Cement and screws: The importance of building (and formalising) evidence on MSK metastases

At the Society of Interventional Oncology (SIO) annual scientific meeting (19–23 January, Washington DC, USA), Sean Tutton (University of California San Diego Health, San Diego, USA) presented evidence on treatment for skeletal metastases, while urging those involved in these patients’ care, as well as collecting data on their experiences, to “harmonise the nomenclature” they use to optimise data and care quality.

Tutton began by suggesting that a reason for inconsistent terminology where bone cancer treatment is concerned, among interventional radiologists, is that it is a “young” part of the interventional radiology (IR) space. “We need to start talking about skeletal-related events—both the cancer as well as the cancer therapies are having a significant impact on the skeleton,” he urged. An example of why this issue is relevant for interventional radiologists, which Tutton gave, was that of a post-menopausal patient who, after chemotherapy, underwent “an 8% year-on-year bone loss”. This increases the risk of fracture, the speaker underlined.

Moving on to focus on pelvic metastases specifically, the presenter noted that they are the second most common type of skeletal metastasis after spinal. In Tutton’s view, it is crucial to understand that patients with cancer metastatic to the pelvis may experience different types of pain—mechanical pain is not the same as bone-tumour interface pain, which, in turn, is not the same as neuropathic pain. “We address them differently,” Tutton emphasised.

Likewise, there are different classifications of disease stage depending on the type of skeletal metastasis. In the pelvis, the Harrington scale runs from one to four, with complete pelvic discontinuity at the end of the gradation, Tutton informed delegates. Treatment for these metastases differs based on the classification—Harrington 1 is “ablation alone”, 2 is a combination of ablation and osteoplasty, and for profound Harrington 3 and 4, the preferred treatment modality is “osteosynthesis, which is a combination of cement and screws,” the presenter outlined.

Tutton proceeded to run through the biomechanics behind using cement and screws, stating that he and IR and orthopaedic colleagues had seen in their experience that using screws alone is “very similar to not treating at all”. While “cement alone only deals with compressive forces”—and the pelvis also has to be able to deal with “bending, sharing and tortional forces,” Tutton detailed—cement and screws work in conjunction with one another to “shift the load-bearing away from the bad bone to the good bone”. He supplemented this by saying that “the key concept is that you are fixing bicortically if possible”. With the two materials combined, you achieve “the highest stiffness and greatest yield strength”. A further point Tutton made was regarding working with orthopaedic colleagues and how there, uniform nomenclature is key.

The speaker was keen to highlight that the cement plus screw combination is for progressive disease, with Nick Kurup and Matt Callstrom having reported on their experience with Harrington 1 and 2 lesions.

SBRT could be an “effective” treatment for patients with lung neuroendocrine tumours

Researchers at Moffitt Cancer Center (Tampa, USA) are investigating new treatment approaches for the primary lung neuroendocrine tumour patient population. In a new article published in the International Journal of Radiation Oncology, Biology and Physics, a team of physicians, led by Daniel Oliver and Stephen Rosenberg, suggests that stereotactic body radiotherapy (SBRT) could be an effective treatment for patients with early-stage lung neuroendocrine tumours.

SBRT IS A TREATMENT approach that delivers high doses of radiation to precise areas of a tumour, minimising damage to surrounding normal cells. Patients receiving SBRT often have less toxicity and sideeffects compared to treatment with conventional radiotherapy that is delivered in smaller doses each day over several weeks.

“SBRT is commonly used as a treatment for early stage non-small cell lung cancer, and our results show strong tumour control. This suggests that SBRT may also be effective for lung neuroendocrine tumours,” said Oliver, assistant member of the Department of Radiation Oncology at the Moffitt Cancer Center. “In fact, SBRT is increasingly being used to treat early-stage lung neuroendocrine tumours in clinical practice, despite the lack of consensus recommendations for this approach and very limited data on its effectiveness and toxicity in lung neuroendocrine tumour patients.”

Because of the lack of data, Oliver and his team wanted to assess the efficacy and long-term outcomes of SBRT in patients with lung

Tutton labelled their use of balloon-assist osteoplasty and ablation as a “very novel way of dealing with periacetabular lesions”.

Regarding the body of data that exists within IR for treating skeletal metastases, Tutton acknowledged that there are “a lot of great retrospective data,” which help interventional radiologists build their “toolbox” and stipulate how to use cone beam computed tomography (CT), how to plot navigation lines and how to improve accuracy.

Speaking on his and colleagues’ experience, Tutton averred that the aforementioned pelvic procedures are “safe”, with no significant blood loss or infection reported. Following treatment, the patients he studied saw an improvement in terms of function and narcotic use. At one-year followup, the presenter shared that they were able to obtain “good data” on 42 of 105 participants—“we are in the process of reporting,” Tutton told attendees.

“The value” of studies like his is that “as we treat these patients and they survive, which is great […] 43% will need some form of additional procedure—you are going to need to see these folks [again],” was one of Tutton’s main messages for the audience. In order to add to their value, he opined that there needs to be, again, “harmonisation” of the outcome metrics, patient-reported and otherwise, “so that when we publish we all speak the same language”. In conclusion, Tutton expressed how patients living longer with pelvic metastases is a “huge win”, but that in order to give them the best possible quality of life, it is necessary to continue along “the right track” that IR is on with evidence surrounding osteosynthesis. “Skeletal metastases are common and devastating for quality of life,” so harmonised evidence reporting and use of nomenclature will contribute to “[allowing patients] to continue their cancer therapies and to get walking and actually enjoying life”.

3 6 9 YEAR YEAR YEAR 97% 91% 91%

Local control rates with SBRT neuroendocrine tumours. They performed a retrospective analysis of 48 lung neuroendocrine tumours from 46 patients who were treated with SBRT from 11 institutions across the USA. The researchers discovered that SBRT provided strong local/regional tumour control—the three-, six-, and nine-year local control rates were 97%, 91%, and 91% respectively, and only one regional recurrence occurred. The treatment was also well tolerated with only one case of SBRT-related toxicities reported, which was considered low-grade.

“The current study is the largest and first multi-institutional series evaluating local control, toxicity and dosimetric outcomes with SBRT for early-stage lung neuroendocrine tumours. Our results suggest that while surgery provides excellent outcomes, SBRT should be considered another treatment option for this patient population,” said Rosenberg, study senior author and director of magnetic resonance imaging-guided radiotherapy in the Moffitt Cancer Center’s Department of Radiation Oncology.