment times for strut-based APBI applicators. The nomogram is intended to provide guidance and a quality assurance check for clinics establishing new treatment techniques or transitioning from balloon-based applicators. Methods: A retrospective analysis was conducted of 486 patients receiving APBI using strut-based applicators at three separate institutions. Strut-based applicators are composed of a central channel surrounded by 6 close-range (“mini”), 6 mid-range, 8, or 10 peripheral channels. Patient data was organized based on applicator size (a surrogate of treatment volume) and number of organs at risk. Three organs at risk categories were determined based on the proximity of the device to the patient’s skin and/or chest wall (0, 1, or 2 OARs). The proximity criterion was defined as being < 5 mm from the cavity wall/peripheral struts. A tabular nomogram of treatment time (based on nominal 10 Ci source strength) was generated from descriptive statistics of each combination of applicator size and organs at risk category. Results: The average treatment time was observed to be directly related to applicator size and, to a lesser extent, inversely related to the number of nearby organs at risk. Distributions of treatment times observed for each combination of applicator size and organs at risk category are depicted in Figure 1. The tabular nomogram featuring average treatment times with standard deviations is presented in Table 1. Conclusion: Strutbased APBI treatment times were observed to depend in a consistent manner on applicator size and number of nearby organs at risk. Information provided in the nomogram presented here represents several hundred treatments performed at multiple institutions. This data can serve as guidance or quality assurance for institutions with limited experience using strut-based APBI applicators.

Outcomes for APBI with strut-based brachytherapy: First 100 accrued patients (5-year median follow-up).

114 Background: The SAVI Collaborative Research Group (SCRG), was created to study the long-term outcomes of women receiving accelerated partial breast irradiation (APBI) using strut-based applicators. The outcomes for the first 100 accrued patients in the study are reported. METHODS Patients for this subset analysis weretaken as the initial 100 treated across all participating sites. Median follow-up of this cohort was 56.3 months at the time of the abstract. Patients were treated with APBI using the strut-based brachytherapy device with conventional dose and fractionation (3.4 Gy x 10 fx, BID). Treatment planning goals for the planning target volume were a V90>90%, V150<50 cc, and V200<20 cc. Patients were followed regularly by their radiation oncologist and outcomes were graded based on the CTCAE v3.0 (common terminology criteria for adverse events, version 3.0). Recurrence (raw and actuarial) rates were also calculated based on the follow up. Cosmesis was graded using the Harvard Scale. RESULTS 75 patients had invasive disease and 25 had ductal carcinoma in situ. The median age was 60.5 yrs (range 40-85 yrs), with 84% post-menopausal. Median tumor size was 10.0 mm (range 0.7-35 mm) with 92% being estrogen receptor positive. 65% of patients had at least one round of hormone therapy and 7% had chemotherapy. All patients completed APBI as planned with no serious adverse events. All patients met the dosimetric criteria. Good/excellent cosmesis was seen in >94% of subjects at all times of follow up (6-60 months). The 5-yr actuarial rates for TR/MM were 2.2%, 1.5% and 4.2% for all subjects, invasive and DCIS subgroups, respectively. The 5-yr actuarial rates for IBTR were 3.3%, 3.0% and 4.2% for all subjects, invasive and DCIS subgroups, respectively. CONCLUSIONS For these initially treated 100 patients with a median 5 years of follow up, strut-based brachytherapy appears to be a well-tolerated, effective treatment with low rates of toxicities and local control as good as other brachytherapy APBI methods.

SU-D-108-06: Dosimetry of 108 Strut-Based Accelerated Partial Breast Irradiation (APBI) Treatments With Applicator Distance Less Than 7 Mm From Both the Skin and Ribs

PURPOSE To report on the dosimetry of 108 strut-based APBI treatments where the applicators were less than 7 mm from both the skin and the ribs Methods: Data from 108 patients whose applicators were sandwiched between the skin and ribs were analyzed. The patients were divided into three cohorts: those where the applicator was less than 7 mm from the skin and ribs (n=67), those where the distance was less than 5 mm (n=33), and those with less than 3 mm between both the skin and ribs (n=8). Dosimetric parameters analyzed include PTVEVAL volume (cm3), V90 (%), V95 (%), V100 (%), V150 (cm3 ), V200 (cm3 ), and the maximum doses to the skin and ribs. RESULTS Over all three cohorts the PTV_EVAL volumes ranged from 20.5 cm3 to 125.7 cm3 with a median value of 55.5 cm3 . In each of the three groups, the V90 averaged between 94% and 95%, the V95 averaged between 90% and 92%, and the V100 averaged between 85% and 87%. The average V150 ranged between 21.8 cm3 and 26.6 cm3, and the average V200 ranged from 10.9 cm3 to 13.1 cm3. Across the three cohorts, the maximum skin dose ranged from 8.4% of the prescription dose to 117% of the prescription dose (median values were between 85% and 87%) and the maximum rib dose fell between 1.8% of the prescription dose and 198% of the prescription dose with the median values falling between 100% and 107%. CONCLUSION This study demonstrates the dosimetric versatility of the strut-based brachytherapy device. It has been used in patients where the proximity of the skin and chest wall precludes the use of other types of single-entry brachytherapy devices. It allows for optimized dose coverage of the target while providing dose sparing to the adjacent critical structures. This project was partially funded by Cianna Medical, Inc.

Accelerated partial breast irradiation using a strut-based brachytherapy device: A multi-institutional initial report on acute and late toxicity with greater than 24-month follow-up.

149 Background: Accelerated partial breast irradiation (APBI) is commonly used in early-stage breast cancer. The SAVI Collaborative Research Group is a multi-institutional group created to study outcomes in patients who received APBI utilizing strut-based brachytherapy. This analysis reports the acute and late toxicities for patients with greater than 2-year follow-up (F/U) from this study. METHODS 904 APBI patients (ductal carcinoma in situ [n=267] or invasive breast cancer [n=637]), received HDR brachytherapy (34 Gy in 10 fractions) using the SAVI device (Cianna Medical). Patients with dosimetry and documented follow-up were evaluated within 6 weeks of treatment for early adverse events (AEs), and at 1 year, 2 years, and beyond for late AEs. Dosimetric parameters were evaluated with respect to toxicity and will be presented. RESULTS In 212 patients (median age 62.9 years, range 40-88) all with follow-up greater than 24 months, the median tumor size was 12mm. As of last follow-up (>24 months) cumulative rates of erythema and hyperpigmentation of grade 2 or higher were 1.4% and 0.5%. The incidence of grade 2 or higher telangiectasia, seroma and fat necrosis were 2.8%, 2.8%, and 0.5% respectively. CONCLUSIONS Adverse events for APBI with SAVI are low in incidence, low in grade and compare favorably to other HDR APBI methods.