Upfront Versus Delayed Systemic Therapy in Patients With Oligometastatic Cancer Treated With SABR in the Phase 2 SABR-5 Trial

PURPOSE

The optimal sequencing of local and systemic therapy for oligometastatic cancer has not been established. This study retrospectively compared progression-free survival (PFS), overall survival (OS), and SABR-related toxicity between upfront versus delay of systemic treatment until progression in patients in the SABR-5 trial.

METHODS AND MATERIALS

The single-arm phase 2 SABR-5 trial accrued patients with up to 5 oligometastases across SABR-5 between November 2016 and July 2020. Patients received SABR to all lesions. Two cohorts were retrospectively identified: those receiving upfront systemic treatment along with SABR and those for whom systemic treatment was delayed until disease progression. Patients treated for oligoprogression were excluded. Propensity score analysis with overlap weighting balanced baseline characteristics of cohorts. Bootstrap sampling and Cox regression models estimated the association of delayed systemic treatment with PFS, OS, and grade ≥2 toxicity.

RESULTS

A total of 319 patients with oligometastases underwent treatment on SABR-5, including 121 (38%) and 198 (62%) who received upfront and delayed systemic treatment, respectively. In the weighted sample, prostate cancer was the most common primary tumor histology (48%) followed by colorectal (18%), breast (13%), and lung (4%). Most patients (93%) were treated for 1 to 2 metastases. The median follow-up time was 34 months (IQR, 24-45). Delayed systemic treatment was associated with shorter PFS (hazard ratio [HR], 1.56; 95% CI, 1.15-2.13; P = .005) but similar OS (HR, 0.90; 95% CI, 0.51-1.59; P = .65) compared with upfront systemic treatment. Risk of grade 2 or higher SABR-related toxicity was reduced with delayed systemic treatment (odds ratio, 0.35; 95% CI, 0.15-0.70; P < .001).

CONCLUSIONS

Delayed systemic treatment is associated with shorter PFS without reduction in OS and with reduced SABR-related toxicity and may be a favorable option for select patients seeking to avoid initial systemic treatment. Efforts should continue to accrue patients to histology-specific trials examining a delayed systemic treatment approach.

Prospective Longitudinal Assessment of Quality of Life After Stereotactic Ablative Radiotherapy for Oligometastases: Analysis of the Population-based SABR-5 Phase II Trial

AIMS

To evaluate longitudinal patient-reported quality of life (QoL) in patients treated with stereotactic ablative radiotherapy (SABR) for oligometastases.

MATERIALS AND METHODS

The SABR-5 trial was a population-based single-arm phase II study of SABR to up to five sites of oligometastases, conducted in six regional cancer centres in British Columbia, Canada from 2016 to 2020. Prospective QoL was measured using treatment site-specific QoL questionnaires at pre-treatment baseline and at 3, 6, 9, 12, 15, 18, 21, 24, 30 and 36 months after treatment. Patients with bone metastases were assessed with the Brief Pain Inventory (BPI). Patients with liver, adrenal and abdominopelvic lymph node metastases were assessed with the Functional Assessment of Chronic Illness Therapy-Abdominal Discomfort (FACIT-AD). Patients with lung and intrathoracic lymph node metastases were assessed with the Prospective Outcomes and Support Initiative (POSI) lung questionnaire. The two one-sided test procedure was used to assess equivalence between the worst QoL score and the baseline score of individual patients. The mean QoL at all time points was used to determine the trajectory of QoL response after SABR. The proportion of patients with 'stable', 'improved' or 'worsened' QoL was determined for all time points based on standard minimal clinically important differences (MCID; BPI worst pain = 2, BPI functional interference score [FIS] = 0.5, FACIT-AD Trial Outcome Index [TOI] = 8, POSI = 3).

RESULTS

All enrolled patients with baseline QoL assessment and at least one follow-up assessment were analysed (n = 133). On equivalence testing, the patients' worst QoL scores were clinically different from baseline scores and met MCID (BPI worst pain mean difference: 1.8, 90% confidence interval 1.19 to 2.42]; BPI FIS mean difference: 1.68, 90% confidence interval 1.15 to 2.21; FACIT-AD TOI mean difference: -8.76, 90% confidence interval -11.29 to -6.24; POSI mean difference: -4.61, 90% confidence interval -6.09 to -3.14). However, the mean FIS transiently worsened at 9, 18 and 21 months but eventually returned to stable levels. The mean FACIT and POSI scores also worsened at 36 months, albeit with a limited number of responses (n = 4 and 8, respectively). Most patients reported stable QoL at all time points (range: BPI worst pain 71-82%, BPI FIS 45-78%, FACIT-AD TOI 50-100%, POSI 25-73%). Clinically significant stability, worsening and improvement were seen in 70%/13%/18% of patients at 3 months, 53%/28%/19% at 18 months and 63%/25%/13% at 36 months.

CONCLUSIONS

Transient decreases in QoL that met MCID were seen between patients' worst QoL scores and baseline scores. However, most patients experienced stable QoL relative to pre-treatment levels on long-term follow-up. Further studies are needed to characterise patients at greatest risk for decreased QoL.

Predictors of Quality of Life Decline in Patients with Oligometastases treated with Stereotactic Ablative Radiotherapy: Analysis of the Population-Based SABR-5 Phase II Trial

AIMS

Most patients experience stable quality of life (QoL) after stereotactic ablative radiotherapy (SABR) treatment for oligometastases. However, a subset of patients experience clinically relevant declines in QoL on post-treatment follow-up. This study aimed to identify risk factors for QoL decline.

MATERIALS AND METHODS

The SABR-5 trial was a population-based single-arm phase II study of SABR to up to five sites of oligometastases. Prospective QoL was measured using treatment site-specific tools at pre-treatment baseline and 3, 6, 9, 12, 15, 18, 21, 24, 30 and 36 months after treatment. The time to persistent QoL decline was calculated as the time from SABR to the first decline in QoL score meeting minimum clinically important difference with no improvement to baseline score on subsequent assessments. Univariable and multivariable logistic regression analyses were carried out to determine factors associated with QoL decline.

RESULTS

One hundred and thirty-three patients were included with a median follow-up of 32 months (interquartile range 25-43). Thirty-five patients (26%) experienced a persistent decline in QoL. The median time until persistent QoL decline was not reached. The cumulative incidence of QoL decline at 2 and 3 years were 22% (95% confidence interval 14.0-29.6) and 40% (95% confidence interval 28.0-51.2), respectively. In multivariable analysis, disease progression (odds ratio 5.23, 95% confidence interval 1.59-17.47, P = 0.007) and adrenal metastases (odds ratio 9.70, 95% confidence interval 1.41-66.93, P = 0.021) were associated with a higher risk of QoL decline. Grade 3 or higher (odds ratio 3.88, 95% confidence interval 0.92-16.31, P = 0.064) and grade 2 or higher SABR-associated toxicity (odds ratio 2.24, 95% confidence interval 0.85-5.91, P = 0.10) were associated with an increased risk of QoL decline but did not reach statistical significance.

CONCLUSIONS

Disease progression and adrenal lesion site were associated with persistent QoL decline following SABR. The development of grade 3 or higher toxicities was also associated with an increased risk, albeit not statistically significant. Further studies are needed, focusing on the QoL impact of metastasis-directed therapies.

Single vs. multiple fraction non-inferiority trial of stereotactic ablative radiotherapy for the comprehensive treatment of oligo-metastases/progression: SIMPLIFY-SABR-COMET

BACKGROUND

Radiotherapy delivery regimens can vary between a single fraction (SF) and multiple fractions (MF) given daily for up to several weeks depending on the location of the cancer or metastases. With limited evidence comparing fractionation regimens for oligometastases, there is support to explore toxicity levels to nearby organs at risk as a primary outcome while using SF and MF stereotactic ablative radiotherapy (SABR) as well as explore differences in patient-reported quality of life and experience.

METHODS

This study will randomize 598 patients in a 1:1 ratio between the standard arm (MF SABR) and the experimental arm (SF SABR). This trial is designed as two randomized controlled trials within one patient population for resource efficiency. The primary objective of the first randomization is to determine if SF SABR is non-inferior to MF SABR, with respect to healthcare provider (HCP)-reported grade 3-5 adverse events (AEs) that are related to SABR. Primary endpoint is toxicity while secondary endpoints include lesional control rate (LCR), and progression-free survival (PFS). The second randomization (BC Cancer sites only) will allocate participants to either complete quality of life (QoL) questionnaires only; or QoL questionnaires and a symptom-specific survey with symptom-guided HCP intervention. The primary objective of the second randomization is to determine if radiation-related symptom questionnaire-guided HCP intervention results in improved reported QoL as measured by the EuroQoL-5-dimensions-5levels (EQ-5D-5L) instrument. The primary endpoint is patient-reported QoL and secondary endpoints include: persistence/resolution of symptom reporting, QoL, intervention cost effectiveness, resource utilization, and overall survival.

DISCUSSION

This study will compare SF and MF SABR in the treatment of oligometastases and oligoprogression to determine if there is non-inferior toxicity for SF SABR in selected participants with 1-5 oligometastatic lesions. This study will also compare patient-reported QoL between participants who receive radiation-related symptom-guided HCP intervention and those who complete questionnaires alone.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT05784428. Date of Registration: 23 March 2023.

Polymetastatic Recurrence-Free Survival in Patients with Repeat Oligometastases on the SABR-5 Trial

PURPOSE/OBJECTIVE(S)

To determine polymetastatic recurrence-free survival (PMRFS) in patients with repeat oligometastases (OM) on the SABR-5 trial.

MATERIALS/METHODS

SABR-5 is a prospective, multi-center trial that evaluated the safety of stereotactic ablative radiotherapy (SABR) in patients with 1-5 OM or oligoprogressive lesions. On SABR-5, patients were followed post-SABR according to standardized protocols. Patients with repeat extra-cranial OM after metastasis-directed therapy (MDT; SABR, surgery, or thermoablation) to all initial OM (including those treated before enrolment on SABR-5) were identified. Exclusion criteria included history of multiple primary malignancies and incomplete re-staging. PMRFS was defined as time from presentation of repeat oligometastases to death or presentation of 6 or more progressing metastases, leptomeningeal metastases, lymphangitic carcinomatosis, malignant ascites, or malignant pleural effusion. PMRFS, overall survival (OS), and progression-free survival (PFS) were calculated using the Kaplan-Meier method.

RESULTS

Seventy-six patients with repeat OM were included, of which 44 (58%) received second MDT to all OM. The most common histology in patients who received second MDT was colorectal cancer (10/44 [23%]) and in those who did not was prostate cancer (17/32 [53%]). Patients who did vs. did not receive second MDT had fewer metastases at repeat OM (mean 1.3 vs 2.2; p<0.001) and no difference in time between initial OM and repeat OM (16 vs. 17 months; p = 0.74). For patients who received second MDT, median follow-up from presentation of repeat OM was 2.6 years. Median PFS after first and second MDT were 15 months (95% CI 11-18) and 11 months (95% CI 7-17), respectively. At last follow-up, 22/44 patients (50%) were alive without polymetastatic recurrence. 3-year PMRFS and OS from presentation of repeat OM were 51% (95% CI 33-66%) and 66% (95% CI 47-79%), respectively.

CONCLUSION

Patients presenting with repeat OM after MDT may still have favorable 3-year PMRFS and OS, which may justify exploring aggressive local treatments in this subpopulation. Further randomized trials in this space are needed.

Prospective Longitudinal Assessment of Quality of Life after Stereotactic Ablative Radiotherapy for Oligometastases: Analysis of the Population-Based SABR-5 Phase II Trial

PURPOSE/OBJECTIVE(S)

To evaluate longitudinal patient-reported quality of life (QoL) in patients treated with stereotactic ablative radiotherapy (SABR) for oligometastases.

MATERIALS/METHODS

The SABR-5 trial was a population-based single-arm phase II study of SABR to up to 5 sites of oligometastases, conducted in 6 regional cancer centers in British Columbia from 2016 to 2020. Prospective QoL was measured using treatment site-specific QoL questionnaires at pre-treatment baseline and 3, 6, 9, 12, 15, 18, 21, 24, 30, and 36 months after treatment. Patients with bone metastases were assessed with the Brief Pain Inventory (BPI). Patients with liver, adrenal, and abdominopelvic lymph node metastases were assessed with the Functional Assessment of Chronic Illness Therapy-Abdominal Discomfort (FACIT-AD). Patients with lung and intrathoracic lymph node metastases were assessed with the Prospective Outcomes and Support Initiative (POSI) lung questionnaire. The two one-sided test procedure was used to assess equivalence between the worst QoL score and baseline score of individual patients. Mean QoL at all time points was used to determine the trajectory of QoL response after SABR. The proportion of patients with "stable," "improved," or "worsened" QoL was determined for all time points based on standard minimal clinically important differences (MCID; BPI worst pain = 2, BPI Functional Interference Score [FIS] = 0.5, FACIT-AD Trial Outcome Index [TOI] = 8, POSI = 3).

RESULTS

All enrolled patients with baseline QoL assessment and at least 1 follow-up assessment were analyzed (n = 135). On equivalence testing, patients' worst QoL scores were clinically different from baseline scores and met MCID (BPI worst pain mean difference: 1.8, 90% CI [1.19 to 2.42]; BPI FIS mean difference: 1.68, 90% CI [1.15 to 2.21]; FACIT-AD TOI mean difference: -8.76, 90% CI [-11.29 to -6.24]; POSI mean difference: -4.61, 90% CI [-6.09 to -3.14]). However, the mean FIS transiently worsened at 9, 18 and 21 months but eventually returned to stable levels. The mean FACIT and POSI scores also worsened at 36 months, albeit with a limited number of responses (n = 4 and 8, respectively). The majority of patients reported stable QoL at all time points (range: BPI worst pain 71-82%, BPI FIS 45-78%, FACIT-AD TOI 50-100%, POSI 25-73%). Clinically significant stability, worsening, and improvement were seen in 70%/13%/18% of patients at 3 months, 53%/28%/19% at 18 months and 63%/25%/13% at 36 months.

CONCLUSION

SABR in the oligometastatic setting can lead to transient decreases in QoL. However, most patients experienced stable QoL relative to pre-treatment levels on long-term follow-up. Further studies are needed to characterize patients at greatest risk for decreased QoL.

Should organs at risk (OARs) be prioritized over target volume coverage in stereotactic ablative radiotherapy (SABR) for oligometastases? a secondary analysis of the population-based phase II SABR-5 trial

BACKGROUND AND PURPOSE

Stereotactic ablative radiotherapy (SABR) for oligometastases may improve survival, however concerns about safety remain. To mitigate risk of toxicity, target coverage was sacrificed to prioritize organs-at-risk (OARs) during SABR planning in the population-based SABR-5 trial. This study evaluated the effect of this practice on dosimetry, local recurrence (LR), and progression-free survival (PFS).

METHODS

This single-arm phase II trial included patients with up to 5 oligometastases between November 2016 and July 2020. Theprotocol-specified planning objective was to cover 95 % of the planning target volume (PTV) with 100 % of the prescribed dose, however PTV coverage was reduced as needed to meet OAR constraints. This trade-off was measured using the coverage compromise index (CCI), computed as minimum dose received by the hottest 99 % of the PTV (D99) divided by the prescription dose. Under-coverage was defined as CCI < 0.90. The potential association between CCI and outcomes was evaluated.

RESULTS

549 lesions from 381 patients were assessed. Mean CCI was 0.88 (95 % confidence interval [CI], 0.86-0.89), and 196 (36 %) lesions were under-covered. The highest mean CCI (0.95; 95 %CI, 0.93-0.97) was in non-spine bone lesions (n = 116), while the lowest mean CCI (0.71; 95 % CI, 0.69-0.73) was in spine lesions (n = 104). On multivariable analysis, under-coverage did not predict for worse LR (HR 0.48, p = 0.37) or PFS (HR 1.24, p = 0.38). Largest lesion diameter, colorectal and 'other' (non-prostate, breast, or lung) primary predicted for worse LR. Largest lesion diameter, synchronous tumor treatment, short disease free interval, state of oligoprogression, initiation or change in systemic treatment, and a high PTV Dmax were significantly associated with PFS.

CONCLUSION

PTV under-coverage was not associated with worse LR or PFS in this large, population-based phase II trial. Combined with low toxicity rates, this study supports the practice of prioritizing OAR constraints during oligometastatic SABR planning.

Treatment With Stereotactic Ablative Radiotherapy for Up to 5 Oligometastases in Patients With Cancer: Primary Toxic Effect Results of the Nonrandomized Phase 2 SABR-5 Clinical Trial

Importance

After the publication of the landmark SABR-COMET trial, concerns arose regarding high-grade toxic effects of treatment with stereotactic ablative body radiotherapy (SABR) for oligometastases.

Objective

To document toxic effects of treatment with SABR in a large cohort from a population-based, provincial cancer program.

Design, Setting, and Participants

From November 2016 to July 2020, 381 patients across all 6 cancer centers in British Columbia were treated in this single-arm, phase 2 trial of treatment with SABR for patients with oligometastatic or oligoprogressive disease. During this period, patients were only eligible to receive treatment with SABR in these settings in trials within British Columbia; therefore, this analysis is population based, with resultant minimal selection bias compared with previously published SABR series.

Interventions

Stereotactic ablative body radiotherapy to up to 5 metastases.

Main Outcomes and Measures

Rate of grade 2, 3, 4, and 5 toxic effects associated with SABR.

Findings

Among 381 participants (122 women [32%]), the mean (SD; range) age was 68 (11.1; 30-97) years, and the median (range) follow-up was 25 (1-54) months. The most common histological findings were prostate cancer (123 [32%]), colorectal cancer (63 [17%]), breast cancer (42 [11%]), and lung cancer (33 [9%]). The number of SABR-treated sites were 1 (263 [69%]), 2 (82 [22%]), and 3 or more (36 [10%]). The most common sites of SABR were lung (188 [34%]), nonspine bone (136 [25%]), spine (85 [16%]), lymph nodes (78 [14%]), liver (29 [5%]), and adrenal (15 [3%]). Rates of grade 2, 3, 4, and 5 toxic effects associated with SABR (based on the highest-grade toxic effect per patient) were 14.2%; (95% CI, 10.7%-17.7%), 4.2% (95% CI, 2.2%-6.2%), 0%, and 0.3% (95% CI, 0%-0.8%), respectively. The cumulative incidence of grade 2 or higher toxic effects associated with SABR at year 2 by Kaplan-Meier analysis was 8%, and for grade 3 or higher, 4%.

Conclusions and Relevance

This single-arm, phase 2 clinical trial found that the incidence of grade 3 or higher SABR toxic effects in this population-based study was less than 5%. Furthermore, the rates of grade 2 or higher toxic effects (18.6%) were lower than previously published for SABR-COMET (29%). These results suggest that SABR treatment for oligometastases has acceptable rates of toxic effects and potentially support further enrollment in randomized phase 3 clinical trials.

Trial Registration

ClinicalTrials.gov Identifier: NCT02933242.

Predictors of early polymetastatic relapse following stereotactic ablative radiotherapy for up to 5 oligometastases: a secondary analysis of the phase II SABR-5 trial

PURPOSE

A subset of patients with oligometastatic cancer experience early widespread cancer dissemination and do not benefit from metastasis-directed therapy such as stereotactic ablative radiotherapy (SABR). This study aimed to identify factors associated with early polymetastatic relapse (PMR).

METHODS AND MATERIALS

The XXX trial was a single arm phase II study conducted at all 6 regional cancer centres across XXX. SABR for oligometastases was only offered on trial. Patients with up to 5 oligometastatic lesions (total, progressing or induced) received SABR to all lesions. Patients were 18 years of age or older, ECOG 0-2 and life expectancy ≥ 6 months. This secondary analysis evaluated factors associated with early PMR, defined as disease recurrence within 6 months of SABR which is not amenable to further local treatment. Univariable and multivariable analyses were performed using binary logistic regression. The Kaplan Meier method and log-rank tests assessed PMR-free survival and differences between risk groups, respectively.

RESULTS

Between November 2016 and July 2020, 381 patients underwent treatment on XXX. A total of 16% of patients experienced PMR. Worse performance status (ECOG 1-2 vs 0; HR=2.01, p=0.018), non-prostate/breast histology (HR=3.64, p<0.001) and oligoprogression (HR=3.84, p<0.001) were independent predictors for early PMR. Risk groups were identified with median PMR-free survival ranging from 5 months to not yet reached at the time of analysis. Rates of 3-year OS were 0%, 53% (95% confidence interval [CI] 48 - 58), 77% (95% CI 73 - 81) and 93% (95% CI 90 - 96) in groups 1-4, respectively (p<0.001).

CONCLUSION

Four distinct risk groups for early PMR are identified, which differ significantly in PMR-free survival and overall survival. The group with all three risk factors had a median PMR-free survival of 5 months and may not benefit from local ablative therapy alone. This model should be externally validated with data from other prospective trials.

SUPR-3D: A randomized phase iii trial comparing simple unplanned palliative radiotherapy versus 3d conformal radiotherapy for patients with bone metastases: study protocol

Background

Bone metastases in the lower spine and pelvis are effectively palliated with radiotherapy (RT), though this can come with side effects such as radiation induced nausea and vomiting (RINV). We hypothesize that high rates of RINV occur in part because of the widespread use of inexpensive simple unplanned palliative radiotherapy (SUPR), over more complex and resource intensive 3D conformal RT, such as volumetric modulated arc therapy (VMAT).

Methods

This is a randomized, multi-centre phase III trial of SUPR versus VMAT. We will accrue 250 patients to assess the difference in patient-reported RINV. This study is powered to detect a difference in quality of life between patients treated with VMAT vs. SUPR.

Discussion

This trial will determine if VMAT reduces early toxicity compared to SUPR and may provide justification for this more resource-intensive and costly form of RT.

Trial registration

Clinicaltrials.gov identifier: NCT03694015.

Date of registration: October 3, 2018.

Cctg MA.39 tailor RT: A randomized trial of regional radiotherapy in biomarker low-risk node-positive breast cancer (NCT03488693)

TPS602

Background: Biomarker low risk, ER positive (+), HER2 negative (-) breast cancer with low burden nodal involvement may be associated with good outcomes (Woodward 2016, Mamounas 2017). There is conflicting data regarding the efficacy of regional radiotherapy after breast conserving surgery (BCS) or mastectomy in these patients (Kyndi 2008, Whelan 2015, Poortmans 2015, Liu 2015). Our hypothesis is that the risk of recurrence in patients with biomarker low risk, ER+, Her2- breast cancer and involvement of 1-3 lymph nodes where regional RT is omitted will not be inferior to the risk of recurrence in patients treated with regional RT. Methods: MA39 is a Canadian Cancer Trials Group led, NCTN sponsored, randomized phase III study comparing breast cancer recurrence free interval (BCRFI) in patients with ER+, Her2-, LN 1-3+ breast cancer that is low risk as defined by Oncotype Dx Recurrence Score < 18. Secondary objectives include a comparison of DFS, breast cancer mortality, OS, locoregional and distant recurrence free intervals, toxicity, arm volume and mobility measurements, patient reported outcomes and cost effectiveness. Key eligibility criteria include: age ≥ 40 years; BCS or mastectomy with axillary dissection and 1-3 positive axillary nodes; BCS and SLNB alone and 1-2 positive axillary nodes; mastectomy and SLNB alone and only 1 positive axillary node; planned endocrine therapy ≥ 5 years; adjuvant chemotherapy allowed. Statistical design: The primary analysis will be a test of non-inferiority (NI) in the intention to treat population. If the upper bound of a one-sided 95% interval for the hazard ratio for BCRFI is < 1.4, NI will be declared. Using a one-sided α of 0.05 and a power of 87%, it is anticipated that 278 events are required. With an expected 5 years of accrual and 4.5 years of follow-up, 2140 patients are needed for the final sample size. Conduct to Date: Study activation May 30 2018. Participation as of February 2019: Registrations 64 Randomizations 26. CIRB approval for continuation of MA.39 was received on January 11 2019. Clinical trial information: NCT03488693.

Population-based phase II trial of stereotactic ablative radiotherapy (SABR) for up to 5 oligometastases: SABR-5

BACKGROUND

Oligometastases refer to a state of disease where cancer has spread beyond the primary site, but is not yet widely metastatic, often defined as 1-3 or 1-5 metastases in number. Stereotactic ablative radiotherapy (SABR) is an emerging radiotherapy technique to treat oligometastases that require further prospective population-based toxicity estimates.

METHODS

This is a non-randomized phase II trial where all participants will receive experimental SABR treatment to all sites of newly diagnosed or progressing oligometastatic disease. We will accrue 200 patients to assess toxicity associated with this experimental treatment. The study was powered to give a 95% confidence on the risk of late grade 4 toxicity, anticipating a < 5% rate of grade 4 toxicity.

DISCUSSION

SABR treatment of oligometastases is occurring off-trial at a high rate, without sufficient evidence of its efficacy or toxicity. This trial will provide necessary toxicity data in a population-based cohort, using standardized doses and organ at risk constraints, while we await data on efficacy from randomized phase III trials.

TRIAL REGISTRATION

Registered through clinicaltrials.gov NCT02933242 on October 14, 2016 prospectively before patient accrual.

Acute Inflammatory Response During Neoadjuvant Chemotherapy for Locally Advanced Breast Cancer: A Case Report

We report on a 56-year-old Caucasian female, diagnosed with locally advanced, hormone-receptor-positive, and human epidermal growth factor receptor 2 (HER2)-positive cancer of the left breast. The patient received neoadjuvant chemotherapy with adriamycin/cyclophosphamide (AC) followed by docetaxel/trastuzumab. A partial clinical and radiographical response was documented after four cycles of AC. Approximately one week after the first cycle of docetaxel and trastuzumab, the patient presented with diffuse edema, erythema, and induration involving the entire left breast. The differential diagnoses included infection, inflammatory response/reaction to docetaxel, or cancer progression. After a multidisciplinary review, the decision was made to stop the docetaxel and deliver neoadjuvant radiation treatment concurrent with trastuzumab. Approximately four weeks after radiation therapy completion, the patient underwent a left total mastectomy and axillary dissection, with pathologic complete response (pCR) in the breast and axillary nodal disease. After surgery, systemic therapy was resumed with paclitaxel and trastuzumab, with a plan to start adjuvant endocrine therapy after completion of chemotherapy. We will discuss clinical considerations in the management of the unexpected findings of acute inflammatory response in the breast and nodal regions during neoadjuvant chemotherapy. Associations between intrinsic breast cancer subtype and pCR in locally advanced breast cancer will also be reviewed.

The experience of people with lung cancer with a volunteer-based lay navigation intervention at an outpatient cancer center

OBJECTIVE

To describe the experiences of patients with lung cancer with a volunteer-based lay navigation intervention.

METHODS

Forty patients with newly diagnosed lung cancer enrolled in a three-step navigation intervention delivered by trained volunteer lay navigators (VLNs), beginning prior to their first oncologist's appointment and ending before the start of treatment. Methodological triangulation of data was used in a mixed method study design. Cases were categorized based on the predominant needs met by the VLN: emotional, practical/informational, family, and complex. Data were analyzed using framework analysis.

RESULTS

The provision of emotional support, information, and referrals to other services by the VLN were of particular benefit to the patient and their families. Satisfaction with the program and its timing was high; it was considered an effective means for patients to share concerns and have their needs attended to before starting treatment.

CONCLUSION

This study demonstrates capacity for lay volunteers to address the multifaceted needs of lung cancer patients during their transition from primary care in the diagnosis to treatment phase.

PRACTICE IMPLICATIONS

Using volunteers as navigators offers an opportunity to meet patient needs with minimal resources, increase access to services for patients, and improve the sustainability of the program.

Deformable versus rigid registration of PET/CT images for radiation treatment planning of head and neck and lung cancer patients: a retrospective dosimetric comparison

Background

The purpose of this study is to evaluate the clinical impact of using deformable registration in tumor volume definition between separately acquired PET/CT and planning CT images.

Methods

Ten lung and 10 head and neck cancer patients were retrospectively selected. PET/CT images were registered with planning CT scans using commercially available software. Radiation oncologists defined two sets of gross tumor volumes based on either rigidly or deformably registered PET/CT images, and properties of these volumes were then compared.

Results

The average displacement between rigid and deformable gross tumor volumes was 1.8 mm (0.7 mm) with a standard deviation of 1.0 mm (0.6 mm) for the head and neck (lung) cancer subjects. The Dice similarity coefficients ranged from 0.76-0.92 and 0.76-0.97 for the head and neck and lung subjects, respectively, indicating conformity. All gross tumor volumes received at least 95% of the prescribed dose to 99% of their volume. Differences in the mean radiation dose delivered to the gross tumor volumes were at most 2%. Differences in the fraction of the tumor volumes receiving 100% of the radiation dose were at most 5%.

Conclusions

The study revealed limitations in the commercial software used to perform deformable registration. Unless significant anatomical differences between PET/CT and planning CT images are present, deformable registration was shown to be of marginal value when delineating gross tumor volumes.

Investigation of variability in image acquisition and contouring during 3D ultrasound guidance for partial breast irradiation

Background

Three-dimensional ultrasound (3DUS) at simulation compared to 3DUS at treatment is an image guidance option for partial breast irradiation (PBI). This study assessed if user dependence in acquiring and contouring 3DUS (operator variability) contributed to variation in seroma shifts calculated for breast IGRT.

Methods

Eligible patients met breast criteria for current randomized PBI studies. 5 Operators participated in this study. For each patient, 3 operators were involved in scan acquisitions and 5 were involved in contouring. At CT simulation (CT1), a 3DUS (US1) was performed by a single radiation therapist (RT). 7 to 14 days after CT1 a second CT (CT2) and 3 sequential 3DUS scans (US2a,b,c) were acquired by each of 3 RTs. Seroma shifts, between US1 and US2 scans were calculated by comparing geometric centers of the seromas (centroids). Operator contouring variability was determined by comparing 5 RT’s contours for a single image set. Scanning variability was assessed by comparing shifts between multiple scans acquired at the same time point (US1-US2a,b,c). Shifts in seromas contoured on CT (CT1-CT2) were compared to US data.

Results

From an initial 28 patients, 15 had CT visible seromas, met PBI dosimetric constraints, had complete US data, and were analyzed. Operator variability contributed more to the overall variability in seroma localization than the variability associated with multiple scan acquisitions (95% confidence mean uncertainty of 6.2 mm vs. 1.1 mm). The mean standard deviation in seroma shift was user dependent and ranged from 1.7 to 2.9 mm. Mean seroma shifts from simulation to treatment were comparable to CT.

Conclusions

Variability in shifts due to different users acquiring and contouring 3DUS for PBI guidance were comparable to CT shifts. Substantial inter-observer effect needs to be considered during clinical implementation of 3DUS IGRT.

Interim cosmetic and toxicity results from RAPID: a randomized trial of accelerated partial breast irradiation using three-dimensional conformal external beam radiation therapy

PURPOSE

To report interim cosmetic and toxicity results of a multicenter randomized trial comparing accelerated partial-breast irradiation (APBI) using three-dimensional conformal external beam radiation therapy (3D-CRT) with whole-breast irradiation (WBI).

PATIENTS AND METHODS

Women age > 40 years with invasive or in situ breast cancer ≤ 3 cm were randomly assigned after breast-conserving surgery to 3D-CRT APBI (38.5 Gy in 10 fractions twice daily) or WBI (42.5 Gy in 16 or 50 Gy in 25 daily fractions ± boost irradiation). The primary outcome was ipsilateral breast tumor recurrence (IBTR). Secondary outcomes were cosmesis and toxicity. Adverse cosmesis was defined as a fair or poor global cosmetic score. After a planned interim cosmetic analysis, the data, safety, and monitoring committee recommended release of results. There have been too few IBTR events to trigger an efficacy analysis.

RESULTS

Between 2006 and 2011, 2,135 women were randomly assigned to 3D-CRT APBI or WBI. Median follow-up was 36 months. Adverse cosmesis at 3 years was increased among those treated with APBI compared with WBI as assessed by trained nurses (29% v 17%; P < .001), by patients (26% v 18%; P = .0022), and by physicians reviewing digital photographs (35% v 17%; P < .001). Grade 3 toxicities were rare in both treatment arms (1.4% v 0%), but grade 1 and 2 toxicities were increased among those who received APBI compared with WBI (P < .001).

CONCLUSION

3D-CRT APBI increased rates of adverse cosmesis and late radiation toxicity compared with standard WBI. Clinicians and patients are cautioned against the use of 3D-CRT APBI outside the context of a controlled trial.

Successful treatment of non-Hodgkin lymphoma associated immune thrombocytopenia with involved field radiotherapy

Immune thrombocytopenia complicates the course and impacts the outcome of non-Hodgkin lymphoma (NHL-ITP, non-Hodgkin lymphoma-immune thrombocytopenic purpura). The response to corticosteroids and/or intravenous immune globulins is usually short lasting, but NHL-ITP usually responds to anti-lymphoma chemotherapy. It is not clear if this success is due to the elimination of the lymphomatous tissue or to the immunosuppressor/immunomodulator effect of chemotherapy. Myelosuppressive anti-lymphoma chemotherapy carries the risk of severe thrombocytopenia that may not respond adequately to platelet transfusion support. We report on a patient with recurrent diffuse large B-cell lymphoma that coincided with immune thrombocytopenia. Both diseases completely responded to involved field radiation therapy. This supports the hypothesis that at least in some cases of NHL-ITP, the lymphomatous clone secretes the anti-platelet antibodies. This supports the therapeutic decision making for these patients.

The impact of dose calculation algorithms on partial and whole breast radiation treatment plans

Background

This paper compares the calculated dose to target and normal tissues when using pencil beam (PBC), superposition/convolution (AAA) and Monte Carlo (MC) algorithms for whole breast (WBI) and accelerated partial breast irradiation (APBI) treatment plans.

Methods

Plans for 10 patients who met all dosimetry constraints on a prospective APBI protocol when using PBC calculations were recomputed with AAA and MC, keeping the monitor units and beam angles fixed. Similar calculations were performed for WBI plans on the same patients. Doses to target and normal tissue volumes were tested for significance using the paired Student's t-test.

Results

For WBI plans the average dose to target volumes when using PBC calculations was not significantly different than AAA calculations, the average PBC dose to the ipsilateral breast was 10.5% higher than the AAA calculations and the average MC dose to the ipsilateral breast was 11.8% lower than the PBC calculations. For ABPI plans there were no differences in dose to the planning target volume, ipsilateral breast, heart, ipsilateral lung, or contra-lateral lung. Although not significant, the maximum PBC dose to the contra-lateral breast was 1.9% higher than AAA and the PBC dose to the clinical target volume was 2.1% higher than AAA. When WBI technique is switched to APBI, there was significant reduction in dose to the ipsilateral breast when using PBC, a significant reduction in dose to the ipsilateral lung when using AAA, and a significant reduction in dose to the ipsilateral breast and lung and contra-lateral lung when using MC.

Conclusions

There is very good agreement between PBC, AAA and MC for all target and most normal tissues when treating with APBI and WBI and most of the differences in doses to target and normal tissues are not clinically significant. However, a commonly used dosimetry constraint, as recommended by the ASTRO consensus document for APBI, that no point in the contra-lateral breast volume should receive >3% of the prescribed dose needs to be relaxed to >5%.

Can We Predict Which Women with a Negative Sentinel Lymph Node Biopsy Are at High Risk of a False Negative Result?

Background: Standard of care for women with a positive sentinel lymph node biopsy (SLNB) is to have a completion axillary lymph node dissection (cALND). For women with a negative SLNB, cALND is often not performed, accepting that a proportion will have a false negative (FN) result. FN rates are commonly reported based on surgeon experience. In the absence of cALND, information on FN rates will not be available, and other means of assessing the risk for FN SLNB is needed.Materials and Methods: Between May 1999 and December 2006, 1661 women with early-stage breast cancer that had undergone SLNB followed by cALND, were identified from our provincial database: 77 FN, 560 true positive (TP), and 1024 true negative (TN). FN cases were matched 1:3 with TN cases by date of SLNB. Chi-square and Wilcoxon Rank-sum tests were used to screen variables and those with moderate association were identified and included in subsequent models. Logistic regression was used to develop a multivariable model to predict the probability of FN vs. TN status. ROC curves were used to estimate the optimal probability cut-off, at which sensitivity (SN) and specificity (SP) were maximized. The model's performance was then assessed using a cross-validation technique.Results: Factors examined that did not significantly affect FN vs. TN status rate included: age, body mass index, previous breast surgery, histology, estrogen receptor status, margin status, tumor palpability, injection technique (peritumoral, periareolar), mapping agent used (yes/no), and SLNB done pre vs. post breast surgery (all p=NS). Factors identified that significantly affected FN vs. TN status (p&lt;0.05) and thus included for potential use in the model included: tumor size, tumor grade, lymphovascular invasion (+/-LVI), tumor site (central/medial, lateral, other), type of breast surgery (mastectomy vs. lumpectomy), pre-operative lymphoscintiscan (yes/no), colloid (yes/no), number of SLN (1 vs. &gt;1). The final model contained 5 variables: T stage (1 vs. 2), tumor grade, number of SLN removed, tumor site, and LVI. ROC identified an optimal probability cut-point for this model of 0.217 (21.7% risk of FN) with a corresponding SN of 71% and SP of 70%. In the cross-validation, the model correctly classified 66% of cases (SN of 73%, SP of 64%) with an AUC of 0.76. With increasing FN risk, SN declined and SP increased such that at a FN risk of 30%, this model had a SN 56%, SP 77%, and accuracy 72%. Using this model a woman with a T1, lateral, grade 3, 1 SLN and LVI- had a predicted FN risk of 21.5%, increasing to 52.2% if she were LVI+.Discussion: For women with early breast cancer, a negative SLNB result has a significant impact on prognosis and recommendations for further systemic and radiation therapy, this model (T size, tumor grade, number of SLN removed, tumor site, and LVI) is the first that would offer a quantitative prediction of FN risk in this setting, which could influence further discussion and therapeutic decision making. Potential refinements of this model will be explored, incorporating 'lower-priority' variables.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 303.

Intervals longer than 20 weeks from breast-conserving surgery to radiation therapy are associated with inferior outcome for women with early-stage breast cancer who are not receiving chemotherapy

PURPOSE

To determine the interval from breast-conserving surgery (BCS) to radiation therapy (RT) that affects local control or survival.

PATIENTS AND METHODS

The 10-year Kaplan-Meier (KM) local recurrence-free survival (LRFS), distant recurrence-free survival (DRFS), and breast cancer-specific survival (BCSS) were computed for 6,428 women who had T1 to 2, N0 to 1, M0 breast cancer that was diagnosed in British Columbia between 1989 and 2003, and who were treated with BCS and RT without chemotherapy. Intervals from BCS to RT were grouped by weeks as follows: < or = 4 (n = 83), greater than 4 to 8 (n = 2,288; reference group); greater than 8 to 12 (n = 2,606); greater than 12 to 16 (n = 961); greater than 16 to 20 (n = 358); and greater than 20 weeks (n = 132). Cox proportional hazards models and matching were used to control for confounding variables.

RESULTS

The median follow-up time was 7.5 years. The 10-year KM outcomes were as follows: LRFS, 95.4%; DRFS, 90.5%; and BCSS, 92.5%. Compared with the greater than 4 to 8 weeks group, hazard ratios (HR) were not significantly different for any outcome among patients who were treated up to 20 weeks after BCS. However, LRFS (hazard ratio [HR], 2.00; P = .15), DRFS (HR, 1.86; P = .02) and BCSS (HR, 2.15; P = .009) were inferior for women with BCS-to-RT intervals greater than 20 weeks compared with those greater than 4 to 8 weeks. The matched analysis yielded similar results.

CONCLUSION

Outcomes were statistically similar for BCS-to-RT intervals up to 20 weeks, but they were inferior for intervals beyond 20 weeks. Time can be reasonably allowed for the breast to heal and for patients to consider treatment options, but RT should start within 20 weeks of BCS.

Palliative radiotherapy knowledge among community family physicians and nurses

BACKGROUND

Primary care physicians and nurses care for patients with advanced cancer and need to be aware of the role for palliative radiotherapy (PR).

METHODS

We surveyed 250 family physicians, family medicine residents, and nurses attending oncology educational symposia to determine their knowledge of PR.

RESULTS

The survey response rate was 59%, and most respondents (77%) were involved with the care of cancer patients. Many (58%) thought that their knowledge of PR was insufficient for their needs. Although bone metastasis and spinal cord compression were frequently recognized indications for PR, only 50% of other assessed indications for PR were correctly identified. Almost all respondents stated that they wanted to learn more about PR.

CONCLUSIONS

More education regarding PR is required for primary care physicians and nurses caring for cancer patients.