Preliminary experience of CyberKnife treatment of lung metastasis: the question about real clinical benefit.

OBJECTIVE: Evaluate the effectiveness of radiotherapy plan and physical parameters including local tumor response and clinical outcome of lung metastasis in patients who received CyberKnife treatment at Ramathibodi Hospital. MATERIAL AND METHOD: Six cases with twenty lesions of lung metastasis patients were evaluated for tumor response after having received CyberKnife treatment. The prescribed radiation dose was calculated approximately to biological equivalent dose (BED) around 60 to 100 gray (Gyz). The response of each lesion to treatment was evaluated from roentgenographic study during follow-up period along with adverse event, status of patients, and disease. RESULTS: At the third month after treatment, roentgenographic partial response (PR, 50% decrease in size) was demonstrated in eight lesions and stable disease (SD, unchanged size) in eight lesions with no complete response (CR, disappearance of tumor) detected. Progressive disease (PD, 25% increase in size) of six treated lesions was detected during the follow-up period. At the time of report, two patients were alive and still received palliative chemotherapy, two patients died from uncontrolled progressive metastases and failed palliative chemotherapy, and two patients lost follow-up after progressive metastases with unknown surviving status. No severe adverse event was observed. The treatment planning parameters demonstrated borderline of radiation dose homogeneity, and conformality coverage of the target volume. CONCLUSION: This preliminary report aimed to provide the idea of choosing the appropriate lung metastasis patient to receive CyberKnife treatment that must strictly clarify the real clinical benefit of each selected case to achieve the best outcome from this special treatment procedure.

Preliminary experience of CyberKnife treatment of primary non-small cell lung cancer.

OBJECTIVE: Provide the effectiveness of treatment protocol, radiotherapy plan, technique, and early clinical results of inoperable primary non-small cell lung cancer (NSCLC) in patients who received CyberKnife treatment at Ramathibodi Hospital. MATERIAL AND METHOD: Six cases of inoperable primary NSCLC patients were evaluated for tumor response after having received CyberKnife treatment. The prescribed radiation dose was 45 gray (Gy) in three consecutive fractions for peripherally located tumor and 50 Gy in five fractions within two weeks for centrally located tumor (biological equivalent dose, BED, 112.5 Gy 10, and 100 Gy 10, respectively). The response to treatment was evaluated from roentgenographic study during follow-up period along with clinical outcome and adverse event. RESULTS: Overall response after the treatment was demonstrated in five cases with roentgenographic complete response (CR, disappearance of tumor) and partial response (PR, 50% decrease in size) in two and three cases, respectively without any severe adverse event. The treatment planning parameters demonstrated the effectiveness of radiation dose homogeneity and conformity coverage of the target volume. CONCLUSION: This preliminary report has provided the effectiveness of treatment plan and local tumor controlled without severe adverse event for primary inoperable NSCLC patients receiving CyberKnife treatment.