Volumetric-modulated arc stereotactic radiotherapyfor intramedullary cervical spinal cord metastases:Report of two cases

The treatment results of intensity-modulated stereotactic radiotherapy (imsrt)by volumetric-modulated arc therapy (vmat) for intramedullary cervicalspinal cord metastases (imcscm) in two cases were presented. case 1: a 76-year-old woman showed left-sided motor weakness and left arm pain anddysesthesia due to imcscm at c [cervical] 6-7 (located a little to the leftlaterally) with multiple small brain metastases from thyroid carcinoma.multiple brain metastases were successfully treated by stereotacticradiosurgery (srs). in addition, imcscm was treated by im-srt. case 2: a 48-year-old man presented with asymptomatic imcscm at c2 (located a little tothe right laterally) after conventional whole brain radiotherapy (wbrt) andmultiple sessions of srs/srt for multiple brain metastases from lungadenocarcinoma. imcscm was treated by im-srt. in both cases 39 gy in 13fractions (without ptv [planning target volume] margin, d95%=95% dose)was delivered to the imcscm (0.3 ml and 0.5 ml in volume respectively) bycoplanar 2-full circular arc vmat. the maximum dose to the tumor was 46.3gy in case 1 and 47.1 gy in case 2. imcscm in both cases shrank markedlywithout adverse effects during the follow-up period of 32 months and 8months respectively. the symptoms of the extremities in case 1 weresubsided completely until the patient’s death at 34 months after srt fromlung metastasis. in case 1 imcscm had been thought to be a relativelyradioresistant thyroid carcinoma metastasis. in case 2 imcscm was near thefield of the prior wbrt. however, both tumors were successfully treatedwithout adverse effects by vmat im-srt.