A Prospective Study Assessing the Efficacy and Toxicity of Stereotactic Body Radiation Therapy for Oligometastatic Bone Metastases

PURPOSE/OBJECTIVE(S)

Stereotactic body radiation therapy (SBRT) is a promising treatment for oligometastatic disease in bone due to its delivery of high dose to target tissue and minimal dose to surrounding tissue. The purpose of this study is to assess efficacy and toxicity of this treatment in patients with previously unirradiated oligometastatic bony disease.

MATERIALS/METHODS

In this prospective phase II trial, patients with oligometastatic bone disease, defined as ≤3 active sites of disease, were treated with SBRT at one of two academic institutions between December 2016 and May 2019. Local progression-free survival (LPFS), progression-free survival (PFS), prostatic specific antigen (PSA) progression, and overall survival (OS) were reported. Treatment-related toxicity was also reported.

RESULTS

A total of 98 patients and 131 lesions arising from various tumor histologies were included in this study. The median age of patients enrolled in the study was 72.8 years (80.6% male, 19.4% female). Median follow-up was 26.7 months. The most common histology was prostate cancer (68.4%, 67/98). The most common dose prescriptions were 27/30 Gy in 3 fractions (26.0%, 34/131), 30 Gy in 5 fractions (19.1%, 25/131), or 30/35 Gy in 5 fractions (16.0%, 21/131). Multiple doses per treatment regimen reflect dose painting employing the lower dose to the clinical target volume (CTV) and higher dose to the gross tumor volume (GTV). Four patients (4.1%, 4/98) experienced local progression at one site for each patient (3.1%, 4/131). Among patients who progressed locally, the median time to local recurrence was 25.8 months (31.0 months among prostate cancer patients, N = 2, and 14.5 months among non-prostate cancer patients, N = 2). Among the entire cohort, 2-year LPFS (including death without local progression) was 85.0%, 2-year PFS (including deaths as well as local, distant, and PSA-based progression) was 47.0%, and 2-year OS was 87.5%. Twenty-seven patients (27.6%, 27/98) developed treatment-related toxicities, and most were Grade 1 (19.4%, 19/98) and 2 (4.1%, 4/98). Four patients (4.1%, 4/98) developed Grade 3 toxicities; there were no Grade 4 toxicities. The most common toxicity was fatigue (10.2%, 10/98). Of 68 treated spine metastases, there were four (5.9%, 4/68) vertebral fractures. Among these four patients, median time to fracture was 23.5 months (range 14.2-39.2 months).

CONCLUSION

Our study supports existing literature in showing that SBRT is effective and tolerable in patients with oligometastatic bone disease. Larger phase III trials are necessary and reasonable to determine long-term efficacy and toxicities.

Prognostic Understanding and Goals of Palliative Radiotherapy: A Qualitative Study

CONTEXT

There is a paucity of data describing patients' expectations of goals of palliative radiotherapy (RT) and overall prognosis.

OBJECTIVES

To explore patients' perceptions of and preferences for communication surrounding goals of palliative RT and cancer prognosis.

METHODS

We conducted a qualitative study utilizing semi-structured interviews with seventeen patients with either bone or lung metastases receiving their first course of palliative RT at a comprehensive cancer center. All patient interviews were recorded, transcribed verbatim, and thematically analyzed.

RESULTS

Themes of goals of palliative RT centered on either restoration, such as through improving quality of life or minimizing pain, or on a desire to combat cancer by eliminating tumor. While most patients perceived that palliative RT would palliate symptoms but not cure their cancer, some patients believed that the goal of palliative RT was to cure. Themes that emerged surrounding patients' understanding of prognosis and what lies ahead included uncertainty and apprehension about the future, a focus on additional treatment, and confronting mortality. Most patients preferred to receive information about goals of treatment and prognosis from their doctors, including radiation oncologists, rather than other members of the medical team. Patients also expressed a desire for written patient education materials on palliative RT.

CONCLUSION

Unclear perceptions of goals of treatment and prognosis may motivate some patients to pursue unnecessarily aggressive cancer treatments. Patients desire prognostic information from their doctors, including radiation oncologists, who are important contributors to goals of care discussions and may improve patient understanding and well-being by using restorative rather than combat-oriented language.

Longitudinal symptoms and temporal trends in palliative care, palliative radiotherapy, and anti-cancer treatment near end of life among patients with metastatic cancer

BACKGROUND

Early specialty palliative care (PC) integration improves oncologic outcomes. We aimed to examine longitudinal relationships between specialty PC and palliative radiotherapy (RT), temporal distribution of symptoms, and predictors of earlier specialty PC.

METHODS

We retrospectively reviewed 135 patients with metastatic cancer who received palliative RT at our institution (7/2017-2/2018) and who had died by final study follow-up (6/2021). Descriptive statistics summarized frequencies of clinical visits and symptoms over relative survival time (quartiles 1-3: first 75% of life remaining from metastatic diagnosis to death versus quartile 4: last 25% of life remaining from metastatic diagnosis to death). Logistic regression analyses revealed predictors of receiving earlier (quartiles 1-3) versus later (quartile 4) specialty PC.

RESULTS

There were 16.3%, 10.4%, 26.7%, and 46.7% of palliative RT consultations, compared to 4.7%, 7.6%, 14.0%, and 73.7% of specialty PC visits, that occurred in quartiles 1, 2, 3, and 4, respectively. On multivariable analysis, pain significantly predicted for receiving earlier specialty PC [odds ratios (OR) =15.34; 95% confidence interval (CI): 2.16-324.23; P=0.020], while patients with ≥2 prior chemotherapy regimens were less likely to have received earlier specialty PC (OR =0.16; 95% CI: 0.04-0.58; P=0.009). The most common reasons for first specialty PC visit were addressing pain (61.0%) and goals of care (19.5%). Overall, 73.3% (99/135) of patients were referred to hospice and 9.6% (13/135) received either palliative RT, chemotherapy, or surgery within 30 days of death.

CONCLUSIONS

Nearly 47% of palliative RT visits compared with 74% of specialty PC visits occurred in the last quarter of life from metastatic diagnosis to death. Multidisciplinary efforts are needed to manage longitudinal symptoms and offer goal-concordant care.

Primary Addiction Medicine Skills for Hospice and Palliative Medicine Physicians: A Modified Delphi Study

CONTEXT

Hospice and palliative medicine (HPM) physicians frequently care for patients with substance use disorders (SUDs), but there is no consensus on which primary addiction medicine (AM) skills are essential.

OBJECTIVES

Identify key primary AM skills that physicians should acquire during an ACGME-accredited HPM fellowship program.

METHODS

A modified Delphi study consisting of 18 experts on SUD in HPM and medical education. A literature review and expert input identified initial AM skills. In three Delphi rounds, participants rated each skill on a nine-point scale from "not at all important to include" to "crucial to include." We calculated medians (IQRs), analyzed panelists' comments, and grouped skills using the RAND / UCLA appropriateness method.

RESULTS

Among 62 proposed AM skills, 53 skills were rated as appropriate to include (38 of which achieved agreement), and nine skills were rated as uncertain. AM skills most relevant to HPM included 1) defining chemical coping, median 8.5 (IQR 2); 2) balancing life expectancy with risks of opioid use for patients with SUD, 9 (IQR 0); 3) explaining best practices to dispose unused opioids postmortem, 8 (IQR 2); 4) managing pain for hospice patients with SUD, 9 (IQR 0.75); and 5) partnering with hospice to manage patients on methadone and buprenorphine, 9 (IQR 2). Experts did not achieve consensus on whether HPM physicians should be encouraged to learn to prescribe buprenorphine for patients with opioid use disorder, 6 (IQR 3).

CONCLUSION

HPM fellowships should consider incorporating the primary AM skills identified in this study in their curricula.

Patient-Provider Communication, Decision-Making, and Psychosocial Burdens in Palliative Radiotherapy: A Qualitative Study on Patients' Perspectives

CONTEXT

Patient-provider communication impacts how patients with cancer make decisions about treatment.

OBJECTIVES

To examine patient perceptions of discussions, decision-making, and psychosocial burdens related to receiving palliative radiotherapy (RT), in order to inform best practices for communication about palliative RT.

METHODS

We conducted an exploratory qualitative study using oral questionnaires and semi-structured interviews. Seventeen patients receiving their first course of palliative RT for lung or bone metastases at a comprehensive cancer center were interviewed. Patient interviews were transcribed verbatim and thematically analyzed using NVivo software.

RESULTS

Themes that impacted patients' decisions to initiate RT included a desire to minimize pain, optimism about what RT could provide for the future, perception of having "no other choice," disappointment about cancer progression, and unfamiliarity with RT. Most patients preferred shared decision-making regarding RT initiation and reported patient empowerment, effective communication, and team collaboration as contributing to shared decision-making. Most patients preferred their physicians to make decisions about RT treatment intensity and described trust in their physicians, institutional reputation, and RT expertise as motivators for this preference. Patients who possessed a proactive decisional mindset about initiating RT as opposed to having "no other choice" were less likely to report experiencing psychosocial burdens.

CONCLUSION

Most patients prefer shared decision-making regarding RT initiation but prefer their radiation oncologists to make decisions regarding treatment intensity. Communication that empowers patients in their desired level of engagement for RT decision-making may help patients make informed decisions, contribute toward a proactive decisional mindset, and reduce their perception of psychosocial burdens.

Patterns of Specialty Palliative Care Utilization Among Patients Receiving Palliative Radiation Therapy

CONTEXT

Palliative radiation therapy (RT) is frequently used to ameliorate cancer-associated symptoms and improve quality of life.

OBJECTIVES

To examine how palliative care (PC) as a specialty is integrated at the time of RT consultation for patients with advanced cancer.

METHODS

We retrospectively reviewed 162 patients with metastatic cancer who received palliative RT at our institution (7/2017-2/2018). Fisher's exact test identified differences in incidence of receiving any specialty PC. Logistic regression analyses determined predictors of receiving PC.

RESULTS

Of the 74 patients (46%) who received any specialty PC, 24 (32%) initiated PC within four weeks of RT consultation. The most common reasons for specialty PC initiation were pain (64%) and goals of care/end-of-life care management (23%). Referrals to specialty PC were made by inpatient care teams (48.6%), medical oncologists (48.6%), radiation oncologists (1.4%), and self-referring patients (1.4%). Patients with pain at RT consultation had a higher incidence of receiving specialty PC (58.7% vs. 37.4%, P = 0.0097). There was a trend toward decreased PC among patients presenting with neurological symptoms (34.8% vs. 50%, P = 0.084). On multivariable analysis, receiving specialty PC significantly differed by race (non-white vs. white, odds ratio [OR] = 6.295 [95% CI 1.951-20.313], P = 0.002), cancer type (lung vs. other histology, OR = 0.174 [95% CI 0.071-0.426], P = 0.0006), and RT consultation setting (inpatient vs. outpatient, OR = 3.453 [95% CI 1.427-8.361], P = 0.006).

CONCLUSION

Fewer than half of patients receiving palliative RT utilized specialty PC. Initiatives are needed to increase PC, especially for patients with lung cancer and neurological symptoms, and to empower radiation oncologists to refer patients to specialty PC.

Characteristics and Predictors of Radiographic Local Failure in Patients With Spinal Metastases Treated With Palliative Conventional Radiation Therapy

Purpose

Although local control is an important issue for longer-term survivors of spinal metastases treated with conventional external beam radiation therapy (EBRT), the literature on radiographic local failure (LF) in these patients is sparse. To inform clinical decision-making, we evaluated rates, consequences, and predictors of radiographic LF in patients with spinal metastases managed with palliative conventional EBRT alone.

Methods and Materials

We retrospectively reviewed 296 patients with spinal metastases who received palliative EBRT at a single institution (2006-2013). Radiographic LF was defined as radiologic progression within the treatment field, with death considered a competing risk. Kaplan-Meier, cumulative incidence, and Cox regression analyses determined overall survival estimates, LF rates, and predictors of LF, respectively.

Results

There were 182 patients with follow-up computed tomography or magnetic resonance imaging; median overall survival for these patients was 7.7 months. Patients received a median of 30 Gy in 10 fractions to a median of 4 vertebral bodies. Overall, 74 of 182 patients (40.7%) experienced LF. The 6-, 12-, and 18-month LF rates were 26.5%, 33.1%, and 36.5%, respectively, while corresponding rates of death were 24.3%, 38.1%, and 45.9%. Median time to LF was 3.8 months. Of those with LF, 51.4% had new compression fractures, 39.2% were admitted for pain control, and 35.1% received reirradiation; median time from radiation therapy (RT) to each of these events was 3.0, 5.7, and 9.2 months, respectively. Independent predictors of LF included single-fraction RT (8 Gy) (hazard ratio [HR], 2.592; 95% confidence interval [CI], 1.437-4.675; P = .002), lung histology (HR, 3.568; 95% CI, 1.532-8.309; P = .003), and kidney histology (HR, 4.937; 95% CI, 1.529-15.935; P = .008).

Conclusions

Patients experienced a >30% rate of radiographic LF by 1 year after EBRT. Single-fraction RT and lung or kidney histology predicted LF. Given the high rates of LF for patients with favorable prognosis, assessing the risk of death versus LF is important for clinical decision-making.

Impact of primary tumor-specific growth rate on treatment failure for nonoropharyngeal head and neck cancers

OBJECTIVES

To investigate the prognostic impact of primary tumor-specific growth rate (TSGR) on treatment outcomes after definitive radiation therapy (RT) for nonoropharyngeal squamous cell carcinoma (non-OPSCC).

METHODS

The diagnostic tumor and nodal volumes of 39 non-OPSCC patients were contoured and compared to corresponding RT planning scan volumes to determine TSGR. Overall survival (OS), disease-free survival (DFS), and local recurrence-free survival were evaluated according to the Kaplan-Meier method; and hazard ratios (HR) were estimated using Cox regression. Based on the 75th percentile TSGR of 2.18%, we stratified patients into a high TSGR group (≥ 2.18% per day) and low TSGR group (< 2.18% per day).

RESULTS

The median follow-up was 22 months (range: 1-86 months) and median time between diagnostic and simulation computed tomography scans was 22 days (range: 7-170 days). Median RT dose was 70 Gy (range: 60-79.2 Gy). Based on the 75th percentile TSGR, OS at median follow-up was 50.0% for the high TSGR group compared to 92.5% for the low TSGR group (HR [95% confidence interval (CI)] = 2.12[1.16-11.42], P = 0.018). There was a trend toward worse DFS at median follow-up for the high versus low TSGR groups, at 55.6% and 82.3%, respectively (HR [95% CI] = 2.29[0.82-6.38], P = 0.103).

CONCLUSION

Our study contributes to growing literature on TSGR as a temporal biomarker in patients with non-OPSCC. Patients with high TSGR ≥2.18% per day have significantly worse OS compared to those with TSGR below this threshold. Efforts to address treatment initiation delays may benefit patients with particularly aggressive and rapidly growing tumors.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:2378-2384, 2020.