Case Studies

Joseph Cirrone, MD, Radiation Oncologist

History & Presentation

The patient is a 68-year-old white male with a past medical history significant for hypertension and hypercholesterolemia.

Patient had a routine physical examination with screening PSA performed in October of 2013. The PSA was noted to be 5.5 ng/ml. The patient was sent for urologic evaluation. A prostate biopsy was performed on December 16, 2013. One of twelve (1/12) cores was positive for invasive adenocarcinoma. The Gleason score was 7 (4+3). There was associated perineural space invasion. The patient had staging evaluation with CT scan of the abdomen and pelvis without evidence of metastatic disease.

The patient was given treatment options by his urologist, and surgery was to be considered. The patient sought a second urologic evaluation at Memorial Sloan-Kettering Cancer Center. The pathology slides were reviewed and again found to be adenocarcinoma of the prostate with a Gleanson of 7, but this time the major and minor components were switched where 3 was major and 4 was the minor Gleason score. The patient was informed by Memorial Sloan-Kettering Cancer physician that surgery was an option but also radiation therapy could be considered in his case. The patient was hesitant to have definitive surgery, and he has been referred to consider definitive radiation therapy for his newly diagnosed prostate cancer.

Treatment Options

Patient was given multiple definitive treatment options for early stage, intermediate risk prostate cancer. Options included: observation; hormonal therapy; external beam radiation therapy, usually with combined hormone therapy or alone or with IGRT technique over 9 weeks; or CyberKnife radiotherapy given in five treatments every other day. Patient was told the exact procedure for each option and specific side effects.

Treatment

The patient opted for definitive therapy using the Precision CyberKnife (PCK) Radiotherapy treatment. In November 2014, patient has his initial consult at PCK and subsequently received the five treatments as outlined to a total dose of 3500 cGy, each daily treatment lasting approximately 40 minutes. Patient completed the therapy without complaints.

 

Post Treatment

For the next two weeks post treatment patient had mild urinary frequency/pressure and mild fatigue. After a month, patient’s urination returned to normal and returned to his baseline activity level.

Three months later he was seen in follow-up, repeat PSA was 0.2 ng/ml compared to the patient’s pre-treatment PSA 5.5 ng/ml.

One year later the patient remains clinically well without complaints, the PSA remains low at 0.2 ng/ml.

Martin Silverstein, MD, Radiation Oncologist

History & Presentation

A 72 year old female presented with a worsening sinus infection and presented to her local hospital’s Emergency Room for evaluation. A CXR was obtained showing a 2.5cm ill-defined opacity in the LUL of lung. This led to a Chest CT showing a 2.7 x 2.6cm mass in the LUL.  APETCT was done for staging showing a 2.7cm x 2.4cm mass in the LUL with an SUV of 9.5. There were no additional PET avid findings.  A CT guided core biopsy showed inflammatory cells.

Her thoracic surgeon felt she was not an ideal surgical candidate due to poor pulmonary function testing. The patient underwent bronchoscopic biopsy and EBUS for tissue diagnosis and staging.  Pathology from the LUL showed a moderate to poorly differentiated squamous cell carcinoma. There were no positive lymph nodes. Stage T1N0.

Treatment Considerations

The patient refused surgery due to concerns for possible peri-operative morbidity in view of poor PFTs. It was determined that the best treatment option for this patient would be Stereotactic Body Radiation Therapy (SBRT).  Several recent clinical trials have shown similar control rates and survival with SBRT compared to surgical excision or wedge resection with short-term follow-up in patients with T1 lung cancers.  Other studies have shown the efficacy in treating stage I lung cancers with the CyberKnife Radiosurgery System. This robotic delivery system is ideally suited to treat lung lesions because of its capability of tracking, detecting and correcting for respiratory motion throughout treatment delivery. No other radiotherapy machine has this capability.

Treatment

One week prior to radiation simulation permanent gold fiducial markers were placed by interventional radiology within the tumor to allow for respiratory tracking with Synchrony during the treatment delivery process. The patient was immobilized with a vac-u-lok cradle and a CT simulation was performed and data was transferred to the Accuray MultiPlan treatment planning system.

On each axial slice the gross tumor volume was contoured as were the surrounding critical organs to digitally reconstruct a 3-D planning tumor volume.  A 5mm margin was placed around the PTV and a treatment plan was optimized to deliver 1200cGy per fraction for a total of 4 fractions and a total dose of 4800cGy to the lung tumor. A total of 150 beams were planned using the IRIS collimator with the dose prescribed to the 79% isodose line with 99.6% coverage of the target volume.

Treatment Delivery

The patient was immobilized with the vac-u-lok cradle. The treatments were delivered using Synchrony respiratory motion management with fiducial soft tissue tracking to compensate for respiratory motion of the tumor target and patient movement. The patient tolerated the treatment very well with no acute effects or changes in her respiratory status during treatment.

Post Treatment

Three months after therapy patient had no ill effects from her SBRT or treatment-related morbidity. On f/u PETCT, the lesion was similar in size but less hypermetabolic with an SUV of 2.8.  At 6 months post-treatment the tumor size decreased significantly to 2.0cm x 1.0cm with post-radiation changes in the LUL lung.  There was no evidence of hilar or mediastinal adenopathy.

Conclusion

The patient had an excellent initial outcome to SBRT treatment using the CyberKnife Radiosurgery System with Synchrony motion management. Radiology imaging showed a significant decrease in size of the lesion which was less FDG-avid on f/u PETCT scanning. Treatment was well tolerated with no treatment-related morbidity. The CyberKnife system has the potential to be an excellent treatment alternative to surgery for patients who are medically inoperable or refuse surgery.