[Serial tomotherapy vs. MLC-IMRT (multileaf collimator intensity modulated radiotherapy) for simultaneous boost treatment large intracerebral lesions]

Intensity-modulated radiation therapy combined with concomitant temozolomide for brain metastases from lung adenocarcinoma

Short-term efficacy, adverse effects and the impact on quality of life (QoL) of a concomitant treatment with intensity-modulated radiation therapy (IMRT) and temozolomide (TMZ) in patients with brain metastases (BMs) from lung adenocarcinoma were evaluated. This study sought to confirm the benefit of adding TMZ to IMRT in patients with BMs from lung adenocarcinoma. Nine patients were enrolled and received a dose of 30 Gy in 10 daily fractions to clinical tumor volume (CTV) according to IMRT, then additional dose of 9 Gy in 3 fractions of IMRT was delivered to gross tumor volume (GTV) only with concomitant TMZ (75 mg/m²/day) orally during RT for 3 weeks. One patient achieved complete response (CR) (11.1%), 6 patients obtained partial response (PR) (66.7%), and there were no patients in progression. Therefore, objective response (OR) reached 77.8%. The main adverse effects included neutropenia, anemia, vomiting, fatigue and dizziness. Grade ≥3 of hematologic toxicities did not occur. However, the other 9 patients who received only intensity-modulated radiation had much worse results. The CR was 0, PR rate was 44.4%, OR rate was 44.4%. The results indicated that the benefit of adding TMZ to IMRT was confirmed in patients with BMs from lung adenocarcinoma. The treatment was active, a significant OR was observed, and achieved an improvement in QoL demonstrated by QoL grade (p<0.05).

On the cutting edge of intensity modulated radiotherapy and simultaneous integrated boost (IMRT-SIB): The case of a patient with 8 brain metastases

BACKGROUND

Patients with multiple brain metastases, especially those with more than 3 lesions, usually undergo to palliative whole brain (WB) radiotherapy (RT).

METHODS

A breast cancer patient with 8 brain metastases was treated on the brain by a radical RT regimen. Prescription doses were according to the simultaneous integrated boost-intensity modulated radiation therapy (SIB-IMRT) technique with all lesions as well brain irradiated simultaneously in 20 daily fractions. Doses of 40.0 Gy (2.0 Gy/fraction) and 50.0 Gy (2.5 Gy/fraction) were prescribed to the whole brain and to eight individual metastases, respectively.

RESULTS

Mean volume of the eight metastases was 8.1 cc (range: 3.8-10.1 cc). For all lesions, the volume receiving 95% of prescribed dose was 100% and dose homogeneity was within 3%. Moreover, maximum doses were less than 105% of prescribed dose, while average mean dose to lesions was 50.6 Gy (range: 49.7-51.5 Gy). Whole brain mean dose was 45.2 Gy. Maximum doses to brainstem and optic chiasma were limited to 44.5 Gy and 42.9 Gy, respectively, while maximum doses to eyes, lens and optic nerves were limited to 9.2 Gy, 4.9 Gy and 41.0 Gy, respectively. From a clinical point of view, subsequent MRI brain controls showed a complete clinical response. Forty months after treatment the patient is disease free and shows no late brain and skin toxicities.

CONCLUSION

This case demonstrates the technical feasibility of a SIB-IMRT treatment in patients with more than 3 brain metastases.

Use of Helical TomoTherapy for the Focal Hypofractionated Treatment of Limited Brain Metastases in the Initial and Recurrent Setting

Background: Whole-brain radiation therapy (WBRT), stereotactic radiosurgery (SRS), or both are commonly employed in the treatment of limited brain metastases in the initial or recurrent setting. Hypofractionated partial volume irradiation is also employed, however, published experience using helical TomoTherapy (HT) for this purposes is limited. We reviewed our institutional experience to assess patient selection factors, fractionation scheme, and outcomes associated with this technique.

Methods: A retrospective chart review was performed to evaluate patients treated with partial volume hypofractionated HT-based IMRT for brain metastases at our institution.

Results: Thirteen patients (7M/6F, median age 62, median KPS 90) with a limited (1–9) number of brain metastases in the primary or recurrent setting were identified. Primary malignancies included colorectal (3), NSCLC (5), RCC (1), breast (1), melanoma (1), uterine (1), and ovarian (1). The median time from initial diagnosis to brain metastases was 20.7 months (range 0–61.3). Treatment was delivered to intact metastases in six patients, to a single resection cavity in six patients, and to both in one patient. A total of 27 lesions were treated. The median number of intact metastases treated was two (range 1–9). Previous treatments included WBRT (5), WBRT + SRS (3), SRS alone (1), and none (4). The most common fractionation schemes were 25 Gy in five fractions and 27.5 Gy in five fractions to each lesion. At a median of 6 months follow up (range 1.26–20.13) after TomoTherapy, 10 patients were deceased, 2 were alive, and 1 was lost to follow up. Systemic progression occurred in seven patients and intracranial progression occurred in five. The median intracranial progression free survival and overall survival after TomoTherapy was 6.3 months. Freedom from local failure for treated lesions was 71% and 59% at 6 and 12 months.

Conclusion: TomoTherapy-based hypofractionated radiotherapy to a limited number of metastatic lesions is associated with acceptable intracranial disease control and survival outcomes and represents a viable treatment option in the primary and recurrent setting for select patients.