Unforeseen Computed Tomography Resimulation for Initial Radiation Planning: Associated Factors and Clinical Impact

Purpose

Repeat computed tomography (CT) simulation is problematic because of additional expense of clinic resources, patient inconvenience, additional radiation exposure, and treatment delay. We investigated the factors and clinical impact of unplanned CT resimulations in our network.

Methods and Materials

We used the billing records of 18,170 patients treated at 5 clinics. A total of 213 patients were resimulated before their first treatment. The disease site, location, use of 4-dimensional CT (4DCT), contrast, image fusion, and cause for resimulation were recorded. Odds ratios determined statistical significance.

Results

Our total rate of resimulation was 1.2%. Anal/colorectal (P < .001) and head and neck (P < .001) disease sites had higher rates of resimulation. Brain (P = .001) and lung/thorax (P = .008) had lower rates of resimulation. The most common causes for resimulation were setup change (11.7%), change in patient anatomy (9.8%), and rectal filling (8.5%). The resimulation rate for 4DCTs was 3.03% compared with 1.0% for non-4DCTs (P < .001). Median time between simulations was 7 days.

Conclusions

The most common sites for resimulation were anal/colorectal and head and neck, largely because of change in setup or changes in anatomy. The 4DCT technique correlated with higher resimulation rates. The resimulation rate was 1.2%, and median treatment delay was 7 days. Further studies are warranted to limit the rate of resimulation.

Followup mammography after breast conservation therapy: Is 3D Tomosynthesis(3DT) worth it?

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Background: Screening three-dimensional tomosynthesis mammography (3DT) is more cost-effective than two-dimensional mammography (2DM) for detecting breast cancer, however cost-effectiveness as a follow-up for treated breast cancer is unknown. We retrospectively analyzed the downstream workup and costs associated with 3DT compared to 2DM when employed as initial follow-up imaging in breast conservation therapy (BCT). Methods: Between the years 2015-2017, 450 consecutive BCT patients ages 32 – 89 with a follow-up 3DT (n = 162) or 2DM (n = 288) were reviewed in this IRB-approved study. The primary endpoint was further workup after follow-up mammogram and associated healthcare costs at 1 year. Downstream workup was secondarily tested for correlation with clinical and treatment-related variables. A single 3DT cost an estimated $149 compared to $111 for a 2DM, based on Centers for Medicare claims data Oncology Care Model. Results: Patient clinical characteristics were : 6% DCIS, 10% T1a, 29% T1b, 35% T1c, 19% T2, 88% N0, 9% N1, 3% N2, 76% ER+/PR+/HerNeu2-, 12% TNBC, and 14% Her2Neu+. Whole breast radiation was given with conventional (59%) and hypo (39%) fractionation (81% with a boost), and 10% received accelerated partial breast irradiation. First post-treatment mammogram was received within 3 months (20%), 3-6 months (32%), and after 6 months (48%) following RT. There were no differences in breast density, patient age, T/N stage, receptor status, type of RT, or mammogram timing between those in the 2DM and 3DT groups. The following downstream workup ensued for 3DT compared to 2D imaging: 18% vs 29% short-interval (6-month) mammogram (OR = 1.83, P = 0.01), 6% vs 11% breast MRI (OR = 1.90, P = 0.08), 4% ultrasound for each, and 3% biopsy for each (1 positive in the 2D group). Including downstream workup, the estimated cost per patient in the 3DT group = $249.00 compared to $253.64 in the 2D group. With multivariable analysis the independent predictors for reduced downstream workup was the use of 3DT and follow-up mammogram at least 6 months after radiation (P < 0.05). Conclusions: Excess workup was reduced with 3DT compared to 2DM in the post-treatment setting. A single 3DT costs approximately 34% more than 2DM, however in this study the associated reduction in downstream workup with 3DT actually made it more cost-effective.

Abstract P6-02-05: Downstream workup after post-treatment mammography in breast conservation therapy: Is there a significant difference between tomosynthesis and 2-dimensional mammograms?

Introduction:

Emerging data suggest that tomosynthesis mammograms (TS) are considerably superior to two-dimensional (2D) screening mammograms (2DMG) at reducing false positive biopsies for breast cancer screening. However, very little is reported about the comparative efficacy of the two modalities in the post-treatment setting. We compared the rate of downstream workup up after undergoing post-radiation screening 2DMG and TS following breast conservation therapy at our institution.

Methods:

Between the years 2011-2017, 712 breast cancer patients (range 31-91 years) were treated with lumpectomy and adjuvant radiotherapy. As per institutional standard, follow up included either screening 2DMG (n=569) or TS(n=143) and reviewed in this IRB-approved study. The primary endpoint for comparison was the rate of further imaging/workup post-treatment . Comparative analysis was conducted via multivariable binomial regression with propensity matching between the 2DMG and TS groups. Patients with clinical suspicion of recurrence otherwise were excluded.

Results:

The patient cohort in both groups included the following clinical characteristics,: 129 patients with ductal carcinoma in-situ (the remainder were invasive carcinoma; ductal or lobular). A total of 418 patients had T1 lesions, 143 T2, and 22 T3/T4. Eighty-five patients were node positive. Of those, 501 ER+/Her2-, 101 triple negative, and 96 triple positive. Adjuvant radiation included conventional fraction (457) or hypofractionation (153) with boost to the surgical cavity in523Accelerated Partial Breast Irradiation (APBI) was delivered in 106 patients. Post treatment scans occurred within 3 months (166), at 3-6 months (256), or 6+ months (281). The aforementioned characteristics were similarly distributed between 2DMG and TS groups, except for slightly more DCIS in the 2D group.

There was a significantly higher proportion of patients that were recommended for immediate downstream workup in the 2D group (40.7%) compared to in the tomo group (16.8%) (HR = 3.40, P &lt;0.001), leading to 12 biopsies in the 2D group (3 positive) and 4 biopsies in the TS group (0 positive). Upon multivariate analysis, the use of tomo was the lone correlate of reduced downstream workup (p &lt; 0.05), although there was a trend toward significance in patients who were first imaged at a post-treatment interval of 6+ months and in patients not undergoing a radiation boost (P &lt; 0.10).

Conclusion:

Post-breast conservation follow-up with tomo synthesis mammography resulted in significantly less downstream workup as compared to conventional 2D screening mammography. Further investigation is warranted to unveil the absolute and relative cost-effectiveness between the two modalities.

Citation Format: Colosimo BL, Weinberger K, Hasan S, Gresswell S, Anderson S, Wegner RE, Trombetta M. Downstream workup after post-treatment mammography in breast conservation therapy: Is there a significant difference between tomosynthesis and 2-dimensional mammograms? [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-02-05.

Effect of Daily and Every Other Day Stereotactic Body Radiation Therapy Schedules on Treatment-Related Fatigue in Patients With Hepatocellular Carcinoma

PURPOSE

We compared the rate and severity of fatigue in patients who completed stereotactic body radiation therapy (SBRT) to the liver daily (QD) compared with every other day (QOD).

METHODS AND MATERIALS

From 2010 to 2017, 91 patients with Child Pugh (CP) A (n = 57) or CP-B (n = 34) cirrhosis who completed 100 SBRT sessions to 110 hepatocellular carcinoma (HCC) lesions were analyzed in this study. Confounding variables with fatigue such as CP-C cirrhosis, Eastern Cooperative Oncology Group score >2, or a history of ascites or encephalopathy were excluded. Fatigue was assessed against several treatment- and patient-related variables with univariate and propensity score-matched multivariate analysis. The median follow-up time was 18 months.

RESULTS

Patients with HCC and Barcelona-Clinic Liver Cancer stages 0 (n = 10), A (n = 32), and B (n = 58), and a median age of 62 years were analyzed. The median tumor diameter was 3 cm (1.1-11 cm). The Eastern Cooperative Oncology Group performance status score was 0 (n = 44), 1 (n = 43), or 2 (n = 13). The median dose was 45 Gy in 5 fractions, and 65 treatments were QD and 45 QOD. Grades 1 and 2 fatigue developed in 49% and 14% of treatments, respectively. Among the patients who were treated daily, 78% developed Grade 1 or 2 fatigue compared with 44% who were treated QOD (odds ratio: 4.52; P = .001). Grade 2 fatigue occurred in 22% of patients compared with 7.3% for QD and QOD treatment, respectively (odds ratio: 3.83; P = .048). There was no difference in fatigue rate for time of treatment (morning or afternoon), dose, treated volume, CP score, Barcelona-Clinic Liver Cancer stage, or performance status, which were not associated with any level of fatigue. There was no difference in local control between QD and QOD treatments.

CONCLUSIONS

Compared with traditional daily treatment fractions, SBRT that is delivered QOD to cirrhotic patients with HCC may reduce the risk of fatigue.

Outcomes of Stereotactic Body Radiotherapy for Hepatocellular Carcinoma with Severe Cirrhosis and Ineligibility for Transplant

BACKGROUND/AIM

Our study reviewed the results of patients with hepatocellular carcinoma and Child-Pugh score 8-11 cirrhosis treated with stereotactic body radiotherapy when liver transplant was not an option.

PATIENTS AND METHODS

A retrospective review was performed on 15 patients with Child-Pugh class B and C cirrhosis treated with stereotactic body radiotherapy. The median total dose was 35 Gy in 4-5 fractions. None were listed for a liver transplant due to either being outside of the Milan criteria or to medical contraindications.

RESULTS

The overall survival was 26.7% at 6 months, with a mean survival of 152 days. The mean survival with and without ascites was 3.3 months and 8.3 months, respectively.

CONCLUSION

For hepatocellular carcinoma with cirrhosis of Child-Pugh score 8 or more, prognosis after liver stereotactic body radiotherapy was suboptimal. While irradiation achieved local tumor control, progressive cirrhosis was a common cause of death. Patients without ascites at the time of radiotherapy had the best prognosis.

Implications of short-term follow-up tomosynthesis mammography on downstream workup after breast conservation therapy

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Background: We previously reported that premature (less than 6 months) follow-up screening mammography after radiotherapy in breast conservation therapy was associated with an increased rate of unnecessary downstream workup. We now present the results of a similar study conducted with follow-up tomosynthesis mammogram (TS). Methods: Between the years 2015-2017, 143 consecutive breast cancer patients between ages 33 – 82 were treated with lumpectomy and adjuvant radiotherapy with follow-up TS and reviewed in this IRB-approved study. Cases were stratified by time interval until the first post-radiation TS, and secondarily by radiation technique: conventional fractionation (n = 84), hypofractionation (n = 59), boost (n = 116), no boost (n = 27), and accelerated partial breast irradiation (n = 10). The primary endpoint was the rate of further imaging/workup following TS, correlated with clinical, treatment, and post-treatment timing related variables using multivariable binomial regression analysis. Results: The patient cohort included the following clinical characteristics: 6 patients with ductal carcinoma in-situ (the remaining demonstrated either invasive ductal or invasive lobular histology), Ninety-seven patients had stage T1 lesions, 34 had T2, and 4 had T3/T4 lesions. Eighteen patients were node+, 95 ER+/ Her2-, 13 were triple negative, and 13 triple positive. No patients had clinical suspicion of recurrence before their first follow-up TS. Conclusions: Unlike with post-treatment screening two-dimensional mammography, there was no association with post-treatment tomosynthesis timing and downstream workup. Further study should be considered to confirm these preliminary findings.

Determining the impact of pre-radiation treatment verification simulation/dry run by analyzing intradepartmental reported incidents and surveying staff and patients

PURPOSE

Error identification in radiation therapy is critical to maintain a safe and efficient therapeutic environment. A verification simulation (VS; also called a dry run for patient information) provides a dedicated time prior to treatment to duplicate steps of patient setup, imaging, and treatment process as a final quality assurance step. Through the use of surveys and analysis of reported incidents, we sought to determine the value of a VS before initiating patient treatment.

METHODS AND MATERIALS

In November 2014, a VS was instituted across our network of 11 radiation oncology clinics. A comparison of the incident rate reported through our departmental incident learning system (ILS) was made between a non-VS group (965 patients who were treated in the 18 months prior to instituting the VS) and a VS group (984 patients who were treated over 18 months with the VS policy in place). From August to December 2016, surveys were completed by 211 patients and 55 physicians, nurses, and therapists detailing their perspectives on the VS.

RESULTS

There were 28 incidents (2.9%) in the non-VS group compared with 18 incidents (1.8%) in the VS group (P = .03). In the VS group, more incidents were detected before the day of treatment (P = .03) and fewer incidents on the day of treatment (P = .02). In addition, a trend toward fewer incidents after treatment started (P = .09) was observed. Patient surveys indicated that 99.5% of patients were informed of the VS, 83% reported decreased anxiety during treatment, and 5% indicated concerns about delaying treatment. The majority of staff members (67%) were satisfied with the VS.

CONCLUSIONS

A VS helps identify and correct incidents before the administration of radiation therapy and reduces patient anxiety.

Dose Effect in Adjuvant Radiation Therapy for the Treatment of Resected Keloids

PURPOSE

Surgical excision of keloids can result in an insidious cycle of tissue injury and repeat keloid formation unless combined with adjuvant therapy to halt this cycle. We present our results of postoperative radiation therapy for keloids with various dose regimens.

METHODS AND MATERIALS

A retrospective review of 124 patients with 250 keloid lesions treated with postoperative radiation therapy was analyzed. In this institutional review board-approved study, 125 keloids were treated to 20 Gy in 5 fractions and 125 keloids were treated to 12 to 16 Gy in 3 to 4 fractions. Local failure was defined as redevelopment of any clinically apparent keloid at the treated site. The median age was 34 years (14-84 years). Keloids were located on the ear (34%), neck/shoulder (19%), abdomen (13%), chest (10%), face (9%), breast (7%), extremities (4%), and back (3%). Median keloid size was 4 cm (0.5-20 cm).

RESULTS

At a median follow-up of 40 months, the recurrence rate for all lesions was 5.6%. Lesions treated to 20 Gy had a recurrence rate of 1.6% compared with 9.6% with <20 Gy and an odds ratio of 0.16 (P = .02). Upon univariate and multivariate analysis there were no differences in recurrence rate with respect to location, race, gender, age, previously treated lesions, and presence of multiple keloids. The lone predictor for improved control rate was the dose of 20 Gy in 5 fractions compared with less than that. Control rate for lesions treated to a biologically equivalent dose₂ of 35 to 36 Gy₂, 48 to 52.5 Gy₂, and 60 to 72 Gy₂ were 10% (P = .007), 8.9% (P = .16), and 1.6% (P = .02), respectively.

CONCLUSIONS

Surgical excision followed by immediate adjuvant radiation therapy for keloids provides excellent local control and cosmesis. Treatment with a biologically equivalent dose₂ > 60 (20 Gy in 5 fractions) yielded superior local control over lower dose regimens.

Stereotactic body radiotherapy used as a bridge to liver transplant in patients with hepatocellular carcinoma and Child-Pugh score ≥8 cirrhosis

INTRODUCTION

To report on SBRT as a bridge to OLT for patients with HCC and Child-Pugh ≥8 cirrhosis.

METHODS

Retrospective review of 15 patients, treated from 2010-2017. Three patients excluded secondary to delisting from prohibitive substance. Twelve patients (17 lesions) included for final analysis. Hepatic SPECT functional treatment planning utilized.

RESULTS

The median age of 60 years with a median CP 9 and MELD 14. The median SBRT dose was 40 Gy in 5 fractions, and median tumor size was 2.3cm (1.2-5.3cm). Median follow-up and survival was 40-months and 46-months, respectively. One patient succumbed to renal/hepatic failure before OLT. Radiographic response was 80%. pCR at explant was 46%. No grade ≥ 3 acute toxicities. Median time to progression of CP ≥ 2 was 9.7-months and MELD progression was not met before OLT.

CONCLUSION

SBRT with functional treatment planning can be used safely as a bridge to OLT in select patients with CP ≥8 cirrhosis.

Hypofractionated image guided radiation therapy followed by prostate seed implant boost for men with newly diagnosed intermediate and high risk adenocarcinoma of the prostate: Preliminary results of a phase 2 prospective study

Purpose

A phase 2 protocol was designed and implemented to assess the toxicity and efficacy of hypofractionated image guided intensity modulated radiation therapy (IG-IMRT) combined with low-dose rate ¹⁰³Pd prostate seed implant for treatment of localized intermediate- and high-risk adenocarcinoma of the prostate.

Methods and materials

This is a report of an interim analysis on 24 patients enrolled on an institutional review board–approved phase 2 single-institution study of patients with intermediate- and high-risk adenocarcinoma of the prostate. The median pretreatment prostate-specific antigen level was 8.15 ng/mL. The median Gleason score was 4 + 3 = 7 (range, 3 + 4 = 7 - 4 + 4 = 8), and the median T stage was T2a. Of the 24 patients, 4 (17%) were high-risk patients as defined by the National Comprehensive Cancer Network criteria, version 2016. The treatment consisted of 2465 cGy in 493 cGy/fraction of IG-IMRT to the prostate and seminal vesicles. This was followed by a ¹⁰³Pd transperineal prostate implant boost (prescribed dose to 90% of the prostate volume of 100 Gy) using intraoperative planning. Five patients received neoadjuvant, concurrent, and adjuvant androgen deprivation therapy.

Results

The median follow-up was 18 months (range, 1-42 months). The median nadir prostate-specific antigen was 0.5 ng/mL and time to nadir was 16 months. There was 1 biochemical failure associated with distant metastatic disease without local failure. Toxicity (acute or late) higher than grade 3 was not observed. There was a single instance of late grade 3 genitourinary toxicity secondary to hematuria 2 years and 7 months after radiation treatment. There were no other grade 3 gastrointestinal or genitourinary toxicities.

Conclusions

Early results on the toxicity and efficacy of the combination of hypofractionated IG-IMRT and low-dose-rate brachytherapy boost are favorable. Longer follow-up is needed to confirm safety and effectiveness.