Single fraction computed tomography-guided high-dose-rate brachytherapy or stereotactic body radiotherapy for primary and metastatic lung tumors?

Abstract

PurposeTo provide a pilot dosimetric study of computed tomography (CT)-guided high-dose-rate (HDR) brachytherapy (BRT) and stereotactic body radiotherapy (SBRT) for primary and metastatic lung lesions.Material and methodsFor nine lung primary and metastasis patients, 3D image-based BRT plan using a single virtual catheter was planned for 34 Gy in single fraction to the gross tumor volume (GTV) + 3 mm margin to account for tumor deformation. These plans were compared to margin-based (MB-) and robustness optimized (RO-) SBRT, assuming the same tumor deformation under real-time tumor tracking. Consistent dose calculation was ensured for both BRT and SBRT plans using the same class of collapsed cone convolution superposition algorithm. Plan quality metrics were compared by Friedman tests and Wilcoxon t-tests.Results and ConclusionsBrachytherapy plans showed significant higher GTV mean dose compared to MB- and RO-SBRT (122.2 Gy vs. 50.4 and 44.7 Gy, p < 0.05), and better dose gradient index (R50) = 2.9 vs. 4.3 and 8.4 for MB- and RO-SBRT, respectively. Dose constraints per the RTOG 0915 protocol were achieved for all critical organs except chest wall in BRT. All other dose-volume histograms (DVH) metrics are comparable between BRT and SBRT. Treatment delivery time of BRT and SBRT plans significantly increased and decreased with increasing GTV size, respectively. SBRT using advanced MLC tracking technique and non-coplanar VMAT can achieve comparable dosimetric quality to HDR BRT. Whether or not, the significantly higher GTV dose can increase killing of radioresistant tumor cells and offset the effect of tumor reoxygenation in single fraction BRT, requires further clinical investigation.

Hypofractionated 192Ir source stereotactic ablative brachytherapy with coplanar template assistance in the primary treatment of peripheral lung cancer

“…Following the law of inverse squared ratio, the dose profile of SABT formed super-high dose peak for GTVL, and the dose fell more rapidly outside the tumor target area compared to that with SBRT (Figure 3D, E), resulting in a higher dose in the tumor target and a lower dose in OARs. A recent study using virtual brachytherapy plan in a single fraction to GTVL indicated comparable dosimetric parameters between brachytherapy and SBRT [21]. Our data based on realistic brachytherapy plan showed that there were no statistically significant differences in the D95% for the lung tumor target between SABT and SBRT plans (all p > 0.05).…”

Comparison of liver exposure in CT-guided high-dose rate (HDR) interstitial brachytherapy versus SBRT in hepatocellular carcinoma

“…A plan comparison was conducted to virtual SBRT plans using the original HDR BT planning CT. In the available literature comparing both modalities, usually CT datasets acquired for SBRT were used and compared to virtual brachytherapy plans [ 26 , 27 ]. To the best of our knowledge only one other study by Hass et al has so far used original BT planning CT data and compared to virtual SBRT plans [ 28 ].…”

The value of brachytherapy in the age of advanced external beam radiotherapy: a review of the literature in terms of dosimetry

“…Differences in the other dosimetric parameters were not significant for OARs, but BT resulted in lower values for three out of five parameters. Chan et al [45] performed a dosimetric analysis between HDR-BT and SBRT for primary and metastatic lung lesions. Virtual BT plans were created for 9 patients treated with SBRT using a single catheter.…”

“…As for BT, the TG-43 formalism was used in all but six studies. In four papers, no information on the method of dose calculation was provided and more advanced model-based dose calculation algorithms (MBDCA) were used only in two studies [45,63]. Chan et al [45] calculated BT dose distributions in the lung using the Advanced Collapsed Cone Engine (ACE; Elekta Brachytherapy, Veenendaal, the Netherlands).…”

“…In four papers, no information on the method of dose calculation was provided and more advanced model-based dose calculation algorithms (MBDCA) were used only in two studies [45,63]. Chan et al [45] calculated BT dose distributions in the lung using the Advanced Collapsed Cone Engine (ACE; Elekta Brachytherapy, Veenendaal, the Netherlands). Boman et al [63] used the Acuros BV (Varian, Palo Alto, CA, USA) and the TG-43 algorithm for dosimetric calculation in surface mould HDR-BT.…”