Metastasis of Malignant Neoplasm to Lymph Node Clinical Trial
Official title:
A Prospective Phase II Clinical Trial of Stereotactic Ablative Radiotherapy for Metastatic Lymphadenopathy
Lymph node metastasis is one of the most common sites to develop disease recurrence or
progression after initial local treatment for primary solid malignancies or systemic
treatment for advanced metastases. No specific treatment modality has been established as the
standard therapy. Systemic therapy is usually considered since lymphadenopathy is considered
as a sign of disease dissemination though aggressive local treatment, including surgical
lymphoadenectomy or radical radiotherapy might result in long-term survival in selected
patients. The concept of stereotactic ablative radiotherapy (SABR), a high dose of radiation
targeted to a pathological entity and delivered in a few fractions, has proven so successful
at treating both benign and malignant lesions that it changed the paradigm for radiation
therapy. The radiobiology of SABR has been shown to be very favorable for tumor control.
Clinical experiences suggested that SABR might offer excellent in-field tumor control with
low toxicity profile in selected patients, although the majority of reports are retrospective
and include small patients series with heterogeneous tumor sites and dose-fractionation
schedules.
At present, there is lack of validated prognostic factors to identify the patients who might
benefit most from ablative local therapy for metastatic lymph node(s). The mechanism of
effect of SABR on the cancer lesions is not yet clear. Apart from its direct effect on
clonogenic cancer cells, an immune-mediated process was also hypothesized. Therefore, the
present study is aimed to provide a better understanding about utilization of SABR for
metastatic lymph node(s). The associated translational researches will also advance our
knowledge in the immune system reactions to SABR.
This is a single institutional, single-arm, phase II trial to assess the local control rate
of oligo-metastatic or oligo-progressive lymph node treated by stereotactic ablative
radiotherapy at 1 year.
Patients with pathologically proven non-hematopoietic malignancy patients with radiographic
evidence of evaluable regional recurrent, oligo-metastatic or oligo-progressive lymph nodes
are eligible for enrolment.
Stereotactic Ablative Radiotherapy:
The lymph node planning target volume (PTV) will receive the prescribed dose according to the
assigned treatment group. The dose is prescribed such as 90-95% of PTV is covered by the
prescription dose. If the critical structures exceed the defined dose limitation, a dose
reduction method is applied as protocol defined. Dose inhomogeneity can exist within the
clinical target volume (CTV).
Treatment will be delivered in six fractions to the target volume and given once per day, 2-3
fractions per week with no more than 2 daily consecutive fractions, over 2 to 2.5 weeks.
Target Radiation Dose: SABR with 45 Gy in six fractions to the defined target volume with met
organ-at-risk constraint criteria using intensity modulated radiotherapy or volumetric
modulated arc therapy (VMAT or RapidArc).
Radiation Dose Reduction:
Reduced Dose 10%: SABR with 40.05 Gy in six fractions to the defined target volume with met
organ-at-risk constraint criteria
Reduced Dose 20%: SABR with 36 Gy in six fractions to the defined target volume with met
organ-at-risk constraint criteria
;