Phase II study of helical tomotherapy in the multidisciplinary treatment of oligometastatic colorectal cancer

Stereotactic body radiation therapy in the treatment of cancer patients with oligometastatic disease: a real world study

PURPOSE

Stereotactic body radiation therapy (SBRT) is a treatment modality with curative intent for oligometastatic cancer patients, commonly defined by a low-burden metastatic disease with 1-5 systemic metastases. Better knowledge of the clinical profile and prognostic factors in oligometastatic cancer patients could help to improve the selection of candidates who may obtain most benefits from SBRT. The objective of this study was to describe the clinical data and outcome in term of overall survival (OS) of patients with oligometastatic disease treated with SBRT over a 6-year period.

METHODS

From 2013 to 2018, 284 solid tumor cancer patients with 1-5 oligometastases underwent SBRT at a large university-affiliated oncological center in Barcelona, Spain. Variables related to the patient profile, tumor, oligometastatic disease, and treatment were evaluated.

RESULTS

A total of 327 metastatic tumors were treated with SBRT. In 65.5% of cases, metachronous tumors were diagnosed at least 1 year after diagnosis of the primary tumor. The median age of the patients was 73.9 years and 66.5% were males. The median follow-up was 37.5 months. The most common primary tumors were lung and colorectal cancer, with lung and bone as the most commonly treated metastatic sites. Ninety-three percent of patients showed a Karnofsky score (KPS) between 80 and 100. Adenocarcinoma was the most common histological type. The median overall survival was 53.4 months, with 1-, 2- and 5-year survival rates of 90.5%, 73.9% and 43.4%, respectively. Overall survival rates of breast (67.6 months, 95% CI 56.4-78.9), urological (63.3 months, 95% CI 55.8-70.8), and colorectal (50.8 months, 95% CI 44.2-57.4) tumors were higher as compared with other malignancies (20 months, 95% CI 11.2-28.8 months) (p < 0.001). Patients with Karnofsky score (KPS) of 90 and 100 showed a significantly better survival than those with impaired performance status (p = 0.001).

CONCLUSION

SBRT appears to be well tolerated and safe approach in oligometastatic patients. Patients with good performance status and with primary breast, urological and colorectal cancer have higher OS compared with other malignancies. More studies are necessary to evaluate the prognostic factors in oligometastatic disease (OMD) in order to select patients who could benefit more from this therapeutic approach.

Effects of locoregional radiotherapy in de novo metastatic nasopharyngeal carcinoma: A real-world study

•

Locoregional radiotherapy can prolong OS for patients with de novo metastatic nasopharyngeal carcinoma.

•

Nasopharyngeal carcinoma patients with oligometastic disease can benefit from locoregional radiotherapy rather than polymetastatic disease.

Background

To evaluate the value of locoregional radiotherapy (LRRT) in de novo metastatic nasopharyngeal carcinoma (dmNPC) and identify predictive factors for additional LRRT after palliative chemotherapy (PCT).

Methods

Overall survival (OS) was the primary endpoint. Patients who underwent PCT and LRRT were categorized as the PCT+LRRT group; patients who only received palliative chemotherapy were categorized as the PCT group. Oligometastatic diseases (OMD) was defined as ≤5 metastatic lesions and ≤2 metastatic organs.

Results

A total of 168 patients were included for this study. The median OS of patients in the PCT+LRRT group was significantly higher than those in the PCT group (57 months vs. 22 months, P<0.001). Multivariate analyses (MVA) showed that LRRT (HR=0.533, 95% CI: 0.319–0.889, P = 0.016) and OMD (HR=0.548, 95% CI: 0.331–0.907, P = 0.019) were independent prognostic factors for dmNPC. Furthermore, Kaplan–Meier analyses showed that the 3-year OS of patients who received LRRT was significantly better than those who did not receive LRRT in the OMD subgroup (66.3% vs. 25.2%, P<0.001). While, the 3-year OS of patients who received LRRT and without LRRT was no different in the polymetastatic disease (PMD) subgroup (38.9% vs.11.5%, P = 0.115). MVA showed that LRRT was a favorable prognosticator in the OMD subgroup (HR=0.308, 95% CI: 0.159–0.598; P<0.001), and not a favorable prognosticator in the PMD subgroup (HR=0.510, 95% CI: 0.256–1.014, P = 0.055).

Conclusions

LRRT has the potential to prolong OS in NPC patients with de novo OMD. These results suggest that OMD is a potential indicator for filtering beneficiaries from LRRT.

Prognostic Value of the C-Reactive Protein/Albumin Ratio and Systemic Immune-Inflammation Index for Patients With Colorectal Liver Metastasis Undergoing Curative Resection

Background: We evaluated the prognostic value of C-reactive protein/albumin (CAR) and systemic immune-inflammation index (SII), which we calculated as neutrophil × platelet/lymphocyte) in patients with colorectal liver metastasis (CRLM) after curative resection.

Methods: We retrospectively enrolled 283 consecutive patients with CRLM who underwent curative resection between 2006 and 2016. We determined the optimal cutoff values of CAR and SII using receiver operating curve (ROC) analysis. Overall survival (OS)- and recurrence-free survival (RFS)-related to CAR and SII were analyzed using the log-rank test and multivariate Cox regression methods.

Results: We found that a high CAR was significantly associated with poor OS (P < 0.001) and RFS (P = 0.008) rates compared with a low CAR; a high SII was significantly associated with poor RFS (P = 0.003) rates compared with a low SII. The multivariate analysis indicated that CAR was an independent predictor of OS (hazard ratio [HR] = 2.220; 95% confidence interval [CI] = 1.387–3.550; P = 0.001) and RFS (HR = 1.494; 95% CI = 1.086–2.056; P = 0.014). The SII was an independent predictor of RFS (HR = 1.973; 95% CI = 1.230–3.162; P = 0.005) in patients with CRLM.

Conclusion: We proved that CAR was an independent predictor of OS and RFS in patients with CRLM who underwent curative resection, and that the prognostic value of CAR was superior to that of SII.

Linear accelerator-based stereotactic body radiation therapy in the treatment of oligometastatic disease

The present study reports the clinical outcomes of hypofractionated stereotactic body radiation therapy (SBRT) for oligometastasis (OM) originating from various tumors. Between February 2012 and April 2017, 40 patients with unresectable OM were treated with SBRT. Of these patients, 92% showed a solitary nodal metastasis and the rest had up to three metastases. The dose prescription was 50 Gy in 10 fractions with three-dimensional conformal techniques or volumetric intensity-modulated arc therapy. Median follow-up was 14 months. Of the 40 patients, none showed local progression at the site of SBRT, but 20 patients showed tumor growth at distant sites during follow-up. The 2- and 3-year overall survival rates were 45.1 and 36.1%, respectively. The 2- and 3-year progression-free survival rates were 35.4 and 26.5%, respectively. The interval between diagnosis and detection of OM (<2 vs. >2 years) and primary tumor site (esophagus vs. others) emerged as significant variables affecting survival. Grade 3 subacute and grade 4 chronic toxicities were observed in 1 and 2 patients, respectively. SBRT of 50 Gy in 10 fractions for OM from various primary tumors was shown to lead to good clinical outcomes from the viewpoints of local control and toxicity frequency. However, additional studies are required to identify the patient groups likely to receive maximal benefits from such treatment.

Preoperative AFU Is a Useful Serological Prognostic Predictor for Colorectal Liver Oligometastasis Patients Undergoing Hepatic Resection

Background: Preoperative alpha-l-fucosidase (AFU) has been used as a diagnostic biomarker for several cancers, but its role as a prognostic predictor in colorectal cancer liver oligometastasis (CLOM) patients after radical surgery has not been well defined. This study aimed to investigate the prognostic significance of preoperative serum AFU for CLOM patients after hepatic resection.

Methods: A retrospective data set was collected to evaluate the prognostic value of preoperative AFU in CLOM patients after radical hepatic resection. A total of 269 patients with histopathologically confirmed CLOM were enrolled. The optimal cut-off value of preoperative AFU was determined using X-tile software. Univariate and multivariate analyses were used to identify the prognostic significance of preoperative serum AFU.

Results: The X-tile software showed that the optimal cut-off value of preoperative AFU was set at 30.8 U/L. Patients with preoperative AFU≤30.8 and >30.8 were classified into high and low AFU groups, respectively. Female patients and those with a single liver metastasis had a higher tendency to have a preoperative AFU≤30.8 U/L; patients with lower clinical risk score (CRS) were more likely to have AFU >30.8 U/L than patients with higher CRS. The results showed that preoperative AFU was an independent prognostic factor for overall survival (OS) (P=0.041). Patients with a preoperative AFU≤30.8 U/L had a lower OS rate than those with AFU>30.8 U/L. Furthermore, for patients with lower CRS scores (0-2), the tendency clearly showed that patients with higher preoperative AFU had a better prognosis (P=0.029).

Conclusions: Higher preoperative serum AFU can predict better survival in CLOM patients after hepatic resection, especially for CLOM patients with lower CRS scores.

The METABANK score: A clinical tool to predict survival after stereotactic radiotherapy for oligometastatic disease

BACKGROUND AND PURPOSE

Stereotactic radiotherapy (SRT, SBRT) is widely used in oligometastatic cancer, but the heterogeneity of the population complicates estimation of the prognosis. We investigated the role of different clinical and inflammatory parameters.

MATERIALS AND METHODS

We included all patients treated with SRT for 1-5 oligometastases between 2003 and 2017 in our center. Patients were randomized between a model training set (2/3) and a separate validation set (1/3). A Cox regression model was built, validated and risk points were attributed to the resulting parameters.

RESULTS

403 patients received SRT for 760 metastases. Treated sites were mainly lung, liver, nodal areas, and brain. Most common primaries were colorectal and lung cancer. Median follow-up for living patients reached 42 months and median overall survival (MS) was 26.6 months (95% CI 23.8-29.3). Five independent adverse factors were discriminated: male sex, synchronous timing of oligometastases, brain metastasis, non-adenocarcinoma histology, KPS <80. A risk score is formed by summation of the points of each factor (M:4, T:2, B:7, N:7, K:8). Four risk groups were defined: (1) 0-2 points: MS 41.2 months (95% CI 30.2-52.3); (2) 3-8 points: 29.3 months (24.6-34.0); (3) 9-13 points: 17.4 months (10.1-24.7), and (4) 14-28 points: 7.9 months (5.5-10.3).

CONCLUSION

We propose a prognostic score applicable in a variety of primary tumors and disease locations, including presence of brain metastases. The nomogram and risk groups can be used to stratify patients in new trials and to support individualized care for oligometastatic patients. An online calculator will become available at predictcancer.org.

Early recurrence in patients undergoing curative resection of colorectal liver oligometastases: identification of its clinical characteristics, risk factors, and prognosis

PURPOSE

Oligometastatic disease can potentially be cured when an optimal approach is performed. Early recurrence after liver resection is an intractable problem, and the clinical implications remain unknown in colorectal liver oligometastases (CLOM) patients. This study aimed to investigate the clinical characteristics, risk factors, and prognosis related to early recurrence in these patients.

METHODS

A total of 307 consecutive patients with CLOM undergoing curative liver resection were retrospectively reviewed between September 1999 and June 2016. Early recurrence was defined as any recurrence or death from CLOM that occurred within 6 months of liver resection.

RESULTS

With a median follow-up time of 31.7 months, the 3-year overall survival (OS) and recurrence-free survival rates were 68.7 and 42.5%, respectively. Forty-nine (16.0%) patients developed early recurrence and showed a poorer 3-year OS than those with non-early recurrence (22.3 vs. 75.8%, P < 0.001) or later recurrence (22.3 vs. 52.8 vs. 63.2%, P < 0.001). Moreover, early recurrence was identified as an independent predictor of 3-year OS [hazard ratio (HR) 6.282; 95% confidence interval (CI) 3.980-9.915, P < 0.001]. In multivariate analysis, a node-positive primary tumor [odds ratio (OR) 2.316; 95% CI 1.097-4.892, P = 0.028) and metastatic diameter > 3 cm (OR 2.560; 95% CI 1.290-5.078; P = 0.007) were shown to be risk factors for early recurrence. The salvage liver resection rate for patients with early recurrence was significantly lower than that for patients with later recurrence (4.1 vs. 19.7%, P = 0.010).

CONCLUSIONS

Early recurrence should be investigated in routine clinical practice, even in patients with CLOM after curative liver resection. Detailed preoperative comprehensive measurements might help stratify high-risk patients, and a non-surgical treatment for early recurrence might represent an effective alternative.

Effect of primary tumor location and tumor size on the response to radiotherapy for liver metastases from colorectal cancer

Metastatic liver tumors (MLTs) from colorectal cancer (CRC) are often treated with stereotactic body radiation therapy (SBRT). The present study aimed to examine the predictive factors for response of MLTs to SBRT. A total of 39 MLTs from 24 patients with CRC were retrospectively analyzed. Radiotherapy for MLT was typically performed with a prescribed dose equivalent to a biologically effective dose (BED)10 of 100 Gy. The median follow-up period was 16 months (range, 5-64 months). The median prescribed dose and total BED10 were 56 Gy (range, 45-72 Gy) and 97.5 Gy (range, 71.7-115.5 Gy), respectively, in a median of 8 fractions (range, 4-33 fractions). The 1- and 2-year local control rates were 67.2 and 35.9%, respectively. For patients with MLT treated with ablative SBRT (BED10 ≥100 Gy in ≤5 fractions), the 1- and 2-year local control rates were 83.3 and 62.5%, respectively. Univariate analysis showed that primary tumor location (left-sided colon), maximum tumor diameter (≤30 mm) and ablative SBRT (BED10 ≥100 Gy in ≤5 fractions) were significantly associated with improved local control (P=0.0058, P=0.0059 and P=0.0268, respectively). Multivariate analysis showed that tumor diameter was significantly associated with improved local control (P=0.0314). In addition, patients who received ablative SBRT had significantly prolonged overall survival times compared with those treated with non-ablative SBRT (P=0.0261). To conclude, tumors ≤30 mm that can be treated with ablative SBRT are associated with good local control rates. The primary tumor location may affect the radiosensitivity of MLTs.

The expanding role of stereotactic body radiation therapy in oligometastatic solid tumors: What do we know and where are we going?

The spectrum hypothesis posits that there are distinct clinical states of metastatic progression. Early data suggest that aggressive treatment of more biologically indolent metastatic disease, characterized by metastases limited in number and destination organ, may offer an opportunity to alter the disease course, potentially allowing for longer survival, delay of systemic therapy, or even cure. The development of stereotactic body radiation therapy (SBRT) has opened new avenues for the treatment of oligometastatic disease. Early data support the use of SBRT for treating oligometastases in a number of organs, with promising rates of treated metastasis control and overall survival. Ongoing investigation is required to definitively establish benefit, determine the appropriate treatment regimen, refine patient selection, and incorporate SBRT with systemic therapies.

Feasibility and response of helical tomotherapy in patients with metastatic colorectal cancer

Purpose

To investigate the treatment outcome and the toxicity of helical tomotherapy (HT) in patients with metastatic colorectal cancer (mCRC).

Materials and Methods

We retrospectively reviewed 18 patients with 31 lesions from mCRC treated with HT between 2009 and 2013. The liver (9 lesions) and lymph nodes (9 lesions) were the most frequent sites. The planning target volume (PTV) ranged from 12 to 1,110 mL (median, 114 mL). The total doses ranged from 30 to 70 Gy in 10-30 fractions. When the α/β value for the tumor was assumed to be 10 Gy for the biologically equivalent dose (BED), the total doses ranged from 39 to 119 Gy₁₀ (median, 55 Gy₁₀). Nineteen lesions were treated with concurrent chemotherapy (CCRT).

Results

With a median follow-up time of 16 months, the median overall survival for 18 patients was 33 months. Eight lesions (26%) achieved complete response. The 1- and 3-year local progression free survival (LPFS) rates for 31 lesions were 45% and 34%, respectively. On univariate analysis, significant parameters influencing LPFS rates were chemotherapy response before HT, aim of HT, CCRT, PTV, BED, and adjuvant chemotherapy. On multivariate analysis, PTV ≤113 mL and BED >48 Gy₁₀ were associated with a statistically significant improvement in LFPS. During HT, four patients experienced grade 3 hematologic toxicities, each of whom had also received CCRT.

Conclusion

The current study demonstrates the efficacy and tolerability of HT for mCRC. To define optimal RT dose according to tumor size of mCRC, further study should be needed.

Dynamic Lung Tumor Tracking for Stereotactic Ablative Body Radiation Therapy

Physicians considering stereotactic ablative body radiation therapy (SBRT) for the treatment of extracranial cancer targets must be aware of the sizeable risks for normal tissue injury and the hazards of physical tumor miss. A first-of-its-kind SBRT platform achieves high-precision ablative radiation treatment through a combination of versatile real-time imaging solutions and sophisticated tumor tracking capabilities. It uses dual-diagnostic kV x-ray units for stereoscopic open-loop feedback of cancer target intrafraction movement occurring as a consequence of respiratory motions and heartbeat. Image-guided feedback drives a gimbaled radiation accelerator (maximum 15 x 15 cm field size) capable of real-time ±4 cm pan-and-tilt action. Robot-driven ±60° pivots of an integrated ±185° rotational gantry allow for coplanar and non-coplanar accelerator beam set-up angles, ultimately permitting unique treatment degrees of freedom. State-of-the-art software aids real-time six dimensional positioning, ensuring irradiation of cancer targets with sub-millimeter accuracy (0.4 mm at isocenter). Use of these features enables treating physicians to steer radiation dose to cancer tumor targets while simultaneously reducing radiation dose to normal tissues. By adding respiration correlated computed tomography (CT) and 2-[(18)F] fluoro-2-deoxy-ᴅ-glucose ((18)F-FDG) positron emission tomography (PET) images into the planning system for enhanced tumor target contouring, the likelihood of physical tumor miss becomes substantially less. In this article, we describe new radiation plans for the treatment of moving lung tumors.

The biology and treatment of oligometastatic cancer

Clinical reports of limited and treatable cancer metastases, a disease state that exists in a transitional zone between localized and widespread systemic disease, were noted on occasion historically and are now termed oligometastasis. The ramification of a diagnosis of oligometastasis is a change in treatment paradigm, i.e. if the primary cancer site (if still present) is controlled, or resected, and the metastatic sites are ablated (surgically or with radiation), a prolonged disease-free interval, and perhaps even cure, may be achieved. Contemporary molecular diagnostics are edging closer to being able to determine where an individual metastatic deposit is within the continuum of malignancy. Preclinical models are on the outset of laying the groundwork for understanding the oligometastatic state. Meanwhile, in the clinic, patients are increasingly being designated as having oligometastatic disease and being treated owing to improved diagnostic imaging, novel treatment options with the potential to provide either direct or bridging therapy, and progressively broad definitions of oligometastasis.

Phase II study of stereotactic body radiotherapy to primary tumor and metastatic locations in oligometastatic nonsmall-cell lung cancer patients

BACKGROUND

Stereotactic body radiotherapy (SBRT) has emerged as a treatment modality in patients presenting with oligometastatic nonsmall-cell lung cancer (NSCLC). SBRT is used as a local consolidative treatment to metastatic disease sites. The majority of patients included in SBRT trials for oligometastatic NSCLC have controlled primary tumors and brain metastases.

PATIENTS AND METHODS

Oligometastatic NSCLC patients with ≤5 metastatic lesions were included in a prospective phase II trial to evaluate efficacy and toxicity of SBRT to all disease sites, primary tumor and metastatic locations. SBRT to a dose of 50 Gy in 10 fractions was delivered. Positron emission tomography-computed tomography (PET-CT) was carried out at baseline and 3 months after SBRT to evaluate the metabolic response rate according to PET Response Criteria in Solid Tumors (PERCIST). The progression-free survival (PFS) and overall survival (OS) were calculated using Kaplan-Meier method from start of chemotherapy or radiotherapy. Side-effects were scored using the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) version 3.0.

RESULTS

Twenty-six patients received SBRT after induction chemotherapy (n = 17) or as a primary treatment (n = 9). Median follow-up was 16.4 months. Overall metabolic response rate was 60% with seven patients (30%) achieving a complete metabolic remission and 7 (30%) a partial metabolic response. Any acute grade 2 toxicity was observed in four patients (15%) and grade 3 pulmonary toxicity in two patients (8%). Median PFS and OS were 11.2 and 23 months. The 1-year PFS and 1-year OS rate were 45% and 67%, respectively.

CONCLUSION

SBRT to all disease sites, primary tumor and metastatic locations, in oligometastatic NSCLC patients produced an acceptable median PFS of 11.2 months.

Helical tomotherapy for cancer treatment: a rapid health technology assessment

OBJECTIVES

Helical tomotherapy (HT) can be applied to treat complex malignant cancer with high-precise radiotherapy, and it can reduce the damage to normal tissues and improve treatment effects. But the procurement of HT must be approved by relevant departments of administration affairs. This study, appointed by the National Health and Family Planning Commission of China and undertook by the National Health Development Research Center and the Chinese Evidence-Based Medicine Centre, was aimed to rapidly assess the effectiveness, safety, costs, and applicability of HT, so as to provide currently available best evidence for decision-makers of health policies.

METHODS

We electronically searched databases including PubMed, EMbase, The Cochrane Library, CNKI, WanFang Data, VIP, CBM, and other professional websites. Two reviewer independently screened literature according to the inclusion and exclusion criteria, extracted data, assessed quality, and then performed descriptive analysis.

RESULTS

(i) We finally included 150 studies, encompassing 5 HTAs, 18 CCTs, and 127 observational studies. (ii) The included HTAs were published during 2006-2009, providing fairly less evidence of low quality and the results of 145 primary studies showed that: HT had been used mainly in the treatments of 14 kinds of cancer, with low total toxicity and high survival rates. Although the quality of the included studies was poor, there was much evidence about prostate cancer, head and neck cancer, nasopharynx cancer, cervical cancer, lung cancer and liver cancer, with enough sample and fairly reliable results in HT efficacy and safety. And (iii) a total of 56 clinical trials were registered in Clinicaltrials.gov, most of which were registered by the occident. Among them, 9 were completed but the results had not been published yet.

CONCLUSIONS

The evidence of this study showed that, HT is safe and effective in clinic. But the abovementioned conclusion needs to be verified by conducting more high-quality studies with long-term follow-up. The costs of HT in procurement, maintenance, and application are high; and the skills, training, and qualification of operators are required. We suggest that the procurement of HT should be reduced; it should be allocated rationally and effectively used after comprehensive assessment in China's cancer epidemiology characteristics, health resource allocation, disease burden, medical service level, etc.; and also high-quality studies with long-term follow-up should be financially supported on the basis of establishing projects, so as to provide local evidence and consistently guide and improve scientific decision-making.

Regional hepatic therapies: an important component in the management of colorectal cancer liver metastases

The treatment of colorectal cancer liver metastases (CRLM) has evolved significantly in the last 15 years. Currently, complete surgical resection remains the only potentially curative option; unfortunately, approximately 80% of patients with CRLM are not candidates for complete tumor resection. For patients with unresectable CRLM the available treatment options were historically limited; however, the development of regional hepatic therapies (RHT) and improvement of systemic chemotherapeutic regimens have emerged as viable options to improve overall survival and quality of life for this group of patients. The selection, sequence and integration of interventions into a multi-modal approach is a complex and evolving discipline. In this article, the currently available RHT modalities for CRLM are presented as a guide to the options for clinical treatment decisions.

Stereotactic radiotherapy for oligometastatic cancer: a prognostic model for survival

BACKGROUND

Stereotactic radiotherapy (SRT) is a safe and locally effective treatment for patients with inoperable oligometastases. The challenge remains identifying subsets of patients that benefit in terms of overall survival (OS).

PATIENTS AND METHODS

Between 2005 and 2011, 309 patients with ≤5 metastases were treated by stereotactic body radiotherapy (n=209) and/or by intracranial single or fractionated stereotactic radiotherapy (n=107). We analyzed OS and carried out a risk factor analysis.

RESULTS

The median survival of all patients was 24 months. The 3-, 4- and 5-year OS rates were 32%, 25% and 19%, respectively. The following four risk factors were independently associated with impaired OS: nonadenocarcinoma histology (P<0.01), intracranial metastases (P<0.01), synchronous oligometastatic disease (P<0.01) and male gender (P=0.02). Patients with 0, 1 and 2 risk factors displayed a median survival (95% CI) of 40 (24-63), 29 (23-35) and 23 (16-29) months, respectively, and are defined as patients with good prognosis. Patients with 3 and 4 risk factors had a median survival of 9 (6-11) and 4 (1-7) months only and are defined as bad prognostic patients.

CONCLUSIONS

We identified subsets of oligometastatic cancer patients with good prognosis after SRT. These patients are candidates for inclusion in prospective randomized trials for defining the role of SRT in the management of oligometastases.

Stereotactic ablative radiotherapy delivered by image-guided helical tomotherapy for extracranial oligometastases

PURPOSE

To investigate the outcomes and risk factors of patients treated with stereotactic ablative radiotherapy (SABR) delivered by image-guided helical tomotherapy (HT) for extracranial oligometastases.

METHODS

From August 2006 through July 2011, 42 consecutive patients (median age 69 years [range 16-87]) with oligometastases (≤3) received HT to all known cancer sites (lung, n = 28; liver, n = 12; adrenal, n = 2). Prognostic factors were assessed by Cox's proportional hazards regression analysis.

RESULTS

A total of 60 lesions were treated with hypofractionated HT (median dose 39 Gy [range 36-72.5]; median dose per fraction 12 Gy [range 5-20]). Complete or partial response was observed in 40 (54 %) patients. With a median follow-up period of 15 months, 1- and 2-year overall survival (OS) was 84 and 63 %, respectively; and 1- and 2-year local control (LC) was 92 and 86 %, respectively. Four patients had pneumonitis Grade ≥2 and two patients had lower gastrointestinal toxicity Grade ≥2. Only the lack of complete/partial response was associated with higher risk of mortality on univariate (HR = 3.8, P = 0.04) and multivariate (HR = 6.6, P = 0.01) analyses.

CONCLUSIONS

SABR delivered by image-guided HT is well tolerated and offers adequate LC with low acute morbidity in patients with extracranial oligometastatic disease. We found that the response to HT was the only predictor for OS.