Hypofractionated radiotherapy with Tomotherapy for patients with hepatic oligometastases: retrospective analysis of two institutions

Outcomes after hypofractionated stereotactic radiotherapy for colorectal cancer oligometastases

BACKGROUND AND OBJECTIVES

To assess the efficacy and the effect of biologic effective dose (BED) on outcomes treated by hypofractionated stereotactic radiotherapy for colorectal cancer (CRC) oligometastases.

METHODS

Patients with CRC oligometastases treated at our hospital between 2009 and 2016 were included. The relationship between BED and risk of local recurrence was assessed. Recursive partitioning analysis (RPA) was used to evaluate the effect of BED on outcomes.

RESULTS

A total of 48 patients were included in this study. Median follow-up time of surviving patient was 15 months (range, 3-82 months). The 1-year local control rate was 85%. The risk of local recurrence decreased sharply when BED was >90 Gy₁₀ . RPA showed BED of 100 Gy ₁₀ was the appropriate dose for recurrence risk stratification. BED ≥ 100 Gy ₁₀ was significantly better than BED < 100 Gy ₁₀ for achieving 1-year local control (94.4% vs 63.2%; P = 0.022) and 1-year OS (100% vs 73.4%; P = 0.028). One patient who received long-term antiangiogenic treatment died of massive intestinal hemorrhage; no other grade 3 or above early or late events were observed.

CONCLUSIONS

Hypofractionated stereotactic radiotherapy provides favorable outcomes with acceptable toxicities in CRC oligometastases. BED ≥ 100 Gy is associated with better outcomes.

Two years' experience with inspiration breath-hold in liver SBRT

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The workflow of inspiration breath-hold SBRT for liver metastases is described.

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Inspiration breath-hold in liver SBRT is feasible for 95% of the patients.

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An individual margin recipe for inspiration breath-hold liver SBRT is explained.

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Margin reduction of 10 mm using inspiration breath-hold compared to free breathing.

Exploration of Superior Modality: Safety and Efficacy of Hypofractioned Image-Guided Intensity Modulated Radiation Therapy in Patients with Unresectable but Confined Intrahepatic Hepatocellular Carcinoma

PURPOSE

To evaluate the efficacy and safety of hypofractioned image-guided intensity modulated radiation therapy (IG-IMRT) for unresectable but confined intrahepatic hepatocellular carcinoma in comparison with conventional 3-dimensional conformal radiotherapy (3D-CRT).

METHODS

Ninety patients with unresectable but confined intrahepatic hepatocellular carcinoma without distant metastasis and tumor thrombosis received external beam radiation therapy. Of these patients, 45 received IG-IMRT and 45 received 3D-CRT. The IG-IMRT design delivered a median total hypofractionated dose of 54 Gy (2.2-5.5 Gy/fx), and 3D-CRT delivered a median total dose of 54 Gy with a conventional fraction (2.0 Gy/fx). The clinical response, overall survival, and side effects were analyzed.

RESULTS

The IG-IMRT group showed significantly higher 1-year survival (93.3 versus 77.8%) and 2-year survival (73.3 versus 51.1%) and longer median survival (44.7 versus 24.0 months) than the 3D-CRT group. Multivariate analysis indicated that the patients with intrahepatic tumors smaller than 8 cm, prior TACE before RT, and IG-IMRT would have a survival benefit. There were no significant differences in the rates of side effects between the two groups.

CONCLUSION

Hypofractioned IG-IMRT could improve the therapeutic response and confer a potential survival of patients with unresectable but confined intrahepatic hepatocellular carcinoma compared to 3D-CRT with acceptable toxicity.

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.

A comparison of dosimetric parameters between tomotherapy and three-dimensional conformal radiotherapy in rectal cancer

PURPOSE

Tomotherapy for intensity-modulated radiation has been demonstrated to reduce unnecessary irradiations to adjacent organs at risk (OARs). The purpose of this study was to compare the dosimetric parameters between Tomotherapy and three-dimensional conformal radiotherapy (3D-CRT) in rectal cancer patients.

MATERIALS AND METHODS

We redesigned three-dimensional conformal plans for 20 rectal cancer patients who had received short-course preoperative radiotherapy with Tomotherapy. The target coverage for 3D-CRT and Tomotherapy was evaluated with the following including the mean dose, V(nGy), D(min), D(max), radiation conformality index (RCI), and radical dose homogeneity index (rDHI).

RESULTS

The mean PTV dose for Tomotherapy is significantly higher than that observed for the 3D-CRT (p = 0.043). However, there is no significant difference in the V(23.25Gy), V(26.25Gy), V(27.5Gy), and RCI values between Tomotherapy and 3D-CRT. However, the average rDHI (p < 0.001) value for Tomotherapy was significantly lower than that reported for the 3D-CRT. Tomotherapy significantly lowered the mean level of irradiation doses to the bladder, small bowel, and femur heads as compared to 3D-CRT.

CONCLUSIONS

Tomotherapy could produce a favorable target coverage and significant dose reduction for the OARs at the expense of acceptable dose inhomogeneity of the PTV compared with 3D-CRT in rectal cancer patients.