Larger Tumors

Whereas the initial studies were focused on assessing the response rates and safety profiles of smaller tumors, it was clear after the first results that also patients suffering from larger tumor recurrences would potentially benefit. One of the first case reports published was the treatment of a large chest wall recurrence of breast cancer, and this subsequently has prompted a phase II clinical investigation ofthe treatment of these tumors (www.clinicaltrials.gov). Initial results show impressive responses in a heavily pretreated patient population, with a favorable safety profile and patient-reported symptom alleviation. 

Particular issues are relevant when treating large tumors. Thus healing time will be delayed as normal tissue needs to grow into the treatment site to replace necrotic tissue. This may be further delayed in previously irradiated tissues, where angiogenesis and wound healing is delayed. 

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Tumor size. In general, patients with a larger tumor have a worse prognosis. 

Serum levels of pi 05 are most useful in breast cancer with some use in ovarian cancer patients. pl05 levels in breast cancer correlate with a worse prognosis and a shorter disease-free state. Elevated HER-2/ ew levels also correlate with larger tumor size, lymph node positivity, and high grading score. HER-2/ eu serum levels are not only to be used for prognosis, but may be used to guide treatment. One study of 719 breast cancer patients showed that elevated levels of... 

For larger tumors, multiple tumors, and tumors in areas where it may be difficult to apply sufficient local anesthesia (e.g., periost involvement in the scalp), general anesthesia is recommended. This may be handled by short-acting anesthetic agents such as propofol combined with short-acting opioids [15]. As pulses should be administered within approximately a 20 min window, the anesthesia can be short and the pahent discharged on the same day [9]. 

One niche where RIT may be particularly useful in solid tumors, is in the eradication of minimal residual disease (MRD). Small tumor deposits and micrometastases accumulate disproportionately high amounts of radioimmunoconjugates compared to larger tumors, and are theoretically more responsive to treatment [49, 50]. Behr et al. [51] reported the results of a Phase II trial of 30 colorectal cancer patients with MRD treated with 2.22 GBq m (60 mCi m ) of I-hMN-14 humanized anti-CEA mAb. Twenty-one patients had chemo-refractory small tumors (diameter <3 cm), and an-... 

Spiral devices have also been used to successfully sort cancer stem cells, such as human prostate epithelial (HPET) cells. The larger tumor cells (>20 pm diameter) eluted in the first outlet closest to the channel iimer wall. The smaller epithelial cells ( 15 pm) eluted in the second outlet, and the smallest 10 pm cells eluted in... 

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